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25F with headache • Xray of the Week Figure 1. What is the diagnosis? Figure 2. MRI Brain without contrast. Nodule of intermediate signal intensity in the anterior third ventricle (red arrow). Subtle on MRI due to intermediate signal intensity on all sequences, but definite contour abnormality in anterior third ventricle. There is no hydrocephalus. A. Sagittal T1-weighted image. Isointense nodule in the anterior third ventricle (red arrow). B. Axial FLAIR image. Isointense nodule in the anterior third ventricle (red arrow). C. Coronal T2* image. Nodule in the anterior third ventricle (red arrow) with low to intermediate signal intensity. Figure 3. CT Brain without contrast. Nodule in the anterior third ventricle is well seen on CT due to high protein content of cyst. A. Sagittal CT brain. B. Axial CT brain. C. Coronal CT brain. Discussion: Colloid cysts are epithelial-lined cysts containing gelatinous material such as mucin, old blood, cholesterol, and ions (1). They are typically located in the rostral third ventricle near the foramen of Monroe (1). The etiology is unclear but the cyst is thought to be a remnant of the paraphysis element, respiratory epithelium, ependymal cyst from the diencephalon, or invagination of the neuroepithelium of the lateral ventricle (1). Colloid cysts are benign growths but they can cause symptoms such as headaches, diplopia, memory issues, and vertigo due to obstructive hydrocephalus when they block the the flow of cerebrospinal fluid from the lateral ventricles at the foramen of Monroe (1). This can occur via a ball-valve mechanism, in which mobile colloid cysts attached to the ceiling of the third ventricle via a thin peduncle can block CSF flow causing intermittent obstructive hydrocephalus and positional headache (1). On CT, colloid cysts appear as a round mass with a hyperdense appearance, especially when the cyst contains protein or cholesterol or is highly viscous (Fig. 3) (2,3). They can appear as hypodense or isodense in rare cases (2). In isodense cysts, it may be possible to visualize hyperdense areas in the lesion which represent acute hemorrhage on CT (4). Increased intraventricular pressure and transependymal cerebrospinal fluid leak can lead to periventricular hypodensity or enlarged temporal horns on CT, and calcification and hemorrhage may be seen as well (2). Colloid cysts have variable appearance on MRI depending on the material in the cyst. Protein and cholesterol cysts shorten the T1 relaxation time and tend to be hyperintense on T1-weighted images and hypointense on T2-weighted images (2). Cysts that are hypointense on T2-weighted images may be more difficult to view on FLAIR (5). As seen in this case, isointense cysts can be seen on CT scan but may be difficult to see on MRI (5). A rim of peripheral enhancement representing the cyst capsule may be seen, but this may represent enhancement of stretched septal veins that are adjacent to the cyst (1). MRI may show intracystic fluid levels or homogeneous appearance (5). Treatment options are craniotomy, endoscopic aspiration or resection, stereotactic aspiration, and permanent CSF diversion via shunt (6). Stereotaxic aspiration can be used for cysts that show hypodensity on CT and hyperintensity on T2-weighted sequences (7). Cysts with a hypointense appearance on T2-weighted images are less likely to be suitable for aspiration and may require alternate surgical intervention (5). ​​​​ References: Tenny, Steven, and William Thorell. Colloid Brain Cyst. StatPearls, StatPearls Publishing, 2020. PubMed, http://www.ncbi.nlm.nih.gov/books/NBK470314/ Algin O, Ozmen E, Arslan H. Radiologic manifestations of colloid cysts: a pictorial essay. Can Assoc Radiol J. 2013;64(1):56-60. doi:10.1016/j.carj.2011.12.011 Mamourian, A. C., et al. Colloid cyst of the third ventricle: sometimes more conspicuous on CT than MR. AJNR. American Journal of Neuroradiology, vol. 19, no. 5, May 1998, pp. 875–78. http://www.ajnr.org/content/19/5/875 Hamidi H, Faizi FR, Rasouly N, Hoshang MM. CT and MRI Features of Pediatric-Aged Colloid Cysts: Report of Two Cases. Case Rep Radiol. 2017;2017:2467085. doi:10.1155/2017/2467085 Armao D, Castillo M, Chen H, Kwock L. Colloid cyst of the third ventricle: imaging-pathologic correlation. AJNR Am J Neuroradiol. 2000;21(8):1470-1477. http://www.ajnr.org/content/21/8/1470.long Morgan JP, McGraw SC, Asfora WT. Treatment of colloid cyst of the third ventricle by stereotactic aspiration followed by radiosurgery: Report of four cases. Surg Neurol Int. 2018;9:3. Published 2018 Jan 10. doi:10.4103/sni.sni_180_17 Noukoua C. Obstructive Colloid Cyst of the Third Ventricle. J Belg Soc Radiol. 2017;101(1):20. Published 2017 Apr 25. doi:10.5334/jbr-btr.1306 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

Why is there air in the aorta? • Xray of the Week Figure 1. A. Axial CT. Note inflated intra-aortic balloon (red arrows). in descending thoracic aorta B. IABP inflated in descending thoracic aorta (red arrow). C. Sagittal CT showing IABP inflated in descending thoracic aorta (red arrow). Figure 2. Frontal chest X-ray showing the intra-aortic balloon inflated in the descending aorta (red arrows). Note the radiopaque marker at the tip (yellow arrow). Figure 3. Diagram demonstrating intra-aortic balloon inflated in diastole and deflated in systole. Image from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3177429/ (Ref.5) Figure 4. Video of IABP function. Discussion: The intra-aortic balloon pump (IABP) is a cardiac assist device. It is used to stabilize patients with hypoperfusion due to acute congestive heart failure, acute mitral regurgitation, myocardial infarction, or low cardiac output after coronary artery bypass grafting surgery (1). It can also be used as prophylaxis in high risk percutaneous coronary intervention (1). The IABP has a polyethylene or polyurethane balloon at the distal tip of a large bore catheter connected to a console that inflates the balloon with helium (2). The catheter is inserted into the aorta through the femoral artery and the balloon sits in the aorta, 2.5 cm from the left subclavian artery (3). During diastole, the balloon appears radiolucent