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Chest Wall Mass & Altered • Xray of the Week This HIV positive 63 year old female patient had an enlarging left anterior chest wall mass which was subsequently biopsied. She presented 2 weeks later with altered mental status, and an MRI brain was performed. Left image: Left parasternal anterior chest wall mass. Right image and image below: Axial T2 FLAIR PROPELLER showing mass in the left lateral aspect of the posterior fossa which is isointense to slightly T2 hyperintense to brain. There is vasogenic edema involving the left cerebellar hemisphere, with mass effect. The mass is causing deviation of the fourth ventricle to the right, as well as partial fourth ventricle effacement. Left image: Axial exponential apparent diffusion coefficient (ADC) map demonstrating low signal at the site of the mass indicating restricted diffusion. Right image: Axial diffusion weighted image (DWI) demonstrating high signal at the site of the mass indicating restricted diffusion, likely reflecting increased cellularity. Differential considerations include lymphoma, metastatic disease, as well as atypical meningeal tumors such as hemangiopericytoma. The patient had a CT guided biopsy of the chest wall mass which proved to be granulocytic sarcoma. Photomicrographs of the biopsy done in this case. Courtesy of Dennis Kasimian, MD - Chair of Pathology at Valley Presbyterian Hospital Left: H&E- Diffuse infiltration of soft tissue by dis-cohesive, immature mononuclear cells with irregular, hyperchromatic nuclei and a moderate amount of faintly granular cytoplasm, consistent with granulocytic sarcoma. Right: Myeloperoxidase immunohistochemical stain: Positive cytoplasmic staining with myeloperoxidase stain confirms myeloid origin. Granulocytic Sarcoma is also known as myeloid sarcoma, chloroma, extramedullary myeloblastoma, and extramedullary myeloid tumor. It is a rare solid tumor composed of primitive precursors of the granulocytic series of white blood cells that include myeloblasts, promyelocytes, and myelocytes The tumor is an extramedullary manifestation of acute myeloid leukemia (AML). History: •1811: First described by the British physician A. Burns. •1853: King initially called it chloroma, because typical forms have a green color caused by high levels of myeloperoxidase in the immature cells. •1966: Rappaport renamed it granulocytic sarcoma, because not all of the cells are green. Granulocytic Sarcoma Associated with: •Acute myelogenous leukemia •Chronic myelogenous leukemia •Myelofibrosis with myeloid metaplasia •Hypereosinophilic syndrome •Polycythemia vera Epidemiology: •Occurs in 2.5-9.1% of patients with acute myelogenous leukemia. •Occurs in <2% of patients with chronic myelogenous leukemia. •Same rate of occurrence in both sexes. •60% of patients are younger than 15 years old. Location: •May involve any part of the body. •Often occur in multiples and preferentially involve orbits and subcutaneous tissue. •Paranasal sinuses, lymph nodes, bone, spine, brain, pleural and peritoneal cavities, breast, thyroid, salivary glands, small bowel, lungs, various pelvic organs. Granulocytic Sarcoma in HIV: In the highly active antiretroviral therapy (HAART) era, the overall survival of patients with AIDS is improving dramatically and, as a result, perhaps the occurrence of malignancies not typically associated with HIV infection, especially those malignancies such as AML in which the incidence increases with age, may become more prevalent as the HIV-infected population ages. Prognosis: •Patients with granulocytic sarcomas who have chronic leukemia or myeloproliferative disorders have a negative prognosis, because these tumors often occur during acute transformation. •Very sensitive to focal irradiation or chemotherapy; they generally resolve completely in less than 3 months. •Poor prognosis in AIDS patients with median survival of 7.5 months if treated and 1 month if not treated. References: 1. Krause JR, and Aburiziq I. Granulocytic sarcoma and HIV. Proc (Bayl Univ Med Cent) 2011;24(4):306–308 2. Navarro WH, Kaplan LD. AIDS-related lymphoproliferative disease. Blood. 2006;107(1):1–13. 3. Rizzo M, Magro G, Castaldo P, Tucci L. Granulocytic sarcoma (chloroma) in HIV patient: a report. Forensic Sci Int. 2004;146(Suppl):S57–S58. 4. Aboulafia DM, Meneses M, Ginsberg S, Siegel MS, Howard WW, Dezube BJ. Acute myeloid leukemia in patients infected with HIV-1. AIDS. 2002;16(6):6–865. Related posts: Pneumocystis pneumonia in AIDS Kevin M. Rice, MD is the president of Global Radiology CME Dr. Rice serves as the Chair of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015 Dr. Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. All Posts by Kevin Rice, MD

