Abdominal Imaging

The duodenum is a unique segment of intestine, occupying both intra and extra-peritoneal locations. There is a wide spectrum of abnormalities of the duodenum that range from congenital anomalies to traumatic, inflammatory, and neoplastic entities. The duodenum may be overlooked on cross-sectional imaging due to its location and small size. Duodenal pathologies may, therefore, be missed or wrongly diagnosed. Knowledge about duodenal pathologies and optimal imaging techniques can increase diagnostic yield and permit optimal patient management. Conventionally, the duodenum was evaluated with upper GI studies on fluoroscopy; however, endoluminal evaluation is better performed with endoscopy. Additionally, a broad array of cross-sectional imaging modalities permits comprehensive assessment of the duodenum and surrounding viscera. While endoscopic sonography is increasingly used to locally stage duodenal malignancies, MDCT remains the primary modality widely used in the detection and characterization of duodenal abnormalities. MRI is used as a "problem solving" modality in select conditions. We present a comprehensive review of duodenal abnormalities with an emphasis on accurate diagnosis and management.

Due to its complementary information to standard morphological imaging, functional renal magnetic resonance imaging is a rapid growing field of radiology. This pictorial essay provides a comprehensive overview of state-of-the-art functional renal imaging techniques including renal magnetic resonance angiography, first pass renal perfusion, assessment of renal function, blood-oxygen level dependent imaging of the kidneys and diffusion-weighted imaging of the kidneys including diffusion-tensor imaging of the kidneys. Basic technical concepts for all sequences are laid out. As renal perfusion imaging becomes a clinical routine examination, particular attention is given to renal perfusion measurements and the potential postprocessing approaches. Advantages and drawbacks of the published methods are illustrated. Future applications of functional renal imaging are presented.

We present three cases of focal eosinophilic infiltration in the liver that mimicked hepatic malignancy on computed tomography during hepatic arteriography (CTHA) and computed tomography during arterial portography (CTAP). In all patients, focal eosinophilic liver infiltration appeared as a solitary nodule or as two nodules without hepatosplenomegaly and showed homogeneous hyperattenuation on CTHA and hypoattenuation on CTAP.

Renal cell carcinoma is the most common malignant renal tumor in the adults. Significant advances have been made in the management of localized and advanced renal cell carcinoma. Surgery is the standard of care and accurate pre-operative staging based on imaging is critical in guiding appropriate patient management. Besides staging, imaging plays a key role in the post-operative surveillance and evaluation of response to systemic therapies. Both CT and MR are useful in the staging and follow up of renal cell carcinoma, but CT is more commonly used due to its lower costs and wider availability. In this article, we discuss and illustrate the role of multi-detector CT in pre-operative staging, post-operative surveillance, and evaluation of response to systemic therapy in renal cell carcinoma.

To evaluate and describe the computed tomography features of pure acinar cell carcinoma (ACC) and its liver metastases. Thirty patients were evaluated. Two radiologists evaluated imaging findings for each tumor for size, location, internal density, enhancement, tumor calcifications, pancreatic, and common biliary ductal obstructions and metastases. 70 % were male. Fourteen tumors were located in the pancreatic head, 14 in the tail, one in the neck, and one in the uncinate process. Abdominal pain was the most common presenting symptom (93 %), 20 % had pancreatitis and 17 % had obstructive jaundice. The average tumor size was 7 cm, 97 % of tumors were solid, well circumscribed (73 %); isodense to normal pancreatic parenchyma (40 %) on the non-contrast study, hypodense on the arterial (47 %), and hypodense on the portal venous (37 %) phase. 30 % patients had pancreatic ductal dilation, 10 % had pancreatic ductal ingrowth, 6 % had calcifications, and 20 % had central necrosis, and 31 % (5/16) showed biliary ductal dilation. At presentation, 50 % had metastatic adenopathy and 40 % patients had liver metastases, which typically were well circumscribed, hypoattenuating to the hepatic parenchyma on all the phases of contrast enhancement and had a lobulated margin. ACCs of the pancreas often present as large, well circumscribed, solid masses commonly in males. Despite their large size, they may not cause CBD obstruction.

A heterogeneous group of uncommon neoplastic and non-neoplastic pancreatic pathologies exists that can mimic pancreatic adenocarcinoma. These “imitators” are unique and may demonstrate characteristic clinical and imaging features. Imaging characteristics of some of these diverse lesions are not well described in the literature, and erroneous diagnoses of these entities as pancreatic carcinoma may be responsible for unnecessary surgeries. Knowledge of these selected pancreatic pathologies is essential to facilitate optimal patient management.