Everything you need to know about Computed Tomography (CT)

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December 2016 Imaging Pearls - Learning Modules | CT Imaging | CT Scan Protocols - CTisus
Imaging Pearls ❯ December 2016
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    • “ The urachus is a ductal remnant that arises embryologically, originating from the involution of the allantois and cloaca and extending between the bladder dome and the umbilicus. During normal gestational development, the urachus involutes and its lumen is obliterated, becoming the median umbilical ligament.”

      
Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063 

    • “The reported incidence of urachal anomalies is approximately one in 5000 population for adults, with a significantly lower rate of one in 150 000 population among infants.There is a higher prevalence in men than women. Most anomalies of the urachus are unexpected, being detected incidentally and more frequently with the increased use of cross-sectional imaging.”

      
Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063
    • “Four types of urachal anomalies have been described, on the basis of the location of the abnormal residual patency along the urachal tract: patent urachus (sometimes referred to as urachal fistula), urachal cyst, umbilical-urachal sinus, and vesicourachal diverticulum.”


      Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063
    • “The reported incidence of urachal anomalies is approximately one in 5000 population for adults, with a significantly lower rate of one in 150 000 population among infants.There is a higher prevalence in men than women. Most anomalies of the urachus are unexpected, being detected incidentally and more frequently with the increased use of cross-sectional imaging.”


      Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063
    • “The urachus extends from the anterosuperior surface of the bladder to the umbilicus and lies in the extraperitoneal space of Retzius (or retropubic space) between the transverse fascia and parietal peritoneum. It is accompanied on both sides by the medial umbilical ligaments, which are the obliterated remnants of the umbilical arteries and may on occasion merge with the urachus, causing it to mildly deviate from the midline. The length of the urachus ranges from 3 to 10 cm and it generally has an approximate diameter of 8–10 mm.”

      
Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063
    • “Urachal cysts develop when both the umbilical and bladder ends of the urachus are obliterated, 
but a focal segment remains patent somewhere along the course of the urachus, more commonly at the lower third of the urachal tract. Cysts are usually small and asymptomatic.The diagnosis is often made only when they become symptomatic in childhood or adulthood because of complications, mainly infection, or as an inciden- tal finding at imaging performed for unrelated reasons .”

      
Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063
    • “Infection represents the most common complication of urachal anomalies and may produce sometimes marked nonspecific symptoms, including abdominal pain and tenderness, fever, erythema, purulent urinary discharge, and occasionally a palpable mass. Infection routes for bacterial migra- tion can be lymphatic, hematogenous, or by direct extension from the bladder; Staphylococcus aureus is the most commonly isolated organism, fol-lowed by Escherichia coli, Enterococcus, Citrobacter, Klebsiella, and Proteus. Although it is unusual, severe infection can result in the formation of complex fistulas and abscesses, with the attendant risk of potential intraperitoneal rupture causing peritonitis and sepsis.”


      Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063
    • “Malignant urachal neoplasms are also rare, accounting for less than 1% of all bladder cancers.They usually remain undiscovered for a long period of time and may be found incidentally at imaging or at an advanced stage when symptoms of local invasion or systemic spread have developed.”

      
Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063
    • “Although urachal remnants are lined by urothelium, 80% of urachal cancers are adenocarcinomas, including mucin-producing adenocarcinomas (69%) and mucin-negative adenocarcinomas (15%).The remaining 20% of urachal cancers are urothelial, squamous, and sarcomatoid neoplasms.This differs from the most common type of bladder cancer, which is typically urothelial. It is unclear why adenocar- cinoma is the predominant type, and it has been hypothesized that chronic irritation is responsible for metaplasia of the transitional epithelium into columnar epithelium.”


      Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063
    • “Approximately 90% of urachal carcinomas develop in the portion of the urachus adjacent to the bladder and gradually grow in the cranial direction. Cystography may reveal a filling defect
in the bladder dome or the presence of extrinsic compression.”


      Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063
    • “Calcifications are present in 70% of cases and are mostly seen at the periphery of the urachal mass; however, they may also be central or a com- bination of both. The presence of calcifications in a midline soft-tissue mass along the course of the urachal tract is considered pathognomonic for the diagnosis of urachal adenocarcinoma.”


      Imaging of the Urachus: Anomalies, Complications, and Mimics 
 ParadaVillavicencio C et al.
RadioGraphics 2016; 36:2049–2063
Liver

    • “The Liver Imaging Reporting and Data System (LI-RADS) is the American College of Radiology standardized reporting and data collection system for patients with cirrhosis, chronic liver disease, or other risk factors for development of HCC. This guideline is based on an algorithm with which lesions are classified into categories that determine the probability that the lesion is a benign lesion or HCC on the basis of CT or MRI findings.”


      Current Guidelines for the Diagnosis and Management of Hepatocellular Carcinoma: A Comparative Review 
Arslanoglu A et al.
AJR 2016; 207:W88–W98
Pancreas


    • Computed Tomography Angiography of the Thoracic Aorta 

      Scheske JA et al. 

