Cross-sectional imaging of congenital and acquired abnormalities of the portal venous system.

Knowing the normal anatomy, variations, congenital and acquired pathologies of the portal venous system are important, especially when planning liver surgery and percutaneous interventional procedures. The portal venous system pathologies can be congenital such as agenesis of portal vein (PV) or can be involved by other hepatic disorders such as cirrhosis and malignancies. In this article, we present normal anatomy, variations, and acquired pathologies involving the portal venous system as seen on computed tomography (CT) and magnetic resonance imaging (MRI)

The use of cryoablation in treating liver tumors.

Percutaneous image-guided tumor ablation techniques have been used as an alternative method for patients with unresectable liver tumors. Although all techniques avoid morbidity and mortality of major surgery and have advantage of preserving non-tumoral liver parenchyma, cryoablation currently is the only percutaneous ablation technique allowing intraprocedural monitoring because of visibility of its ablation effect with computed tomography and MRI. Cryoablation uses extremely low temperatures to induce local tissue necrosis to treat both primary and metastatic liver tumors. This article discusses the principles of liver tumor percutaneous cryoablation, including mechanisms of tissue injury, technique, equipment, image-guidance used, patient selection criteria, clinical outcome and complications as well as current trends and future goals

Cystic tumors of the pancreas: a radiological perspective.

The purpose of this article is to highlight the imaging features of cystic pancreatic tumors. Common cystic pancreatic tumors include serous microcystic adenomas, mucinous cystic tumors, intraductal papillary mucinous neoplasms and solid pseudopapillary tumors. These tumors have characteristic imaging features, especially on magnetic resonance imaging (MRI) and MR cholangiopancreaticography examinations. Imaging findings allow a reasonable differential diagnosis between benign and malignant cystic pancreatic tumors. Thus, accurate imaging characterization of these lesions may lead to accurate patient care and prevent unnecessary surgical interventions

Nonhemorrhagic Adrenal Infarction With Magnetic Resonance Imaging Features During Pregnancy.

BACKGROUND: Adrenal infarction is an infrequent cause of severe abdominal pain during pregnancy. The magnetic resonance imaging (MRI) features of adrenal infarction have not previously been thoroughly described. CASES: A 20-year-old woman, gravida 1 para 0, presented at 27 4/7 weeks of gestation with sudden-onset right upper quadrant and flank pain. A 29-year-old woman, gravida 2 para 1, presented at 17 5/7 weeks of gestation with sudden-onset right abdominal and flank pain and again at 35 5/7 weeks of gestation with sudden-onset severe left flank and upper quadrant pain. In both patients, unilateral adrenal infarction was diagnosed on contrast-enhanced computed tomography after initial nondiagnostic ultrasonography and MRI. Clinical presentation and MRI features of nonhemorrhagic adrenal infarction are described. CONCLUSION: Nonhemorrhagic adrenal infarction may be an underdiagnosed cause of acute abdominal pain during pregnancy and can be diagnosed with MRI

Contrast-enhanced CT and MR imaging of renal vessels.

In the evaluation of renal vessels, the accepted diagnostic gold standard digital subtraction angiography is now being challenged by state of the art CT and MR imaging. Currently in many centers, cross-sectional imaging modalities are being used as a first line diagnostic tool to evaluate arterial and venous system of the kidneys and conventional angiography has been reserved only for therapeutic intervention. CT and MR imaging display not only the lumen of the vessel as in conventional angiography, but also allow the visualization of the vessel wall, renal parenchyma, collecting system, and other adjacent soft tissue structures. Therefore, CT and MRI have each become a one-stop shop for a thorough evaluation of kidneys. In this pictorial essay, we reviewed normal anatomical variants and wide range of pathologies involving renal arteries and veins with illustrated contrast-enhanced CT and MR imaging samples

CT for intracardiac thrombi and tumors.

Although cardiac tumors are rare, they nevertheless represent an important subgroup, the diagnosis of which is challenging for the primary care physician. Symptoms are not characteristic and serious complications including stroke, myocardial infarction and even sudden death from arrhythmia may be the first signs of tumor. The most common primary cardiac neoplasm is the benign myxoma and the most frequent primary malignant lesion is sarcoma. Cardiac metastases from distant primary carcinomas are now frequently encountered. Echocardiography until the past decade was the only consistently reliable and available non-invasive diagnostic tool. New non-invasive CT and MRI exams are changing the diagnostic approach. Echocardiography and angiocardiography with or without coronary arteriography remain routine methods for evaluating cardiac neoplasms. However, CT provides additional diagnostic information and is regarded as essential for adequate staging and treatment planning, particularly when surgical resection is being considered. This chapter reviews the wide spectrum of intracardiac thrombi and tumors including their incidence and imaging characteristics with particular reference to the CT findings and differential diagnosis

MRI in local staging of rectal cancer: an update.

Preoperative imaging for staging of rectal cancer has become an important aspect of current approach to rectal cancer management, because it helps to select suitable patients for neoadjuvant chemoradiotherapy and determine the appropriate surgical technique. Imaging modalities such as endoscopic ultrasonography, computed tomography, and magnetic resonance imaging (MRI) play an important role in assessing the depth of tumor penetration, lymph node involvement, mesorectal fascia and anal sphincter invasion, and presence of distant metastatic diseases. Currently, there is no consensus on a preferred imaging technique for preoperative staging of rectal cancer. However, high-resolution phased-array MRI is recommended as a standard imaging modality for preoperative local staging of rectal cancer, with excellent soft tissue contrast, multiplanar capability, and absence of ionizing radiation. This review will mainly focus on the role of MRI in preoperative local staging of rectal cancer and discuss recent advancements in MRI technique such as diffusion-weighted imaging and dynamic contrast-enhanced MRI

Short pancreas: evaluation with multi-detector row CT.

PURPOSE: The purpose of this study was to analyze the length variations of the pancreas using computed tomography (CT) and establish a database for short pancreas. METHODS: We retrospectively reviewed CT examinations of 228 adults and rated pancreatic lengths qualitatively on a scale of 1-3 using transverse images. 1, normal pancreas length; 2, mildly short pancreas; and 3, markedly short pancreas. The length of the pancreas from head to tail was also measured using the curved line tool through the midline of the organ on curved planar reconstructed (CPR) images. The pancreatic neck-tail length and the abdominal radius were measured on transverse images, and the ratio of pancreatic neck-tail length to abdominal radius was calculated to avoid the effect of body mass differences. All data were analyzed statistically. RESULTS: The pancreas length was normal (group 1) in 180 (78.9%) patients, mildly short (group 2) in 38 (16.7%), and markedly short (group 3) in 10 (4.4%). The average pancreatic length on CPR evaluation was 207.5 ± 19.1 mm in group 1, 168.9 ± 8.5 mm in group 2, and 135.1 ± 10.7 mm in group 3. There were statistically significant differences between three groups. Although it was not statistically significant, percentage of diabetes mellitus was higher in group 3 (20%) than other two groups (13.2% in group 2, and 8.9% in group 1). CONCLUSIONS: CT examination of the pancreas is an effective imaging method to classify the pancreatic length and to detect short pancreas. We suggest that pancreatic length variations should be reported on routine abdominal CT examinations