Biliary stricture dilatation: multicenter review of clinical management in 73 patients

Eighty-nine biliary strictures in 73 patients who had undergone percutaneous balloon dilatation were reviewed to determine long-term patency rates and clinical management problems. The majority of dilatations were performed in patients with anastomotic strictures (n = 44), iatrogenic strictures (n = 28), and strictures associated with sclerosing cholangitis (n = 17). Patency rates after 36 months or more were 67%, 76%, and 42%, respectively. Complications, mostly minor, occurred in less than 7% of patients. Of patients with significant biliary obstruction, 15% had little or no intrahepatic biliary duct dilatation demonstrated by cross-sectional imaging and/or direct cholangiography. No definite conclusions could be drawn about the utility of long-term internal/external stenting.     

Superparamagnetic iron oxide: enhanced detection of focal splenic tumors with MR imaging

Superparamagnetic iron oxide (AMI-25), a reticuloendothelial cell-specific contrast agent for magnetic resonance (MR) imaging, was evaluated for its ability to permit detection of splenic metastases in 18 patients. Superparamagnetic iron oxide, at a dose of 30 mumol of iron per kilogram, decreased the signal intensity of spleen from 19.5 +/- 4.8 to 3.1 +/- 2.2 (spin-echo sequence, repetition time msec/echo time msec = 1,500/42; P less than .05), without changing the signal intensity of tumor. As a result, the tumor-spleen contrast-to-noise ratio increased from 0.2 (tumor isointense relative to spleen) to 18.0 (tumor hyperintense relative to spleen). As a consequence of increased contrast, splenic tumors were detected in four of 18 patients (45 individual lesions; P less than .05), whereas nonenhanced MR imaging permitted detection of splenic lesions in only two of 18 patients (four individual lesions). Maximum tumor-spleen contrast was achieved within 60 minutes after intravenous administration. These initial clinical results indicate that MR imaging with superparamagnetic iron oxide may offer improved accuracy in the diagnosis of splenic tumors.     

Rapid MR imaging with suspended respiration: clinical application in the liver

The authors demonstrate that it is possible to obtain highly T1-weighted images of the abdomen using a suspended respiration partial saturation (SRPS) method in a breath-holding interval. T2*-weighted images, which reflect tissue T2 as well as variations in the static magnetic field, can also be rapidly obtained. The authors studied five healthy subjects and 19 patients with a variety of liver abnormalities, including benign and malignant hepatic neoplasms, fatty liver infiltration, ascites, and hematoma. On T1-weighted multisection acquisitions, the entire liver can be screened for mass lesions in a single 20-second breath-holding interval. Phase-contrast SRPS images are sensitive to fatty infiltration of the liver. SRPS images are more sensitive to variations in magnetic susceptibility than spin-echo images are, which has been proved to be of value in the detection of hemorrhage. With continued pulse sequence development and clinical study, this method has the potential to become the method of choice for evaluation of the upper abdomen.     

Ferrite particles for bowel contrast in MR imaging: design issues and feasibility studies

Diverse materials with varying physical and magnetic properties have been evaluated as gastrointestinal contrast agents for magnetic resonance (MR) imaging. Uniform marking of the small bowel remains the greatest challenge. Ferrites are magnetically active iron oxide particles that are miscible with water and cause loss of signal on MR images. The decrease in MR signal intensity produced by ferrites occurs with a wide range of iron concentrations (0.1-10 mM) and with both T1- and T2-weighted pulse sequences. These effects of ferrites are explained by predominant T2 shortening with negligible T1 effects. The ferrite preparation used in this study was stable in vitro, with little iron solubilized by acid. Intragastric administration of ferrite (5 mg of iron per kg in 6 ml) routinely marked the small bowel of rats. The authors conclude that ferrites represent a promising new class of contrast agents for gastrointestinal MR imaging.     

Tetrahydrocannabinol vs. prochlorperazine. The effects of two antiemetics on patients undergoing radiotherapy

The authors tested the effectiveness of orally administered delta-9-tetrahydrocannabinol (THC) as compared to prochlorperazine for the alleviation of symptoms, such as vomiting and nausea, experienced by patients receiving radiotherapy. The test subjects rated the severity of their illness, as well as the extent of their subsequent moods, their level of concentration, their amount of physical activity, and their desire for social interaction. They chose the drug they preferred and recorded its side effects. The use of THC was slightly more beneficial than the use of prochlorperazine.     

Complicated pancreatic abscesses: problems in interventional management

Twenty-five patients with grade D or E pancreatitis underwent percutaneous drainage. These patients required multiple computed tomography (CT) examinations, multiple catheter insertions, multiple catheter manipulations, and long-term catheter drainage. Eight of the 25 patients were successfully treated with catheter drainage alone. Sixteen underwent surgical drainage, ten after attempts at percutaneous drainage and six prior to radiologic drainage. Of the ten patients who had initial percutaneous drainage, only four were clinically improved from the drainage procedure alone. Although the fluid component of the abscess was often adequately drained in all ten patients, surgery was required to remove pieces of necrotic debris. Six patients who underwent surgical debridement had residual abscesses in the post-operative period and were all successfully treated with percutaneous drainage. One patient died from unrelated causes. Successful interventional management of patients with pancreatic abscesses requires intensive radiologic intervention and monitoring and may be better served by a combination of radiologic and surgical means.