      Radiol Clin N Am 54 (2016) 13–33

    • Computed Tomography Angiography of the Thoracic Aorta 

      Scheske JA et al. 

      Radiol Clin N Am 54 (2016) 13–33
    • Pancreatic Cancer Facts
    • Pancreatic Cancer: New Cases 2016
    •  “In case of unusual imaging features, endoscopic ultrasonography with fine needle aspiration should be considered to reach a definite diagnosis and avoid an aggressive surgical procedure.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)

    •  “The presence of a fatty component within a pancreatic tumor is highly suggestive of a benign lesion.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 

    •  “An enhancing pancreatic tumor without upstream dilatation of the main pancreatic duct should suggest primary pancreatic lymphoma.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)
    •  “Imaging features of a small tumor of the pancreatic tail should be compared to that of the spleen to rule out the possibility of an intrapancreatic accessory spleen.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)
    •  “The presence of hemorrhage within a mixed solid and cystic tumor suggests solid and pseudopapillary tumor.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)
    •  “The pancreas is an unusual site of secondary tumors. Melanoma, lung cancer and breast carcinoma are the most common origins of multiple pancreatic metastases, whereas renal cell carcinoma usually leads to a single pancreatic metastasis. The interval between the diagnosis of the primary tumor and the development of pancreatic metastases varies between 1 and 3years, except for renal cell carcinoma for which pancreatic metastases may appear after more than 20 years.”

      
Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)
    •  “Intrapancreatic accessory spleen is the second location of accessory spleens accounting for 17% of all locations . It is usually located 3-4cm from the splenic hilum, adjacent to the pancreatic tail. Embryologically, acces- sory spleen is a result of failure of fusion of splenic tissue buds of the dorsal mesogastrium. Pathologically pancreatic accessory spleen has the same histological features than the main spleen, surrounded by a thin capsule.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)

    • “On imaging, intrapancreatic accessory spleen appears as a less than 4 cm solid enhancing mass with a smooth, round, ovoid or minimally lobulated shape within the tail of the pancreas . The patterns of enhancement parallel those of the main spleen with an arterial serpiginous pattern followed by a homogeneous enhancement during the portal and late phases.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)

    • “Primary pancreatic lymphoma is usually a non-Hodgkin lymphoma. Primary pancreatic lymphoma is extremely rare whereas secondary involvement of the pancreas by an abdominal lymphoma is more common. Mostly located in the head, primary pancreatic lymphoma may mimic pancreatic carcinoma. Behrns et al. have reported suggestive criteria for the diagnostic of primary pancreatic lymphoma. They include a tumor predominantly located within the pancreas, with lymph node involvement confined to the peripancreatic region, no superficial or mediastinal lymphadenopathy, hepatic or splenic involvement, and normal white blood cell count.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)
    • “Pancreatic hamartoma is considered as a strictly benign malformation rather than a tumor. Pancreatic hamartoma has no gender predilection and may present as a solid, or solid and cystic lesion. Most of pancreatic hamartomas are located in the pancreatic head . Pathologically, pancreatic hamartomas is a well- demarcated mass consisting of mature acini and ducts with distorted architecture embedded in a fibrous stroma. The solid component of the tumor consists of fibrous and adipose tissue, whereas the cystic component consists of dilated ducts. Islets cells of Langerhans may be present. Tumor serum markers are usually normal.”

      
Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)

    • “The pancreas is a rare location of lipoma. Head and tail of the pancreas are the most frequent locations . Embryological theory suggests a trapping of the retroperitoneal or mesenteric fat during the fusion of the ventral and dorsal bud of the pancreas. It is mostly composed of lobules of mature adipose cells with a thick connective tis- sue capsule [46]. It has characteristic imaging features so that histological biopsy sample is not needed for a definite diagnosis.”

      
Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)

    • “Pancreatoblastoma is the most common pancreatic tumor in children within the first decade, whereas it is exceptional in adults. Its etiology is unknown, however, it has been reported in association with genetic syndromes such as familial adenomatous polyposis syndrome and Beckwith-Weidemann syndrome. In contrary to the children population, there is no male predominance in adults. Pancreatoblastoma involves the pancreatic head in almost half of the cases.”

      
Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)

    • “On imaging, pancreatoblastoma appears as a large, heterogeneous, exophytic multiloculated and well- circumscribed necrotic lesion with enhancing septa. Of interest, higher-grade tumors may have progressively less-defined margins. Rim-shaped or clustered calcifications, biliary and pancreatic ductal dilatation, 
ascites, hepatic and pelvic metastases, adenopathy and vascular invasion may be present.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)

    • “ SPT, or Frantz tumor, accounts for 3% of all pancreatic tumors and 6% of all exocrine pancreatic tumors . SPT is mostly found in women in the 2nd and 3rd decade because of its progesterone dependency. The mean size of SPT is 50 mm at the time of diagnosis and the pancreatic head is the most common location. SPT is considered as a benign condition even if distant metastases or recurrence after resection have been reported. Histopathologically SPT consists of an encapsulated mixed tumor with cystic and pseudopapillary component.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)
    • “Unenhanced CT shows calcifications in one third of the tumors. After intravenous administration of iodinated contrast material, SPT shows vivid enhancement during the arterial phase that persists during the portal and late phases.” 


      Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)

    • “Pancreatic ductal carcinoma continues to be the most lethal malignancy with rising incidence. It is the fourth most common cause of cancer death in the western world due to its low treatment success rate. In addition, because of its rapid growth and silent course, diagnosis is often only established in the advanced stages. As one of the most aggressive malignancies, the treatment of this disease is a great challenge to clinicians. This paper reviewed the natural history of pancreatic cancer, the current clinical practice and the future in pancreatic cancer management.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “Pancreatic cancer is one of the most aggressive human malignancies, as 50% present with metastatic disease and 35% with locally advanced disease. It is the 13th commonest cancer with 200,000 cases per year world-wide, 6000 cases per year in the UK and the fourth leading cause of cancer death in the Western world. There is an increasing incidence of this disease affecting 8-12 per 100,000 of the population per year. Whether this increased incidence is real or whether it reflects advances in diagnostic imaging is unknown.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “Diagnostic problems arise because the symptoms are late and non-specific, there is no effective screening process and there is no specific high-risk group. Since conservative oncological therapies have failed to show any benefit in long-term survival, resection remains the only modality of treatment offering any possibility of cure. Unfortunately, only 10-20% with head and less than 3% of body/tail cancers are candidates for resection. In the past 20 years, there is also only a modest increase in long-term survival with a median survival of 12 months, and 5-year survival rate of 15-26% after potentially curative resection.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “Traditional chemotherapy remains the standard treatment for advanced pancreatic cancer. Regimens like FOLFIRINOX (5-FU, leucovorin, irinotecan, and oxaliplatin) or gemcitabine and nab-paclitaxel have been used to palliate symptoms and prolong survival.”
How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “Although there are no specific genetic mutations identified for the majority of FPC (70%), relatives of FPC kindred have a high risk of pancreatic cancer. K-Ras gene mutations have been found in most pancreatic cancers. As a prediction of poor prognosis, the detection of K-ras mutations may be a useful prognostic factor for pancreatic cancer patients. K-Ras mutations are associated with a worse overall survival in pancreatic cancer patients, especially when mutations are detected in liquid biopsies or fresh frozen tumor tissue samples.”

      
How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “Regional lymph-node metastasis occurred in 30% of patients with very small primary cancers and 64% of T1 primary cancer had lymph node involvement.28 Careful histological studies in a large series of resected pancreatic cancers revealed cancer dissemination in the lymph nodes in 89%; lymph node metastases in 77%, intrapancreatic neural invasion in 92% and a neural and nerve plexus invasion outside the pancreas in 45%.29 Thus even though the surgeon may be able to offer resection to >20% of patients with pancreatic cancer, the possibility of cure is gravely limited by the extent of early or occult micrometastases.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “A tumor is potentially resectable if it can be technically removed with negative margins (R0 resection) without compromising the vascular supply to the liver (hepatic artery) or small bowel (superior mesenteric artery). Involvement of adjacent organs (e.g, duodenum or transverse colon), regional lymph nodes, portal vein (partial involvement), gastroduodenal artery, are not contraindications to resection, as these structures can be removed en bloc with the tumor to achieve an R0 (no tumor cells within 1 mm) resection.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “A tumor is unresectable in the presence of: major comorbidity, metastatic disease (including involved lymph nodes out with the resection field, locally advanced disease with extrapancreatic involvement, superior mesenteric artery or coeliac artery involvement, and main portal venous occlusion/thrombosis. PV encasement from external compression with occlusion and thrombosis is a contraindication to resection because arterial involvement is likely to co-exist. An R0 resection for ductal pancreatic cancer must include an N1 and N2 lymph node dissection, perivascular connective tissue dissection and a standardized retroperitoneal soft-tissue dissection.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “The results of the Gastrointestinal Tumor Study Group using adjuvant radio-chemotherapy following resection of pancreatic cancer revealed a median survival of 21 months in the group randomized to treatment compared to 10.9 months in the control group. The two-year actuarial survival was 46%, and 18% in the control group and the five-year probability survival in the treatment group was above 20%.”

