Michael G. Velchik

The clinical utility of the Tc-99m SC intraperitoneal scan in CAPD patients.

The intraperitoneal instillation of dialysate increases intra-abdominal pressure and consequently predisposes to subcutaneous infiltration, leaks, and herniations through defects in the abdominal wall. In this setting, the incidence of abdominal hernias ranges between 9% and 24%. Life-threatening complications (incarceration/ strangulation) occur in up to 13.2% of hernias. Therefore, the authors evaluated the efficacy of the Tc-99m sulfur colloid (SC) intraperitoneal scan in the detection of abdominal leaks and hernias in 11 continuous ambulatory peritoneal dialysis (CAPD) patients over a 2- year period at the Hospital of the University of Pennsylvania. Eleven patients (7M, 4F) ranging in age from 24 to 72 (mean=50.8), on CAPD, were evaluated for clinically suspected abdominal hernias or dialysate leaks with intraperitoneally administered Tc-99m SC. After the injection of 3-5 mCi of Tc-99m into a standard 2 liter dialysate bag, multiple sequential anterior images of the abdomen were obtained in the supine position over the course of one hour. Delayed images were obtained after ambulation and post-drainage two or more hours postinjection in multiple projections and positions in order to demonstrate any abnormal focal accumulations of fluid to the best advantage. Any detected abnormalities were marked and correlated with the physical examination and the patients symptoms. Two patients had normal scans. Of the nine abnormal scans, five hernias were identified in four patients and six leaks were detected in the other five patients. One leak and two hernias were confirmed at surgery and repaired. The Tc-99m intraperitoneal scan is a simple noninvasive means of detecting abnormal abdominal fluid collections that have a propensity to develop in CAPD patients and therefore may be an important impact upon patient management.

Ventilation-perfusion scintigraphy in an adult with congenital unilateral hyperlucent lung.

A variety of congenital and acquired etiologies can give rise to the radiographic finding of a unilateral hyperlucent lung. An unusual case of congenital lobar emphysema diagnosed in a young adult following the initial discovery of a hyperexpanded, hyperlucent lung is reported. Although subsequent bronchoscopy and radiologic studies detailed extensive anatomic abnormalities, functional imaging also played an important role in arriving at this rare diagnosis. In particular, ventilation-perfusion scintigraphy identified the small contralateral lung as the functional lung and helped narrow the differential diagnosis to etiologies involving obstructive airway disorders.

Osteogenic sarcoma with pulmonary metastasis visualized by bone imaging.

Extraosseous soft tissue metastases from osteosarcoma occasionally accumulate Tc-99m MDP. The authors present a case of osteogenic sarcoma of the femur with a pulmonary metastasis detected by bone imaging with radiographic correlation including CT and magnetic resonance imaging. The implication of the detection of osseous and extraosseous metastasis in these patients by bone imaging is discussed. The changing role of bone imaging in the initial workup and follow-up of patients with osteogenic sarcoma is reviewed in light of the change in course and prognosis of the disease as a result of recent advances in adjuvant chemotherapy.

Rapid resolution of massive pulmonary embolism due to streptokinase therapy: documented by ventilation/perfusion imaging

A case of massive pulmonary embolism is presented, with dramatic complete resolution within 36 hours due to anticoagulant and lytic therapy, documented by perfusion scintigraphy.

Pleuroperitoneal communication in a patient with right pleural effusion and ascites diagnosed by technetium-99m sulfur colloid imaging

A 55-year-old man with an 11-year history of intermittent right pleural effusions had continued fevers and a large right transudative pleural effusion. Minimal ascites was noted by ultrasound examination. A communication between the thorax and intraperitoneal cavity was established by radionuclide examination of the chest and abdomen. Tc-99m sulfur colloid was injected into the peritoneal cavity, and imaging at 1 and 4.5 hours confirmed passage from the peritoneal to the pleural cavity. Repeated attempts to sclerose the pleural cavity failed to decrease the transudative accumulations. The patient was subsequently treated with the placement of a LeVeen shunt.

Gallium uptake in cutaneous sarcoidosis.

A case of biopsy-proven cutaneous sarcoidosis was detected by gallium imaging.

Osteomalacia. An imposter of osseous metastasis.

A case of osteomalacia with multiple asymmetrically distributed pseudofractures (Loosers zones) simulating metastases is presented. Radiographic correlation is essential to increase specificity and avoid misinterpretation.

Quantitative analysis of liver function in percutaneous transhepatic biliary drainage patients

The diagnostic usefulness of Tc-99m DISIDA cholescintigraphy as a predictor of eventual catheter and hepatic function in patients who have undergone percutaneous transhepatic biliary drainage (PTBD) for extrahepatic biliary obstruction was evaluated. Twentynine cholescintigrams were performed in 14 patients. The examinations were divided into two groups: Group A (N=17), in which the patients clinical status deteriorated within two to three days post-PTBD, and Group B (N=12), in which the patients did well clinically post- PTBD. No significant difference between the two groups was demonstrated by visual analysis of the analog images or by analysis of serum bilirubin levels. A computer program, developed by the authors, quantitates several parameters of DISIDA kinetics, reflecting hepatic function based upon compartmental analysis. A significant difference (P<.001) was demonstrated between the mean transport constants (blood clearance constant=k1; hepatic clearance constant=k2) for the two groups. It is concluded that serum bilirubin levels and visual inspection of analog images are inadequate independent predictors of hepatic function in patients post PTBD. The transport constants k1, and k2 are quantitative parameters of hepatic function that may be of prognostic value in patients post PTBD.

The ''liver scan'' appearance in cholescintigraphy. A sign of complete common bile duct obstruction

One hundred consecutive Tc-99m IDA hepatobiliary scans were reviewed revealing 14 scans (14%), that showed nonvisualization of the common bile duct (CBD), gallbladder (GB), and small bowel (SB), but good hepatic uptake of Tc-99m IDA derivative, a pattern designated by us as “the liver scan appearance.” In 11 of 14 cases (79%), the diagnosis of complete CBD obstruction was confirmed by surgery, percutaneous transhepatic cholangiogram (PTC), endoscopic retrograde cholangiopancreatography (ERCP), and/or percutaneous needle biopsy (PBx). Common bile duct obstruction was suspected but not proven in the other three cases. The cholescintigraphic, ultrasound, PTC, ERCP, intraoperative cholangiogram, clinical, laboratory, and surgical findings are presented and correlated. The “liver scan-appearance” by cholescintigraphy should suggest a diagnosis of complete common bile duct obstruction; however, it does not specifically differentiate between stone or tumor as the cause of obstruction.

Wilms' tumor: diagnostic therapeutic implications.

Twenty-four cases of Wilms’ tumor were analyzed. The gray-scale echographic characteristics of the tumors were categorized. Correlation with pathologic characteristics, clinical presentation, prognosis, and therapy response was assessed.Two echographic patterns emerged: (a) hypoechoic solid — 3; and (b) hyperechoic solid — 21. Necrotic degeneration as well as decrease in tumor size were echographic features correlated with positive response to therapy.The results of this analysis showed no initial correlation between the echographic patterns and the clinical presentation or prognosis. On the other hand, the echographic features of Wilms’ tumor seem distinctive enough to help in etiologic differentiation and therapy management.