Refused to Remove Vest • Xray of the Week This patient refused to remove his vest prior to getting a chest X-ray. The concerned tech called the radiologist. Fortunately, the radiologist knew that the radiopaque objects were due to the LifeVest wearable defibrillator made by Zoll which is a treatment option for sudden cardiac arrest. Unlike an implantable cardioverter defibrillator (ICD), the LifeVest is worn outside the body rather than implanted in the chest. This device continuously monitors the patient's heart with dry, non-adhesive sensing electrodes to detect life-threatening arrhythmias. If a life-threatening rhythm is detected, the device alerts the patient prior to delivering a treatment shock, and thus allows a conscious patient to delay the treatment shock. If the patient becomes unconscious, the device releases a Blue™ gel over the therapy electrodes and delivers an electrical shock to restore normal rhythm. Chest Xray of a patient wearing the Zoll LifeVest. We have seen this device used increasingly while patients are waiting for their ICD placement. Dr. Kamran Toluie, a cardiologist in Beverly Hills, California describes how the LifeVest can be used as a temporary potentially life-saving measure in patients with cardiomyopathy who may respond to conservative medical management before an ICD is needed. Illustration of the Zoll LifeVest and how it looks on a patient. (from http://lifevest.zoll.com) Video of the Zoll LifeVest and how it works. References: 1. Adler A, Halkin A, Viskin S. Wearable cardioverter-defibrillators. Circulation. 2013;127 (7): 854-60. 2. Chung MK, Szymkiewicz SJ, Shao M, et al. Aggregate national experience with the wearable cardioverter-defibrillator: event rates, compliance, and survival. J Am Coll Cardiol. 2010;56:194–203. 3. Zoll LifeVest Online Information for Medical Professionals. http://lifevest.zoll.com/medical-professionals Kevin M. Rice, MD is the president of Global Radiology CME Dr. Rice serves as the Chair of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015 Dr. Rice 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 Rice, MD

Thirteen Year Old Female with Vague Abdominal Pain • Xray of the Week This 13 year old girl presented with vague abdominal pain and nausea. The patient went to surgery 2 days after the CT and MRI shown here. What did the surgeon find? Figure 1 A: CT showing a large pancreatic mass with peripheral enhancement. B: Coronal T1 weighted image demonstrates the pancreatic mass with central necrosis and peripheral enhancement. Figure 2 A: Axial FSE T2 weighted image showing a large pancreatic mass with central necrosis and hemorrhage. B: Axial LAVA post contrast T1 weighted image demonstrates the pancreatic mass with central necrosis and peripheral enhancement. Discussion: Solid pseudopapillary tumor of the pancreas (SPT) is a rare neoplasm of the pancreas seen predominantly in young Asian and African-American females between ages 10 and 20. Although most tumors are benign, about 15% may be malignant. As in this case, CT and MRI usually demonstrate a peripheral enhancing large mass. MRI shows heterogeneity on all sequences due to necrosis and hemorrhage. Differential diagnosis includes serous cystadenoma, mucinous cystic neoplasm, islet cell tumors, and pancreatoblastoma. Complete surgical resection is usually curative. References: 1. Coleman KM, Doherty MC, Bigler SA. Solid-pseudopapillary tumor of the pancreas. Radiographics. 23 (6): 1644-8 2. Choi JY, Kim MJ, Kim JH et-al. Solid pseudopapillary tumor of the pancreas: typical and atypical manifestations. AJR Am J Roentgenol. 2006;187 (2): W178-86. Kevin M. Rice, MD is the president of Global Radiology CME Dr. Rice serves as the Chair of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015 Dr. Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. Due to his online teaching initiative, Dr. Rice was nominated and became a semifinalist for a "Minnie" award for the Most Effective Radiology Educator in 2016. Follow Dr. Rice on Twitter @KevinRiceMD All Posts by Kevin Rice, MD