      
How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “The arguments against surgical resection are: i) pancreatic carcinoma usually has an insidious presentation and physical signs of metastatic spread are commonly present at initial consultation; ii) it is a disease of elderly patients and 50% are >72 years. Many are unfit, weak, emaciated and suffer from other concomitant medical conditions. Endoscopic bypass is all that can be offered iii) bypass procedures are all that can be achieved in the vast majority; iv) an unsuccessful resection for a carcinoma can result in a high mortality, a very high morbidity and an extremely costly period of treatment for the patient”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “The results of the Gastrointestinal Tumor Study Group using adjuvant radio-chemotherapy following resection of pancreatic cancer revealed a median survival of 21 months in the group randomized to treatment compared to 10.9 months in the control group.59 The two-year actuarial survival was 46%, and 18% in the control group and the five-year probability survival in the treatment group was above 20%.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “Over 80% of patients have positive regional lymph nodes or distant metastases at the time of diagnosis.77,78 Studies have revealed that even in small pancreatic tumors, which have not spread through the pancreatic capsule and with a diameter of less than 2 cm, there are positive para-aortic lymph nodes in 40% and therefore classified as stage II disease.81,82 Thus small tumor size cannot automatically be equated with early tumor stage.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “The most widely used marker is CA 19-9 antigen as it is expressed in 86% of pancreatic cancers with a sensitivity of 89% compared to the sensitivity of 37% with CEA. 70% of patients with a tumor <4 cm already show elevated serum levels.86 Additionally CA 19-9 levels correlate with prognosis as it is more significantly lower in small resectable tumors than in larger ones. However, its sensitivity is not high enough for the primary diagnosis of pancreatic cancer. CA 19-9 is elevated in patients with non-malignant diseases, such as chronic pancreatitis or obstructive jaundice of various origins and in smoking. Its determination has a high clinical value if a CT scan indicate a pancreatic cancer and in the follow-up of patients following resection. If the CA 19-9 level returns to normal after tumor resection and increases during follow-up, then cancer relapse is extremely probable.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “Progress in identifying new therapies has been hampered by the genetic complexity of the disease with each tumor cell carrying an average of 63 mutations, and the lack of prognostic markers.89 Most alterations occur with very low frequency and so are challenging to exploit therapeutically. The future lies on the better understanding of the molecular oncology of pancreatic cancer, which entails the genetics and the pathophysiology of metastasis of pancreatic cancer. About 75% of human pancreatic adenocarcinomas have acquired a mutation in codon 12 of the K-ras gene and there could be a role for biological therapy countering the effects of specific mutant oncogenes.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “Genetic data have been interpreted to suggest that development of invasive disease from precursor lesions occurs over a considerable length of time (17 years on average), with death following after 2-3 years, highlighting the importance of identifying early diagnostic markers of pre-invasive pancreatic cancer.93,94 The recent major break- through is in the identification of early protein markers (cancer exosomes) that may provide early diagnosis and represent a valid screening test.95 This would lead to early surgical intervention with a better chance of curing this essentially incurable disease.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
    • “Pancreatic ductal adenocarcinoma is still a disease with a very poor prognosis. It is genetically very complex with a high diversity of mutations compared with other cancers. Early diagnosis with the new protein markers may lead to early intervention and better prognosis. The main surgical goal in performing an R0 resection facilitated by improved staging and patient selection would result in hospital mortality of <5% in specialist centers. As pancreatic carcinoma is largely resistant to standard chemotherapy, consideration of multimodal treatment including immunotherapy is necessary.”


      How Grim is Pancreatic Cancer?
Weledji EP et al.
Oncol Rev. 2016 Jul 6;10(1):294
Practice Management

    • What is your profile on Google?
    • “By now, it’s almost old news: big data will transform medicine. It’s essential to remember, however, that data by themselves are useless. To be useful, data must be analyzed, interpreted, and acted on. Thus, it is algorithms — 
not data sets — that will prove transformative.

      "
Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016 


    • “Most computer-based algorithms in medicine are “expert systems” — rule sets encoding knowledge on a given topic, which are applied to draw conclusions about specific clinical scenarios, such as detecting drug interactions or judging the appropriateness of obtaining imaging. Expert systems work the way an ideal medical student would: they take general principles about medicine and apply them to new patients.”


      Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016
    • “Machine learning, conversely, approaches problems as a doctor progressing through residency might: by learning rules from data. Starting with patient-level observations, algorithms sift through vast numbers of variables, looking for combinations that reliably predict outcomes.”

      
Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016
    • “But where machine learning shines is in handling enormous numbers of predictors — sometimes, remarkably, more predictors than observations — and combining them in nonlinear and highly interactive ways.This capacity al- lows us to use new kinds of data, whose sheer volume or complexity would previously have made analyzing them unimaginable.”

      
Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016
    • “Another key issue is the quantity and quality of input data. Machine learning algorithms are highly data hungry, often re- quiring millions of observations to reach acceptable performance levels.In addition, biases in data collection can substantially affect both performance and generalizability. Lactate might be a good predictor of the risk of death, for example, but only a small, nonrepresentative sample of patients have their lactate levels checked.”


      Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016
    • “Machine learning has become ubiquitous and indispensable for solving complex problems in most sciences. In astronomy, algorithms sift through millions of images from telescope surveys to classify galaxies and find supernovas.”


      Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016
    • “Increasingly, the ability to transform data into knowledge will disrupt at least three areas of medicine. First, machine learning will dramatically improve the ability of health professionals to es- tablish a prognosis. Current prognostic models (e.g., the Acute Physiology and Chronic Health Evaluation [APACHE] score and the Sequential Organ Failure Assessment [SOFA] score) are restricted to only a handful of vari- ables, because humans must enter and tally the scores. But data could instead be drawn directly from EHRs or claims databases, allow- ing models to use thousands of rich predictor variables.”

