Oncologic imaging: kidney and ureter.

Malignant cancers of the kidney and ureter account for only 2-3% of all neoplasms in man. However, early diagnosis and treatment can have a profound effect on patient prognosis and survival. This article seeks to amalgamate a large body of information related to the pathology or primary renal tumors and metastatic disease with current imaging strategies to assist the clinician and enhance his understanding of the wide variety of modern imaging techniques available. Current tumor staging classifications are presented and the various imaging strategies are keyed to detection, definition and treatment options for tumors of the renal parenchyma and ureter. The strengths and limitations of all available imaging modalities are reviewed. An optimal approach to the imaging work up is developed with regard to availability, evolving technology and most importantly, cost efficacy. The controversies and conflicts in imaging and treatment options are explored while constructing a step by step approach that will be both flexible and utilitarian for the clinician faced with daily oncologic management choices.

Testicular tumors: oncologic imaging and diagnosis.

The extreme radiosensitivity of testicular seminomas plus recent advances in chemotherapy for nonseminomatous tumors and for advanced seminomas have made long term survival possible in the large majority of patients with testis cancer. Since choice of therapy is determined by tumor histology and extent of disease, accurate clinical staging is critical. Computed tomography (CT) of the abdomen and chest is the imaging procedure of choice for staging testis cancer. Clinical staging accuracy of 80 to 90% can be achieved using CT in combination with radioimmunoassays for beta-HCG and AFP. Ultrasonography (US), while less sensitive and specific than CT for determining nodal status, may be useful in thin patients with sparse retroperitoneal fat; in addition US may play an important role in detecting occult testicular neoplasms and in assessing primary tumor extent within the scrotum. Lymphangiography should be reserved for Stage I patients in whom elective treatment of the retroperitoneum is not planned. Follow-up should include serial radioimmunoassays for serum AFP and beta-HCG and periodic CT examinations of the abdomen and chest. Technical improvements in CT scanners and further experience with the use of tumor markers should help refine our ability to stage and manage patients with testicular tumors. In addition, nuclear magnetic resonance (NMR) imaging and radionuclide imaging following injection of radioactively labelled antibodies to AFP and beta-HCG are new techniques which offer great promise for the future.

CT appearance of intestinal ischemia and intramural hemorrhage.

CT scans have become an important diagnostic tool in the evaluation of abdominal disease. Patients with intestinal ischemia or intramural hemorrhage often are referred for radiologic evaluation because clinical and laboratory findings are not sufficiently specific for the physician to make a definitive diagnosis. The cross-sectional capability of CT scans permits direct visualization of mural, serosal, and mesenteric processes that usually can only be indirectly evaluated by conventional plain film or barium studies. Although the CT scan findings in intestinal ischemia and intramural hemorrhage often are relatively nonspecific, knowledge of these findings as well as an understanding of the pathophysiology and clinical features of these disorders will allow one to suggest a diagnosis, allowing further evaluation and treatment to proceed in a timely manner.

Radiologic staging of gastrointestinal neoplasms.

In this article, the ability of computed tomography as well as other imaging methods to detect local and distant metastases in patients with either newly diagnosed or suspected recurrent gastrointestinal tumors is discussed. The role of the radiologic examination in the diagnosis of complications resulting from different types of treatment is also addressed.

Dynamic contrast-enhanced MR imaging of the liver: parenchymal enhancement patterns.

A retrospective study of 164 patients undergoing dynamic contrast-enhanced magnetic resonance (MR) imaging was performed to assess hepatic parenchymal enhancement patterns and to correlate these patterns with hepatic function and disease. Rapid T1-weighted images were acquired before and after gadolinium administration. Hepatic enhancement patterns were analyzed blindly by two observers. Medical records were reviewed to document known liver pathology and liver function test results. A total of 72% of patients had homogeneous enhancement of the liver parenchyma; 28% had heterogeneous enhancement. Of the latter group, 61% of patients had enhancement conforming to segmental or lobar boundaries. Patients with heterogeneous enhancement patterns were more likely to have abnormal liver function test results and hepatic morphological abnormalities on their MR examinations than patients with homogeneous enhancement patterns. Heterogeneous hepatic enhancement on dynamic MR images is associated with a higher likelihood of liver disease and biochemical evidence of hepatic dysfunction than homogeneous enhancement.

Spiral computed tomographic colonography: determination of the central axis and digital unraveling of the colon.

RATIONALE AND OBJECTIVES: The authors developed and tested automated and semiautomated bowel-lumen tracking and colon-unraveling techniques for determining the central axis of the bowel. METHODS: A computer-simulated gastrointestinal tract phantom was used to test the accuracy of an automated algorithm for central axis determination and bowel unraveling. Variations in cross-sectional features between straight and unraveled formats were compared in a canine bowel segment in vitro and a human colon in vivo by using spiral computed tomography. Three readers each performed three semiautomated evaluations. RESULTS: Accuracy of the automated algorithm was confirmed by the high degree of correlation in the cross-sectional feature measurements (length error, < 1%). For the canine colon segment, accuracy of the semiautomated algorithm was confirmed by comparison with the automated tracing. For the human colon, readings were reproducible with 3.3% (+/- 1.9 standard deviation) mean variation in length. CONCLUSION: An automated algorithm for central axis deterioration and unraveling the colon has been validated in a gastrointestinal tract phantom. A semiautomated algorithm has been shown to be reproducible and time-efficient.

