New technology has combined the endoscope with ultrasound in an effort to enhance the visualization of the gastrointestinal tract. With a modified standard endoscope that has an ultrasound transducer built into the tip, high frequency ultrasonic beams can be targeted in close proximity to existing lesions. This results in better quality resolution which enhances the evaluation of the targeted lesion. In addition, esophageal wall thickness can be evaluated and assessed as to its role in esophageal function.

Although IV injection of contrast material is widely used for detection and follow-up of hepatic metastases on CT, the optimal method of contrast enhancement has not yet been defined. A prospective study was performed in 50 consecutive patients with suspected hepatic metastases. Lesion size and detectability were compared on unenhanced CT scans, scans obtained during a bolus injection of contrast material (early bolus phase), and scans obtained during a rapid infusion after the loading bolus. A total of 60 hepatic lesions were evaluated in 26 patients, 19 with histologic confirmation of metastases and seven with strong supportive evidence. The bolus phase allowed detection of 15% more lesions than did examination during the rapid-infusion phase. Lesion size varied, depending on the timing and method of contrast administration; the largest measurements were obtained during bolus injection of contrast material. In addition, bolus administration of contrast material subjectively resulted in the best lesion detection. Because the three techniques of IV contrast enhancement may produce different size measurements, sequential examinations must be tailored appropriately. Scanning during the bolus phase is technically possible with current CT equipment and is recommended as the primary CT screening examination for hepatic metastases.

Esophageal dilatation by endoscopists is a commonly performed procedure. The introduction of tapered polyvinyl dilators by Savary has made the procedure even more popular. In the United States, esophageal dilatation with guide wires has been traditionally performed with fluoroscopy. By using a marked guide wire and by adhering to specific safety guidelines, the passage of the guide wire can be precise, even without fluoroscopy, and radiographic definition is not always required. This study describes the new guide wire and the technique.

We report a case in which a focally spared area of pancreatic tissue in a gland otherwise replaced by fat created a "pseudomass" mimicking neoplasm on sonography and CT. The "pseudomass" appearance was related to the anomalous ductal anatomy in pancreas divisum. The spared area of pancreas creating a "pseudomass" was drained by the dorsal duct and the remainder of the pancreas that had undergone relative fatty replacement was drained by the ventral duct.

The members of the Society of Body Computed Tomography were surveyed to determine the most frequently used method of administering contrast material in CT studies of the liver. The respondents represented CT departments performing liver examinations in 22 institutions. No department relied solely on noncontrast scans. In 12 (54%) of 22 institutions, only contrast-enhanced scans were performed. The preferred dose for enhancement was 150 ml of 60% contrast material. Eight (36%) of the 22 respondents obtained images during the administration of a bolus of contrast material, whereas nine (41%) obtained images during the administration of a sustained drip infusion given after a loading bolus. Follow-up in 1987 revealed that two departments had switched to obtaining images during the administration of a bolus. The availability of CT power injectors and refinements in the rapid-scanning capabilities of CT scanners have increased the popularity of obtaining images of the liver during the administration of a bolus of contrast material. Despite this, in many departments, contrast material is still administered via drip infusion in CT studies of the liver.

Twelve patients with known pancreas divisum underwent thin-section computed tomography (CT) to determine the capability of CT to depict this pancreatic anomaly. Focal pancreatic enlargement was present in five patients. Two distinct pancreatic moieties separated by a fat cleft were noted in three patients; a fourth patient had focal atrophy in the distribution of the dorsal pancreas. The two pancreatic moieties were identified at the same craniocaudal level in all four of these patients. The dorsal duct was depicted in all 12 patients, while the short ventral duct was seen in only five of the 12 patients. Failure of the ventral and dorsal pancreatic ducts to fuse was identified in all five patients in whom both ducts were seen. CT may not enable specific diagnosis of pancreas divisum in the majority of patients. If, however, distinct pancreatic moieties or unfused ductal systems are evident, the diagnosis may be confidently suggested.

Dynamic thin-section computed tomography (CT) was used to evaluate renal cell carcinoma in 80 patients. The lesion was correctly staged with CT in 90% of patients. With use of the dynamic technique, the ipsilateral renal vein was depicted in 99% of patients. Extension of the tumor to the renal vein or the inferior vena cava was correctly detected in 18 of 19 patients. Actual depiction of tumor thrombus was a far more accurate indicator of renal vein invasion than was the identification of isolated renal vein enlargement. Dynamic thin-section CT of the kidney should be considered the routine method for comparison studies with other newer cross-sectional techniques in the evaluation of renal cell carcinoma.

