Search Results

SOB and Hypotension Following Coronary Artery Rotational Atherectomy • Xray of the Week This 85 year old female became short of breath, hypotensive, and lethargic shortly after rotational atherectomy of the right coronary artery. The cardiologist was concerned that there may be a retroperitoneal hemorrhage related to the femoral artery puncture, and ordered a CT abdomen and pelvis. What is the diagnosis and treatment? Figure 1A: Axial CT of lower chest. Figure 1B: Axial CT at the level of the vascular sheaths in the RLQ. Figure 1C: Coronal CT abdomen and pelvis. Figure 2A: Axial CT showing pericardial effusion (white arrows). Figure 2B: Axial CT showing no abnormality at the level of the vascular sheaths in the RLQ (white arrow). Figure 2C: Coronal CT showing pericardial effusion (white arrows). The images demonstrate no retroperitoneal abnormality. However, the CT scan demonstrates a large pericardial effusion (Figs. 1A, 1C, 2A, 2C) and, based on the clinical findings cardiac tamponade is suspected. An echocardiogram was performed which demonstrates right ventricular collapse in early diastole and right atrial inversion in late diastole in addition to the moderate sized pericardial effusion. (Fig. 3) A dilated inferior vena cava without respiratory variation was also seen, all signs of cardiac tamponade. Emergent pericardiocentesis and pericardial drainage catheter placement was performed resulting in rapid improvement in the patient's condition, no longer requiring pressors. Figure 3: Apical 4 chamber view showing right ventricular collapse in early diastole and right atrial inversion in late diastole. There is also a moderate sized pericardial effusion. Discussion Rotational atherectomy is increasingly being used for percutaneous coronary intervention due to the of the expansion of indications to more complex lesions (1,2,3). However, the compared to angioplasty, percutaneous transluminal rotational atherectomy has four times the risk for coronary artery perforation (1,3). The incidence of important procedure-related complications from rotational atherectomy is 1.3%, and the incidence of tamponade is 0.64% (4). Beck's triad consisting of jugular venous distension, distant heart sounds, and hypotension is the classic presentation of cardiac tamponade. Other symptoms of tamponade include severe respiratory distress, tachycardia, and agitation. Pulsus paradoxus, low voltage QRS complex on EKG, and a chest x-ray with enlarged cardiac silhouette may also be seen with tamponade (5). Even a small amount of pericardial fluid may cause tamponade in the acute setting, whereas a large amount of fluid accumulated over a long period of time may not cause tamponade. Treatment is pericardiocentesis and placement of a pericardial drain preferably with ultrasound guidance. Rapid treatment is often life-saving, resulting in prompt improvement in the patient's condition. Thoracotomy may be required in severe trauma. (6) Cardiac tamponade is in the differential diagnosis of pulseless electrical activity (PEA). References: 1. Wasiak J, Law J, Watson P, Spinks A. Percutaneous transluminal rotational atherectomy for coronary artery disease. Cochrane Database Syst Rev. 2012 Dec 12 2. Lee MS. Rotational Atherectomy: An Invaluable Tool for Complex Lesions. Cath Lab Digest Issue Number: Volume 19 - Issue 6 - June 2011 3. Gunning, MG, et al. Coronary artery perforation during percutaneous intervention: incidence and outcome. Heart. 2002 Nov; 88(5): 495–498. 4. Sakakura K, Inohara T, Kohsaka S, et al. Incidence and Determinants of Complications in Rotational Atherectomy. Circulation: Cardiovascular Interventions. 2016;9:e004278 5. Spodick DH. Acute Cardiac Tamponade. N Engl J Med 2003; 349:684-690 August 14, 2003 6. Shekar PS, Leacche M ,Farnam KA, et al. Surgical Management of Complications of Percutaneous Coronary Rotational Atherectomy Interventions. Ann Thorac Surg 2004;78:e81–2 Kevin M. Rice, MD is the president of Global Radiology CME Dr. Rice has served in many leadership positions; he has been the Chair of the Radiology Department and Chief of Staff 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. 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

RLQ Pain in 54 M • Xray of the Week This 54 year old male presented to the Emergency Department with right lower quadrant pain and vomiting. What is the diagnosis? Axial CT with contrast. There is a thick-walled diverticulum arising from the distal ileum with surrounding mesenteric edema, and mural enhancement diagnostic of Meckel diverticulitis. (blue arrow) Discussion Present in 2% of the population, Meckel diverticulum forms as a result of incomplete closure of the intestinal end of the omphalomesenteric duct, and is present within 40–100 cm of the ileocecal valve. The total lifetime complication rate of a Meckel diverticulum is approximately 4%. Complications include intestinal obstruction (40%) and diverticulitis (20%), torsion, intussusception, and hemorrhage. The symptoms are non specific and are most commonly attributed to appendicitis. CT scan demonstrates an inflamed diverticulum in the RLQ or midline with a normal appendix. The diverticulum may contain calcified enteroliths. Treatment is surgical excision. References: 1. Bennett GL, Birnbaum BA, Balthazar EJ. CT of Meckel's diverticulitis in 11 patients. AJR Am J Roentgenol. 2004;182 (3): 625-9. AJR Am J Roentgenol (full text) 2. Wong CS, Dupley L, Varia HN, Golka D, Linn T. Meckel's diverticulitis: a rare entity of Meckel's diverticulum. J Surg Case Rep. 2017;2017(1):rjw225. Published 2017 Jan 6. doi:10.1093/jscr/rjw225 3.Thurley PD, Halliday KE, Somers JM et-al. Radiological features of Meckel's diverticulum and its complications. Clin Radiol. 2009;64 (2): 109-18. DOI: https://doi.org/10.1016/j.crad.2008.07.012 4. Milam RA, Fonseca RB. Case 240: Meckel Diverticulitis. Radiology 2017; 283:303–307 https://pubs.rsna.org/doi/full/10.1148/radiol.2017150885 5. Elsayes KM, Menias CO, Harvin HJ et-al. Imaging manifestations of Meckel's diverticulum. AJR Am J Roentgenol. 2007;189 (1): 81-8. 6. Kotha VK, Khandelwal A, Saboo SS, et al. Radiologist's perspective for the Meckel's diverticulum and its complications. Br J Radiol. 2014;87(1037):20130743. doi:10.1259/bjr.20130743 7. Platon A, Gervaz P, Becker CD, Morel P, Poletti PA. Computed tomography of complicated Meckel's diverticulum in adults: a pictorial review. Insights Imaging. 2010;1(2):53–61. doi:10.1007/s13244-010-0017-8 Kevin M. Rice, MD is the president of Global Radiology CME Dr. Rice has served in many leadership positions; he has been the Chair of the Radiology Department and Chief of Staff of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances and given 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