structure in the descending thoracic aorta (Figs. 1,2). The tip is marked by a linear metallic density on imaging (Fig. 2) (3). The intra-aortic balloon uses counterpulsation to inflate and deflate. It inflates in diastole during aortic valve closure, which increases blood flow to the coronary arteries through retrograde flow (4). It deflates at onset of ventricular systole to increase the cardiac output by decreasing afterload (Fig. 4) (1,4). Overall, the IABP reduces left ventricular wall stress and reduces myocardial oxygen demand while improving stroke volume (4). Contraindications to IABP include uncontrolled sepsis, uncontrolled bleeding diathesis, moderate to severe aortic regurgitation, aortic aneurysm, aortic dissection, or severe peripheral artery disease that has not been pretreated with stenting (1,4). Balloon entrapment and rupture can occur, resulting in gas embolus (4). Improper positioning of the IABP can cause cerebral or renal compromise (4). ​​​​ References: Khan, Tahir M., and Abdul H. Siddiqui. “Intra-Aortic Balloon Pump (IABP).” StatPearls, StatPearls Publishing, 2020. PubMed, http://www.ncbi.nlm.nih.gov/books/NBK542233/ Francolini, I., and A. Piozzi. “12 - Antimicrobial Polyurethanes for Intravascular Medical Devices.” Advances in Polyurethane Biomaterials, edited by Stuart L. Cooper and Jianjun Guan, Woodhead Publishing, 2016, pp. 349–85. ScienceDirect, doi:10.1016/B978-0-08-100614-6.00012-3 Dipoce, J., et al. “Radiology of Cardiac Devices and Their Complications.” The British Journal of Radiology, vol. 88, no. 1046, Feb. 2015. PubMed Central, doi:10.1259/bjr.20140540 Krishna, Murli, and Kai Zacharowski. “Principles of Intra-Aortic Balloon Pump Counterpulsation.” Continuing Education in Anaesthesia Critical Care & Pain, vol. 9, no. 1, Feb. 2009, pp. 24–28. academic.oup.com, doi:10.1093/bjaceaccp/mkn051 Ginat D, Massey HT, Bhatt S, Dogra VS. Imaging of mechanical cardiac assist devices. J Clin Imaging Sci. 2011;1:21. doi:10.4103/2156-7514.80373 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

Diabetes and urosepsis. What procedure is indicated? • Xray of the Week Figure 1. Axial CT image of the abdomen with contrast shows right renal abscess with ring enhancement around the fluid collection. Figure 2. Axial CT images of the abdomen with contrast highlighting right renal abscess with subsequent drainage. A. Right renal abscess (white arrow) with ring of hyperdensity surrounding the fluid collection. B. Percutaneous access needle entering the renal abscess (white arrow). C. Insertion of drainage catheter into the abscess (white arrow). D. Drainage catheter coiled in the abscess (white arrow). Discussion: Renal abscesses are collections of walled-off, infected, and purulent fluid in the renal parenchyma that are commonly associated with underlying pyelonephritis. Other factors that predispose patients to formation of renal abscesses include diabetes mellitus and anatomical abnormalities such as vesicoureteral reflux, neurogenic bladder, polycystic kidney disease, and ureteral calculi (1,2). Clinical manifestations of renal abscesses include fever and chills, flank pain with radiation to the abdomen and costovertebral tenderness (1,2,3). Laboratory findings exhibit leukocytosis with elevation of erythrocyte sedimentation rate and C-reactive protein, however this is non-specific. Contrast enhanced CT is useful to evaluate urosepsis and may reveal renal abscess formation (Fig. 1) (4). CT is also helpful in visualizing the renal parenchyma, suppurative changes, and nearby viscera (4,5,6). CT findings of renal abscesses are a focal collection of fluid with a thickened, irregular enhancing wall (Fig. 1) (2). Other findings of renal abscess may include gas within the central fluid, fascial and septal changes, and perinephric fat plane dissipation (2,3). Beyond CT imaging, ultrasound has some usage in identifying renal abscesses. Ultrasound findings show a hypoechoic or cystic mass with lack of vascular flow indicating an infectious process rather than neoplasm (1). Treatment of renal abscesses includes antibiotic therapy and minimally invasive, percutaneous drainage via CT or ultrasound guidance (Fig. 2). The percutaneous approach is favored over surgical drainage due to improved outcomes and reduced morbidity (1). Abscesses less than 5 cm can be treated conservatively with antibiotics and close follow up (1). When larger than 5 cm, renal abscesses should be treated with percutaneous drainage in conjunction with antibiotics (1). ​​​​ References: 1. Siegel JF, Smith A, Moldwin R. Minimally invasive treatment of renal abscess. The Journal of Urology. 1996; 155(1):52-55. https://doi.org/10.1016/S0022-5347(01)66536-46 2. Yen DH, Hu SC, Tsai J, et al. Renal abscess: early diagnosis and treatment. Am J Emerg Med. 1999;17(2):192-197. https://doi.org/10.1016/S0735-6757(99)90060-8 3. Lee BE, Seol HY, Kim TK, Seong EY, Song SH, Lee DW, Lee SB, Kwak IS. Recent clinical overview of renal and perirenal abscesses in 56 consecutive cases. Korean J Intern Med. 2008;23(3):140. https://doi.org/10.3904/kjim.2008.23.3.140 4. Demertzis, J., Menias, C.O. State of the art: imaging of renal infections. Emerg Radiol. 2007; 14, 13–22. https://doi.org/10.1007/s10140-007-0591-3 5. Kawashima A, Sandler CM, Goldman SM, Raval BK, Fishman EK. CT of renal inflammatory disease. Radiographics. 1997;17(4):851-868. https://doi.org/10.1148/radiographics.17.4.9225387 6. Mitreski G, Sutherland T. Radiological diagnosis of perinephric pathology: pictorial essay 2015. Insights Imaging. 2017;8(1):155-169. https://doi.org/10.1007/s13244-016-0536-z Corey Stump is a medical student and aspiring radiologist at the Marian University College of Osteopathic Medicine in Indianapolis, Indiana. Prior to medical school, he graduated summa cum laude from Wittenberg University where he received a B.S. degree in Biology. He is excited to pursue a career in Diagnostic Radiology with interests in medical education. His current project involves a webinar titled “Navigating The Virtual Match; Program Directors Vs Medical Students” through the Academy of Online Radiology Education with other medical students and radiologists around the country in an effort to provide insight on the upcoming residency match. He is passionate about teaching and he hopes to provide a meaningful experience to medical students one day. Follow Corey Stump on Twitter @corey_stump All posts by Corey Stump 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

