Letitia R. Clark

Perirenal cobwebs: the expanding CT differential diagnosis.

Although initially described as representing collateral venous structures, perirenal cobwebs may be due to a variety of benign and malignant conditions. Six representative cases illustrating the broad differential diagnosis are presente.

Dynamic CT vs 0.5 T MR imaging in the detection of surgically proven hepatic metastases.

Seventeen patients with 52 surgically proven hepatic metastases were studied preoperatively with dynamic CT and 0.5 T magnetic resonance (MR). Dynamic CT detected 38 metastases (73%), and the combination of short echo time (T1-weighted) and T2-weighted pulse sequences detected 46 lesions (88%). Magnetic resonance was also superior at assessing potential resectability. This study suggests that MR excels in detecting and anatomically localizing individual hepatic metastases.

Computed tomography of acute renal failure secondary to rhabdomyolysis

Two patients with rhabdomyolysis and renal failure were imaged with CT. The presence of a striate nephrogram, nephromegaly, and perinephric fluid has not previously been described on CT. Although nonspecific, these findings suggest the diagnosis of acute tubular blockade, and, once identified, administration of additional urographic contrast medium should be avoided.

A Complete Image Management and Communications Network for the Neuroradiology Service at Georgetown University Hospital

A complete image management and communications system has been installed at Georgetown University Hospital (GUH). The network is based on the A T & T CommView® System. In the Neuroradiology Division, this comprehensive network supports a multiscreen workstation with access to multiple imaging modalities such as CT and MRI from both the hospital and a remote imaging center. In addition, the radiologist can access these images from various workstations located throughout the hospital as well as from remote sites such as the home. Among the radiology services supported by the network, neuroradiology has the greatest need for such a system with extensive daily requirements involving the remote imaging center and on-line consultation around the clock. By providing neuroradiology with all available communication links, the radiologist can monitor, diagnose, and consult. The remote site has a subsystem capable of acquiring images and transmitting them over a high speed T1 data circuit. The GUH neuroradiologist can view these images on the neuro workstation or any of the workstations available in the Hospital. Fast and easy access to the images allows a radiologist to monitor multiple examinations as well as to utilize the workstation for diagnosis. To provide the neuroradiologist quick access to images at all times, a PC-based Results Viewing Station (RVS) has been placed in a doctors home. Images may be sent to the RVS, or the user may request images from the central database at the hospital. Images can be viewed at home either as they are transmitted, or following transfer of a whole study. The efficiency and effectiveness of the systems capabilities with special regard to remote and teleradiology (RVS) operations have been studied for the neuroradiology service. This paper will discuss the current clinical acceptance and use, problems in implementation, and ways these difficulties are being surmounted.

Imaging of the Liver, Biliary Tract, and Pancreas

The interaction between the various noninvasive and invasive imaging modalities used to evaluate the liver, biliary tract, and pancreas is demonstrated in this article. By understanding this interaction and correlating noninvasive studies, the clinician will avoid diagnostic redundancy and the need for invasive testing may be reduced.

Enhanced pancreatic CT imaging utilizing a geometric magnification technique.

Computed tomography (CT) using a geometric magnification technique was found to improve spatial resolution in phantom studies when compared with conventional third-generation geometry images. The clinical feasibility of using geometric magnification, small focal spot size, and dynamic contrast enhancement was studied in 143 patients referred to CT for clinically suspected pancreatic disease. This population included 46 patients with a normal pancreas and 36 patients subsequently proven to have primary pancreatic carcinoma. Using this new technique in conjunction with dynamic contrast enhancement resulted in high quality pancreatic images. Despite the limitations in tube current associated with a small focal spot size and low total heat capacity of the system, clinical imaging was not adversely affected. Use of the geometric magnification technique is recommended in departments where it is technically feasible.