What is the diagnosis? • Xray of the Week Figure 1. What is the diagnosis? Figure 2. Frontal chest radiograph reveals a curvilinear radiopaque tubular structure paralleling the right cardiac border (red arrows) —the classic “scimitar vein.” The right lung is also mildly hypoplastic. Figure 3. (Contrast-Enhanced CT):  Coronal images demonstrate the anomalous right pulmonary vein (red arrows) draining into the inferior vena cava (yellow arrows), confirming the diagnosis. Scimitar Syndrome (Congenital Pulmonary Venolobar or Hypogenetic Lung Syndrome) Definition & Epidemiology Scimitar Syndrome is a rare congenital condition characterized by partial anomalous pulmonary venous return (PAPVR), where pulmonary veins from the right lung drain into systemic veins—most commonly the inferior vena cava. The condition derives its name from the characteristic curvilinear vascular shadow on chest radiography, which resembles a scimitar sword. The estimated incidence is approximately 1–3 per 100,000 live births [1,12]. Imaging Findings On chest radiography, the hallmark finding is a vertically oriented, curved opacity along the right cardiac border representing the anomalous pulmonary vein, the “scimitar sign.” Associated features may include right lung hypoplasia, dextroposition of the heart due to reduced right lung volume, and sometimes systemic arterial supply to the right lower lobe. These findings, although classic, are variably present and require confirmatory cross-sectional imaging. [2,3,10,13]. Contrast-enhanced CT better delineates the anomalous venous drainage, confirms the connection to the IVC, and demonstrates associated anomalies—such as right pulmonary artery hypoplasia, anomalous systemic arterial supply from the aorta, bronchial anomalies and atrial septal defects, which frequently coexist. [3,16,11]. Clinical Relevance & Classification Two clinical variants exist: the infantile form, which often presents with pulmonary hypertension, heart failure, and more complex anatomy; and the adult/adult-variant form, frequently asymptomatic and diagnosed incidentally in adulthood [5,12]. Treatment & Prognosis Management depends on symptom severity and associated anomalies. Asymptomatic patients with adequate right lung function may not require intervention. Symptomatic infants with recurrent infections, pulmonary hypertension, or significant left-to-right shunt often undergo surgical rerouting of the anomalous vein to the left atrium, or coil/embolization of anomalous systemic arterial supply [6,7]. Prognosis is variable, with better outcomes in isolated cases without pulmonary hypertension or cardiac malformations [7]. References Dupuis C, Charaf LA, Brevière GM, Abou P, Rémy-Jardin M, Helmius G. The "adult" form of the scimitar syndrome. Am J Cardiol . 1992;70(4):502-507. doi: 10.1016/0002-9149(92)91198-d Roehm JOF, Jue KL, Amplatz K. Radiographic features of the scimitar syndrome. Radiology . 1966;86(5):856-859. https://doi.org/10.1148/86.5.856 Canter CE, Martin TC, Spray TL, Weldon CS, Strauss AW. Scimitar syndrome in childhood. Am J Cardiol . 1986;58(7):652-654. doi: 10.1016/0002-9149(86)90296-1 Masrani A, McWilliams S, Bhalla S, Woodard PK. Anatomical associations and radiological characteristics of scimitar syndrome on CT and MR. J Cardiovasc Comput Tomogr . 2018;12(4):286-289. https://doi.org/10.1016/j.jcct.2018.02.001 Konen E, Raviv-Zilka L, Cohen RA, et al. Congenital pulmonary venolobar syndrome: spectrum of helical CT findings with emphasis on computerized reformatting. RadioGraphics . 2003;23(5):1175-1184. https://doi.org/10.1148/rg.235035004 Berrocal T, Madrid C, Novo S, Gutiérrez J, Arjonilla A, Gómez-León N. Congenital anomalies of the tracheobronchial tree, lung, and mediastinum: embryology, radiology, and pathology. RadioGraphics . 2004;24(1):e17. https://doi.org/10.1148/rg.e17 Ngai C, Freedberg RS, Latson L, et al. Multimodality imaging of scimitar syndrome in adults: A report of four cases. Echocardiography . 2018;35(10):1684-1691. DOI: 10.1111/echo.14124 Kevin M. Rice, MD is the president of Global Radiology CME and is a radiologist with Cape Radiology Group . He has held several leadership positions including Board Member and Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator. He was once again a semifinalist for a "Minnie" for 2021's Most Effective Radiology Educator by AuntMinnie.com . He has continued to teach by mentoring medical students interested in radiology . Everyone who he has mentored has been accepted into top programs across the country including Harvard, UC San Diego, Northwestern, Vanderbilt, and Thomas Jefferson. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD

What is this foreign body in the abdomen? • Xray of the Week Figure 1. What is this foreign body in the abdomen? Figure 2. Plain abdominal radiograph at approximately 30 hours after ingestion of patency capsule. A radio‑opaque foreign body (~2.6 cm × 1.1 cm) is noted in the abdomen, consistent with retained patency capsule. Figure 3. Enlarged and abdomen radiograph demonstrates foreign body consistent with Patency Capsule in the bowel. Patency Capsule: Imaging Appearance and Clinical Utility The patency capsule  is a dissolvable, radio-opaque capsule used to assess small bowel patency prior to capsule endoscopy (Figs. 1-3). It is particularly important in patients at risk for strictures, such as those with Crohn disease or a history of abdominal surgery [1,3]. The capsule is similar in size to a standard video capsule (approximately 26 mm × 11 mm ) and contains a barium-impregnated lactose core, sometimes with an RFID tag for scanner detection [1,2]. After oral ingestion, no specific bowel prep is typically required. Imaging is performed at ~28–30 hours  to confirm whether the capsule has passed [2,4]. If not seen on X-ray, functional patency is assumed. If visible, retention is suspected—though location (small bowel vs colon) can be difficult to determine on planar images alone [2,3]. If retained, CT can help confirm location and avoid false-positive findings [2,5]. Delayed imaging (e.g., at 72 hours) may further improve diagnostic yield without increasing risk [4]. The capsule begins to dissolve at ~30–33 hours, minimizing the risk of obstruction [1,2]. Conclusion The patency capsule is a valuable tool to assess small bowel patency and reduce the risk of capsule retention . Radiologists should recognize its appearance and assess for passage at ~30 hours post-ingestion, using adjunct imaging if needed. References Spada C, Spera G, Riccioni ME, et al. A novel diagnostic tool for detecting functional patency of the small bowel: the Given patency capsule. Endoscopy . 2005;37(9):793–800. https://doi.org/10.1055/s-2005-870246 Costigan C, O’Hara FJ, McNamara D. Patency testing improves capsule retention rates but at what cost? Front Med (Lausanne) . 2023;10:1046155. https://doi.org/10.3389/fmed.2023.1046155 Nemeth A, Kopylov U, Koulaouzidis A, et al. Use of patency capsule in patients with established Crohn’s disease. Endoscopy . 2016;48(4):373–379. https://doi.org/10.1055/s-0034-1393560 O’Hara FJ, Costigan C, McNamara D. Extended 72-hour patency capsule protocol improves functional patency rates in high-risk patients undergoing capsule endoscopy. World J Gastrointest Endosc . 2024;16(12):661–667. https://doi.org/10.4253/wjge.v16.i12.661 Kim YE, Kim YJ, Kim KO, et al. Patency Capsule and Cross-Sectional Imaging for Predicting Capsule Endoscopy Retention: A Systematic Review and Meta-Analysis. Dig Dis Sci . 2025;70(2):761–773. https://doi.org/10.1007/s10620-024-08835-6 Kevin M. Rice, MD is the president of Global Radiology CME and is a radiologist with Cape Radiology Group . He has held several leadership positions including Board Member and Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator. He was once again a semifinalist for a "Minnie" for 2021's Most Effective Radiology Educator by AuntMinnie.com . He has continued to teach by mentoring medical students interested in radiology . Everyone who he has mentored has been accepted into top programs across the country including Harvard, UC San Diego, Northwestern, Vanderbilt, and Thomas Jefferson. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD

63 year old male. Headache for 1 month and unsteady gait. What is the diagnosis? • Xray of the Week Figure 1. Brain CT. Name the significant findings. Figure 2. A, B, C: Non-contrast axial CT displaying subtle bilateral isodense subdural hematomas. There is medial displacement of gray matter with left (orange arrows) worse than right (red arrows). Shift of midline structures to the right is also a clue to the diagnosis. D: Non-contrast coronal CT indicating isodense subdural hematoma (orange arrows). Note again the midline shift to the right. Figure 3. Post op CT brain on same patient. Note the lower attenuation fluid after treatment. Partial evacuation of hematoma with hypodense regions indicating residual fluid and blood products (red and orange arrows). Discussion: Subacute subdural hematomas (SDH) are usually due to clinically undetected acute SDH. Two leading causes are tearing of the bridging vessels due to abrupt acceleration-deceleration of the head or accumulation around a parenchymal laceration (1). This trauma leads to blood accumulation between the arachnoid and dura layers of the brain (2). Risk factors include cerebral atrophy (elderly patients or chronic alcoholics), anticoagulation use, or recent thrombolysis (3). The patient may or may not have a history of head trauma. Common presenting features include headache, decreased memory, confusion, and motor dysfunction (4). SDH can cross suture lines since they occur deep to the dura mater; this differs from epidural hematomas which usually do not cross suture lines since blood cannot extend beyond the point where the dura attaches to the cranial sutures (5). Subacute subdural hematomas are categorized as isodense biconcavities on CT. When blood clots degrade, the density decreases and becomes more similar to the brain parenchyma. Furthermore, subacute (and chronic) SDHs may show septations within an iso/hypodense hematoma due to reactive granulation tissue formation (6). Subacute hemorrhages can be challenging to recognize because of the isodense characteristics. Therefore, one must also look for signs of mass effect such as asymmetry of the lateral ventricles, shifting of midline structures, sulcal effacement, and sulci that do not extend into the skull (Figs. 1-2) (7). Management of subacute SDH is determined by whether a patient is symptomatic or exhibiting signs of mass effect; those who are asymptomatic may be candidates for conservative treatment (8). Mainstay surgery modalities include twist-drill craniostomy, burr-hole craniostomy, and craniotomy (8). Figure 2 shows this patient following bilateral craniotomy. ​​​​ References: Williams KA Jr, Kouloumberis P, Engelhard HH. Subacute subdural hematoma in a 45-year-old woman with no significant past medical history after a roller coaster ride. Am J Emerg Med . 2009;27(4):. doi: 10.1016/j.ajem.2008.08.005 Pierre L, Kondamudi NP. Subdural Hematoma. [Updated 2019 Dec 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532970/ Lupescu IC, Stefanescu VC, Lupescu IG, Dulamea AO. Subacute Subdural Hematoma Presenting as Non-Fluent Aphasia. Maedica (Bucur) . 2019;14(1):63-66. doi: 10.26574/maedica.2019.14.1.63 Yadav YR, Parihar V, Namdev H, Bajaj J. Chronic subdural hematoma. Asian J Neurosurg . 2016;11(4):330-342. doi: 10.4103/1793-5482.145102 Heit JJ, Iv M, Wintermark M. Imaging of Intracranial Hemorrhage. J Stroke . 2017;19(1):11-27. doi: 10.5853/jos.2016.00563 Grainger and Allison. Adam Kenji Yamamoto and Ashok Adams: Grainger & Allison's Diagnostic Radiology, 54, 1387-1410 Emergency Radiology. Glenn D. Barest, Asim Z. Mian, Rohini N. Nadgir and Osamu Sakai: Emergency Radiology: The Requisites, Chapter 1, 1-60 Cai Q, Guo Q, Zhang F, et al. Evacuation of chronic and subacute subdural hematoma via transcranial neuroendoscopic approach. Neuropsychiatr Dis Treat . 2019;15:385-390. Published 2019 Jan 30. doi: 10.2147/NDT.S193548 Deven Champaneri is a medical student at Edward Via College Osteopathic Medicine (VCOM) – Carolinas and plans to pursue residency in diagnostic radiology. While he was rotating through various specialties, he realized his passion for DR and valued its role in all aspects of medicine. He graduated from the University of South Carolina in 2017 with a degree in Business Marketing. During his undergraduate studies, he was involved with multiple volunteer organizations, such as Camp Kemo a summer camp for children with cancer and Palmetto Richland Children’s Hospital . Currently, he mentors at-risk high-school students and tutors students for Step 1/COMLEX 1. In his spare time he enjoys, golfing, backpacking, cooking, and spending time with family. UPDATE 2025: Dr. Champaneri is now a radiology resident at Medical University of South Carolina Follow Deven Champaneri on Twitter @ devenchampaneri All posts by Deven C hampaneri Kevin M. Rice, MD is the president of Global Radiology CME Dr. Rice is a radiologist with Renaissance Imaging Medical Associates and is currently the Vice Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD

Global Radiology CME is pleased to congratulate the Award Winners for Best E-Posters and The Donald Resnick MSK Quiz at Imaging in Prague 2019. Awards were presented at The Gala Dinner at the Prague Municipal House on June 10, 2019. Neuroradiology E-Poster: Victor Teng - Flexion MRI in Hirayama Disease Dr. Teng is a radiologist at National University Health System Singapore. He was presented with the Award by Dr. Blake Johnson, Co-Scientific Director and Neuroradiology Faculty for Imaging in Prague 2019. Body Imaging E-Poster: Grace Rubin - Breast Tuberculosis - A review of 62 cases Dr. Rubin is Clinical Head of Radiology, at Helen Joseph Hospital in Johannesburg, a University of Witwatersrand affiliated academic hospital. She was presented with the Award by Dr. Neil Rofsky, Body Imaging Faculty at Imaging in Prague 2019. MSK Imaging E-Poster: Junsiyuan Li - Fibrolipomatous Hamartoma of the Median Nerve Dr. Li is a senior radiology resident at Singapore General Hospital, SingHealth. He was presented with the Award by Dr. Phillip Tirman, Co -Scientific Director and MSK Imaging Faculty at Imaging in Prague 2019. Donald Resnick MSK Quiz Award: Andrew Kingzett Taylor Dr. Kingzett Taylor serves as an MSK radiologist at Pacific Radiology, located in Wellington and Manawatu, New Zealand. He completed a visiting fellowship at the MSK Section of UCSF and the San Francisco MRI Centre. Dr. Donald Resnick, an ACR Gold Medalist and esteemed MSK Imaging faculty member of Global Radiology CME, is seen presenting him with the Award. More award winners here .