      
Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016
    • “Second, machine learning will displace much of the work of radiologists and anatomical pathologists. These physicians focus largely on interpreting digitized images, which can easily be fed directly to algorithms instead. Massive imaging data sets, com- bined with recent advances in computer vision, will drive rapid improvements in performance, and machine accuracy will soon exceed that of humans. Indeed, radiology is already partway there: algorithms can replace a second radiologist reading mammograms and will soon exceed human accuracy.”


      Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016
    • “The patient- safety movement will increasingly advocate the use of algorithms over humans — after all, algorithms need no sleep, and their vigilance is the same at 2 a.m. as at 9 a.m. Algorithms will also monitor and interpret streaming physiological data, replacing aspects of anesthesiology and criti- cal care. The time scale for these disruptions is years, not decades.”


      Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016
    • “Machine learning will become an indispensable tool for clinicians seeking to truly understand their patients. As patients’ conditions and medical technologies become more complex, the role of machine learning will grow, and clinical medicine will be challenged to grow with it.”


      Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016
    • “As in other industries, this challenge will create winners and losers in medicine. But we are optimistic that patients, whose lives and medical histories shape the algorithms, will emerge as the biggest winners as machine learning transforms clinical medicine.”

      
Predicting the Future — Big Data, Machine Learning, and Clinical Medicine
Obermeyer Z, Emanuel EJ
N Engl J Med 375;13 September 29, 2016
    • “More than 85% of physicians in the United States use smart phones and 53% use tablets daily in their practice areas. There are four major app stores (iTunes, Google Play, Windows, and BlackBerry), but the majority of apps are offered through the iTunes and Google Play stores. In February 2015, the iTunes App Store contained approximately 32,000 medical mobile apps, whereas Google Play’s app store had about 23,000 medical apps. Medical apps fall under many different categories, including reference apps, such as the Physician’s Desk Reference app, medical calculators, and apps designed to access electronic health records or personal health information.” 


      Exploring the Usability of Mobile Apps Supporting Radiologists’ Training in Diagnostic Decision Making
Kim, Min Soon et al.
Journal of the American College of Radiology , Volume 13 , Issue 3 , 335 - 343
    • “ Social media is defined as a ‘set of interactive technology tools designed to encourage social networking and dialogic communication in virtual communities and networks’. Social media platforms include online forums, networking sites, online professional networks, content posting sites and research forums . A recently published comprehensive analysis of social media encourages health care staff to embrace the ‘e-society’ and social media revolution as it has shown to provide improved outcomes for healthcare staff and patients.”


      Social media in clinical radiology: have you updated your status?
Kassamali RH, Palkhi EYA, Hoey ET
Quant Imaging Med Surg. 2015 Aug; 5(4): 491–493.
    • “The revolution in social media enables radiologists to showcase their roles and responsibilities in the healthcare setting, and provides an interface to engage with patients and other healthcare members. Social media can therefore be a tool to improve patient education; this can be in the form of twitter feeds or health blogs tailored to discuss essential or topical issues in the media or local community .”


      Social media in clinical radiology: have you updated your status?
Kassamali RH, Palkhi EYA, Hoey ET
Quant Imaging Med Surg. 2015 Aug; 5(4): 491–493.
    • “From a patient perspective, the increased self-education through social media risks the possibility of becoming unnecessarily or inadequately concerned, due to lack of sufficient knowledge or contradicting information on social media; this can jeopardize patient safety especially if some patients use the social media as a replacement for traditional forms of consultation.”


      Social media in clinical radiology: have you updated your status?
Kassamali RH, Palkhi EYA, Hoey ET
Quant Imaging Med Surg. 2015 Aug; 5(4): 491–493.
    • “The results show that 85 % of all survey participants are using social media, mostly for a mixture of private and professional reasons. Facebook is the most popular platform for general purposes, whereas LinkedIn and Twitter are more popular for professional usage. The most important reason for not using social media is an unwillingness to mix private and professional matters. Eighty-two percent of all participants are aware of the educational opportunities offered by social media.”


      Radiologists' Usage of Social Media: Results of the RANSOM Survey.
Ranschaert ER et al.
J Digit Imaging. 2016 Feb 3. [Epub ahead of print]
    • “An increasing number of hospitals and health systems utilize social media to allow users to provide feedback and ratings. The correlation between ratings on social media and more conventional hospital quality metrics remains largely unclear, raising concern that healthcare consumers may make decisions on inaccurate or inappropriate information regarding quality.”


      Hospital Evaluations by Social Media: A Comparative Analysis of Facebook Ratings among Performance Outliers.
Glover M et al. 
J Gen Intern Med. 2015 Oct;30(10):1440-6
    • “Hospitals performing better than the national average on 30-day readmissions were more likely to use Facebook than lower-performing hospitals (93.3 % vs. 83.5 %; p < 0.01). The average rating for hospitals with low readmission rates (4.15 ± 0.31) was higher than that for hospitals with higher readmission rates (4.05 ± 0.41, p < 0.01). Major teaching hospitals were 14.3 times more likely to be in the high readmission rate group. A one-star increase in Facebook rating was associated with increased odds of the hospital belonging to the low readmission rate group by a factor of 5.0 (CI: 2.6-10.3, p <  0.01), when controlling for hospital characteristics and Facebook-related variables.”