Thirty nine year old Female with Rapidly Enlarging Right Breast Mass • Xray of the Week This 39 year old female presented with a rapidly enlarging right breast mass. Mammogram and ultrasound were performed. The patient had an ultrasound guided biopsy of the mass, and subsequent excision. What did the surgeon find? Left: Right breast ultrasound showing a large mass measuring 13.8 x 6.4 cm with peripheral heterogeneity. Right: Bilateral MLO mammogram images. Normal left breast and large mass throughout most of the right breast. Ultrasound-guided biopsy of the large right breast mass. Phyllodes tumor is a rare mass of the breast, comprising less than 1% of breast cancers. Usually found as a rapidly enlarging mass in women between ages 35 and 60, the tumor is almost always benign. Some case are classified as borderline, and less than 10% of these tumors are frankly malignant with distant metastases. However, at least 25% of the time there is local recurrence following excision and a wide resection margin is required. Very large masses often require mastectomy. In the rare cases of metastatic disease, treatment is similar to sarcoma, rather than breast cancer regimens. References: 1. Fibrous Lesions of the Breast: Imaging-Pathologic Correlation RadioGraphics 2005; 25:1547–1559 http://pubs.rsna.org/doi/full/10.1148/rg.256045183 2. Tan H, Zhang S, Liu H et-al. Imaging findings in phyllodes tumors of the breast. European J Radiology. 2011; 81 (1):e62–e69 doi:10.1016/j.ejrad.2011.01.085 3. Buchberger W, Strasser K, Heim K et-al. Phylloides tumor: findings on mammography, sonography, and aspiration cytology in 10 cases. AJR Am J Roentgenol. 1991;157 (4): 715-9. 4. Lifshitz OH, Whitman GJ, Sahin AA et-al. Radiologic-pathologic conferences of the University of Texas M.D. Anderson Cancer Center. Phyllodes tumor of the breast. AJR Am J Roentgenol. 2003;180 (2): 332. 5. Wurdinger S, Herzog AB, Fischer DR et-al. Differentiation of phyllodes breast tumors from fibroadenomas on MRI. AJR Am J Roentgenol. 2005;185 (5): 1317-21. 6. Chao TC, Lo YF, Chen SC et-al. Sonographic features of phyllodes tumors of the breast. Ultrasound Obstet Gynecol. 2002;20 (1): 64-71. 7. Yabuuchi H, Soeda H, Matsuo Y et-al. Phyllodes tumor of the breast: correlation between MR findings and histologic grade. Radiology. 2006;241 (3): 702-9. doi:10.1148/radiol.2413051470 Kevin M. Rice, MD is the president of Global Radiology CME Dr. Rice serves as the Chair of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a Radiologist with Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015 Dr. Rice 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

57 yo Female with Intermittent Chest Pain • Xray of the Week This 57 year old female presented with atypical chest pain and an echocardiogram showed an abnormality of the aortic valve. Blood cultures and cardiac enzymes were both normal. Coronal CT (left panel) and axial (right panel) images showing lobulated mass arising from the right cusp of the aortic valve. Papillary fibroelastomas are the third most common type of primary tumor of the heart, behind cardiac myxomas and cardiac lipomas, and are the most common benign neoplasms of the cardiac valvular structures. Papillary fibroelastomas may cause chest pain due to intermittent occlusion of the coronary arteries. Fragments of the tumor may embolize and cause stroke if they enter the intracranial circulation. Myocardial infarction or sudden cardiac death may be due to embolization of a portion of the tumor into a coronary artery. Surgical resection should be considered for all patients who have symptoms and for asymptomatic patients who have pedunculated lesions or tumors larger than 1 cm. Valve-sparing excision usually results in good long-term results. References: 1. Sun, JP, et al. Clinical and Echocardiographic Characteristics of Papillary Fibroelastomas: A Retrospective and Prospective Study in 162 Patients. Circulation.2001; 103: 2687-2693 2. Kumbala D, Sharp T, Kamalesh M. "Perilous pearl"-papillary fibroelastoma of aortic valve: a case report and literature review. Angiology. 