A 61-year-old female presented with left upper quadrant abdominal pain and hypotension following a motor vehicle collision. How would you grade this injury? • Xray of the Week Figure 1. Contrast enhanced CT of abdomen and pelvis. How would you grade this injury? What action should be taken for this patient who is hemodynamically unstable? Figure 2. Contrast enhanced CT of abdomen and pelvis demonstrating IV contrast extravasation from the spleen (red arrows). Note also the hematomas adjacent to the spleen and liver. Figure 3. Initial selective splenic artery angiogram and subsequent coil embolization. Discussion: Splenic trauma occurs frequently in patients who sustain blunt abdominal injury, especially following high-energy mechanisms such as motor vehicle collisions. The injury can range from capsular tears to complete devascularization of the spleen. The American Association for the Surgery of Trauma (AAST) Splenic Injury Scale is a standardized grading system ranging from Grade I to Grade V used to classify the severity of splenic injuries based on imaging and surgical findings [1]. Imaging criteria for a Grade I injury includes subcapsular hematomas involving less than 10% of the surface area, parenchymal lacerations <1cm in depth, and capsular tear. Grade II injuries include subcapsular hematomas covering 10% to 50% of the surface area, intraparenchymal hematomas under 5 cm, or 1-3 cm lacerations (do not involve the trabecular vessels). Grade III injuries are characterized by subcapsular hematomas greater than 50% of the surface area or ruptured subcapsular or intraparenchymal hematomas larger than 5 cm, or lacerations deeper than 3 cm (involve the trabecular vessels) [1]. Grade IV injuries include lacerations that extend into segmental or hilar vessels and result in major devascularization of more than 25% of the spleen and any injuries with the presence of a splenic vascular injury or active bleeding within the splenic capsule. Since there is contrast extravasation, this is case is considered a Grade IV injury (Figs. 1-2). Grade V injuries are the most severe form, involving a shattered spleen or hilar vascular injury leading to devascularization of the organ and active bleeding extending beyond the spleen into the peritoneum [1]. Prompt identification of the injury grade is essential for guiding treatment decisions. Higher-grade injuries (Grades IV and V), especially when accompanied by active contrast extravasation as in this case, typically indicate ongoing hemorrhage and necessitate urgent intervention, often through angioembolization or surgery. Lower-grade injuries (Grades I–III) can be managed non-operatively in hemodynamically stable patients [2]. Imaging: Computed tomography (CT) is the imaging modality of choice for evaluating blunt abdominal trauma and identifying splenic injury. Contrast-enhanced CT, particularly with arterial and portal venous phases, allows for accurate detection and grading of splenic lacerations, hematomas, and vascular injuries. Key findings on CT include subcapsular and intraparenchymal hematomas, depth and extent of lacerations, active contrast extravasation, pseudoaneurysms, and areas of devascularization. Multiphase imaging increases sensitivity for detecting active bleeding, which appears as hyperdense contrast pooling in the arterial phase and persistent enhancement in delayed images. The sensitivity and specificity of contrast-enhanced CT in identifying clinically significant splenic injuries are both high, with CT also serving as the basis for injury grading using the AAST Splenic Injury Scale. Prompt and accurate identification of injury grade and vascular involvement is essential in guiding appropriate management, ranging from non-operative observation to embolization or surgery [3]. Treatment: In this case, the patient presented with significant splenic trauma and active extravasation on imaging, which required urgent intervention. Given the hemodynamic instability and the severity of the injury, the patient underwent splenic embolization. Transcatheter arterial embolization (TAE) is considered the treatment of choice for high-grade splenic injuries and avoids the need for splenectomy in many cases. During embolization, selective catheterization of the splenic artery allows for precise delivery of embolic agents to the bleeding vessels, controlling the hemorrhage. It can successfully treat most splenic injuries with a low risk of complications. As an alternative to splenectomy, it is minimally invasive and effective in achieving hemostasis while preserving splenic function. However, patients with more severe injuries, such as complete splenic rupture or failure of embolization, may require splenectomy [4]. Prognosis: Prognosis after splenic injury is dependent on degree of injury and time until treatment. Low grade injuries often have a very favorable prognosis, though delayed splenic rupture may occur up to 10 days post injury. The prognosis for patients undergoing TAE is generally favorable, especially in cases of successful embolization. When embolization effectively controls the bleeding, the patient can recover without the need for splenectomy and typically experience a full recovery. In up to 20% of patients, splenic infarction may occur after embolization (defined as more than 25% devascularization of the spleen). The risk of other complications such as recurrence of bleeding or abscess formation is low. However, patients who undergo splenectomy due to failed embolization or more severe injury are at higher risk for post-splenectomy infection, particularly with encapsulated organisms. This risk is highest in the first 2 years after splenectomy but can occur at any time. Vaccinations and long-term follow-up are essential in these patients. Early diagnosis, timely embolization, and careful post-procedural monitoring contribute to favorable long-term outcomes for most patients with splenic injuries [5]. ​​​​ References: Injury scoring scale. The American Association for the Surgery of Trauma. (2025, Jan. 16). https://www.aast.org/resources-detail/injury-scoring-scale#spleen Coccolini F, Montori G, Catena F, et al. Splenic trauma: WSES classification and guidelines for adult and pediatric patients. World J Emerg Surg . 2017;12:40. Published 2017 Aug 18. DOI: 10.1186/s13017-017-0151-4 Steven R Klepac, M. (2023, September 14). Splenic trauma imaging. Practice Essentials, Radiography, Computed Tomography. https://emedicine.medscape.com/article/373694-overview Quencer KB, Smith TA. Review of proximal splenic artery embolization in blunt abdominal trauma. CVIR Endovasc . 2019;2(1):11. Published 2019 Mar 18. PMCID: PMC7224246 DOI: 10.1186/s42155-019-0055-3 Oelhaf RC, Sugumar K, King KC. Splenic Trauma. [Updated 2023 Jun 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430920/ Sriya Kosaraju is a medical student at University of Missouri-Kansas City (UKMC) School of Medicine and is pursuing radiology. Her interest is in the field radiology from its central role in patient care and the dynamic intersection of technology, innovation, and impactful clinical decision-making. At UMKC, she currently serves as the Director of Research Initiatives for UMKC’s Vascular and Interventional Radiology Interest Group, where she helps organize journal clubs, connects students with mentors, and supports research opportunities in interventional radiology. She also serves as a Student Ambassador, guiding and mentoring prospective students through tours, panels, and other recruitment efforts. On a national level, she currently serves on the Society of Interventional Radiology's membership committee and volunteers with both the Society of Interventional Radiology (SIR) and the American College of Radiology (ACR) Rad Reserves, contributing to projects to enhance radiology resources and outreach. Sriya is passionate about preventative health care and the role of radiology in improving clinical outcomes. She is the founder and president of Mam4Mom, a nonprofit dedicated to increasing access to women’s health services. Through Mam4Mom, she has led initiatives including free mammogram and Pap smear days, community awareness campaigns, and care baskets for hospitalized cancer patients. She hopes to continue to explore ways to bridge medicine, service, education, and advocacy in her future career. Follow Sriya Kosaraju on X (formerly Twitter) @sriyakosaraju All posts by Sriya Kosaraju Kevin M. Rice, MD  is the president of Global Radiology CME and is a radiologist with Cape Radiology Group . He has held several leadership positions including Board Member and Chief of Staff at Valley Presbyterian Hospital  in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide  innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.  