      Hospital Evaluations by Social Media: A Comparative Analysis of Facebook Ratings among Performance Outliers.
Glover M et al. 
J Gen Intern Med. 2015 Oct;30(10):1440-6
    • “The most important reason for not using social media is an unwillingness to mix private and professional matters. Eighty-two percent of all participants are aware of the educational opportunities offered by social media. The survey results underline the need to increase radiologists' skills in using social media efficiently and safely. There is also a need to create clear guidelines regarding the online and social media presence of radiologists to maximize the potential benefits of engaging with social media.”

      
Radiologists' Usage of Social Media: Results of the RANSOM Survey.
Ranschaert ER et al.
J Digit Imaging. 2016 Feb 3. [Epub ahead of print]
    • “ Hospitals with lower rates of 30-day hospital-wide unplanned readmissions have higher ratings on Facebook than hospitals with higher readmission rates. These findings add strength to the concept that aggregate measures of patient satisfaction on social media correlate with more traditionally accepted measures of hospital quality.”


      Radiologists' Usage of Social Media: Results of the RANSOM Survey.
Ranschaert ER et al.
J Digit Imaging. 2016 Feb 3. [Epub ahead of print]
    • “Online social media provides a platform for women to share their experiences and reactions in undergoing mammography, including humor, positive reflections, and encouragement of others to undergo the examination. Social media thus warrants further evaluation as a potential tool to help foster greater adherence to screening guidelines.”


      What Do Patients Tweet About Their Mammography Experience?
Rosenkrantz AB et al.
Acad Radiol. 2016 Nov;23(11):1367-1371.
    • “Identified themes included breast compression (24.4%), advising other patients to undergo screening (23.9%), recognition of the health importance of the examination (18.8%), the act of waiting (10.1%), relief regarding results (9.7%), reflection that the examination was not that bad (9.1%), generalized apprehension regarding the examination (8.2%), interactions with staff (8.0%), the gown (5.0%), examination costs or access (3.4%), offering or reaching out for online support from other patients (3.2%), perception of screening as a sign of aging (2.4%), and the waiting room or waiting room amenities (1.3%).”


      What Do Patients Tweet About Their Mammography Experience?
Rosenkrantz AB et al.
Acad Radiol. 2016 Nov;23(11):1367-1371.
    • “Patients are increasingly seeking online information regarding their health and their health care providers. Concurrently, more patients are accessing their electronic medical records, including their radiology reports, via online portals. Thus, this study aims to characterize what patients find when they search for radiologists online.”


      JOURNAL CLUB: Radiologists' Online Identities: What Patients Find When They Search Radiologists by Name.
Vijayasarathi A et al.
AJR Am J Roentgenol. 2016 Nov;207(5):952-958.
    • “Of all U.S. health care providers recognized by CMS, 30,601 self-identified as radiologists. There was at least one search result for 30,600 radiologists (99.997%), for a total of 305,795 websites. Of all the domains, 69.8% were third party-controlled physician information systems, 17.7% were physician or institution controlled, 1.0% were social media platforms, 2.1% were other, and 9.5% were not classified. Nine of the top 10 most commonly encountered domains were commercially controlled third-party physician information systems.”


      JOURNAL CLUB: Radiologists' Online Identities: What Patients Find When They Search Radiologists by Name.
Vijayasarathi A et al.
AJR Am J Roentgenol. 2016 Nov;207(5):952-958.
    • “Most U.S. radiologists lack self-controlled online content within the first page of Google search results. Opportunities exist for individual radiologists, radiology groups, academic departments, and professional societies to amend their online presence, control the content patients discover, and improve the visibility of the field at large.”


      JOURNAL CLUB: Radiologists' Online Identities: What Patients Find When They Search Radiologists by Name.
Vijayasarathi A et al.
AJR Am J Roentgenol. 2016 Nov;207(5):952-958.
Spleen

    • “ Splenic metastases can occur with widespread disease, and parenchymal disease is caused by hematogenous dissemination. The most common primary cancers with splenic metastases include melanoma and cancers of the breast, lung, ovary, stomach, and prostate.” 


      Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities
Thipphavong S et al.
AJR 2014;203: 315-322

    • “Lymphoma is the most common malig- nant tumor of the spleen. Lymphoma either can be primary splenic or can be involved in diffuse systemic disease. Splenic involvement is seen at presentation in 33% of all patients with Hodgkin lymphoma and in 30–40% of patients with non-Hodgkin lymphoma.” 


      Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities
Thipphavong S et al.
AJR 2014;203: 315-322

    • “Lymphoma can infiltrate the spleen diffusely, causing splenomegaly, or can present as discrete nodules or masses. Necrosis of lymphoma is rare. Infarction of the spleen involved by lymphoma can occur. On ul- trasound, discrete lesions are usually hypoechoic and on CT, lesions are low attenuation, which are best seen on portal venous phase images.”