Name the Cardiac Device • Xray of the Week Fig. 1. A. Frontal chest xray showing the Amulet® over the expected location of the left atrial appendage (LAA). Fig. 1. B. Magnified chest xray. The self-expanding distal lobe (blue arrow) and proximal disc (red arrow) are seen. Fig. 2. Amulet® is very similar to the Amplatzer™ Cardiac Plug (ACP) device. Fig. 3 Video demonstrating percutaneous placement technique for the Amplatzer™ Cardiac Plug (ACP) and Amulet® device for LAA closure. Fig. 4. Watchman™ LAAC device from Boston Scientific shows the self-expanding nitinol frame and fabric covering the face of the device. Fig. 5. CT scan of Watchman™ LAAC device in the left atrial appendage on axial and coronal images. Fig. 6 Video explaining percutaneous placement technique for the Watchman™ LAAC device. Fig. 7. AtriClip® Left Atrial Appendage Exclusion System. A. The AtriClip® in the deployment device. B. The layers of the AtriClip®. Fig. 8. AtriClip® Left Atrial Appendage Exclusion System. A. Frontal CXR with yellow arrow pointing to the device. B. Lateral CXR with red arrow pointing to the AtriClip®. Note the parallel tubes and Nitinol springs at each end. Discussion: LAA closure or occlusion devices are indicated for patients with atrial fibrillation in whom oral anticoagulation is contraindicated or an alternative to oral anticoagulation therapy for stroke prevention in patients with atrial fibrillation. Percutaneous LAA closure devices include the Watchman, Amplatzer Amulet, Amplatzer Cardiac Plug (ACP), and the PLAATO system. The Amulet and ACP both consist of a self-expanding distal lobe and proximal disc made of nitinol mesh with an articulating waist (Figs 1,2,3). The Watchman consists of a self-expanding nitinol frame, with a fabric covering the face of the device (Figs 4-6). Placed by open surgery or minimally invasive techniques, the AtriClip (Fig 7,8) is a self-closing clip placed on the epicardial surface of the heart on the base of the LAA . It is visualized on radiographs as a metallic structure with parallel tubes over the expected location of the LAA (Fig 6,7). Complications of percutaneous LAA closure devices include malposition, migration, or embolization. The Watchman, AtriClip, Amplatzer Amulet, and Amplatzer Cardiac Plug LAA closure devices are MR imaging conditional at 1.5 T and 3 T. References: 1. Swaans MJ, Wintgens LI, Alipour A, Rensing BJ, Boersma LV. Percutaneous left atrial appendage closure devices: safety, efficacy, and clinical utility. Med Devices (Auckl). 2016;9:309-316. Published 2016 Sep 2. doi:10.2147/MDER.S65492 Full Text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5015878/ 2. Onalan O, Crystal E. Left atrial appendage exclusion for stroke prevention in patients with nonrheumatic atrial fibrillation. Stroke. 38 (2 Suppl): 624-30. Full Text: doi:10.1161/01.STR.0000250166.06949.95 3. Sigakis CJG, Mathai SK, Suby-Long TD, Restauri NL, Ocazionez D, Bang TJ, Restrepo CS, Sachs PB, Vargas D. Radiographic Review of Current Therapeutic and Monitoring Devices in the Chest. (2018) Radiographics : a review publication of the Radiological Society of North America, Inc. 38 (4): 1027-1045. doi:10.1148/rg.2018170096 Full Text: https://pubs.rsna.org/doi/10.1148/rg.2018170096 4. Bedeir K, Warriner S, Kofsky E, Gullett C, Ramlawi B. Left Atrial Appendage Epicardial Clip (AtriClip): Essentials and Post-Procedure Management. (2019) Journal of atrial fibrillation. 11 (6): 2087. doi:10.4022/jafib.2087 Full Text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6652788/ 5. Moussa Pacha H, Al-Khadra Y, Soud M, Darmoch F, Moussa Pacha A, Alraies MC. Percutaneous devices for left atrial appendage occlusion: A contemporary review. World J Cardiol. 2019;11(2):57–70. doi:10.4330/wjc.v11.i2.57 Full Text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6391622/ 6. Sick PB, Schuler G, Hauptmann KE, et al. Initial worldwide experience with the WATCHMAN left atrial appendage system for stroke prevention in atrial fibrillation. J Am Coll Cardiol. 2007;49(13):1490-1495. doi:10.1016/j.jacc.2007.02.035. Full Text: https://www.sciencedirect.com/science/article/pii/S0735109707007474 Related posts: CardioMEMS Device 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 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

50-year-old male in a motor vehicle collision (MVC) presenting with hypotension. What is the diagnosis? • Xray of the Week Figure 1. Abdominal CT. Name the significant findings. Figure 2. A) Axial CT - bilateral striated nephrogram (red arrows). B) Axial CT - retroperitoneal hematoma (yellow arrows). C) Coronal CT – bilateral striated nephrogram (red arrows). Discussion: As a result of trauma this patient is hypotensive due to a large retroperitoneal hematoma which is partially visualized on these images. Patients with blunt trauma who are hypotensive and tachycardic are deemed to be in hemorrhagic shock until proven otherwise [1]. A striated nephrogram refers to a mixture of alternating low-attenuating and normal-enhancing bands within the kidney arranged radially on CT [2]. The pattern is due to any process that causes inflammation or edema in the renal cortex or medulla [3]. Striated nephrograms can be unilateral or bilateral, depending on the underlying pathology. Common causes of unilateral striated nephrogram include ureteric obstruction, acute pyelonephritis, renal contusion, and renal vein thrombosis. Bilateral striated nephrogram can be seen with hypotension, autosomal recessive polycystic kidney disease, acute pyelonephritis, and acute tubular necrosis [2,4]. Retroperitoneal hematoma is frequently due to traumatic vascular injury but can be associated with ruptured