He was once again a semifinalist for a "Minnie" for 2021's Most Effective Radiology Educator  by AuntMinnie.com . He has continued to teach by mentoring medical students interested in radiology . Everyone who he has mentored has been accepted into top programs across the country including Harvard, UC San Diego, Northwestern, Vanderbilt, and Thomas Jefferson. Follow Dr. Rice on X (formerly Twitter) @KevinRiceMD All posts by Kevin M. Rice, MD

26 M jumped to catch a baseball and landed on his left foot while rotating to the right . Diagnosis? • Xray of the Week Figure 1. The patient jumped to catch a baseball and landed on his left foot while rotating to the right . Diagnosis? Figure 2. Lateral Subtalar Joint Dislocation . (A) AP radiograph demonstrates the talus (yellow arrow) with anatomical alignment to the distal tibia. The calcaneus (blue arrow) and navicular are rotated laterally. (B) Lateral radiograph demonstrates the talus (yellow arrow) with anatomical alignment to the distal tibia. The calcaneus (blue arrow) is rotated laterally. Subtalar Joint Dislocation Subtalar joint dislocation is a rare but significant orthopedic injury characterized by the disruption of the talocalcaneal and talonavicular articulations while preserving the tibiotalar and calcaneocuboid joints. It accounts for approximately 1% of all dislocations and typically results from high-energy trauma, such as motor vehicle accidents, falls from height, or sports injuries. Medial dislocations, also known as acquired clubfoot , constitute about 80% of cases, whereas lateral dislocations ( acquired flatfoot ) account for the remaining 20%. Posterior and anterior dislocations are exceedingly rare. Etiology and Pathophysiology The injury mechanism involves forced inversion or eversion of the foot with an axial load. Medial dislocations result from inversion forces, leading to disruption of the lateral ligamentous structures and impingement of the talar head against the extensor tendons. As in this case, lateral dislocations result from eversion forces, causing injury to the deltoid ligament and potentially the posterior tibial tendon. Associated fractures, particularly of the lateral process of the talus or the anterior calcaneal process, are present in up to 50% of cases and may complicate reduction. Imaging Findings Radiographic evaluation is the first-line imaging modality, with anteroposterior, lateral, and oblique foot radiographs demonstrating misalignment of the talocalcaneal and talonavicular joints (Figs. 1,2). Medial dislocations present with the talar head displaced laterally and the calcaneus medially, while lateral dislocations exhibit the opposite pattern. Fractures of the lateral talar process, anterior calcaneal process, or posterior malleolus should be carefully assessed. CT imaging is invaluable in evaluating associated fractures, assessing articular congruity post-reduction, and planning surgical intervention if necessary. Multiplanar reconstructions can aid in identifying subtle talar dome impaction or osteochondral injuries. MRI is reserved for evaluating ligamentous and tendinous injuries, particularly in chronic or irreducible cases. Treatment and Prognosis Closed reduction under sedation or anesthesia is the primary treatment modality. Reduction is typically achieved by applying traction and reversing the mechanism of injury, followed by immobilization in a short-leg cast or boot for 4–6 weeks. Open reduction may be required in cases of interposed soft tissue or osteochondral fragments preventing closed reduction. Post-reduction imaging, including CT, should be obtained to confirm alignment and exclude occult fractures. The prognosis is generally favorable if early, stable reduction is achieved. However, complications such as post-traumatic arthritis, subtalar instability, and avascular necrosis of the talus may occur, particularly in cases of delayed treatment or associated fractures. Long-term outcomes depend on the severity of cartilage damage and the presence of concomitant injuries. References Bohay DR, Manoli A 2nd. Subtalar joint dislocations. Foot Ankle Int . 1995;16(12):803-808. doi: 10.1177/107110079501601212 Richter M, Wippermann B, Krettek C, Schratt HE, Hufner T, Therman H. Fractures and fracture dislocations of the midfoot: occurrence, causes and long-term results. Foot Ankle Int . 2001;22(5):392-398. doi: 10.1177/107110070102200506 Prada-Cañizares A, Auñón-Martín I, Vilá Y Rico J, Pretell-Mazzini J. Subtalar Dislocation: Management and Prognosis for an Uncommon Orthopaedic Condition. Int Orthop. 2016;40(5):999-1007. doi:10.1007/s00264-015-2910-8 - Pubmed Rammelt S & Goronzy J. Subtalar Dislocations. Foot Ankle Clin. 2015;20(2):253-64. doi:10.1016/j.fcl.2015.02.008 - Pubmed Ruhlmann F, Poujardieu C, Vernois J, Gayet L. Isolated Acute Traumatic Subtalar Dislocations: Review of 13 Cases at a Mean Follow-Up of 6 Years and Literature Review. J Foot Ankle Surg. 2017;56(1):201-7. doi:10.1053/j.jfas.2016.01.044 - Pubmed Cheruvu M, Narayana Murthy S, Siddiqui R. Subtalar Dislocations: Mechanisms, Clinical Presentation and Methods of Reduction. World J Orthop. 2023;14(6):379-86. doi:10.5312/wjo.v14.i6.379 - Pubmed Kevin M. Rice, MD  is the president of Global Radiology CME and is a radiologist with Cape Radiology Group . He has held several leadership positions including Board Member and Chief of Staff at Valley Presbyterian Hospital  in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide  innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.   He was once again a semifinalist for a "Minnie" for 2021's Most Effective Radiology Educator  by AuntMinnie.com . He has continued to teach by mentoring medical students interested in radiology . Everyone who he has mentored has been accepted into top programs across the country including Harvard, UC San Diego, Northwestern, Vanderbilt, and Thomas Jefferson. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD

What is the device in the chest? What are potential complications? • Xray of the Week Figure 1. What is the device in the chest? Figure 2. Frontal and lateral chest radiograph demonstrates foreign body consistent with Bravo pH Capsule in the esophagus. Figure 3. Enlarged and lateral chest radiograph demonstrates foreign body consistent with Bravo pH Capsule in the esophagus. Bravo pH Monitoring System: Radiologic Considerations and Clinical Implications The Bravo pH monitoring system is a catheter-free, ambulatory device designed to evaluate esophageal acid exposure over 48–96 hours. It is widely used in the diagnosis of gastroesophageal reflux disease (GERD), particularly in patients with persistent symptoms despite medical therapy or in those being considered for anti-reflux surgery. The system consists of a small pH capsule that is temporarily affixed to the esophageal mucosa via endoscopy and transmits pH data to an external receiver. The capsule typically detaches within 5 days and passes though the GI tract into the stool. Radiographically, the device is typically positioned about 5–6 cm above the gastroesophageal junction. Unlike traditional catheter-based monitoring, Bravo improves patient tolerance and compliance, leading