MR imaging of the peritoneum and abdominal wall.

Knowledge of the peritoneal cavity and the peritoneal folds that subdivide it is useful in evaluating for the presence and spread of disease processes that affect the peritoneum. Many disease processes of the peritoneum and abdominal wall are well evaluated with MR imaging, especially as MR techniques improve. In some cases, information is obtained that is not available with other imaging techniques.

Blunt renal and ureteral trauma in childhood: CT patterns of fluid collections.

The CT scans of 25 children with blunt renal and ureteral trauma were analyzed to determine the severity of injury, the appearance of retroperitoneal fluid collections, and whether the extent of these collections correlated with the severity of injury. CT showed renal parenchymal injuries in 23 patients and ureteral injuries in two patients. Retroperitoneal fluid was detected in 19 (76%) of 25 patients. Perirenal fluid collections were present in all 19, periureteral fluid in 12, interfascial fluid in eight, anterior pararenal fluid in four, and psoas hemorrhage in three. The presence of perirenal and periureteral fluid was not a good predictor of the extent of renal injury. Fluid collections in the interfascial or anterior pararenal spaces and psoas muscle appeared to correlate with the severity of injury. Patients with these fluid patterns usually had renal fractures, arterial injuries, or ureteral disruptions. The presence of perirenal and periureteral fluid did not correlate with the extent of renal injury, while the presence of interfascial, anterior pararenal, and psoas muscle fluid correlated somewhat with renal fractures and renal pedicle disruption.

Lymphoma in the wall of the bile ducts: radiologic imaging.

Extranodal lymphoma is not uncommon; however, lymphomatous involvement of the wall of the bile duct is rare, with only a few case reports available. Three cases were imaged with computed tomography (CT) and direct cholangiography at our institution. In one, Hodgkin disease recurred in the duct wall, producing a radiographic pattern indistinguishable from sclerosing cholangitis. In another, central sclerosis on cholangiography was associated with a separate liver mass identified by CT. This presentation of non-Hodgkin lymphoma mimicked cholangiocarcinoma. The third patient had multifocal, diffuse histiocytic lymphoma arising in the gallbladder and cystic duct, as well as in the kidneys and pancreas. Although the condition is unusual, the diagnosis of lymphoma in the bile duct wall should be considered, particularly when the cholangiographic picture of diffuse central sclerosis is associated with little or no observable mass on CT.

Fluoroscopically guided nasoenteric feeding tube placement: results of a 1-year study.

Nasoenteric tube feeding is a widely used alternative to parenteral intravenous nutritional support or gastrostomy tube placement. Unmonitored tube passage may result in complications and delays the beginning of tube feedings. The authors studied the results of 882 fluoroscopically guided feeding tube placements in 448 patients in 1 year to determine rates of success and complications, as well as the long-term outcome of this population of patients. Seven hundred sixty-four attempts (86.6%) were successful in positioning the tube distal to the third portion of the duodenum. Four major complications (three fatal arrhythmias and one tracheobronchial injury) were encountered. Only seven patients (2%) experienced aspiration events that were due to positioning of the tube in the distal duodenum. Seventy-seven percent of patients required either one or two tubes; the average "tube life" was 7.8 days. Most repositionings were required because of patient noncompliance or inappropriate administration of solid medications. Fluoroscopically guided nasoenteric tube passage is safe, easily performed, and highly successful, and has resulted in widespread clinical acceptance in our institution.

Portal vein calcification and associated biliary stricture in idiopathic portal hypertension (Banti's syndrome).

We present a case of dense portal vein calcification with secondary extrahepatic biliary stricture and cholangitis in an adult patient diagnosed with idiopathic portal hypertension at age three. Biliary ductal dilation proximal to echogenic shadowing foci near the porta hepatis mimicked choledocholithiasis on sonographic examination. Portal vein calcification and biliary stricture from portal venopathy each represent rare findings. The obstruction was successfully managed with biliary stenting.

Abdominal computed tomography in children with unexplained prolonged fever.

Twenty-eight children with unexplained fever lasting at least 1 week were referred for CT of the abdomen. Of the 28 patients, 22 had clinical and radiographic findings localizing disease to the abdomen prior to CT. In these 22 patients CT correctly detected an abnormality in 19 of 22 (86%) and favorably affected therapy in 13 of 22 (59%). In the six patients without localizing findings CT was abnormal in two and normal in four. Computed tomography was correct in all six patients and favorably affected management in two patients. Our results suggest that in children with fever and findings localizing disease to the abdomen--especially the retroperitoneum--CT is helpful in diagnosing a wide variety of lesions, as well as influencing therapy. If no localizing signs are present, CT has a relatively lower yield.