      
Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities
Thipphavong S et al.
AJR 2014;203: 315-322

    • “Splenic angiosarcoma is the most common (nonhematolymphoid) primary malignant neo- plasm of the spleen and arises from the endo- thelial lining of splenic blood vessels. Angio- sarcoma either appears as a well-defined mass or can be diffusely infiltrative in appearance.”

      
Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities
Thipphavong S et al.
AJR 2014;203: 315-322

    • “Unlike primary hepatic angiosarcoma, there is no reported association between splenic angiosarcoma and chemical exposures of vinyl chloride, arsenic, or prior injection of Thorotrast, a suspension containing particles of the radioactive compound thorium dioxide that was once used as a radiographic contrast agent. Patients typically present with left upper quadrant pain, anemia, or thrombocytopenia.” 


      Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities
Thipphavong S et al.
AJR 2014;203: 315-322

    • “CT shows an enlarged spleen with areas of low and high attenuation, due to acute hemor- rhage or hemosiderin deposits, and calci- fications can be seen. Contrast enhancement of angiosarcoma is variable depending on the degree of tumoral necrosis and can mimic that of a hepatic hemangio- ma by showing avid peripheral enhancement.” 


      Nonneoplastic, Benign, and Malignant Splenic Diseases: Cross-Sectional Imaging Findings and Rare Disease Entities
Thipphavong S et al.
AJR 2014;203: 315-322

Vascular

    • “ In 6.6% of people, the left vertebral artery arises directly from the arch. The bovine arch is another normal variant in which the left common carotid ar- tery arises from the brachiocephalic trunk rather than the aorta, occurring in up to one-fourth of the population. Although ingrained in the medical literature, the bovine arch is a misnomer for this aortic variant; cows actually have a single brachiocephalic trunk that splits into the bilateral subclavian arteries and a bicarotid trunk.” 


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “Another arch variant is the ductus diverticulum, a focal bulge along the inner aspect of the isthmus representing a remnant of the ductus arteriosus. Traumatic aortic transection also occurs in this location and can occasionally be difficult to differentiate from a ductus diverticulum. However, the ductus diverticulum has smooth margins with obtuse angles relative to the adjacent aorta. Aortic transection has irregular margins with acute angles relative to the adjacent aorta.” 


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “Acute aortic syndrome is a group of aortic pathol- ogies that are acute emergencies. Underlying aortic diseases include penetrating atherosclerotic ulcer, intramural hematoma, aortic dissection, rupturing aneurysms, and traumatic aortic injury. MDCT is the preferred examination because of its rapid acquisition and excellent depiction of the aorta, its wall, and the end organs. ECG-gated CT is preferred, if readily avail- able, especially if ascending aortic involvement is suspected.” 


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “Intramural hematoma (IMH) is hemorrhage local- ized to the aortic media in the absence of a visible intimal tear. IMH is considered equivalent to aortic dissection regarding prognostic and therapeutic implications because an IMH may progress to aortic dissection and rupture. IMH may develop secondary to spontaneous rupture of vasa vasorum of the medial aortic layer, penetrating aortic ulceration, or blunt trauma. Hypertension is the most common predisposing risk factor.” 


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “Several findings help differentiate IMH from a thrombosed false lumen of an aortic dissection: IMHs do not enhance; no intimal tear is seen; IMHs maintain a constant circumferential relationship with the aortic wall; the false lumen of a dissection has a longitudinal spiral geometry.Involvement of the ascending aorta, pericardial or pleural effusion, and an aortic diameter of greater than 5 cm may predict progression of an IMH to a true dissection.” 


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “Unenhanced CT is extremely valuable in identi- fying intramural hematomas. Typically, circumferential or crescent-shaped high-attenuation thickening of the aortic wall is present, representing hematoma within the medial wall of the aorta , which sometimes narrows the aortic lumen.” 


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
      “Penetrating aortic ulcer (PAU) represents an ulcer- ated atheroma disrupting the aortic intima. PAU occurs when an atheromatous plaque ruptures, disrupting the elastic lamina, with variable exten- sion into the media. Hypertension and advanced age are the most common risk factors. The descending aorta is most often affected CT commonly shows extensive aortic atherosclerosis. On CT, a discrete contrast-filled ‘collar button’ is often seen out-pouching beyond the expected confines of the aorta. PAUs are often multifocal, which is not surprising considering the diffuse nature of atherosclerosis.” 


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “PAU can be difficult to differentiate from simple ulcerated atherosclerotic plaque. The presence of contour deformity of the vessel is highly suggestive of PAU. Extension of the aortic ulcer into the medial layer can result in an IMH, localized aortic dissection, saccular pseudoaneurysm, or mediastinal hematoma. Invasive intervention (surgery or endovascular repair) should be considered in patients with pain, hemodynamic instability, or signs of aortic expansion. Asymptomatic patients can be followed closely with optimization of medical management. If treated medically, imaging follow-up for both IMH and PAU is recommended at the time of discharge from the hospital, at 1, 3, and 6 months, and then yearly.” 