to more accurate symptom correlation and better diagnostic yield. Complications of Bravo pH Monitoring Although Bravo pH monitoring is minimally invasive, several potential complications have been reported, including: Chest pain and discomfort, occurring in 15–20% of patients, occasionally severe enough to require early capsule removal. Dysphagia or globus sensation, particularly if the capsule is placed too proximally. Mucosal ulceration and bleeding, especially in patients with pre-existing esophagitis or delayed esophageal clearance. Capsule misplacement or detachment failure, leading to inaccurate pH readings and potential patient discomfort. Aspiration or prolonged capsule retention, although rare, requiring endoscopic retrieval if retained beyond 30 days. Radiologic Considerations: Bravo pH Capsule on Imaging Although not an imaging-based diagnostic tool, radiology plays a key role in evaluating capsule placement and identifying complications. Confirming Capsule Placement The Bravo capsule appears as a small, radiopaque metallic-density structure in the distal esophagus, typically 5–6 cm above the gastroesophageal junction, on fluoroscopy, chest X-ray, or CT (Figs 1-3). Fluoroscopy can confirm proper adherence in cases of chest discomfort or suspected misplacement. Assessing for Complications CT imaging may reveal adjacent mucosal thickening, edema, or ulceration in patients with persistent symptoms. In suspected prolonged retention, an abdominal X-ray can confirm whether the capsule has passed through the GI tract or remains in place beyond the expected detachment period. In rare cases of suspected esophageal perforation, contrast esophagography may demonstrate extraluminal leakage . Avoiding Misinterpretation The Bravo capsule can be misinterpreted as a foreign body or endoscopic clip, particularly in oncologic imaging. Awareness of its expected location and morphology prevents unnecessary biopsy or surgical consultation. Conclusion The Bravo pH monitoring system remains integral to GERD diagnosis, offering prolonged, catheter-free acid monitoring. However, it presents unique radiologic challenges, as it can be mistaken for a foreign body, endoscopic clip, or pathologic mass. Understanding the expected imaging characteristics, potential complications, and appropriate differential considerations allows radiologists to optimize patient management and avoid unnecessary procedures . References Gyawali CP, Kahrilas PJ, Savarino E, et al. Modern diagnosis of GERD: the Lyon Consensus. Gut . 2018;67(7):1351-1362. DOI: 10.1136/gutjnl-2017-314722 Savarino E, Bredenoord AJ, Fox M, et al. Expert consensus document: Advances in the physiological assessment and diagnosis of GERD [published correction appears in Nat Rev Gastroenterol Hepatol. 2018 May;15(5):323. DOI: 10.1038/nrgastro.2018.32 .]. Nat Rev Gastroenterol Hepatol . 2017;14(11):665-676. DOI: 10.1038/nrgastro.2017.130 Gawron AJ, Pandolfino JE. Ambulatory reflux monitoring in GERD--which test should be performed and should therapy be stopped?. Curr Gastroenterol Rep . 2013;15(4):316. doi: 10.1007/s11894-013-0316-6 Sigakis CJG, Mathai SK, Suby-Long TD, et al. Radiographic Review of Current Therapeutic and Monitoring Devices in the Chest. Radiographics . 2018;38(4):1027-1045. DOI: 10.1148/rg.2018170096 Bredenoord AJ, Pandolfino JE, Smout AJ. Gastro-oesophageal reflux disease. Lancet . 2013;381(9881):1933-1942. DOI: 10.1016/S0140-6736(12)62171-0 Weusten BL, Roelofs JM, Akkermans LM, Van Berge-Henegouwen GP, Smout AJ. The symptom-association probability: an improved method for symptom analysis of 24-hour esophageal pH data. Gastroenterology . 1994;107(6):1741-1745. DOI: 10.1016/0016-5085(94)90815-x Spechler SJ. Epidemiology and natural history of gastro-oesophageal reflux disease. Digestion . 1992;51 Suppl 1:24-29. DOI: 10.1159/000200911 Naik RD, Meyers MH, Vaezi MF. Treatment of Refractory Gastroesophageal Reflux Disease. Gastroenterol Hepatol (N Y) . 2020;16(4):196-205. PMCID: PMC8132683 Yadlapati R, Pandolfino JE. Personalized Approach in the Work-up and Management of Gastroesophageal Reflux Disease. Gastrointest Endosc Clin N Am . 2020;30(2):227-238. DOI: 10.1016/j.giec.2019.12.002 Vakil N, van Zanten SV, Kahrilas P, Dent J, Jones R; Global Consensus Group. The Montreal definition and classification of gastroesophageal reflux disease: a global evidence-based consensus. Am J Gastroenterol . 2006;101(8):1900-1943. DOI: 10.1111/j.1572-0241.2006.00630.x Richter JE, Pandolfino JE, Vela MF, et al. Utilization of wireless pH monitoring technologies: a summary of the proceedings from the esophageal diagnostic working group. Dis Esophagus . 2013;26(8):755-765. DOI: 10.1111/j.1442-2050.2012.01384.x Zerbib F, Roman S, Bruley Des Varannes S, et al. Normal values of pharyngeal and esophageal 24-hour pH impedance in individuals on and off therapy and interobserver reproducibility. Clin Gastroenterol Hepatol . 2013;11(4):366-372. DOI: 10.1016/j.cgh.2012.10.041 Katz PO, Dunbar KB, Schnoll-Sussman FH, Greer KB, Yadlapati R, Spechler SJ. ACG Clinical Guideline for the Diagnosis and Management of Gastroesophageal Reflux Disease. Am J Gastroenterol . 2022;117(1):27-56. DOI: 10.14309/ajg.0000000000001538 Boeckxstaens GE, Rohof WO. Pathophysiology of gastroesophageal reflux disease. Gastroenterol Clin North Am . 2014;43(1):15-25. DOI: 10.1016/j.gtc.2013.11.001 Tutuian R, Castell DO. Reflux monitoring: role of combined multichannel intraluminal impedance and pH. Gastrointest Endosc Clin N Am . 2005;15(2):361-371. DOI: 10.1016/j.giec.2004.10.002 Spechler SJ. Comparison of medical and surgical therapy for complicated gastroesophageal reflux disease in veterans. The Department of Veterans Affairs Gastroesophageal Reflux Disease Study Group. N Engl J Med . 1992;326(12):786-792. DOI: 10.1056/NEJM199203193261202 Kevin M. Rice, MD is the president of Global Radiology CME and is a radiologist with Cape Radiology Group . He has held several leadership positions including Board Member and Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator. He was once again a semifinalist for a "Minnie" for 2021's Most Effective Radiology Educator by AuntMinnie.com . He has continued to teach by mentoring medical students interested in radiology . Everyone who he has mentored has been accepted into top programs across the country including Harvard, UC San Diego, Northwestern, Vanderbilt, and Thomas Jefferson. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD

Name the Device • Xray of the Week Routine CXR for cough demonstrates metallic device. Name the cardiac implant. Figure 1. The circled device is a CardioMEMS HF System used to measure and monitor pulmonary artery (PA) pressure and heart rate. The patient also has a biventricular pacemaker. (Image courtesy of Mark Beller, MD.) Figure 2. Video Explaining percutaneous placement technique for the CardioMEMS. Figure 3. The CardioMEMS HF System. A. Implantable monitoring device. B. RemoteCare external electronics unit. The CardioMEMS™ HF System is indicated for wirelessly measuring and monitoring pulmonary artery (PA) pressure and heart rate in New York Heart Association (NYHA) Class III heart failure patients who have been hospitalized for heart failure in the previous year. Using a percutaneous approach (Fig. 2), the sensor (Fig. 3A) is implanted in the pulmonary artery. Once the device is implanted, daily pressure readings are obtained with the external electronics unit (Fig. 3B) and wirelessly transmitted to the patient's physician for continuous monitoring. Fig 4. Magnified views of the CXR and CT Scan of a second patient with the CardioMEMS HF System in the right lower lobe pulmonary artery. References: 1. Abbott CardioMEMS Website 2. Chaudhry SI, Mattera JA, CurtisJP, et al., (2010). Telemonitoring in patients with heart failure. NEJM, 363(24), 2301-2309.  