aortic aneurysm, coagulopathy, or iatrogenesis [5]. Hypotension is the principal finding; yet some patients may present with abdominal tenderness, distension and/or flank pain. CT is the imaging modality of choice if retroperitoneal hematoma is suspected clinically [5]. Acute and subacute hematomas have high attenuation on CT whereas chronic hematomas are often low in attenuation [6]. Treatment is dependent on the cause of the hematoma and patient condition with supportive care including blood transfusion, reversal of any coagulopathy, and observation for stable patients. Angiography with embolization or rarely surgery may be required for unstable patients [5]. ​​​​ References: Barkin AZ, Fischer CM, Berkman MR, Rosen CL. Blunt abdominal trauma and a diaphragmatic injury. J Emerg Med. 2007;32(1):113-117. doi:10.1016/j.jemermed.2006.11.001 Wolin EA, Hartman DS, Olson JR. Nephrographic and pyelographic analysis of CT urography: differential diagnosis. AJR Am J Roentgenol. 2013;200(6):1197-1203. doi:10.2214/AJR.12.9692 Moinuddin I, Bracamonte E, Thajudeen B, Sussman A, Madhrira M, Costello J. Allergic Interstitial Nephritis Manifesting as a Striated Nephrogram. Case Rep Med. 2015;2015:250530. PMCID: PMC4667022 doi:10.1155/2015/250530 Saunders HS, Dyer RB, Shifrin RY, Scharling ES, Bechtold RE, Zagoria RJ. The CT nephrogram: implications for evaluation of urinary tract disease. Radiographics. 1995;15(5):1069-1088. doi:10.1148/radiographics.15.5.7501851 Mondie C, Maguire NJ, Rentea RM. Retroperitoneal Hematoma. [Updated 2020 Nov 12]. In: StatPearls https://www.ncbi.nlm.nih.gov/books/NBK558928/ Rajiah P, Sinha R, Cuevas C, Dubinsky TJ, Bush WH Jr, Kolokythas O. Imaging of uncommon retroperitoneal masses. Radiographics. 2011;31(4):949-976. doi:10.1148/rg.314095132 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. Follow Deven Champaneri on Twitter @devenchampaneri All posts by Deven Champaneri 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

Trauma in a 31 yo F due to a motor vehicle collision (MVC) • Xray of the Week Figure 1. What are the important findings on this CT scan. What is the diagnosis? Figure 2. A,B. Sagittal reformatted CT images. C-E. Axial CT images Images show horizontal fracture through the right lamina (orange arrows), right pedicle (green arrows) and left pedicle (red arrows). Fracture of the spinous process (blue arrows) is also present. Discussion: Chance fractures are horizontal spinal fractures that extend through the spinous process, pedicles, and vertebral body at the thoracolumbar junction [1]. They typically result from flexion-distraction injury of the spine and may be referred to as “seat belt fractures” because they can occur in motor vehicle collisions where rapid deceleration causes flexion of the spine over the seat belt [1]. This causes distraction of the middle and posterior elements of the spine [1]. Table 1. Francis Denis Spine Fracture Classification System Source: https://www.researchgate.net/figure/Column-involvement-in-major-Denis-fracture-types_tbl1_288817814 The Chance fracture is classified as an unstable flexion-distraction spinal injury according to the Francis Denis three-column concept (Table 1) because it involves two or more columns: a distraction-type injury of the middle and posterior columns; compression-type injury of the anterior column may also be present in some cases [1,2]. Chance fractures can be identified as pure osseous, pure ligamentous, or osteoligamentous [1,2]. Chance fractures are difficult to identify as they do not present with neurological deficits but can present with intra-abdominal injuries [1]. Delays in diagnosis can result in progressive kyphosis and pain, so early diagnosis is essential. Differential diagnosis includes burst fracture, compression fracture, and distraction injury [1,3]. Figure 3. Axial CT image demonstrating the seat belt sign in this patient with stranding in the subcutaneous fat of the abdominal wall (red arrows). CT shows the horizontal fracture as well as vertebral body compression [1]. Stranding in the subcutaneous fat of the abdominal wall results in the “seat belt sign” on CT [1] (Fig. 3). CT also shows “dissolving pedicle,” which refers to the progressive decrease in pedicle definition from anterior to posterior [3]. On MRI, there may be a bright T2 signal signifying edema with low signal intensity fracture lines, intervertebral disc injury, and spinal cord edema [1]. Plain radiograph shows empty vertebral body sign, which results from displacement of the spinous processes [3]. Increased distance between the pedicles and facet joints on plain X-ray may also be seen in a Chance fracture [3]. Treatment includes immobilization with a stabilizing brace in patients without neurological deficits [1]. Surgical stabilization may be required in patients who have neurological deficits or damage to the posterior ligaments [1]. ​​​​ References: Koay J, Davis DD, Hogg JP. Chance Fractures. In: StatPearls. Treasure Island (FL): StatPearls Publishing; December 2, 2020. https://pubmed.ncbi.nlm.nih.gov/30725611/ Raniga SB, Skalski MR, Kirwadi A, Menon VK, Al-Azri FH, Butt S. Thoracolumbar Spine Injury at CT: Trauma/Emergency Radiology. Radiographics. 2016;36(7):2234-2235. doi:10.1148/rg.2016160058 Bernstein MP, Mirvis SE, Shanmuganathan K. Chance-type fractures of the thoracolumbar spine: imaging analysis in 53 patients. AJR Am J Roentgenol. 2006;187(4):859-868. doi:10.2214/AJR.05.0145 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 All posts by Amara Ahmed 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