2008;59 (5): 625-8. 3. Araoz PA, Eklund HE, Welch TJ et-al. CT and MR imaging of primary cardiac malignancies. Radiographics. 1999;19 (6): 1421-34. 4. Lembcke A, Meyer R, Kivelitz D, et al. Papillary Fibroelastoma of the Aortic Valve. Appearance in 64-Slice Spiral Computed Tomography, Magnetic Resonance Imaging, and Echocardiography. Circulation. 2007;115:e3-e6 5. Gopaldas RR, Atluri PV, Blaustein AS, Bakaeen FG, Huh J, Chu D. Papillary fibroelastoma of the aortic valve: operative approaches upon incidental discovery. Tex Heart Inst J. 2009; 36(2): 160–163. Kevin M. Rice, MD is the president of Global Radiology CME Dr. Rice serves as the Chair of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015 Dr. Rice launched 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 at @KevinRiceMD All posts by Kevin M. Rice, MD

A Boxing Match Left President T. Roosevelt with Blindness due to This Condition • Xray of the Week This 47 year old female presented with left visual field defect. What is the diagnosis? Figure 1. A: Ultrasound of the normal right globe. Figure 1. B: Ultrasound of the left globe, demonstrating an irregular echogenic region posteriorly due to the detached retina. Notice the tenting, due to retinal tissue adherent to the optic disc. There are adjacent subtle echoes representing vitreous hemorrhage. Figure 2. A different patient with a large retinal detachment of the right globe. Figure 3. Another patient with retinal detachment, neglected for 3 days, now with associated severe hemorrhage. Figure 4. There are many treatments for retinal detachment; however, scleral banding (or scleral buckling) as seen in this patient's left eye is one of the methods commonly used by ophthalmologists. Note the high attenuation surgical foreign body which surrounds the left orbit, causing an elongation of the globe. The detached retina has healed and is not visualized. Figure 5. Diagram of scleral buckle. Causes of retinal detachment include diabetes, myopia, trauma, and various inflammatory disorders. Theodore Roosevelt's Detached Retina Roosevelt was an avid boxer in college and often invited sparring partners to box when he was governor of New York. After reaching the White House, Roosevelt continued this hobby. However, in 1908 an opponent landed a punch to the president's left eye, ending his boxing hobby. The blow caused a detached retina and eventually blindness in the eye. He was 50 years old at the time. Roosevelt later wrote in his autobiography: "I had to abandon boxing as well as wrestling, for in one bout a young captain of artillery cross-countered me on the eye, and the blow smashed the little blood vessels. Fortunately it was my left eye, but the sight has been dim ever since, and if it had been the right eye I should have been entirely unable to shoot. "Accordingly I thought it better to acknowledge that I had become an elderly man and would have to stop boxing. I then took up jiujitsu for a few years." References: 1. Chu, HC, Chan MY, Chau CYJ, et al. The use of ocular ultrasound for the diagnosis of retinal detachment in a local accident and emergency department. Hong Kong Journal of Emergency Medicine 2017, Vol. 24(6) 263–267 2. Shinar Z, Chan L, Orlinsky M. Use of ocular ultrasound for the evaluation of retinal detachment. J Emerg Med. 2011 Jan;40(1):53-7. 3. Bedside Ocular Ultrasound for the Detection of Retinal Detachment in the Emergency Department. Academic Emergency Medicine. 2010 Vol. 17(9), 913–917 4. Chicago Tribune. Teddy Roosevelt's little-known secret. http://articles.chicagotribune.com/2002-10-07/features/0210070158_1_boxing-final-bout-theodore-roosevelt-association Kevin Rice, MD is the President of Global Radiology CME and serves as the Chair of Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015 Dr. Rice 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. All Posts by Kevin M Rice, MD Follow Dr. Rice on Twitter @KevinRiceMD