http://dx.doi.org/10.1056/NEJMoa1010029 3. Kohler F, Winker S, Schieber M, et al. (2010, November). Telemedical interventional monitoring in heart failure (TIM-HF), a randomized, controlled, intervention trial investigating the impact of telemedicine on mortality in ambulatory patients with chronic heart failure. Presented at the meeting of the American Heart Association, Chicago, IL. http://dx.doi.org/10.1161/CIR.0b013e318200c0b5 4. van Veldhuisen DJ, Braunschweig F, Conraads V, et al, for the DOT-HF Investigators. (2011). Intrathoracic impedance monitoring, audible patient alerts, and outcome in patients with heart failure. Circulation, 124(16), 1719-1726.  http://dx.doi.org/10.1161/circulationaha.111.043042 5. Adamson PB, Abraham WT, Bourge RC, et al. (2014). Wireless pulmonary artery pressure monitoring guides management to reduce decompensation in heart failure with preserved ejection fraction.Circulation: Heart Failure, 7(6), 935- 944. http://dx.doi.org/10.1161/circheartfailure.113.001229 6. Abraham WT, Stevenson L, Bourge RC, et al. (2016). Sustained efficacy of pulmonary artery pressure to guide to adjustment of chronic heart failure therapy: Complete follow-up results from the CHAMPION randomized trial. The Lancet, 387(10017), 453-461.  http://dx.doi.org/10.1016/S0140-6736(15)007233-0 7. Adamson PB, Abraham WT, Bourge RC, et al. (2010). CardioMEMS heart sensor allows monitoring of pressures to improve outcomes in NYHA class III heart failure patients (CHAMPION) Trial: Impact of hemodynamic guided care on patients with preserved ejection fraction. Journal of Cardiac Failure, 16(11), 913.  http://dx.doi.org/10.1016/j.cardfail.2010.09.012 8. Weiner S, Abraham WT, Adamson PB, et al. (2011). Effect of CRT on heart failure related hospitalizations in patients with reduced EF utilizing remote pulmonary artery pressures in the CHAMPION Trial. Heart Rhythm, 8(5S), S437. http://dx.doi.org/10.1016/j.hrthm.2011.03.033 9. Conyers JM, Rajiah P, Ahn R, Abbara S, et al. Imaging features of leadless cardiovascular devices. Diagn Interv Radiol. 2018 Jul; 24(4): 203–208. d oi: 10.5152/dir.2018.17462 10. How to Implant the CardioMEMS Heart Failure SensorA step-by-step review of the sensor implantation procedure, including pre- and postprocedural assessment.By David M. Shavelle, MD, FACC, FSCAI. https://citoday.com/2018/02/how-to-implant-the-cardiomems-heart-failure-sensor/ Related posts: Bicuspid Aortic Valve and Aortic Stenosis Implanted Cardiac Loop Recorder Cardiac Tamponade Following Coronary Artery Rotational Atherectomy Papillary Fibroelastoma of Aortic Valve Micra Intracardiac Pacemaker Kevin M. Rice, MD is the president of Global Radiology CME Dr. Rice serves as the Chair of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates . Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD

RUQ pain, septic, unstable BP • Xray of the Week Figure 1. What is the important finding on these images. Figure 2. A. HIDA scan showing liver, common bile duct, small bowel B. Magnified view HIDA scan showing common bile duct (green arrow) and duodenum (blue arrow). Note that tracer is not present in the gallbladder due to cystic duct obstruction. C. Abdominal CT showing enlarged gallbladder with gas in the gallbladder wall (yellow arrow) and cholelithiasis (red arrow). Discussion: Emphysematous cholecystitis is a rare, life-threatening form of acute cholecystitis that occurs when gas-producing bacteria invade the gallbladder wall and cause necrosis (1). Air accumulates in the wall as seen in figure 2C, which can be attributed to gallbladder ischemia, tissue infarction, drugs, abdominal trauma, or incompetence of the sphincter of Oddi (1). Emphysematous cholecystitis typically occurs in diabetic men and puts patients at increased risk of gallbladder perforation (2). Emphysematous cholecystitis has echogenic foci with reverberation artifact on ultrasound, but ultrasound is less sensitive and specific than CT scan (3). The appearance of air in the lumen on ultrasound is also known as the “ring-down artifact” or “dirty shadowing” (4). Emphysematous cholecystitis can be distinguished from acute cholecystitis on CT due to the presence of gas in the gallbladder wall or lumen (1,5). On CT, emphysematous cholecystitis may also demonstrate pericholecystic inflammatory changes, intrahepatic abscess, gallbladder wall thickening, cholelithiasis, and intraperitoneal free air (1,3). On MRI, emphysematous cholecystitis shows intraluminal gas and intramural necrosis as well as gallstones in the neck of the gallbladder (1). Emphysematous cholecystitis may also present with the “champagne sign” or effervescent gallbladder sign on MRI, which refers to the foci of gas in the wall (1). Treatment of emphysematous cholecystitis includes broad-spectrum antibiotics and emergency cholecystectomy, although patients not suitable for surgery may undergo temporary percutaneous cholecystostomy (2,3). Click here to see what was done for this patient: Treatment of Emphysematous Cholecystitis ​​​​ References: Safwan M, and Penny SM. Emphysematous Cholecystitis: A Deadly Twist to a Common Disease. Journal of Diagnostic Medical Sonography, vol. 32, no. 3, May 2016, pp. 131–37. doi:10.1177/8756479316631535 Yen WL, Hsu CF, Tsai MJ. Emphysematous cholecystitis. Tzu Chi Medical Journal. 2016;28(1):37-38. doi:10.1016/j.tcmj.2015.12.001 Sunnapwar A, Raut AA, Nagar AM, Katre R. Emphysematous cholecystitis: Imaging findings in nine patients. Indian J Radiol Imaging. 2011;21(2):142-146. doi:10.4103/0971-3026.82300 Aherne A, Ozaki R, Tobey N, Secko M. Diagnosis of emphysematous cholecystitis with bedside ultrasound in a septic elderly female with no source of infection. J Emerg Trauma Shock. 2017;10(2):85-86. doi:10.4103/JETS.JETS_75_16 Chen, Ming-Yu, et al. Emphysematous Cholecystitis in a Young Male without Predisposing Factors: A Case Report. Medicine, vol. 95, no. 44, Nov. 2016, p. e5367. doi:10.1097/MD.0000000000005367 Amara Ahmed is a medical student at the Florida State University College of Medicine. She serves on the executive board of the American Medical Women’s Association and Humanities and Medicine. She is also an editor of HEAL: Humanism Evolving through Arts and Literature, a creative arts journal at the medical school. Prior to attending medical school, she graduated summa cum laude from the Honors Medical Scholars program at Florida State University where she completed her undergraduate studies in exercise physiology, biology, and chemistry. In her free time, she enjoys reading, writing, and spending time with family and friends. Follow Amara Ahmed on Twitter @Amara_S98 UPDATE: Dr. Ahmed will be a radiology resident at University of Florida in July 2024. All posts by Amara Ahmed Kevin M. Rice, MD is the president of Global Radiology CME and is a radiologist with Cape Radiology Group. He has held several leadership positions including Board Member and Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator. He was once again a semifinalist for a "Minnie" for 2021's Most Effective Radiology Educator by AuntMinnie.com. He has continued to teach by mentoring medical students interested in radiology. Everyone who he has mentored has been accepted into top programs across the country including Harvard, UC San Diego, Northwestern, Vanderbilt, and Thomas Jefferson. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD

Septic Shock and Abdominal pain • Xray of the Week 2018 A 57 yo M presented to the Emergency Department with septic shock and vague abdominal pain. What is the diagnosis and what is the treatment of choice? Figure 1. (A) Axial non-contrast CT of the upper abdomen. (B) Gallbladder ultrasound. Figure 2. (A) Axial non-contrast CT of the upper abdomen. (B) Gallbladder ultrasound. Red arrow: Thick-walled gallbladder with surrounding mesenteric fat stranding indicative of acute cholecystitis seen on CT scan. Green arrow: Edema in thickened gallbladder wall seen on ultrasound. Figure 3. CT images following placement of cholecystostomy tube (Green arrow). Discussion: Acute cholecystitis is the main complication of gallstones and is a common cause of acute right upper quadrant pain. While the vast majority are associated with gallstones, 5-10% of cases are due to acalculous cholecystitis. As in this case, if there are no gallstones, the diagnosis of acute acalculous cholecystitis can be suggested if there is gallbladder wall thickening and surrounding edema (Fig. 1-2). Adjacent fluid, abscess, and positive ultrasonographic Murphy sign may also be present. Severe trauma, critical illness, burn, diabetes, malignant disease, abdominal vasculitis, congestive heart failure, cholesterol embolization, shock, and cardiac arrest are all associated with acute acalculous cholecystitis. The most common indication for percutaneous cholecystostomy is with cases of known cholecystitis -either calculous or acalculous- in patients who are too high risk for surgery. However, the procedure should be considered in critically ill patients with unexplained sepsis. Complications of the procedure include bile leak, bleeding, and bowel injury. The most common cause of bile leak and recurrent sepsis is catheter dislodgement, which is why it is advised to coil the tube inside the gallbladder if possible. References: 1. Barie PS, Eachempati SR. Acute acalculous cholecystitis. Gastroenterol. Clin. North Am. 2010;39 (2): 343-57, x. 2. Mirvis SE, Vainright JR, Nelson AW et-al. The diagnosis of acute acalculous cholecystitis: a comparison of sonography, scintigraphy, and CT. AJR Am J Roentgenol. 1986;147 (6): 1171-5. 3. Joseph T, Unver K, Hwang GL et-al. Percutaneous cholecystostomy for acute cholecystitis: ten-year experience. J Vasc Interv Radiol. 2012;23 (1): 83-8.e1 . 4. Huang CC, Lo HC, Tzeng YM et-al. Percutaneous transhepatic gall bladder drainage: a better initial therapeutic choice for patients with gall bladder perforation in the emergency department. Emerg Med J. 2007;24 (12): 836-40 Kevin M. Rice, MD is president of Global Radiology CME and serves as the Chief of staff and Chair of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates . Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. Dr. Rice co-founded Global Radiology CME with Natalie Rice to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" award for the Most Effective Radiology Educator. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD

Sepsis and hypotension. What procedure is indicated? • Xray of the Week Figure 1. What action should be taken for this patient with sepsis and hypotension? Figure 2. A. HIDA scan showing liver, common bile duct, small bowel B. Magnified view HIDA scan showing common bile duct (green arrow) and duodenum (blue arrow). Note that tracer is not present in the gallbladder due to cystic duct obstruction. C. Abdominal CT showing enlarged gallbladder with gas in the gallbladder wall (yellow arrow) and cholelithiasis (red arrow) indicating emphysematous cholecystitis. Figure 3. Percutaneous Cholecystostomy Abdominal CT showing percutaneous access needle (green arrow) entering the patient’s gallbladder via a transhepatic approach. The final CT image shows the drainage catheter (yellow arrow) correctly placed in the gallbladder with the tip coiled in the gallbladder fundus (red arrow). Discussion: Percutaneous cholecystostomy (PCS) is an image-guided, minimally invasive catheterization of the gallbladder [1]. It is indicated for gallbladder drainage in acute cholecystitis (including calculous, acalculous , gangrenous, and emphysematous varieties) or gallbladder perforation among high-risk patients with contraindications to surgical intervention. It can also be employed to allow percutaneous removal of biliary stones, or catheterization of the biliary tree to resolve obstruction [1,2]. Among patients treated for acute cholecystitis, PCS is commonly followed by cholecystectomy if the patient’s condition can be optimized, as its use as a definitive therapy in this population has not found consistent support [3]. PCS may be guided by US, CT, and/or fluoroscopy, and involves transhepatic or transperitoneal insertion of an access needle followed by gallbladder catheterization with either the Seldinger technique or a trocar system [1,4,5]. Figures 1 and 2 are imaging studies on a patient with sepsis and hypotension due to emphysematous cholecystitis who was too unstable to undergo surgery. The patient underwent a percutaneous cholecystostomy using the Seldinger technique and CT guidance, as illustrated in Figure 3. After stabilization and maturation of the tract, the patient had a surgical cholecystectomy and fully recovered. Though ultrasound is typically the favored imaging modality for needle insertion due to mobility, lack of ionizing radiation, and continuous visualization, CT may be necessary if the gallbladder lumen cannot be observed sonographically (e.g. cholecystitis, wall thickening; 1,5). Access needles can be clearly visualized on either US or CT. Following US-guided needle insertion, fluoroscopy is frequently used to aid catheter placement [1,5]. Choice of transhepatic or transperitoneal approaches should be employed according to patient anatomy and operator discretion, since there has been no demonstrated difference in outcome or complications [6]. The former method involves traversing the liver with intent to puncture the bare area of the gallbladder, while the latter simply accesses the gallbladder via the peritoneal cavity [1,6]. Rationales favoring the transhepatic approach include increased catheter stability, quicker fistula tract maturation, and a theoretically decreased risk of bile leakage [1,6]. It is also preferred in cases of ascites or bowel interposition [1]. A transperitoneal route is favored in patients with coagulopathy or diffuse liver disease [1]. Major complications of PCS include hemorrhage, pneumothorax, biliary leak, and peritonitis, with the transhepatic approach having increased risk of pleural or hepatic damage [1,2,4]. ​​​​ References: Ginat D and Saad W. Cholecystostomy and Transcholecystic Biliary Access. Tech Vasc Interv Radiol. 2008;11(1):2-13. DOI: 10.1053/j.tvir.2008.05.002 Hatzidakis A, Venetucci P, Krokidis M, Iaccarino V. Percutaneous biliary interventions through the gallbladder and cystic duct: What radiologists need to know. Clin Radiol. 2014;69(12):1304-1311. DOI: 10.1016/j.crad.2014.07.016 Gurusamy KS, Rossi M, Davidson BR. Percutaneous cholecystostomy for high risk surgical patients with acute calculous cholecystitis. Cochrane Database Syst Rev. 2013;(8): CD007088. DOI: 10.1002/14651858.CD007088.pub2 Little Mw. Percutaneous cholecystostomy: The radiologist’s role in treating acute cholecystitis. Clin Radiol. 2013;68(7): 654-660. DOI: 10.1016/j.crad.2013.01.017 Venara A, Carretier V, Lebigot J, E Lermite. Technique and indications of percutaneous cholecystostomy in the management of acute cholecystitis in 2014. J Visc Surg. 2014;151(6):435-439. DOI: 10.1016/j.jviscsurg.2014.06.003 Beland MD, Patel L, Ahn SH, Grand DJ. Image-Guided Cholecystostomy Tube Placement: Short- and Long-Term Outcomes of Transhepatic Versus Transperitoneal Placement. AJR Am J Roentgenol. 2019;212: 201-204. DOI: 10.2214/AJR.18.19669 Ian Rumball is a medical student and aspiring radiologist at the Zucker School of Medicine at Hofstra/Northwell in Hempstead, NY. He serves as chair for his school’s radiology interest group. Prior to medical school, he attended the University of Wisconsin - Madison and graduated with degrees in biology, history, global health, and African studies. As an undergraduate, he did research in the fields of oncology, hematology, and neuroendocrinology. He also published work in undergraduate journals of creative writing, history, and physiology. In his free time, Ian enjoys playing guitar, hiking his local state parks, and watching classic films. Follow Ian Rumball on Twitter @RumballIan All posts by Ian Rumball UPDATE: Dr. Rumball will be a radiology resident at Medical College of Wisconsin in July 2024, after his Transitional Year at Gundersen Health System in La Crosse, Wisconsin. Kevin M. Rice, MD  is the president of Global Radiology CME and is a radiologist with Cape Radiology Group . He has held several leadership positions including Board Member and Chief of Staff at Valley Presbyterian Hospital  in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide  innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.  He was once again a semifinalist for a "Minnie" for 2021's Most Effective Radiology Educator  by AuntMinnie.com . He has continued to teach by mentoring medical students interested in radiology . Everyone who he has mentored has been accepted into top programs across the country including Harvard, UC San Diego, Northwestern, Vanderbilt, and Thomas Jefferson. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD

Biventricular Pacemaker Dysfunction • Xray of the Week Figure 1. Abnormal position of pacemaker. Figure 2. CXR done 19 days after pacemaker placement. A- Note the retracted right atrial lead (green arrow) and right ventricular lead with shock coil (yellow arrow). The coronary sinus lead is also partially retracted (blue arrow). B- Coiled up electrodes adjacent to the generator (red arrow). Figure 3. Immediate postoperative CXR obtained 19 days earlier demonstrating the correct position of the pacemaker. A- Note the correct position of the RA lead with the characteristic "J" shape (green arrow) as it curves superiorly and laterally with the tip in the right atrial appendage. The RV lead with shock coil has a gentle curve and the tip is at the RV apex (yellow arrow). The LV lead is also correctly positioned deep in the coronary sinus (blue arrow). B- Well positioned electrodes adjacent to the generator (red arrow). Figure 4. Fluoroscopy images from the time of placement of the left ventricular/coronary sinus lead initially show contrast in the coronary sinus (orange arrows), followed by positioning of the lead in the coronary sinus (blue arrow). Discussion: Biventricular pacing also known as cardiac resynchronization therapy (CRT) is a modality of cardiac pacing used in congestive heart failure (CHF) patients with left ventricular (LV) systolic dysfunction and dys-synchronous ventricular activation. Biventricular pacemakers provide simultaneous or nearly simultaneous electrical activation of the LV and right ventricle (RV) via leads placed in the coronary sinus and the RV. As seen in this case, a right atrium (RA) lead is often present as well [1]. CRT has been shown to reduce heart failure hospitalization and/or mortality by up to 34% in patients with less advanced, predominantly NYHA class II heart failure patients [2]. CRT devices are inserted via the subclavian vein and are attached to a pulse generator unit which is then implanted subcutaneously, over the pectoralis muscle. Gentle loops of leads into the heart and to the generator will avoid the problems of recoil from the ventricle or advancement into the pericardium. A snug pocket for the generator is desirable in order to avoid its motion with traction upon the catheter [3]. In this case, electrode dislodgement was caused by the patient twisting the pulse generator and coiling the electrode (red arrow- Image A & B) adjacent to the generator known as the “pacemaker twiddler’s syndrome” [4-6]. The tip of of the atrial lead (green arrow) is superior to level of right atrium and has come to rest in the superior vena cava (Figs. 1A, 2A). The right ventricle lead (yellow arrow) and coronary sinus lead (blue arrow) have also migrated proximally (Figs. 1A, 2A). Ventricular capture depends upon the intimate contact between the pacing electrode and the endocardium. Dislodged pacemakers may begin to pace the diaphragm due to phrenic-nerve stimulation resulting in the sensation of continuous abdominal pulsation. [6] Additional retraction of the wire may lead to brachial plexus stimulation with resultant upper extremity twitching. [6] Other complications of pacemaker placement include lead migration, improper initial placement, and perforation. Migration of the RV lead across the tricuspid valve and into the inferior vena cava or migration into the LV via the interventricular septum or the interatrial septum may have catastrophic clinical results [3]. RV leads may rarely pass through a patent foramen ovale or perforate in the area near the fossa ovalis or pass through a persistent sinus venosus. Left ventricular pacing has also been reported due to inadvertent trans arterial placement, which allows the lead to cross the aortic valve and enter the left ventricular cavity [7]. Close abutment of the tip against the ventricle can lead to perforation of the myocardium and entrance of the catheter into the pericardial space leading to failure of ventricular capture or tamponade [3]. Malposition of a transvenous pacing lead into the left ventricle can cause thromboembolism. Other electrode associated complications include fracture, pneumothorax, hematoma (pocket or mediastinal), hardware infection, and inappropriate shocks [3, 8]. It is essential that lead position be correct and verified on frontal and lateral imaging before the placement procedure is terminated. A frontal projection alone cannot define appropriate lead position [3]. This patient had his pacemaker replaced at which time additional sutures were used to secure the generator. References: Aguilera AL, Volokhina YV, Fisher KL. Radiography of cardiac conduction devices: a comprehensive review. Radiographics. 2011;31(6):1669-1682. doi: 10.1148/rg.316115529 Zaręba W. Comparison of clinical trials evaluating cardiac resynchronization therapy in mild to moderate heart failure. Cardiol J. 2010;17(6):543-548. https://pubmed.ncbi.nlm.nih.gov/21154255/ McHenry, M.M. and C.E. Grayson, Roentgenographic Diagnosis of Pacemaker Failure. American Journal of Roentgenology, 1970. 109(1): p. 94-100 DOI: 10.2214/ajr.109.1.94 . Tegtmeyer, C.J. and J.M. Deignan, The cardiac pacemaker: a different twist. AJR Am J Roentgenol, 1976. 126(5): p. 1017-8 DOI: 10.2214/ajr.126.5.1017 Bayliss CE, Beanlands DS, Baird RJ. The pacemaker-twiddler's syndrome: a new complication of implantable transvenous pacemakers. Can Med Assoc J . 1968;99(8):371-373. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1924435/ Nicholson WJ, Tuohy KA, Tilkemeier P. Twiddler's Syndrome. N Engl J Med . 2003;348(17):1726-1727. DOI: 10.1056/NEJM200304243481722 Bauersfeld, U.K., et al., Malposition of transvenous pacing lead in the left ventricle: radiographic findings. American Journal of Roentgenology, 1994. 162(2): p. 290-292 DOI: 10.2214/ajr.162.2.8310911 Costelloe, C.M., et al., Radiography of pacemakers and implantable cardioverter defibrillators. AJR Am J Roentgenol, 2012. 199(6): p. 1252-8 DOI: 10.2214/ajr.12.8641 Shama Jaswal is an International Medical Graduate, currently doing research at Mallinckrodt Institute of Radiology (MIR), Saint Louis. She aims at pursuing Diagnostic Radiology residency and poses a keen interest in research alongside academics. At MIR, she has been fortunate to work on various oncology projects including the project in which they studied how the difference in fat metabolism in both sexes can affect the cancer survival and outcome, and how this study can further improve prognosis through treatment modification. Shama is both an accomplished sprinter and singer having won several national competitions in in each discipline in India. She also has a strong passion for cooking and gardening. Follow Shama Jaswal on Twitter @Jaswal_Shama All posts by Shama Jaswal Kevin M. Rice, MD  is the president of Global Radiology CME Dr. Rice is a radiologist with Cape Radiology Group . Formerly the Chief of Staff at Valley Presbyterian Hospital  in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME  to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.   He was once again a semifinalist for a "Minnie" for 2021's Most Effective Radiology Educator  by AuntMinnie.com . Follow Dr. Rice on X formerly Twitter @KevinRiceMD All posts by Kevin M. Rice, MD