54-year-old female with an Incidental Finding • Xray of the Week Name the device and location. Figure 1. CT scan of the abdomen and pelvis. Figure 2. CT scan of the abdomen and pelvis. A: Axial view of the pelvis showing the extrauterine IUD located in the right lower quadrant (orange arrow) and the normal uterus (green arrow). B: Sagittal oblique view of the abdomen and pelvis displaying the IUD (orange arrow) superior to the bladder dome and inferior to the uterus. C: Sagittal view of the abdomen and pelvis displaying a normal anteflexed uterus (green arrow). The IUD is not visible in this view and is clearly not in the endometrial canal. Discussion: Intrauterine devices (IUD) are a form of long-acting contraception designed to be inserted into the uterine cavity. Examples include the copper IUD, which can be used for up to 10 years, and the levonorgestrel IUD, which can be used for up to 5 years [1]. The copper IUD functions by acting as a spermicidal agent via a local inflammatory response to the copper material [1]. The levonorgestrel IUD functions by thickening the cervical mucus, which impairs sperm penetration and subsequent fertilization [2]. In women over 35, the copper IUD can be effective for more than 10 years [3]. The main complication during or after IUD insertion is total or partial uterine perforation. A prospective cohort study published in 2013 identified an overall uterine perforation rate of 1.6 per 1000 insertions for copper IUD users and 2.1 per 1000 insertions for levonorgestrel IUD users [4]. One-third of perforations were detected at 12 months after insertion [4]. Most IUDs that become intra-abdominal are associated with complete uterine perforations [5]. If the strings of the IUD are not visible during a pelvic exam, ultrasound is the preferred method of locating the IUD in the uterus. While transabdominal and transvaginal approaches can both be used, transvaginal ultrasounds provide better resolution [5]. An IUD is ideally visualized on transabdominal ultrasound when the uterus is at a 90-degree angle in an anteflexed position [5]. IUDs are identified by their echogenic appearance relative to uterine tissue (Figs. 1,2). If the ultrasound confirms that the IUD is no longer intrauterine, the next step is to obtain an abdominal radiograph or CT scan to determine the exact location of the device (Figs. 1,2). Studies have shown that half of all cases of extrauterine IUDs causing bowel perforations were due to copper IUDs [6]. The most common presenting symptom was abdominal pain (55%), although 38% of patients were asymptomatic at the time of diagnosis [6]. In order of prevalence, the most commonly perforated regions are the sigmoid colon, small bowel, and rectum [6]. Given the risk of colon perforation and other complications, surgical removal of extrauterine IUDs via laparoscopy or laparotomy is recommended [6]. However, some studies suggest that surgical removal of asymptomatic extrauterine IUDs is unnecessary because the development of adhesions around the misplaced IUD prevents further migration and damage from the IUD [8, 9]. ​​​​ References: Bahamondes L, Fernandes A, Monteiro I, Bahamondes MV. Long-acting reversible contraceptive (LARCs) methods. Best Pract Res Clin Obstet Gynaecol. 2020;66:28-40. doi:10.1016/j.bpobgyn.2019.12.002 Moraes LG, Marchi NM, Pitoli AC, et al. Assessment of the quality of cervical mucus among users of the levonorgestrel-releasing intrauterine system at different times of use. European Journal of Contraception & Reproductive Health Care. 2016;21(4):318-322. doi:10.1080/13625187.2016.1193139 Bahamondes L, Faundes A, Sobreira-Lima B, Lui-Filho JF, Pecci P, Matera S. TCu 380A IUD: a reversible permanent contraceptive method in women over 35 years of age. Contraception. 2005;72(5):337-341. doi:10.1016/j.contraception.2004.12.026 Barnett C, Moehner S, Do Minh T, Heinemann K. Perforation risk and intra-uterine devices: results of the EURAS-IUD 5-year extension study. Eur J Contracept Reprod Health Care. 2017;22(6):424-428. doi:10.1080/13625187.2017.1412427 Carmody K, Schwartz B, Chang A. Extrauterine migration of a mirena® intrauterine device: a case report. J Emerg Med. 2011;41(2):161-165. doi:10.1016/j.jemermed.2010.04.024 Arslan A, Kanat-Pektas M, Yesilyurt H, Bilge U. Colon penetration by a copper intrauterine device: a case report with literature review. Arch Gynecol Obstet. 2009;279(3):395-397. doi:10.1007/s00404-008-0716-2 Inal HA, Ozturk Inal Z, Alkan E. Successful Conservative Management of a Dislocated IUD. Case Rep Obstet Gynecol. 2015;2015:130528. doi:10.1155/2015/130528 Markovitch O, Klein Z, Gidoni Y, Holzinger M, Beyth Y. Extrauterine mislocated IUD: is surgical removal mandatory?. Contraception. 2002;66(2):105-108. doi:10.1016/s0010-7824(02)00327-x Adoni A, Ben Chetrit A. The management of intrauterine devices following uterine perforation. Contraception. 1991;43(1):77-81. doi:10.1016/0010-7824(91)90128-3 Leslie Shang is a 6th-year medical student at the University of Missouri – Kansas City Six-Year BA/MD Program and an aspiring radiologist. At UMKC, she serves as the social media coordinator of the Radiology Interest Group. She is also the vice president of the Help a Life Organization (HALO) which serves free meals to patients at the student-run free clinic and provides educational lectures to students on healthy eating and diet counseling for patients. In her free time, she enjoys exploring new restaurants in Kansas City, hiking, and spending time with friends. Follow Leslie on Twitter @LeslieFShang All posts by Leslie Shang 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

BACKGROUND Due to its high mobility, the shoulder is the most unstable joint in the human body. Its instability is explained by a narrow glenohumeral joint contact surface, estimated at 30% of the humeral head (Fig. 1). Thus, this instability requires stabilizers that include both active (Fig. 2) and dynamic/passive (Fig. 3) elements (Table 1). Passive stabilizers are now often termed dynamic stabilizers due to the coordinated action of the muscles keeping the humeral head in the joint. The passive component of the musculature is actually only at the end range of motion when they are fully tightened. Imaging procedures for glenohumeral instability include plain film, CT (Figs. 4, 8) and MR arthrogram (Figs. 6, 7, 9-11). Figure 1. Frontal left shoulder plain radiograph showing a narrow contact area (red line) between the humeral head and glenoid. This contact area represents about 30% of the humeral head surface which explains the joint instability. Figure 2: A and B, Sagittal T1-weighted (A) and Sagittal proton density fatsat MR arthrogram (B) showing normal rotator cuff muscles which stabilize shoulder joint and consist of subscapularis (green arrow), supraspinatus (yellow arrow), infraspinatus (red arrow) and teres minor muscle (white arrow). The long head of the biceps is also seen (blue arrow). Table 1. Table of active and passive shoulder stabilizers. Figure 3: A and B, Sagittal (A) and axial (B) proton density fatsat MR arthrogram of the right shoulder demonstrates a normal labrum which is represented by a low signal intensity triangular structure (blue arrows). Figure 4: Frontal and scapular Y-view of the left shoulder demonstrates an anterior dislocation with Bankart avulsion fracture (red arrow). Anterior gleno-humeral dislocation (Fig. 4) is a frequent traumatic injury among the population and accounts for 90% of shoulder instability. It most commonly occurs in young patients. It is therefore important for general radiologists to become familiar with the imaging assessment and the semiology of an unstable shoulder. Figure 5: Left shoulder CT in same patient as Figure 4 shows the Bankart fracture and the CT allows improved evaluation of the involved glenoid surface. Figure 6: Arthrography of the left shoulder (A) with MR arthrogram (B) demonstrates the normal characteristic J-shaped axillary recess (green arrows). Figure 7: A and B, Coronal (A) and axial (B) T2 fatsat MR images of the left shoulder with a region of edema of the humeral head corresponding to a Hill-Sachs lesion (yellow arrow). Figure 8: Frontal and scapular-Y view of the left shoulder showing sequelae of anterior dislocation with Hill-Sachs deformity (yellow arrow) and Bankart fracture (red arrow). Pathological bone lesions: Bony lesions mainly include Hill-Sachs and Bankart fractures that are the results of an impaction. Hill-Sachs deformity (Figs. 7,8) is located in the posterior and lateral area of the humeral head. Bankart fracture corresponds to a fracture of the inferior rim of the glenoid (Figs. 5,8,9). Table 2: Bankart lesions and main variants. Figure 9: Axial proton density fatsat MR images shows a probable Bankart lesion (red arrow). However, an anterior labral periosteal sleeve avulsion (ALPSA) may have a similar appearance. Figure 10: Humeral avulsion of the glenohumeral ligament (HAGL). Coronal proton density fatsat MR image of the left shoulder shows a humeral avulsion of the inferior gleno-humeral ligament (red arrow). Figure 11: Anterior labral periosteal sleeve avulsion (ALPSA). Axial and coronal MR arthrogram images of the right shoulder show an avulsion of the antero-inferior labrum complex which is medially displaced (yellow arrows). Images courtesy of Phillip F. Tirman, MD Pathological soft tissues lesions: Soft tissues lesions are mainly due to labrum tears which can present several ways on MR arthrography (Table 2). Soft tissues lesions mainly include: 1) Bankart avulsion: corresponds to a complete avulsion of the inferior labrum complex (with tear of scapular periosteum) which can be associated with bone avulsion of the inferior glenoid (Fig. 9). This lesion is seen in 86% of patients after anterior gleno-humeral dislocation. 2) Perthes lesion: Consists of labral tear without scapular periosteum disruption 3) Humeral avulsion of the glenohumeral ligament (HAGL): corresponds to a glenohumeral ligament avulsion of its insertion on the humerus (Fig. 10). 4) Gleno-labral articular disruption (GLAD): consists of superficial antero-inferior labral tear with an associated anterior inferior glenoid articular cartilage injury. 5) Anterior labral periosteal sleeve avulsion (ALPSA): corresponds to a disruption of the antero-inferior labral complex which is medially displaced (Fig. 11). Additional Reading: 1. Ruiz Santiago F, Martínez Martínez A, Tomás Muñoz P, Pozo Sánchez J, Zarza Pérez A. Imaging of shoulder instability. Quant Imaging Med Surg. 2017 Aug;7(4):422-433. 2. Sheehan SE, Gaviola G, Gordon R, et al. (2013). Traumatic shoulder injuries: a force mechanism analysis—glenohumeral dislocation and instability. American Journal of Roentgenology. 2013;201: 378-393. 3. Bencardino JT, Gyftopoulos S, Palmer WE, et al. Imaging in anterior glenohumeral instability. Radiology. 2013;269(2):323–337. 4. Vande Berg B, Omoumi P. Dislocation of the Shoulder Joint - Radiographic Analysis of Osseous Abnormalities. J Belg Soc Radiol. 2016 Nov 19;100(1):89. 5. Tirman PF, Palmer WE, Feller JF. MR arthrography of the shoulder. Magn Reson Imaging Clin N Am. 1997 Nov;5(4):811-39. 6. Grigorian M, Genant HK, Tirman PF. Magnetic resonance imaging of the glenoid labrum. Semin Roentgenol. 2000;35(3):277-285. doi:10.1053/sroe.2000.7337 7. Tirman PF, Steinbach LS, Feller JF, Stauffer AE. Humeral avulsion of the anterior shoulder stabilizing structures after anterior shoulder dislocation: demonstration by MRI and MR arthrography. Skeletal Radiol. 1996;25(8):743-748. DOI: 10.1007/s002560050172 8. Hottya GA, Tirman PF, Bost FW, Montgomery WH, Wolf EM, Genant HK. Tear of the posterior shoulder stabilizers after posterior dislocation: MR imaging and MR arthrographic findings with arthroscopic correlation. AJR Am J Roentgenol. 1998;171(3):763-768. DOI: 10.2214/ajr.171.3.9725313 9. Wischer TK, Bredella MA, Genant HK, Stoller DW, Bost FW, Tirman PF. Perthes Lesion (A Variant of the Bankart Lesion). AJR 2002; 178:233-237. DOI: 10.2214/ajr.178.1.1780233 Quoc Duy VO, MD is a Swiss physician and head of the Radiology Department at the Hospital of Morges (Ensemble Hospitalier de la Côte, Switzerland). He completed his undergraduate training in the University of Lausanne (UNIL) and his postgraduate Radiology Board Certification at the Hospital of Fribourg (Switzerland) where he worked for 2 years as Breast Imaging consultant. During this period, he was a core member of the Fribourg Breast Center where he took part in the cancer screening program. During the same period, he obtained a Swiss Diploma in Senology and a University Diploma in Breast Pathologies at the University of Saint-Quentin-en-Yvelines (Paris, France). He also perfected his skills in musculoskeletal radiology with a University Diploma in Musculoskeletal Imaging at the University of Montpellier (France). Over the years, Dr. Vo has also developed a great interest in healthcare management which motivated him to pursue a formal education in this field and to obtain a Diploma of Advanced Studies in Healthcare Management at the University of Geneva (UNIGE).

