Absolute 24 h quantification of 99Tcm-DMSA uptake in patients with severely reduced kidney function: a comparison with 51Cr-EDTA clearance.

The aim of this study was to determine whether absolute 24 h DMSA uptake measurements (%DMSA) correlate well with 51Cr-EDTA clearance measurements in patients with severely reduced kidney function (SRKF). Between 1990 and 1997, 55 of 482 patients who underwent EDTA clearance measurements also underwent %DMSA within 1 week. Of these, 31 were women and 24 were men (mean age 60 years; range 19-77 years). EDTA clearance was determined using the slope-intercept method. Absolute depth- and background-corrected %DMSA were determined 24 h following the injection of 185 MBq per 1.73 m2 freshly prepared 99Tcm-DMSA. All patients had EDTA clearance < or = 60 ml.min-1. Eighteen patients (group A: 9 men and 9 women, mean age 55.8 years, range 28-73 years) had EDTA clearance > 20 ml.min-1 (mean +/- S.D. = 30.9 +/- 13.8 ml.min-1), whereas 37 patients (group B: 22 women and 15 men, mean age 62.0 years, range 19-77 years) had EDTA clearance < 20 ml.min-1 (mean +/- S.D. = 10.2 +/- 6.6 ml.min-1). EDTA clearance correlated well with %DMSA for the patients as a whole and for group A (r = 0.87, P = 0.73; r = 0.79, P = 0.0001 respectively). The regression equation suggests that %DMSA is not a marker of early renal dysfunction. In group B, the r-value (r = 0.48, P = 0.004) suggests that %DMSA is reliable as a marker of severe renal dysfunction to the extent that it provides rough information. In conclusion, %DMSA may not be used as a marker of early renal impairment. Additionally, in patients with severely reduced kidney function (EDTA clearance < 20 ml.min-1), it only provides a rough estimate.

Laparoscopic adjustable silicone gastric banding leakage assessed by 99mTc-pertechnetate scintigraphy.

UNLABELLED: The purpose of this study was to assess the value of 99mTc-pertechnetate scanning in the diagnosis of gastric banding leaks. METHODS: Three patients with morbid obesity received laparoscopic adjustable silicone gastric banding (ASGB), but no significant weight reduction was obtained. To exclude band leakage as the cause, four scintigraphic procedures were performed, consisting of imaging the upper abdomen 30 min and 3 h after injection of 3 mL (111 MBq) pertechnetate solution into the ASGB reservoir. In one patient, the integrity of the ASGB device was first assessed radiologically after injection of a water-soluble contrast agent into the ASGB reservoir. RESULTS: In two normally functioning ASGB devices, radiotracer was observed within the device on both early and late images. In two patients with a surgically proven small leak in the reservoir or the connecting tube, late images showed little tracer in the reservoir and the connecting tube. However, intense tracer accumulation was observed in the stomach as a result of resorption of pertechnetate in the subcutaneous or peritoneal blood vessels and subsequent gastric uptake. In one of the latter patients, radiographic assessment of the ASGB device revealed no abnormalities. CONCLUSION: 99mTc-pertechnetate scanning is a valuable technique to diagnose small leaks in an ASGB device.