Why is there contrast in the liver? • Xray of the Week Pt with renal failure and multiple prior hemodialysis catheters resulting in SVC occlusion. Figure 1. CT scan of patient with SVC occlusion. What is the enhancing liver lesion? Figure 2. A. Axial chest CT showing internal mammary vein (orange arrow), azygos vein (blue arrow), small mediastinal collateral veins (white arrow), and chest and abdominal wall collateral veins (yellow arrow) B. Axial CT showing chest and abdominal wall collateral veins (yellow arrow), hepatic capsule and phrenic veins (green arrow) and portal vein in liver (red arrow) C. Axial chest CT showing azygos vein (blue arrow), internal mammary vein (orange arrow), and mediastinal collateral veins (white arrows) D. Chest and abdominal wall collateral veins (yellow arrows), mediastinal collateral veins (white arrows), hepatic capsule and phrenic veins (green arrow) and portal vein in liver (red arrow). Figure 3. Coronal MIP CT image with thisck slab through the anterior and mid chest demonstrates the caval-mammary-phrenic–hepatic capsule–portal collaterals. Complete obstruction of the superior vena cava has resulted in a pseudolesion in segment 4. Figure 4. Diagram illustrating caval-mammary-phrenic-hepatic capsule-portal pathway. From http://dx.doi.org/10.1594/ECR2014/C-1159 Discussion: Superior vena cava (SVC) occlusion has multiple causes including mediastinal neoplasms, central venous catheters, pacemaker wires, aneurysms, trauma, and granulomatous diseases (1). As a result of SVC occlusion, venous drainage is maintained via collateral pathways between the SVC and portal vein (2). Four well-established collateral routes are the azygous-hemiazygous route, internal mammary vein route, thoracic and superficial thoracoabdominal vein route, and the vertebral venous plexus route (1). The patient in this case presents with SVC occlusion due to renal failure and multiple prior hemodialysis catheters. There is caval-mammary-phrenic-hepatic capsule-portal pathway-to segment 4 of the liver. Blood flows from the internal mammary vein to the inferior phrenic vein, which communicates with hepatic capsular veins (3). The hepatic capsular veins then drain into intrahepatic portal tributaries (3). This causes a hypervascular pseudolesion that can be visualized on imaging as a “focal hot spot” or hyperenhancement along the anterior portion of segment 4 of the liver (3). In nuclear studies, a warm spot near the bare area can be observed using Tc sulfur colloid (1). Along the superior aspect of the liver, there may also be focal contrast enhancement with dilation of inferior phrenic veins and hepatic capsular veins (4). Treatment involves addressing the cause of the SVC obstruction (5). Palliative stenting has been suggested as a possible treatment, but thrombosis is a common complication of this procedure (5). ​​​​ References: Rastogi R, Thulkar S, Garg R, Gupta A. Infraphrenic collaterals in malignant superior vena cava obstruction. Clin Imaging. 2007;31(5):321-324. doi:10.1016/j.clinimag.2007.04.031 Vilgrain V, Lagadec M, Ronot M. Pitfalls in liver imaging. Radiology. 2015;278(1):34-51. doi:10.1148/radiol.2015142576 Kapur S, Paik E, Rezaei A, Vu DN. Where there is blood, there is a way: unusual collateral vessels in superior and inferior vena cava obstruction. RadioGraphics. 2010;30(1):67-78. doi:10.1148/rg.301095724 Keraliya AR, Tirumani SH, Shinagare AB, Ramaiya NH. Beyond PET/CT in Hodgkin lymphoma: a comprehensive review of the role of imaging at initial presentation, during follow-up and for assessment of treatment-related complications. Insights Imaging. 2015;6(3):381-392. doi:10.1007/s13244-015-0407-z Marini TJ, Chughtai K, Nuffer Z, Hobbs SK, Kaproth-Joslin K. Blood finds a way: pictorial review of thoracic collateral vessels. Insights Imaging. 2019;10. doi:10.1186/s13244-019-0753-3​ 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

Right eye loss of vision • Xray of the Week What is the the name of the right globe abnormality? Figure 1. Phthisis Bulbi on CT and MR Imaging A. Axial CT scan of the orbits demonstrating the phthisis bulbi with dystrophic calcification (yellow arrow). The globe is small and deformed with enophthalmos. B. Coronal CT scan of the orbits demonstrating the phthisis bulbi with dystrophic calcification (yellow arrow). C and D. Axial MRI T1WI and Axial MRI T2WI of the orbits demonstrating the phthisis bulbi. Note the heterogeneous small, shrunken, calcified, deformed and irregularly shaped right globe, with enophthalmos (green arrow). Figure 2. Phthisis bulbi clinical image in a different patient. Ophthalmic Atlas Image by EyeRounds.org, The University of Iowa is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. https://webeye.ophth.uiowa.edu/eyeforum/atlas/pages/cataract-phthisis-bulbi-post-cataract-surgery.html Discussion: Phthisis bulbi (PB) is a term given to an anatomically misshapen and atrophied ocular globe, secondary to severe injury or long-standing pathology. PB develops due to persistent inflammation and the eye becomes visibly disfigured and shrunken. Common etiologies of PB include penetrating trauma, radiation, infection, and tumor. After the inciting trauma or pathology, the affected eye undergoes profound inflammatory sequelae including proliferation of fibrosis and scarring. There are three stages leading to the progression of PB: stage I is atrophia bulbi without shrinkage, II is atrophia bulbi with shrinkage, III is atrophia bulbi with shrinkage and disorganization (phthisis bulbi) (1). Patients can be asymptomatic in initial stages or present with a wide spectrum of pain, irritation and blindness. The most common features of PB include a small-sized asymmetrical affected eye with enophthalmos, corneoscleral scarring, hypotonia, and cataracts (Fig.2). End-stage PB can result in retinal detachment. Intraocular exam will demonstrate extremely low intraocular pressure, sometimes reaching 0 mmHg. (2) On