Small bowel obstruction due to Garren gastric bubble: radiographic diagnosisRK Zeman, SB Benjamin, MB Cunningham, RJ Nauta, DF Fleischer, JH Lewis, MJ Collen, EL Cattau, Jr and MH JaffeAudio Available | Share

The clinical and radiologic features of 27 patients with renal metastases arising from eight different types of nonlymphomatous primary malignancies are presented. Renal metastases were generally detected late in the course of the malignancy. In 23 patients there were no symptoms referable to the kidney. Urinalysis was normal in nine patients and showed microscopic hematuria in nine, gross hematuria in four, and proteinuria in four. Radiologically, metastases were usually multifocal; however, metastases arising from colon, lung, and breast carcinoma were sometimes large, solitary, and otherwise indistinguishable from primary renal cell carcinoma. Three of four melanoma metastases and three of seven lung metastases infiltrated the perinephric space. Computed tomography was the most sensitive modality, depicting renal metastases in all 24 cases in which it was employed, followed by ultrasound and intravenous urography. In patients with a history of malignancy, renal metastases outnumbered renal cell carcinomas by approximately 4:1. This study indicates that a new renal lesion in a patient with advanced, noncurable cancer is more likely metastatic than primary and that biopsy in this setting is unlikely to be of aid.

Fifty-one patients with advanced cancer of the esophagus underwent 191 endoscopic palliative procedures, including bouginage, laser therapy, bipolar electrocoagulation, and stent placement. In three patients free perforations developed; these were treated immediately and no sequelae developed. Perforations confined within the tumor mass were diagnosed with CT in two patients and did not require treatment. Methods of endoscopic palliation are discussed with reference to the radiologic studies and techniques. The radiologist must evaluate tumor topography and esophageal wall thickness with computed tomography and esophagography to aid in the choice of palliative therapy. Knowledge of each technique and its risks by the radiologist is essential for useful consultation with the endoscopist before, during, and after the procedure.

A Haitian man with acquired immunodeficiency syndrome (AIDS), fever, malaise, and diarrhea is described. A computed tomographic (CT) scan showed a retrogastric mass with an associated ulcer. An upper gastrointestinal tract study showed an ulcer with both benign and malignant features. Endoscopy revealed a malignant-appearing ulcer, but cultures and histologic examinations of surgical biopsy specimens indicated gastric tuberculosis. The relationship between tuberculosis and AIDS is discussed.

The clinical diagnosis of cervical aortic arch rests on the detection of a pulsatile mass in the supraclavicular fossa. Unfortunately, clinical differentiation of a cervical arch from an aneurysm of the great vessels can be difficult. Dynamic computed tomography (CT) can aid in this differentiation and avert the need for angiography.

We report 10 carcinomas in 8 patients with regional enteritis. Five of the cancers were in the ileum, 4 in the right colon, and 1 in the rectum. The visualized small bowel cancers appeared as benign strictures in small bowel involved by regional enteritis. Most were poorly differentiated. The colon cancers had a more typical radiographic appearance of malignancy. In some patients with small bowel cancer the malignancy was discovered only on histologic evaluation; the malignant nature of the lesion was not appreciated by radiography or gross examination at surgery.

An awareness of potential pitfalls in CT imaging of renal masses helps to reduce needless imaging procedures and surgery.

Although vast differences exist among the many pelvic malignancies, several unifying concepts emerge from this discussion. First, there is a different role for diagnostic imaging for each type of pelvic malignancy. The radiologist should be aware that although the radiographic findings may be similar, the clinical impact varies greatly with a particular tumor. Second, although clinical staging is notoriously inaccurate, nevertheless diagnostic imaging techniques only improve upon but do not replace it because of false-positive and false-negative results. Third, because of the high false-negative rates of most of the modalities in use, negative studies do not in fact rule out the presence of disease. A surgical procedure may still be needed. Finally, several new techniques, including MRI and transrectal or transurethral ultrasound, may improve the accuracy rates. These developments will probably further enliven the controversies surrounding the radiologic evaluation of pelvic malignancies.

The authors present their algorithmic approach to the detection, characterization, and staging of renal masses. Based on classification of urographic findings, the patient may be triaged to the appropriate cross-sectional or invasive imaging modality that will result in the most cost-effective management.

In this article, the pancreas is evaluated with regard to the controversies surrounding this organ from a clinical standpoint, and an approach to imaging modalities is examined. The roles of computed tomography, ultrasound, endoscopic retrograde cholangiopancreatography, and magnetic resonance imaging are put into proper perspective.

A case of common hepatic duct stricture secondary to hepatic artery chemotherapy infusion is described. CT and endoscopic retrograde cholangiopancreatography (ERCP) may be used in concert to differentiate this entity from other causes of jaundice--namely, hepatic replacement by tumor, porta hepatis adenopathy, and chemotherapy hepatotoxicity.