64-year-old male with sudden onset abdominal pain and lactic acidosis. Diagnosis? • Xray of the Week Figure 1. What are the important findings? Figure 2. A: Axial CT. Gas in the wall of the transverse colon (orange arrow). B: Axial CT- lung window. Gas in the wall of the transverse colon- pneumatosis intestinalis (orange arrow). C: Coronal CT. Gas in the wall of the transverse colon (orange arrow). Gas in the mesenteric portal venous system (red arrow). Gas in the intrahepatic portal venous system (green arrow). D: Coronal CT- lung window. Gas in the wall of the transverse colon- pneumatosis intestinalis. (orange arrow). E: Axial CT. Gas in the intrahepatic portal venous system (green arrow). F: Axial CT- lung window. Gas in the mesenteric portal venous system (red arrow). Discussion: Bowel ischemia is an often fatal condition caused by reduction in blood supply to the bowel and its mesentery. Three possible causes include severe hypotension, atherosclerosis, and thromboembolism which usually manifest as ischemic colitis, chronic mesenteric ischemia (CMI), and acute mesenteric ischemia (AMI), respectively [1]. AMI carries a high mortality rate of approximately 70% with an estimated incidence of 1 to 2 per 1000 hospital admissions [2,3]. Most AMI patients present with sudden onset of abdominal pain that is disproportionate to physical findings, especially with a history of cardiovascular disease. Unfortunately, no laboratory test is sufficiently sensitive or specific to rule in or rule out early bowel ischemia thus imaging and compatible history and physical examination are the cornerstone of early diagnosis [4]. CT angiography is the current standard for diagnosis of AMI with a sensitivity of 96% and specificity of 94%, especially with findings of pneumatosis intestinalis (Fig. 2 orange arrows) and hepatic portal venous gas (Fig. 2 green arrows) as seen in this patient [5]. Furthermore, data suggests combination of pneumatosis intestinalis and hepatic portal venous gas is associated with the presence of bowel ischemia in approximately 70% of all cases indicating advanced stage disease [2,6]. The quantity of hepatic portal venous gas is associated with bowel necrosis, whereas the presence of free air or air-type pneumatosis intestinalis (pneumatosis intestinalis of the entire circumference of the intestine without wall edema) is associated with non-necrosis of the bowel [7]. However, for non-occlusive mesenteric ischemia (NOMI), digital subtraction angiogram is the standard for both diagnosis and treatment. Treatment of mesenteric ischemia is multimodal depending on the etiology. Non surgical treatment may include drug therapy with thrombolysis, heparin, or vasodilators. Interventional radiology rarely may play a role with angioplasty and stenting [8]. However, surgery remains the treatment of choice for patients with acute abdominal pain, peritoneal signs, and suspected AMI as seen in this case [3,9]. Despite treatment mortality remains high ranging between 30 and 90% [9]. ​​​​ References: 1. Dhatt HS, Behr SC, Miracle A, Wang ZJ, Yeh BM. Radiological Evaluation of Bowel Ischemia. Radiol Clin North Am. 2015;53(6):1241-1254. Accessed May 15, 2021. doi:10.1016/j.rcl.2015.06.009. 2. Milone M, Di Minno, Matteo Nicola Dario, Musella M, et al. Computed tomography findings of pneumatosis and portomesenteric venous gas in acute bowel ischemia. World J Gastroenterol. 2013;19(39):6579-6584. Accessed May 15, 2021. doi:10.3748/wjg.v19.i39.6579. 3. Endean ED, Barnes SL, Kwolek CJ, Minion DJ, Schwarcz TH, Mentzer RM. Surgical management of thrombotic acute intestinal ischemia. Ann Surg. 2001;233(6):801-808. Accessed May 15, 2021. doi:10.1097/00000658-200106000-00010. 4. Oldenburg WA, Lau LL, Rodenberg TJ, Edmonds HJ, Burger CD. Acute mesenteric ischemia: a clinical review. Arch Intern Med. 2004;164(10):1054-1062. Accessed May 15, 2021. doi:10.1001/archinte.164.10.1054. 5. van den Heijkant, Teun C., Aerts BAC, Teijink JA, Buurman WA, Luyer MDP. Challenges in diagnosing mesenteric ischemia. World J Gastroenterol. 2013;19(9):1338-1341. Accessed May 15, 2021. doi:10.3748/wjg.v19.i9.1338. 6. Angelelli G, Scardapane A, Memeo M, Stabile Ianora AA, Rotondo A. Acute bowel ischemia: CT findings. Eur J Radiol. 2004;50(1):37-47. Accessed May 15, 2021. doi:10.1016/j.ejrad.2003.11.013. 7. Muratsu A, Muroya T, Yui R, et al. Factors associated with bowel necrosis in patients with hepatic portal venous gas and pneumatosis intestinalis. Acute Med Surg. 2020;7(1):e432. Accessed May 15, 2021. doi:10.1002/ams2.432. 8. Goldberg MF, Kim HS. Treatment of acute superior mesenteric vein thrombosis with percutaneous techniques. AJR Am J Roentgenol. 2003;181(5):1305-1307. doi:10.2214/ajr.181.5.1811305 9. Fitzpatrick LA, Rivers-Bowerman MD, Thipphavong S, Clarke SE, Rowe JA, Costa AF. Pearls, Pitfalls, and Conditions that Mimic Mesenteric Ischemia at CT. Radiographics. 2020;40(2):545-561. doi:10.1148/rg.2020190122 Savan V. Patel is a medical student and aspiring diagnostic radiologist at Rowan University School of Osteopathic Medicine in New Jersey. During his time as a medical student, Savan served as the vice president of Inclusion, Diversity, Equity, and Action (IDEA) council. Prior to medical school, he earned MS in Pharmaceutical Sciences with summa cum laude at Rowan University where he published research on novel compounds composed of cyanopyrrolidines and β-amino alcohol scaffolds tested in vitro against Dipeptidyl Peptidase IV (DPP-IV) enzyme, a key regulator of incretin hormones in the management of type 2 diabetes. He graduated magna cum laude from Rowan University where he completed his studies in biochemistry with a minor in biology. Outside of medical school, Savan loves to travel with his wife, cook new cuisines and listen to Bollywood music. All posts by Savan Patel 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