52 year old Male on Dialysis with Chronic Swelling of the Right Arm • Xray of the Week 2016 • Week #11 This 52 year old male with a dialysis fistula in the right arm presented with chronic swelling of the right arm. The dialysis nurse also reported decreasing efficiency of the dialysis. The patient had a venogram shown here. What has occurred and what is the treatment? Contrast venogram via the dialysis fistula demonstrating a completely occluded right subclavian vein and no contrast entering the superior vena cava (SVC). The guidewire has been maneuvered such that it is across the occluded segment, traverses the right atrium, and the tip is in the inferior vena cava (IVC). A 12 mm balloon is inflated across the occluded segment in the brachiocephalic vein. Post venoplasty. Right subclavian vein and superior vena cava are now wide open. The patient's arm swelling resolved within a few hours of the venoplasty. A dialysis fistula is a surgically created connection between an artery and vein, usually in the upper extremity. The fistula takes about 6 weeks following surgery to mature before it can be used for dialysis. Due to the abnormal high pressure within the outflow vein, it is susceptible to stenosis or occlusion. These narrowings or blockages may be treated with balloon venoplasty as in this case. Other treatments include stents and thrombolysis, depending on the individual situation. Kevin Rice, MD serves as the Medical Director of the Radiology Department of Valley Presbyterian Hospital in Van Nuys, California and is a Member of 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 launched Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. All posts by Kevin Rice, MD Follow Dr. Rice on Twitter @KevinRiceMD

Sudden Onset Right Side Weakness • Xray of the Week This 76 year old female presented with sudden onset of right side weakness. What is the diagnosis? Figure 1. Non-contrast axial CT scan of the brain. Figure 2. A. Non-contrast axial CT scan of the brain demonstrates high attenuation within the left middle cerebral artery (MCA), appearing as a high attenuation dot (red arrow) as the MCA is in the short axis. Figure 2. B. The high attenuation MCA is visualized as a line (red arrow) as the artery is in the long axis. Figure 2. C. There is also an old infarct in the left basal ganglia. (yellow arrow) Note that the gray and white matter differentiation is normal indicating that the high attenuation MCA is the only sign of infarct. Figure 3. A. Axial T2-weighted image demonstrating the old lacunar infarct in the left basal ganglia (blue arrows). High signal intensity is present throughout the left MCA distribution due to the acute infarct. Figure 3. B. The axial diffusion weighted image (DWI) demonstrates high signal intensity due to restricted diffusion in the left MCA distribution. Figure 3. C. Axial apparent diffusion coefficient (ADC) map demonstrates the left MCA infarct with low signal, confirming this is an acute infarct rather than "T2 shine through". Discussion: The hyperdense artery sign (HAS) has a 90-100% specificity (1-5) for acute infarct and was first reported in 1983(6). Other causes of HAS include high hematocrit(5), viral infection(3), dissection(7), and retained contrast (4). However, sensitivity is only 30%. In order to have objective criteria for HAS, Koo et al (3) set a ratio of 1.2 when compared to the non-affected contralateral vessel or an absolute value of > 43 HU. In patients with the hyperdense artery sign, the outcome is often poor with a large infarct and significant neurological deficit. This is likely due to the high volume of thrombus required to produce the high attenuation within the artery. References: 1. Unnikrishnan D, Yada S, Gilson N A case of large right MCA stroke with hyperdense MCA sign in CT imaging Case Reports 2017;2017:bcr-2017-222529. http://dx.doi.org/10.1136/bcr-2017-222529 2. Abd Elkhalek YI, Elia RZ. Qualitative and quantitative value of hyperdense MCA sign as a prognostic marker for infarction. The Egyptian Journal of Radiology and Nuclear Medicine (2016)47, 1043-1048. https://doi.org/10.1016/j.ejrnm.2016.06.005 3. Koo CK, Teasdale E, Muir KW. What constitutes a true hyperdense middle cerebral artery sign? Cerebrovasc Dis. 2000 Nov-Dec;10(6):419-23. https://doi.org/10.1159/000016101 4. Jensen-kondering U, Riedel C, Jansen O. Hyperdense artery sign on computed tomography in acute ischemic stroke. World J Radiol. 