CT imaging the globe will be notably shrunken with increased attenuation in the thickened sclera due to diffuse scarring. Possible ossification and foci of dystrophic calcifications can often be seen and it is difficult to assess normal structures of the eye (Fig. 1). MRI will demonstrate various areas of increased signal depending on the degree of calcification in T1-weighted images. T2-weighted images of PB can show filling defects due to calcifications, and FLAIR sequence will exhibit increased signal in the damaged eye contrasting with the contralateral eye (Fig. 1). (3) In the beginning stages of PB, patients can be given a topical steroid and cycloplegic agent to mild symptomatic relief but PB will continue to progress. Currently, the only permanent treatment for PB involves enucleation of the eye when pain becomes severe. Prosthetic rehabilitation of the affected eye has resulted in good cosmetic outcomes especially following enucleation. (1,2) ​​​​ References: 1. Kaiser PK, Friedman NJ, Pineda R. The Massachusetts Eye and Ear Infirmary Illustrated Manual of Ophthalmology. 4th ed. Saunders; 2014. https://bit.ly/2R7bbYG 2. Dohlman CH, D’Amico DJ. Can an Eye in Phthisis Be Rehabilitated? A Case of Improved Vision With 1-Year Follow-up. Archives of ophthalmology. 1999;117(1):123-124. doi:10.1001/archopht.117.1.123 3. Midyett FA, Mukherji SK. Phthisis bulbi. Orbital Imaging; 2015:29-31. doi:10.1016/B978-0-323-34037-3.00017-3 Nirali Dave is a medical student at Medical University of Lublin in Poland, currently doing clinical rotations in New York. Before that she completed her undergraduate education at Rutgers University, and worked as a medical scribe. Nirali was first exposed to basic radiologic imaging while scribing, and was very quickly taken by the field. Her passion for radiology comes from the bridging of anatomy, health technologies, and patient care. In the future, she hopes to complete a diagnostic radiology residency and stay committed to clinical research and patient education. Follow Nirali Dave on Twitter @ndave08 All posts by Nirali Dave 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

What is the significance of this anomaly? • Xray of the Week Figure 1. What is the significance of this anomaly? Figure 2. Axial and coronal CT images of the cervical spine along with 3D CT reconstruction demonstrating a right cervical rib. A. Axial CT of the cervical spine detailing a unilateral, right cervical rib at the level of C7 (red arrow) B. Axial CT image further demonstrating the unilateral right cervical rib (red arrow) C. 3D CT reconstruction of a right cervical rib arising from the transverse process of C7 (red arrow). D. Coronal CT image of the cervical spine showing unilateral cervical rib on the right (red arrow). Discussion: There is a total of 12 pairs of ribs that articulate with each segment of the thoracic vertebrae posteriorly and function to protect the thoracic viscera and help promote respiration. In regards to rib anatomy, the first seven pairs are considered true ribs as they attach directly to the sternum via their costal cartilage while the 8th-10th ribs are considered false ribs since their cartilages fuse and then join at the 7th rib costal cartilage to attach indirectly to the sternum. Finally, there are also ribs 11 and 12 which are considered floating due to their lack of connection to the sternum in any fashion. Another classification regarding rib structure is typical vs atypical ribs, which separates ribs 1, 11, and 12 from 2-10 due to specific anatomical features. Cervical ribs are a rare occurrence in the population with an incidence of under 1% and are often an incidental finding on radiographic imaging (1). A cervical rib is defined as an accessory rib that develops most commonly at the level of C7, but some cases have been reported at C6, C5, and as high as C4 (1). To classify a cervical rib, there must be evidence of a supernumerary rib that attaches to the transverse process of a cervical vertebra (Figs. 1,2) (1,2). When they are bilateral, they are often asymmetric, however, when they are unilateral, they tend to be found on the right (1). Cervical ribs are normally clinically silent, and individuals may never know that they have one. However, this becomes clinically relevant and warrants investigation when patients start to develop symptoms of thoracic outlet syndrome due to compression of the brachial plexus, subclavian artery, or subclavian vein in the extremity on the side of the cervical rib (2,3). In rare cases, cervical ribs have been shown to cause recurrent strokes in younger individuals, subclavian artery aneurysms, subclavian artery thromboses, and significant ischemia leading to gangrene of the distal phalanges (4). Without clinical manifestations of a cervical rib, there is no dedicated imaging protocol to detect them. They will most likely be picked up incidentally on plain radiographs for other medical indications (1,2). When there are clinical manifestations of thoracic outlet syndrome, an initial plain radiograph would be an appropriate first study. In the setting of unilateral ischemic arm pain, paresthesia, weakened pulse, and numbness, CT scan will definitively demonstrate a rib articulating with the transverse process of C7 if it is present (Figs. 1,2) (3). Three-dimensional computed tomography is especially useful for surgical planning purposes (Figs. 1,2 C) (5). With 3D CT, anatomical detail is significantly enhanced, especially the attachment sites of the rib, presence of pseudoarthrosis, and the location of nearby vasculature and neural structures (5). ​​​ References: Spadliński Ł, Cecot T, Majos A, et al. The Epidemiological, Morphological, and Clinical Aspects of the Cervical Ribs in Humans. Biomed Res Int. 2016;2016:8034613. DOI: 10.1155/2016/8034613 Jeung MY, Gangi A, Gasser B, et al. Imaging of chest wall disorders. Radiographics. 1999;19(3):617-637. DOI: 10.1148/radiographics.19.3.g99ma02617 Viertel VG, Intrapiromkul J, Maluf F, et al. Cervical ribs: a common variant overlooked in CT imaging. AJNR Am J Neuroradiol. 2012;33(11):2191-2194. DOI: 10.3174/ajnr.A3143 Kataria R, Sharma A, Srivastava T, Bagaria H, Sharma A. Cervical rib, a rare cause of recurrent stroke in the young: case report. Neurologist. 