28 year-old male. Long term intubation 2 months ago secondary to COVID pneumonia. Presents with shortness of breath, difficulty speaking and stridor for the past 2 weeks • Xray of the Week Figure 1. What is the diagnosis? Figure 2. CT scan of the neck and chest demonstrating circumferential hourglass-like narrowing of the trachea (red arrows). Note the normal diameter of the trachea on the axial images proximal (green arrows) and distal (yellow arrows) to the stenosis. Figure 3. Myer Classification of tracheal stenosis (5). Discussion: The most severe complication of COVID-19 has been acute respiratory distress syndrome, which requires oxygen and ventilation therapy for a median of 17 days (1). However, this prolonged intubation also comes with the risk of tracheal stenosis. Post-intubation tracheal stenosis is a rare but serious condition that occurs after long-term intubation. The stenosis occurs when compression from the endotracheal tube (ETT) cuff causes ischemia of the tracheal mucosal tissue, resulting in fibrotic scarring (2). According to Ramalingam et al, tracheal stenosis can also be caused by ETT size relative to the tracheal lumen, ETT material, intubation duration, hemodynamics, tube movement, steroids, and age/sex of the patient (2). It presents as gradual onset dyspnea and dry cough (2). Additional symptoms include shortness of breath, difficulty speaking, and stridor as seen in this patient. Tracheal stenosis can be diagnosed using bronchoscopy (2) or CT scan (3,4). The degree of stenosis can be described using the classification grades established by Myer et al. (Fig. 3) (5). Chest radiography shows focal luminal narrowing with hourglass stenosis about 3-4 cm below the cricoid cartilage (Fig.2) (4). Acute stenosis presents with edema and granulation tissue with concentric soft tissue thickening while chronic stenosis shows focal expiratory airway collapse on dynamic CT (4). Stenosis can usually be prevented by using low pressure cuffs. Treatment includes surgical intervention, bronchoscopic balloon dilation, or laser coblation (2,4). Endoscopic or radiologic guided metallic stent placement has also been used as a first line treatment in cases of simple stenoses. However, it is usually only used if surgery or dilatation are unsuccessful (5). ​​​​ References: 1. Mattioli F, Marchioni A, Andreani A, Cappiello G, Fermi M, Presutti L. Post-intubation tracheal stenosis in COVID-19 patients [published online ahead of print, 2020 Oct 3]. Eur Arch Otorhinolaryngol. 2020;1-2. doi:10.1007/s00405-020-06394-w 2. Ramalingam H, Sharma A, Pathak V, Narayanan B, Rathod DK. Delayed Diagnosis of Postintubation Tracheal Stenosis due to the Coronavirus Disease 2019 Pandemic: A Case Report. A A Pract. 2020;14(8):e01269. doi:10.1213/XAA.0000000000001269 3. Webb EM, Elicker BM, Webb WR. Using CT to diagnose nonneoplastic tracheal abnormalities: appearance of the tracheal wall. AJR Am J Roentgenol. 2000;174(5):1315-1321. doi:10.2214/ajr.174.5.1741315 4. Heidinger BH, Occhipinti M, Eisenberg RL, Bankier AA. Imaging of Large Airways Disorders. AJR Am J Roentgenol. 2015;205(1):41-56. doi:10.2214/AJR.14.13857 5. Myer CM 3rd, O'Connor DM, Cotton RT. Proposed grading system for subglottic stenosis based on endotracheal tube sizes. Ann Otol Rhinol Laryngol. 1994;103(4 Pt 1):319-323. doi:10.1177/000348949410300410 6. Galluccio G, Lucantoni G, Battistoni P, et al. Interventional endoscopy in the management of benign tracheal stenoses: definitive treatment at long-term follow-up. Eur J Cardiothorac Surg. 2009;35(3):429-934. doi:10.1016/j.ejcts.2008.10.041 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 All posts by Amara Ahmed 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

Chronic wrist pain • Xray of the Week This often results from undiagnosed or under treated non-displaced scaphoid fractures. Progressive collapse & deformity usually occur at fracture site, leading to subluxation of midcarpal joint and dorsal rotation of the lunate. Axial CT: Note the remodeling and pseudarthrosis in this case. Coronal CT: Note the remodeling and pseudarthrosis in this case. Phillip Tirman, MD is the Medical Director of Musculoskeletal Imaging at the Renaissance Imaging Center in Westlake Village, California. A nationally recognized expert in the applications of MRI for evaluating MSK and spine disorders, Dr. Tirman is the co-author of three textbooks, including MRI of the Shoulder and Diagnostic Imaging: Orthopedics. He is also the author or co-author on over sixty original scientific articles published in the radiology and orthopedic literature. Dr. Tirman will be sharing his expertise at Imaging in Israel -2017 in Tel Aviv. All Posts by Phillip Tirman, MD

Pain in Medial Knee • Xray of the Week 2016 • Week #43 This 14 year old bent over while showering and felt sudden “pop” with pain in the medial knee. What is the diagnosis? Figure 1. Coronal PD with fat saturation image with red arrow showing the avulsion fragment and donor site. There is surrounding bone marrow edema (green arrows). Sagittal T1 weighted image shows avulsed fragment at attachment of medial gastrocnemius (orange arrow). Figure 2. Axial image shows the avulsed fragment (red arrow). Note the cortical defect indicating a fracture (green arrow). Sagittal T2 “fat sat” image shows 2 mm of distraction (orange arrows). Figure 3. Five weeks after conservative management, there is healing with no physeal bar. Avulsion fracture of the gastrocnemius muscle is a rare injury caused by traction on the origin of the medial head of the muscle on the medial femoral condyle. As in this case, MRI demonstrates a fracture of the medial femoral condyle with mild distraction of the avulsed fracture fragment [Fig. 1-2]. Invariably there is associated bone marrow edema which resolves over time [Fig. 2-3]. A previous case report was of a patient who had an avulsion fracture of the medial head of the gastrocnemius muscle due to a skiing injury. The fracture was successfully treated with open reduction and internal fixation with a screw[1]. A second case of case of a 14-year-old male wrestler presented with a radiographically occult avulsion fracture of the medial gastrocnemius tendon sustained during competition[2]. This was treated conservatively with return to competition after non-operative management. Other more common avulsion fractures of the knee are described in detail by Gottsegen et al [3]. References: 1. Maehara H, Sakaguchi Y. Avulsion Fracture of the Medial Head of the Gastrocnemius Muscle: A Case Report. The Journal of Bone & Joint Surgery. 