The hot skull sign on bone scans of obese patients resulting from disparate soft tissue attenuation.

We have frequently observed diffusely increased skull activity on bone scans of obese patients, who do not have evidence of metabolic or metastatic bone disease. Skull activity of 25 obese patients were compared to that of age and sex-matched nonobese 25 patients visually and quantitatively. The results clearly indicated that diffusely increased skull activity is significantly more common on bone scans of obese patients because of disparate attenuation of overlying soft tissues.

Incremental diagnostic value of preoperative 99mTc-MIBI SPECT in patients with a parathyroid adenoma.

Unlabelled: The purpose of this prospective study was to evaluate the diagnostic value of early parathyroid SPECT combined with quantitative analysis as compared with planar imaging in patients undergoing minimally invasive radioguided surgery.

Methods: A total of 52 consecutive patients with primary hyperparathyroidism underwent planar and SPECT parathyroid scintigraphy 2-5 d before surgery. Each patient had a single-tracer dual-phase technique using (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) and a double-tracer subtraction technique using a delayed (99m)Tc-pertechnetate scan.

Renal depth estimates to improve the accuracy of glomerular filtration rate.

Unlabelled: This study was performed to validate a computer implementation of the Gates' method for radionuclide glomerular filtration rate (RGFR) calculation. The accuracy of the original method was improved by replacing the Tonnesen formula that estimated renal depth with direct measurement from lateral views to calculate tissue attenuation correction.

Methods: Both the creatinine clearance test (CCT) and dynamic 99mTc-diethylenetriamine pentaacetic acid (DTPA) renal scintigraphy (DRS) were performed on 38 patients on the same day.