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “The incidence of thoracic aortic aneurysms is currently 10.4 cases per 100,000 persons per year. Affected individuals are most often in their 60s, and men are affected 2 to 4 times more often than women. Hypertension is present in 60% of cases. Thoracic aortic aneurysms are less common than abdominal aortic aneurysms. Up to 25% of patients with thoracic aneurysm will also have an abdominal aortic aneurysm.”

      
Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “Size is the only established risk factor predicting aortic rupture. No significant risk for aortic rupture is associated with aneurysms smaller than 4.0 cm. The risk for aortic rupture increases incrementally with aneurysm size; aneurysms 4.0 to 5.9 cm have a 16% risk for rupture, and those greater than 6.0 cm have a 31% risk for rupture. The average growth rate of thoracic aortic aneurysms is 1.0 mm per year.49 Descending midaortic aneurysms have the fastest growth rate, and ascending aneurysms have the slowest despite larger initial diameter.49 In general, larger aneurysms grow faster. Aneurysms larger than 5.0 cm in diameter grow on average 7.9 mm per year versus 1.7 mm per year for smaller aneurysms.” 


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “Aortic root aneurysms may also occur in the setting of bicuspid aortic valves and familial thoracic aortic aneurysm syndrome (FTAAS). Most aneurysms of the tubular ascending aorta are idiopathic but may also occur with bicuspid aortic valve, FTAAS, giant cell arteritis, and syphilis. Nineteen percent of patients with thoracic aneurysms have a family history independent of Marfan or Ehlers-Danlos syndromes.55–58 Bicuspid aortic valve is known to be an independent predictor of ascending aortic aneurysm formation after surgical correction of coarctation.”

      
Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “Surgery is usually recommended for thoracic aortic aneurysms 5.5 cm or greater. Lower thresholds are used in patients with bicuspid aortic valve and genetic and syndromic conditions predisposing to aortic aneurysms. Surgery may be recommended for aneurysms of 5.0 cm or greater or a growth rate greater than 3 mm/y in Marfan syndrome, Turner syndrome, Loeys-Dietz, Ehlers-Danlos, and bicuspid aortic valve or 4.5 cm or greater in the these patients when addi- tional risk factors are present, including family history of aortic dissection, severe aortic regurgitation, or desire for pregnancy.”

      
Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “ Aortic coarctation is focal narrowing of the thoracic aorta, which can occur anywhere in the aorta, although it is most common at the isthmus. Aortic coarctation is a common malformation, affecting men 2 to 5 times more often than women. Aortic coarctation has 3 major subtypes: focal (aortic coarctation), diffuse (hypoplastic isthmus), and complete (aortic arch interruption). The narrowing in aortic coarctation is caused by a fibrous ridge, arising from abnormal hyperplasia of the tunica media. Hemodynamic compromise leads to the development of collaterals to bypass the narrowed aorta. The extent of collaterals depends on the severity of stenosis. Collaterals may compress the spinal cord or may rupture.”


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “Aortic coarctations are associated with multiple other abnormalities. Among patients with aortic coarctation, 30% to 40% will also have a bicuspid aortic valve. Patients with Turner syndrome have a higher prevalence of aortic coarctation. Other abnormalities associated with aortic coarctation include ventricular septal defect, patent ductus arteriosus, aortic stenosis, and mitral stenosis. Patients with aortic coarctation must also be evaluated for intracerebral berry aneurysms. Intracerebral aneurysms can rupture, leading to subarachnoid or intracerebral hemorrhage, even long after successful coarctation repair.”


      Computed Tomography Angiography of the Thoracic Aorta 
Scheske JA et al. 
Radiol Clin N Am 54 (2016) 13–33
    • “CTA of the lower extremities is an important and versatile noninvasive tool for diagnosis as well as surgical or endovascular interventional planning. Although lower extremity CTA is most commonly performed in patients who suffer from PAD or trauma affecting the lower extremities, it also plays a role in the workup of nonischemic etiologies and congenital vascular malformations. CT scanner protocols should adjust bolus timing and multi- phasic imaging to account for the clinical question of interest, and 3-dimensional postprocessing plays an important role in the visualization and interpretation of these high-resolution imaging examinations.”


      Computed Tomography Angiography of the Lower Extremities 
Cook TS
Radiol Clin N Am 54 (2016) 115–130
    • “Trauma to the lower extremities can occur from blunt or penetrating causes. Blunt trauma includes motor vehicle collisions, falls, athletic injuries, and occupational injuries, and is often associated with severe pelvic, femoral, and/or tibial fractures. Penetrating trauma may occur secondary to ballistics, shrapnel, or low-velocity sharp objects, and may or may not affect the bones of the extremity depending on the trajectory of the ballistic missile. Arterial injury in the setting of trauma may result in active extravasation, subcutaneous or intramuscular hematoma, pseudoaneurysm, vessel narrowing/stretching, occlusion, or arteriovenous fistula.”


      Computed Tomography Angiography of the Lower Extremities 
Cook TS
Radiol Clin N Am 54 (2016) 115–130
All images on this site are © 2016 Elliot K. Fishman, MD.