2004; 86:373-375 2. Patterson, J.T., Jokl, P., Katz, L.D. et al. Isolated avulsion fracture at the medial head of the gastrocnemius muscle. Skeletal Radiol (2014) 43: 1491. doi:10.1007/s00256-014-1915-5 3. Gottsegen C, Eyer B, et al. Avulsion Fractures of the Knee: Imaging Findings and Clinical Significance. RadioGraphics 2008; 28:1755–1770 Phillip Tirman, MD is the Medical Director of Musculoskeletal Imaging at the Renaissance Imaging Center in Westlake Village, California. A nationally recognized expert in the applications of MRI for evaluating MSK and spine disorders, Dr. Tirman is the co-author of three textbooks, including MRI of the Shoulder and Diagnostic Imaging: Orthopedics. He is also the author or co-author on over sixty original scientific articles published in the radiology and orthopedic literature. Kevin Rice, MD is president of Global Radiology CME and also a radiologist with Renaissance Imaging as the Chair of the Radiology Department at Valley Presbyterian Hospital in Los Angeles, California. All posts by Phillip Tirman, MD 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

First toe pain in a professional football player • Xray of the Week First toe pain in a 30 y/o professional football player. What is the diagnosis? Figure 1. Sagittal T1 (A) and "fat sat" (B) images show a tear of the tibial sesamoid phalangeal ligament (red arrow). The tear is a complete tear (grade III) with retraction of the tibial sesamoid. Figure 2. Sagittal “fat sat” images show a normal (green arrow) and a torn (red arrow) sesamoid phalangeal ligament. Figure 3. Axial “fat sat” images show a normal (green arrow) and a torn (red arrow) sesamoid phalangeal ligament. Figure 4. This football player is at high risk for turf toe. Note the hyperextension of the first metatarsal phalangeal joint (insert) and the massive downward pressure by the opposing player. Figure 5. Accelerated arthrosis in a 27 year old with chronic turf toe. Sagittal (A) and coronal (B) images show a shortened scarred sesamoid phalangeal ligament (red arrow) and a chronic osteochondral defect of the first metatarsal head (green arrows). Discussion: Turf toe is a tear of the sesamoid phalangeal ligament [Figs. 1-3]. The mechanism of injury in the acute setting is a hyperextension of the first metatarsal phalangeal joint when the hallux is fixed in equinus [Fig.4]. Chronic tear may occur with hyperextension or repeatedly pushing off when running or jumping. Playing football especially on artificial turf is a predisposing factor. Significant morbidity can occur with up to half of patients still symptomatic at 5 years. Most cases are managed conservatively with ice, elevation, and NSAIDS. Immobilization is used in higher grade injuries. However, surgery may be needed for failed conservative management or if there are complications such as sesamoid fracture, bipartite sesamoid separation, sesamoid proximal migration, instability with pain/synovitis, hallux rigidus, or an unstable chondral flap of the first metatarsal phalangeal joint [Fig.5]. References: 1. McCormick JJ, Anderson RB. The great toe: failed turf toe, chronic turf toe, and complicated sesamoid injuries. Foot Ankle Clin. Jun 2009;14(2):135-50. 2. Crain JM, Phancao JP, Stidham K. MR imaging of turf toe. Magn Reson Imaging Clin N Am. Feb 2008;16(1):93-103, vi. 3. Sanders TG, Rathur SK. Imaging of painful conditions of the hallucal sesamoid complex and plantar capsular structures of the first metatarsophalangeal joint. Radiol Clin North Am. Nov 2008;46(6):1079-92, vii. 4. Yao L, Do HM, Cracchiolo A, et al. Plantar plate of the foot: findings on conventional arthrography and MR imaging. Am J Roentgenol 1994;163:641-4. 5. Kubitz ER. Athletic injuries of the first metatarsophalangeal joint. J Am Podiatr Med Assoc. Jul-Aug 2003;93(4):325-32. 6. Resnick D, Kang HS. Internal derangement of joints: emphasis on MR imaging Philadelphia, Pa: Saunders, 2nd Ed. 2006. Buy it on Amazon 7. Linklater JM. Imaging of Sports Injuries in the Foot. AJR 2012; 199:500–508 8. Stoller D, Tirman P, Bredella M et-al. Diagnostic imaging. AMIRSYS. (2004) ISBN:0721629202. www.amazon.com/gp/product/0721629202 9. Ashman CJ, Klecker RJ, Yu, JS. Forefoot Pain Involving the Metatarsal Region: Differential Diagnosis with MR Imaging. RadioGraphics 2001; 21:1425–1440 10. http://radsource.us/clinic-turf-toe/ 11. Allen LR, Flemming D, Sanders TG. Turf toe: ligamentous injury of the first metatarsophalangeal joint. Mil Med. 2004 Nov;169(11):xix-xxiv. Phillip Tirman, MD is the Medical Director of Musculoskeletal Imaging at the Renaissance Imaging Center in Westlake Village, California. A nationally recognized expert in the applications of MRI for evaluating MSK and spine disorders, Dr. Tirman is the co-author of three textbooks, including Shoulder Magnetic Resonance Imaging and Diagnostic Imaging: Orthopedics. He is also the author or co-author on over sixty original scientific articles published in the radiology and orthopedic literature. In 2018, Dr. Rice was nominated and became a semifinalist for a "Minnie" award for the Most Effective Radiology Educator. All posts by Phillip Tirman, MD 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 and 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 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