2010;2 (9): 354-7. 5. Rauch RA, Bazan C 3rd, Larsson EM, Jinkins JR. Hyperdense middle cerebral arteries identified on CT as a false sign of vascular occlusion. AJNR Am J Neuroradiol. 1993;14:669–673. https://www.ncbi.nlm.nih.gov/pubmed/8517357 6. Gács G, Fox AJ, Barnett HJ, Vinuela F. CT visualization of intracranial arterial thromboembolism. Stroke.1983;14:756–762. 7. Yakushiji Y, Haraguchi Y, Soejima S, Takase Y, Uchino A, Koizumi S, Kuroda Y. A hyperdense artery sign and middle cerebral artery dissection. Intern Med. 2006;45:1319–1322. https://www.ncbi.nlm.nih.gov/pubmed/17170508 Kevin M. Rice, MD is the president of Global Radiology CME Dr. Rice serves as the Chair of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015 Dr. Rice along with Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. All Posts by Kevin M Rice, MD

Hemoptysis and Lung Nodule • Xray of the Week This 40 year old female presented with hemoptysis. What is the diagnosis? Left image: CXR with mass in RUL Right image: Coronal CT showing RUL mass with feeding artery and draining vein diagnostic of pulmonary AVM. Video of pulmonary AVM in this patient, and a surprising second finding. Discussion Pulmonary arteriovenous malformations (AVM) are caused by an abnormal connection between the pulmonary arterial system and pulmonary venous system due to a direct fistula between a branch of the pulmonary artery and a branch of the pulmonary vein. This is a rare anomaly with an incidence of approximately 2/100,000. The patients may be seen with an incidental lung nodule. However, due to the right to left shunt, patients may present with shortness of breath, hemoptysis, or paradoxical emboli to the brain or elsewhere in the systemic circulation. Pulmonary AVM's are associated with hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome. Approximately a third of patients with a single AVM and up to half of patients with multiple AVM's have HHT. On plain radiographs, the AVM's usually have the appearance of a nodule or multiple nodules. On CT scan, the nodule has a feeding artery and draining vein. Treatment options include percutaneous catheter directed embolization and surgical excision. References: 1. Gossage JR, Kanj G. Pulmonary arteriovenous malformations. A state of the art review. Am J Respir Crit Care Med. 1998; 158(2): 643-61. 2. Remy-Jardin M, Dumont P, Brillet PY, Dupuis P, et. al. Pulmonary arteriovenous malformations treated with embolotherapy: helical CT evaluation of long-term effectiveness after 2-21-year follow-up. Radiology. 2006;239(2): 576-85. 3. Pulmonary Arteriovenous Malformations: Safety and Efficacy of Microvascular Plugs. AJR: 1135-1143. 10.2214/AJR.17.19200 4. Guttmacher AE, Marchuk DA, White RI Jr. Hereditary hemorrhagic telangiectasia. N Engl J Med. 1995; 333(14): 918-24. 5. Remy J, Remy-Jardin M, Wattinne L, Deffontaines C. Pulmonary arteriovenous malformations: evaluation with CT of the chest before and after treatment. Radiology. 1992; 182(3): 809-16. Kevin M. Rice, MD is the president of Global Radiology CME and serves as the Chair of the Radiology Department of Valley Presbyterian Hospital in Van Nuys, 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 co-founded Global Radiology CME with Natalie Rice to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" award for the Most Effective Radiology Educator. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD

Headache, Altered, Pancreas Cancer • Xray of the Week This 61 year old female with a history of pancreatic cancer presented with altered mental status, and had a CT scan and MRI brain. A subsequent lumbar puncture revealed the diagnosis. What is the abnormality and what is the diagnosis? Upper row: CT brain without contrast. Note the high attenuation overlying the right cerebral convexity. There is no abnormality in the basal cisterns. Bottom left and right: T1 weighted images with contrast demonstrate abnormal leptomeningeal enhancement along the right cerebral hemisphere, over the right frontal lobe, parietal lobe, operculum, Sylvian fissure, and temporal