The hypertrophied anal papilla: recognition on air-contrast barium enema examinations.

Anal papillae are acquired structures that arise from the base of the rectal columns of Morgagni at the dentate line. They enlarge in response to congestion, irritation, injury, or infection. Although anal papillae are commonly seen endoscopically, they are rarely demonstrated radiographically. Three cases are reported of hypertrophied anal papillae that were demonstrated on air-contrast barium enema examinations. Radiographically an enlarged anal papilla appears as a smooth polyp located just inside the anal verge. Endoscopically it is differentiated from an adenomatous polyp by its white appearance and its origin from the lower (squamous) aspect of the dentate line in the anal canal. Hypertrophied anal papilla should be included in the differential diagnosis of a smooth mass located near the anal verge, especially in a patient with a history of chronic and irritation or infection.

Biliary carcinoma: CT evaluation of extrahepatic spread.

The authors studied the computed tomographic (CT) images obtained in 56 patients with pathologically proved biliary cancer and 75 patients with no evidence of biliary disease, attempting to define the normal anatomy of the lymphatic system draining the bile ducts and the prevalence of extrahepatic spread of primary biliary cancer into these retroperitoneal planes. Of 20 patients with gallbladder cancer, 14 (70%) had proved adenopathy and nine (45%) had peritoneal spread at presentation, and another three later developed carcinomatosis. Of 22 patients with proximal cholangiocarcinoma, 16 (73%) had nodal involvement at presentation, four later developed adenopathy, and five had peritoneal dissemination. Distal or diffuse cholangiocarcinomas were less associated with metastatic nodes or peritoneal spread. For all biliary cancers, the nodes most commonly involved were the node of the foramen of Winslow, the superior pancreatoduodenal node, and the posterior pancreatoduodenal chain. Extrahepatic tumor spread produced proximal intestinal obstruction in 13 patients (23%). CT reliably demonstrates lymphatic or other extrahepatic spread of biliary cancers, which may have an important bearing on management decisions.

Multimodal imaging in evaluation of two cases of adenocarcinoma of the renal pelvis.

Primary adenocarcinoma arising in the renal pelvis is a rare entity. Two cases are presented in which computed tomography (CT), ultrasound, and antegrade pyelography were performed in addition to conventional urographic methods. One patient's multifocal tumor involving several calyces was best demonstrated by ultrasound; the other patient's centrally placed pelvic mass was seen by CT. Adenocarcinomas are etiologically linked to repeated infection. Although it has been stated in previous reviews that the diagnosis of malignancy is seldom made preoperatively in these patients, the use of CT, ultrasound, and antegrade pyelography allowed the diagnosis to be made prospectively in both cases.

Cervical esophageal web associated with a patch of heterotopic gastric mucosa.

Cervical esophageal webs are a relatively common finding on esophograms. We report a web resulting from the squamocolumnar junction produced by heterotopic gastric mucosa. The clinical significance of this lesion is discussed and the importance of differentiating it from Barrett's esophagus is stressed.

Computed tomography of portal vein thrombosis: unusual appearances and pitfalls in diagnosis.

In a review of 25 cases examined by CT in whom the diagnosis of visceral vein thrombosis had been made, we encountered four cases in which problematic CT findings led to an error in diagnosis by the prospective interpreter. In one case, gas in collateral periportal veins mimicked an abscess; in one case, segmentally occluded portal veins resembled dilated bile ducts; and in one case, expansion of the inferior mesenteric vein was interpreted as a pancreatic pseudocyst. One additional case of multiple intrahepatic stones mimicked calcified portal vein thrombus. Although most cases are straightforward, there is a spectrum of findings in visceral vein thrombosis that may lead to confusion; alternative imaging techniques may be necessary in these situations.

Small bowel disease in children: diagnosis with CT.

The computed tomographic (CT) scans of 22 children with small bowel disease and those of 110 children with no small bowel disease were analyzed by two observers who were blinded with respect to clinical history and final diagnoses in order to determine which CT findings reliably indicated neoplastic, inflammatory, or noninflammatory processes. Bowel-wall thickening was the most reliable sign of disease. Five of six patients (83%) with bowel-wall thickness greater than 1 cm had neoplastic disease. Nine of ten patients (90%) with bowel-wall thickness between 3 mm and 1 cm had inflammatory disease, while four of six patients (66%) with wall thickness less than 1 cm and increased attenuation of mesenteric fat or an increase in the number of mesenteric vessels had noninflammatory edema. The presence of mesenteric masses was not a helpful sign for differentiating various disease processes. The results of this retrospective study suggest that the identification and classification of small bowel disease in children is possible from the objective analysis of CT findings.