2012;18(5):321-323. DOI: 10.1097/NRL.0b013e31826754a9 Chandak S, Kumar A. Usefulness of 3D CT in Diagnosis of Cervical Rib Presenting as Supraclavicular Swelling of Short Duration. J Clin Diagn Res. 2014;8(5):RD01-RD2. DOI:10.7860/JCDR/2014/7977.4374 Corey Stump is a medical student and aspiring radiologist at the Marian University College of Osteopathic Medicine in Indianapolis, Indiana. Prior to medical school, he graduated summa cum laude from Wittenberg University where he received a B.S. degree in Biology. He is excited to pursue a career in Diagnostic Radiology with interests in medical education. His current project involves a webinar titled “Navigating The Virtual Match; Program Directors Vs Medical Students” through the Academy of Online Radiology Education with other medical students and radiologists around the country in an effort to provide insight on the upcoming residency match. He is passionate about teaching and he hopes to provide a meaningful experience to medical students one day. Follow Corey Stump on Twitter @corey_stump All posts by Corey Stump 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

Name the implant and potential complications • Xray of the Week Figure 1. What is the name of this implant? Discussion: Mentoplasty refers to cosmetic chin augmentation that is often used to treat deficient chin projection caused by soft-tissue atrophy and retrusion of the chin (1). Chin retrusion may be further classified as underdevelopment of mandibular symphysis (microgenia) or mandibular retrusion (retrognatia) (2). Augmentation mentoplasty can be performed using various implant materials, autografts, and homografts, and silicone as in this case (1,2). Silicone rubber is preferred over other materials for its resistance to changes in body temperature, calcification, absorption, and degeneration as well as its pliability (2). The silicone implant is typically positioned inferior to the mental foramen in a subperiosteal pocket via an extraoral approach (1,2). Silicone implants are best seen on CT using bone windows, and there is typically variable attenuation with density that is higher than soft tissue but less than bone (1). On MRI, there is very low signal intensity on T1- and T2- weighted sequences (1). Complications include infection, migration, heterotopic bone formation, and foreign body giant cell reaction (1). Mandibular bone erosion is also a common complication and can be evaluated on CT with dental CT software (3). ​​​​ References: Schatz CJ, Ginat DT. Imaging of cosmetic facial implants and grafts. AJNR Am J Neuroradiol. 2013;34(9):1674-1681. doi:10.3174/ajnr.A3214 Vuyk HD. Augmentation mentoplasty with solid silicone. Clin Otolaryngol Allied Sci. 1996;21(2):106-118. doi:10.1111/j.1365-2273.1996.tb01312.x Abrahams JJ, Caceres C. Mandibular erosion from silastic implants: evaluation with a dental CT software program. AJNR Am J Neuroradiol. 1998;19(3):519-522. 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

Lung mass. Diagnosis? • Xray of the Week Figure 1. What is the lung mass? Figure 2. Pulmonary hamartoma Figures 2A and 2B: Axial CT chest demonstrating well-demarcated, solitary peripheral, and inhomogeneous pulmonary mass arising from right lower lung lobe (yellow arrows). Note the low attenuation fat in the mass which is diagnostic of hamartoma. Small calcifications are also present. Figure 2C: Sagittal CT chest demonstrates posteriorly located well-demarcated solitary peripheral pulmonary mass. The mass is above the intact diaphragm (red arrow). Figure 2D: Coronal CT chest and abdomen demonstrates solitary lung mass arising from the right lung superior to the diaphragm with evidence of calcification. The mass is above the intact diaphragm (red arrow). Discussion: A hamartoma is a noncancerous focal proliferation of cells that is typically found in the organ or surrounding structures from which it arises (1). Hamartomas are commonly composed of mesenchymal tissue such as adipose tissue, epithelium, fibrous tissue, and cartilaginous tissue (2,3). Pulmonary hamartomas, dominantly composed of cartilaginous and adipose tissue, are the most common benign lung neoplasm, accounting for approximately 6% of solitary pulmonary nodules (3). They are commonly incidental findings found in the fourth to sixth decades of life with a male predilection and no current identifiable risk factors (3,9). Though often incidentally diagnosed as most patients are asymptomatic, symptoms can present depending on the location of the hamartoma (5). If located within the endobronchial structures, patients can present with cough, hemoptysis, or endobronchial obstruction with associated fever and dyspnea (5). Pulmonary hamartomas are found on diagnostic imaging; however, some cases may require definitive diagnosis with cytological evaluation after biopsy. On imaging, computed tomography (CT) is more sensitive to detecting pulmonary hamartomas compared to chest radiographs (4). Findings on CT demonstrate solitary, well-defined, round or lobulated masses or lobules that are predominantly peripherally located in the lungs (3,4). The size of the mass or nodule can be variable, typically around 2 to 5 cm. However, pulmonary hamartomas can also be larger than 10 cm, as seen in Figure 1 and 2 (8). Approximately 60% of the masses or nodules contain adipose tissue and 30% contain popcorn-like calcifications (6,7). A well-circumscribed solitary pulmonary nodule which contains fat and remains stable in size is virtually pathognomonic of a pulmonary hamartoma (7). If asymptomatic, patients with pulmonary hamartomas do not require treatment. Surgical resection is reserved for rapidly proliferating or symptomatic masses for which malignancy cannot be ruled out (9). Prognosis is typically excellent as hamartomas are commonly slow growing with rare malignant transformation (9). ​​​​ References: Batsakis JG. Pathology consultation. Nomenclature of developmental tumors. Ann Otol Rhinol Laryngol. 1984 Jan-Feb;93(1 Pt 1):98-9. doi: 10.1177/000348948409300122. PMID: 6703601 Leiter Herrán F, Restrepo CS, Alvarez Gómez DI, Suby-Long T, Ocazionez D, Vargas D. Hamartomas from head to toe: an imaging overview. Br J Radiol. 