lobe. Bottom middle: T2* GRE image shows no blood products, with no region of low signal. The history of pancreatic carcinoma and the lack of high attenuation material in the basal cisterns on the CT scan may give the reader a clue that the findings are not due to subarachnoid hemorrhage (SAH). The leptomeningeal enhancement on the MRI may be due to leptomeningeal carcinomatosis, meningitis, or other inflammatory processes. A subsequent lumbar puncture revealed pancreatic carcinoma on cytology. Therefore, the findings are due to leptomeningeal carcinomatosis. Differential diagnosis of pseudo-subarachnoid hemorrhage on CT: •Meningitis •Leptomeningeal carcinomatosis •Artifacts on CT: anoxic encephalopathy, spontaneous intracranial hypotension •Iatrogenic causes: recently administered intrathecal or IV contrast material; and following endovascular procedures such as aneurysm coiling and stroke intervention. Highly proteinaceous material in the subarachnoid space causes increased attenuation which may be due to purulent fluid seen with meningitis or leptomeningeal carcinomatosis, mimicking SAH. Anoxic encephalopathy and spontaneous intracranial hypotension both cause a perceptual error due to relatively higher attenuation of the basal cisterns related to the low attenuation seen with these conditions. Iodinated contrast in the subarachnoid space either due to IV or intrathecal administration causes high attenuation in the subarachnoid space which should be easily differentiated from SAH if the history is known. Likewise, endovascular procedures may result in leakage of iodinated contrast which could be confused with SAH, especially given that the procedures are often done for patients with SAH or aneurysms. Follow up CT scan within 3-4 hours after the procedure will show clearing of the contrast, whereas SAH will persist. References: 1. Carrie P. Marder, et al. Subarachnoid Hemorrhage: Beyond Aneurysms. American Journal of Roentgenology. 2014;202: 25-37. 10.2214/AJR.12.9749 2. Mendelsohn DB, Moss ML, Chason DP, Muphree S, Casey S. Acute purulent leptomeningitis mimicking subarachnoid hemorrhage on CT. J Comput Assist Tomogr 1994; 18:126–128 3. Tsuchiya K, Katase S, Yoshino A, Hachiya J. FLAIR MR imaging for diagnosing intracranial meningeal carcinomatosis. AJR 2001; 176:1585–1588 4. al-Yamany M, Deck J, Bernstein M. Pseudo-subarachnoid hemorrhage: a rare neuroimaging pitfall. Can J Neurol Sci 1999; 26:57–59 Case courtesy of my friend and colleague Gregory P. Lekovic, M.D., Ph.D. Kevin Rice, MD serves as the Medical Director of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015 Dr. Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. Due to his online teaching activities, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator in 2016. Follow Dr. Rice on Twitter @KevinRiceMD All Posts by Kevin M Rice, MD

Abdominal Pain and Vomiting in 76 M with Melanoma • Xray of the Week A 76 yo male with a history of malignant melanoma presented with blood in the stool. Twenty days later he returned with vomiting. CT scan of abdomen and pelvis was performed. Day 1: Axial and coronal images showing masses in the small bowel due to melanoma metastases. 20 days later: Axial and coronal images showing dilated small bowel indicating obstruction. There is also also a target sign due to intussusception. The lead point is a metastatic focus of melanoma. Note also the enhancing metastatic masses in the gallbladder. Day 1: Larger coronal image showing mass in the small bowel due to melanoma metastases (blue arrow). Note also the enhancing metastatic masses in the gallbladder. (red arrow) 20 days later: Coronal image showing dilated small bowel indicating obstruction. There is also a target sign due to intussusception. (green arrow) The lead point is a metastatic focus of melanoma. Discussion In children intussusception is usually idiopathic; whereas, with adult intussusception a lead point is present in greater than 90% of cases. Melanoma metastases to the small bowel is seen in approximately 60% of patients with malignant melanoma. However, these only become symptomatic in less than 5% of patients. Symptoms may include abdominal pain, intestinal obstruction with vomiting, weight