2017;90(1071):20160607. doi:10.1259/bjr.20160607 Singh H, Khanna SK, Chandran V, Jetley RK. PULMONARY HAMARTOMA. Med J Armed Forces India. 1999;55(1):79-80. doi:10.1016/S0377-1237(17)30328-3 Radosavljevic V, Gardijan V, Brajkovic M, Andric Z. Lung hamartoma--diagnosis and treatment. Med Arch. 2012;66(4):281-2. doi: 10.5455/medarh.2012.66.281-282. PMID: 22919888 Thomas JW, Staerkel GA, Whitman GJ. Pulmonary hamartoma. AJR Am J Roentgenol. 1999 Jun;172(6):1643. doi: 10.2214/ajr.172.6.10350308. PMID: 10350308 Chai JL, Patz EF. CT of the lung: patterns of calcification and other high-attenuation abnormalities. AJR Am J Roentgenol. 1994;162 (5): 1063-6 doi:10.2214/ajr.162.5.8165982 Klein JS, Braff S. Imaging evaluation of the solitary pulmonary nodule. Clin. Chest Med. 2008;29 (1): 15-38, v. doi:10.1016/j.ccm.2007.11.007 Siegelman SS, Khouri NF, Scott WW Jr, Leo FP, Hamper UM, Fishman EK, Zerhouni EA. Pulmonary hamartoma: CT findings. Radiology. 1986 Aug;160(2):313-7. doi: 10.1148/radiology.160.2.3726106. PMID: 3726106 Lundeen KS, Raj MS, Rajasurya V, et al. Pulmonary Hamartoma. [Updated 2020 Jul 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan. https://www.ncbi.nlm.nih.gov/books/NBK539806/ Rabab Zaidi is an aspiring radiologist and fourth year medical student at the Loyola University Chicago Stritch School of Medicine (SSOM). She currently serves as the Community Support Co-Lead for the Loyola University COVID-19 Response Team and Co-President of the Radiology Interest Group at SSOM. At the Stritch School of Medicine, she has also worked with the Department of Radiation Oncology to study prostate cancer imaging and adaptive radiotherapy techniques, where she learned about the intersection of patient care and radiology. Rabab graduated magna cum laude with a degree in Economics from Loyola University Chicago in 2016. She is further passionate about mentorship, advocacy, and photography. Follow Rabab Zaidi on Twitter @ZaidiRabab All posts by Rabab Zaidi 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

History of arrhythmias • Xray of the Week What is the diagnosis? Figure 1. What is the important finding seen on these CT images? Figure 1A: Axial CT image of abdomen with hyperdense liver Figure 1B: Zoomed-in axial CT image of liver- note the ROI is 154 HU Figure 1C: Zoomed-in axial CT image of spleen- note the ROI is 63 HU Figure 1D: Coronal CT image of abdomen with hyperdense liver Discussion: Amiodarone is an antiarrhythmic agent used to treat ventricular arrhythmias and atrial fibrillation. It is a class III drug, based on the Vaughan Williams classification, and works by prolonging the QT interval (1). The drug can also cause bradycardia, atrioventricular nodal conduction, increased refractoriness, and decreased intracardiac conduction (1). Moreover, since amiodarone is highly lipid soluble, it is stored in high concentrations in the liver, lungs, eyes, thyroid, and skin (1). One study found that all patients undergoing ophthalmologic examinations were found to have asymptomatic corneal microdeposits (2). It was further noted that a rise in hepatic enzyme levels was correlated to dosage and plasma drug and metabolite concentrations (2). Older patients pose a higher risk of developing hypothyroidism and those with abnormal lung functions prior to therapy may be predisposed to pulmonary alveolitis (2). Most of the observed unwanted effects resolve when amiodarone is decreased in dose or discontinued (2). Though it is uncommon, liver toxicity can occur and is manifested by elevated liver transaminase levels (1). Since amiodarone accumulates in lipid reservoirs and is released slowly, the concentration in the liver can be as high as 500-fold of the serum level (3,4). Characteristics of amiodarone-induced hepatotoxicity include histologic steatosis, inflammation, fibrosis, and phospholipidosis (5). On imaging, we can appreciate increased density in the liver on non-contrast CT which is thought to be secondary to increased iodine content from the amiodarone (3,4). Increased liver attenuation on CT is a nonspecific finding and can also be seen with iron deposition in primary hemochromatosis, thalassemia, and hemosiderosis(6). Increased attenuation can also be seen with gold deposition, copper deposition in Wilson disease, and type IV glycogen storage disease (6). In Figure 1A, 1B, and 1D we can visualize the increased density of the liver on CT due to the chronic use of amiodarone. Normally, the liver has a similar density to the spleen on non-contrast CT scans (7), whereas in this case the liver is markedly hyperdense (154 HU) compared to spleen (63 HU). In the initial paper on hepatic Amiodarone deposition, liver hyperdensity measured 95 to 145 HU (Normal is 30-70) (4). Treatment of amiodarone toxicity involves reducing the dosage or discontinuing the usage (2); however, hepatic deposition without toxicity is usually an incidental finding that does not require any treatment. ​​​​ References: Siddoway, L. A. (2003). Amiodarone: guidelines for use and monitoring. American family physician, 68(11), 2189-2196. https://www.aafp.org/afp/2003/1201/p2189.html Harris, L., McKenna, W. J., Rowland, E., & Krikler, D. M. (1983). Side effects and possible contraindications of amiodarone use. American heart journal, 106(4), 916-923. doi:10.1016/0002-8703(83)90016-9 Hussain, N., Bhattacharyya, A., & Prueksaritanond, S. (2013). Amiodarone-induced cirrhosis of liver: what predicts mortality?. Isrn Cardiology, 2013. doi:10.1155/2013/617943 Goldman IS, Winkler ML, Raper SE, et al. Increased hepatic density and phospholipidosis due to amiodarone. AJR Am J Roentgenol. 1985;144(3):541-546. doi:10.2214/ajr.144.3.541 Buggey J, Kappus M, Lagoo AS, Brady CW. Amiodarone-Induced Liver Injury and Cirrhosis. ACG Case Rep J. 2015;2(2):116-118. Published 2015 Jan 16. doi:10.14309/crj.2015.23 Ros P.R. (2018) Imaging of Diffuse and Inflammatory Liver Disease. In: Hodler J., Kubik-Huch R., von Schulthess G. (eds) Diseases of the Abdomen and Pelvis 2018-2021. IDKD Springer Series. Springer, Cham. doi:10.1007/978-3-319-75019-4_22 Herring W. Learning Radiology: Recognizing the Basics. Elsevier; 2015.​ Amer Ahmed is a fourth-year medical student at Midwestern University Chicago College of Osteopathic Medicine. There, he has served as the President for the Medical Business Association and Secretary for the Radiology Interest Group. Before medical school, Amer earned a degree in Economics at Loyola University Chicago and spent some time as an Investment Specialist at Merrill Edge before deciding to pursue his interest in medicine. Radiology intrigued Amer following a back injury requiring him to get an MRI. That is when he was able to appreciate the eye for detail Radiologists possess. Amer is passionate about finance, medicine, and technology. Follow Amer Ahmed on Twitter @amer_ahmed401 All posts by Amer 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

34 year old male with chest pain and shortness of breath • Xray of the Week Figure 1. 34 year old male with chest pain and shortness of breath. Figure 2. A and B: Axial and coronal CT with cardiomegaly due to markedly dilated heart. Right pleural effusion (blue arrow). Low EF with contrast only in RA (red arrows) and RV (orange arrow). Reflux of contrast into the IVC (green arrow) and hepatic veins (white arrow) indicates tricuspid valve regurgitation. C: Echocardiogram apical 4 chamber view. Mitral regurgitation as evidenced by a regurgitant jet extending into the RA (yellow arrow). Discussion: Methamphetamine (MA) and related compounds are the most widely abused drugs in the world after cannabis. It is a psychostimulant that causes an increase in the synapse of monoamine neurotransmitters, including dopamine, norepinephrine, and serotonin [1]. Methamphetamines can be smoked, snorted, injected, or ingested orally. Methamphetamine is more potent, and its effects last longer than cocaine. Methamphetamine associated cardiomyopathy (MACM) is more common in younger age groups compared to patients with cardiomyopathy attributable to other causes. The development of MACM has been shown to be dose-dependent and amplified by repetitive use, binge pattern use, and concomitant use of other substances. Autopsy studies have shown MACM to be associated with extensive myocardial fibrosis, cellular vacuolization, and myocyte destruction [2, 3]. Cardiac complications of MA use include chest pain, hypertension, arrhythmia, aortic dissection, coronary vasospasm, cardiomyopathy, sudden cardiac death, and pulmonary arterial hypertension [2]. Figure 3. A. Axial and B. Coronal CT Scan. Same patient with RV thrombus (red arrows). Typical findings reported on echocardiography are severe multi-chamber dilatation, reduced EF, mitral regurgitation (MR) Patients with MACM are also prone to developing intracardiac thrombi, with up to 33% for LV thrombus and 3.3% for RV thrombus [4, 5] (Fig. 3). Thrombus is likely due both to severe cardiac dysfunction and the prothrombotic state seen in MACM [5]. And tricuspid regurgitation (TR), and pericardial effusion [6-9]. In general, patients with MACM have significantly larger LA, LV, and RV size, lower LVEF, and a higher rate of mitral regurgitation (MR) compared to other causes of dilated cardiomyopathy [6]. In this case, there is severe tricuspid regurgitation (TR) with reflux of contrast into the inferior vena cava (IVC) and hepatic veins; pleural effusion is indicative of heart failure (Figs. 2 A, B). There is also MR visualized on the echocardiogram with a large regurgitant jet extending into the LA during systole (Fig. 2C). Aside from cessation of MA use, treatment of MACM is aimed at the specific pathology such as anticoagulation for intracardiac thrombus and diuresis/venodilators for volume overload. ​​​​ References: [if supportFields]> ADDIN EN.REFLIST

32 F with Vaginal Bleeding • Xray of the Week Patient at 25 weeks gestational age. Figure 1. Sagittal transvaginal ultrasound of the cervix. Figure 2. Sagittal transvaginal ultrasound of the cervix. A. Gray scale images show the fetal umbilical cord blood vessels (red arrow) across or near the internal os (orange arrow). B. Color doppler images show the fetal umbilical cord vessels across or near the internal os (yellow arrow). Discussion: Vasa previa is a rare and serious complication of pregnancy in which fetal umbilical cord blood vessels run across or near the internal opening of the cervix (1). Because the vessels run within the membranes, they are unsupported by the umbilical cord, placental tissue, or Wharton jelly (1). This increases risk of vessel rupture when the membranes rupture during labor. There are two types of vasa previa. In type I, there is a velamentous cord insertion between the umbilical cord and the placenta (2). Thus the fetal vessels that run freely within the amniotic membranes run across the cervix or near it (Figs. 1, 2) (2) In type II, fetal vessels run between lobes of succenturiate or bilobate placentas over or near the cervix (1,2). There are several methods used to diagnose vasa previa including identification of placental cord insertion, applying color Doppler over the cervix, 3D ultrasound, and transvaginal ultrasound (3). Linear echolucent structures can be seen over the cervix on gray-scale US (Fig. 2A) (4). These linear echolucent structures can also be seen in marginal sinus previa, which appears as a discontinuous venous lake at the placental margin (1,4). Pulsed Doppler will show a fetal umbilical or venous waveform in vasa previa whereas marginal sinus previa present with flow of a maternal heart frequency (1). Color doppler sonography shows vascular structures over the internal cervical os with a “fixed position during maternal repositioning” (Fig. 2B) (4).Funic presentation (also known as cord presentation) is also commonly confused for vasa previa, but they are different in that the funic presentation demonstrates shifting in position of the cord by tapping the transducer (1). Rupture of the fetal blood vessels can be fatal in vasa previa, so it typically requires elective C-section at 35 weeks (1). Hospitalization with corticosteroids at 32 weeks has also been recommended to promote lung maturity (1). ​​​​ References: 1. Derbala Y, Grochal F, Jeanty P. Vasa previa. J Prenat Med. 2007;1(1):2-13. 2. Sinkey RG, Odibo AO, Dashe JS. #37: Diagnosis and management of vasa previa. American Journal of Obstetrics & Gynecology. 2015;213(5):615-619. doi:10.1016/j.ajog.2015.08.031 3. Marr S, Ashton L, Stemm A, Cincotta R, Chua J, Duncombe G. Vasa praevia: ultrasound diagnosis at the mid‐trimester scan. Australas J Ultrasound Med. 2013;16(1):8-15. doi:10.1002/j.2205-0140.2013.tb00091.x 4. Fadl S, Moshiri M, Fligner CL, Katz DS, Dighe M. Placental imaging: normal appearance with review of pathologic findings. RadioGraphics. 2017;37(3):979-998. doi:10.1148/rg.2017160155 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