loss or anemia. Rarely, masses from metastatic melanoma within the small bowel can cause intussusception. Treatment is surgical, usually requiring resection of the mass and the adjacent segment of bowel. Related Global Rad CME case: Ileo-colic intussusception in a 6 month old References: 1. Frederico Ferreira de SouzaI; Felipe Ferreira de SouzaII, et al. Metastatic melanoma causing small bowel intussusception: diagnosis by 18F-FDG PET/CT. Radiol Bras vol.42 no.5 São Paulo Sept./Oct. 2009 2. P Floros, B Rai; Small Bowel Intussusception Due To Malignant Melanoma of Unknown Primary With Adrenal Metastasis At Presentation. The Internet Journal of Surgery. Volume 26. Number 2. http://ispub.com/IJS/26/2/11652 3. Ahmed Guirata, Gadiel Lisciaa; Acute ileo-ileal intussusception due to intestinal metastatic melanoma. Polish Annals of Medicine. Volume 22, Issue 1, June 2015, Pages 41–44 4. Fernando A. Alvarez, Matías Nicolás; Ileocolic intussusception due to intestinal metastatic melanoma. Case report and review of the literature. Int J Surg Case Rep. 2011; 2(6): 118–121 Kevin Rice, MD 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

LLQ Pain in 44 F • Xray of the Week This 44 year old female presented to the Emergency Department with sudden onset left lower quadrant pain. There was no fever or vomiting. What is the diagnosis? Fig. 1 Axial (left) and coronal (right) CT with contrast. There is a well defined region of fat attenuation with surrounding mesenteric edema with a central dot representing a thrombosed vein, diagnostic of epiploic appendagitis. Fig. 2 Axial (left) and coronal (right) CT. Central thrombosed vein in epiploic appendage (blue arrow) with surrounding mesenteric edema diagnostic of epiploic appendagitis. Fig. 3 A Second patient with epiploic appendagitis in RLQ mimicking appendicitis clinically and on CT: Central thrombosed vein in a fatty lesion with a thin high attenuation rim (blue arrows on coronal images and red arrow on axial image). Findings consistent with epiploic appendagitis. Case courtesy of Geoffrey Sigmund, MD. Fig. 4 A third patient with subtle epiploic appendagitis in LLQ mimicking diverticulitis clinically. CT demonstrates the central thrombosed vein in a fatty lesion with a thin high attenuation rim (yellow arrows). Findings consistent with epiploic appendagitis. Fig. 5 A different patient with ascites outlining normal epiploic appendages (blue arrows) Discussion: Epiploic appendagitis is an uncommon inflammatory process of the epiploic appendices of the colon which can mimic diverticulitis clinically. The etiology is probably due to torsion of a large epiploic appendage or spontaneous thrombosis of a vein in the appendage. The hallmark appearance of epiploic appendagitis on CT scan is a well defined 2-4 cm region of fat attenuation, a thin surrounding high attenuation rim, surrounding mesenteric edema, and a central dot representing a thrombosed mesenteric vein. (Fig. 1-2) If present in the right lower quadrant, it may also be confused clinically with appendicitis. (Fig. 3) The findings on CT may be subtle as seen in Figure 4. The normal epiploic appendages are usually not visualized on CT unless outlined by free fluid. (Fig. 5) The radiologist plays an important role in the management as a correctly interpreted CT scan alerts the clinician to the diagnosis and the fact that it is self-limiting. This often prevents unnecessary surgery. Treatment is anti-inflammatory drugs and symptoms usually resolve within a week. References: 1. Singh AK, Gervais DA, Hahn PF et-al. Acute epiploic appendagitis and its mimics. Radiographics. 25 (6): 1521-34. 2. Purysko AS, Remer EM, Filho HM et-al. Beyond appendicitis: common and uncommon gastrointestinal causes of right lower quadrant abdominal pain at multidetector CT. Radiographics. 2011;31 (4): 927-47. 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 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 founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. Due to his online teaching activities, Dr. Rice was nominated and became a semifinalist for a "Minnie" award for the Most Effective Radiology Educator in 2016. Follow Dr. Rice on Twitter @KevinRiceMD All posts by Kevin M. Rice, MD