41 year old female. COVID-19 positive. SOB • Xray of the Week 41 yo female COVID-19 positive with LLE edema and Shortness of breath. Figure 1. Describe the abnormalities. Figure 2. A. Bilateral lower lobe peripheral ground-glass opacities (GGO) with confluent patchy consolidation (blue arrows). B. Loss of color flow in left popliteal vein (red arrow). C. Thrombosed non-compressible left common femoral vein (red arrow). D. and E. Axial and coronal CT showing partially occlusive left lower lobe pulmonary embolism (orange arrows) Discussion: The SARS-CoV-2 novel virus was first isolated in Wuhan, China. [1,2] In the United States, COVID-19 has been the cause of more than 380,000 deaths as of Jan 12, 2021 [3]. Patients typically present with fever, tachypnea, cough, and sore throat. Severe complications like pulmonary embolism (PE), multiorgan failure, and death can occur [2]. The radiologist plays a vital role in the COVID-19 pandemic due to the importance of imaging in diagnosis and management. The exact pathophysiology and management of this virus is still evolving, however COVID-19 is known to cause a hypercoagulable state with abnormal D-dimer, IL-6, and fibrinogen levels leading to an increased incidence of thrombotic events [1]. In hospitalized COVID-19 patients, the incidence of thrombotic events is between 7.7-49%. Among these, the most commonly occurring thrombotic event is venous thromboembolism [4]. A meta-analysis reported that the incidence of deep vein thrombosis (DVT) patients is 27% and PE is 15% in COVID-19 positive hospitalized patients [5]. If a DVT is suspected, compression ultrasonography of the lower extremity will often show an enlarged, noncompressible vein with corresponding loss of color flow if thrombus is occlusive [6]. The virus’ preferred access to host cells is via angiotensin-converting enzyme 2 (ACE-2) found in the respiratory epithelium. Therefore, the lungs are the most affected organ and visible signs of disease are typically present on imaging [1]. Chest x-rays may demonstrate diffuse ground-glass opacities, however, CT scans are more sensitive for these findings and are considered the first-line imaging modality. CT scans most often demonstrate peripherally distributed ground-glass opacities with reticular and/or interlobular septal thickening, with consolidation [7]. If associated pulmonary embolism is suspected, CT pulmonary angiography will demonstrate a complete or partial filling defect. The “polo mint” sign of partial filling defects is caused by the partial defect surrounded by contrast material [8]. Management of COVID-19 is a work in progress however, hospitalized patients confirmed to have COVID-19 should be on prophylactic anticoagulation unless contraindicated to prevent VTE. Typically low-molecular-weight heparin (LMWH) is preferred for anticoagulation prophylaxis and VTE management but unfractionated heparin can be an alternative, and Fondaparinux can be used in cases of heparin-induced thrombocytopenia (HIT). Tissue plasminogen activator (tPA) can be used as indicated in severe complications of COVID-19 such as limb-threatening DVT or massive PE [9]. ​​​​ References: Connors JM, Levy JH. COVID-19 and its implications for thrombosis and anticoagulation. Blood. 2020;135(23):2033-2040. doi:10.1182/blood.2020006000 Zheng P, Bao L, Yang W, Wang J. Clinical symptoms between severe and non-severe COVID-19 pneumonia: A protocol for systematic review and meta-analysis. Medicine (Baltimore). 2020;99(33):e21618-. doi:10.1097/MD.0000000000021618 Johns Hopkins Coronavirus Resource Center. 2020. Home - Johns Hopkins Coronavirus Resource Center. https://coronavirus.jhu.edu/ [20 October 2020]. Hajra, A., Mathai, S.V., Ball, S. et al. Management of Thrombotic Complications in COVID-19: An Update. Drugs 80, 1553–1562 (2020). doi:10.1007/s40265-020-01377-x Lu Y, Pan L, Zhang W-W, et al. A meta-analysis of the incidence of venous thromboembolic events and impact of anticoagulation on mortality in patients with COVID-19. International journal of infectious diseases. 2020;100:34-41. doi:10.1016/j.ijid.2020.08.023 Karande GY, Hedgire SS, Sanchez Y, et al. Advanced imaging in acute and chronic deep vein thrombosis. Cardiovascular diagnosis and therapy. 2016;6(6):493-507. doi:10.21037/cdt.2016.12.06 Zhao W, Zhong Z, Xie X, Yu Q, Liu J. Relation Between Chest CT Findings and Clinical Conditions of Coronavirus Disease (COVID-19) Pneumonia: A Multicenter Study. American journal of roentgenology (1976). 2020;214(5):1-6. doi:10.2214/ajr.20.22976 Wittram C, Maher MM, Yoo AJ, Kalra MK, Shepard J-AO, McLoud TC. CT Angiography of Pulmonary Embolism: Diagnostic Criteria and Causes of Misdiagnosis. Radiographics. 2004;24(5):1219-1238. doi:10.1148/rg.245045008 Bikdeli B, Madhavan MV, Jimenez D, et al. COVID-19 and Thrombotic or Thromboembolic Disease: Implications for Prevention, Antithrombotic Therapy, and Follow-up. Journal of the American College of Cardiology. 2020;75(23):2950-2973. doi:10.1016/j.jacc.2020.04.031 Nirali Dave is a medical student at Medical University of Lublin in Poland, currently doing clinical rotations in New York. Before that she completed her undergraduate education at Rutgers University, and worked as a medical scribe. Nirali was first exposed to basic radiologic imaging while scribing, and was very quickly taken by the field. Her passion for radiology comes from the bridging of anatomy, health technologies, and patient care. In the future, she hopes to complete a diagnostic radiology residency and stay committed to clinical research and patient education. Follow Nirali Dave on Twitter @ndave08 All posts by Nirali Dave 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