Biomedical subjects

M S Potsaid

Publications and source records attributed to M S Potsaid.

At least 37 records · Page 2Linked to original sources

PubMed1976

Initial assessment of a simple functional image of ventilation.

Several methods for quantitatively measuring regional ventilation using an inert gas such as Xe133 have been described. One such method provides a functional image of washout. A particularly simple functional image may be derived from the mean transit time for clearance. Regional ventilation may thus be represented as a single image in which the spatial distribution of washout from multiple small regions of the lung is displayed. In 100 patients for whom such a functional image of ventilation was obtained, the functional image was found to be generally more useful and easier to interpret than sequential images taken during the period of washout. Distributions of half-time (t1/2) for washout and the mean transit time (t) in the same population were similar in shape, but the t distribution peaked about 15 sec later than the t1/2 distribution. The mathematical simplicity of the functional image described here should permit its implementation on virtually any nuclear medicine computer system.

Adult↗

PubMed1976

Technetium-99m-human serum albumin: evaluation of a commercially produced kit.

Results are reported on the use of a commercial kit for the labeling of human serum albumin with 99mTc. One-hour blood levels obtained in 20 subjects undergoing gated cardiac imaging were found to be 46.0 +/- 10.5% (s.d.) of the administered dose. The highest labeling efficiencies (94.2 +/- 9.3%) were obtained when human serum albumin 25% (salt-poor) was used. Satisfactory nuclear cardiac ventriculographic images were obtained in patients receiving the radiopharmaceutical when the labeling efficiency was at least 85%. Occasional batches were milky in appearance, contained black particulate matter, were acidic, or contained a high percentage of unbound 99mTc activity. Although this kit makes 99mTc-human serum albumin accessible to most nuclear medicine facilities for general clinical use, an active quality control program is required prior to use in patients.

Evaluation Studies as Topic↗

PubMed1976

Accumulation of 99mTc-diphosphonate in four patients with hepatic neoplasm: case reports.

The accumulation of bone-seeking radiopharmaceuticals in extraosseous lesions has been reported in patients with myocardial infarctions, cerebral infarctions, and some soft-tissue tumors. While the precise mechanisms involved remain uncertain, the spectrum of abnormalities exhibiting such accumulation increases. In our laboratory, 99mTc-diphosphonate concentrated in four hepatic tumors (one cholangiocarcinoma and three metastases from colon carcinoma). This property of phosphate-related radiopharmaceuticals has not been reported previously. Awareness of the possibility of focal diphosphonate accumulation in the liver should help avoid confusion with right lower rib-cage metastasis or pleural effusion.

Adenocarcinoma↗

PubMed1975

Comparison of 125I fibrinogen count scanning with phlebography for detection of venous thrombi after elective hip surgery.

A comparison was made of 125I fibrinogen count scanning and phlebography in 142 limbs of 83 patients without known prior deep venous thrombosis who underwent total hip replacement. A localized accumulation of fibrinogen located away from the hip wound represented a fresh thrombus in 25 of 29 cases (86 per cent). However, of all the fresh thrombi demonstrated by phlebography, the fibrinogen scan detected only approximately 50 per cent. Major reasons for failure to detect thrombi were the presence of the wound and the small size of some thrombi. In defining whether or not fresh venous thrombosis was present in a given patient, the scan was accurate in three quarters of the cases. We conclude that fibrinogen scanning is a useful examination in patients after elective hip surgery, but less accurate than previously reported.

Fibrinogen↗

PubMed1975

Relative efficacy of radionuclide imaging and computed tomography of the brain.

Computed tomography (CT) with the EMI scanner has been demonstrated to possess a wide spectrum of capabilities in the diagnosis of suspected intracranial disease. This review of 418 dual CT and radionuclide (RN) brain images indicates that RN and CT are complementary in the diagnosis of cerebral infarction, but that CT has a greater capability in brain tumor detection. The classical RN static brain image does not detect cerebral atrophy, hydrocephalus or intraventricular hemorrhage; these conditions are clearly defined by CT.

Acute Disease↗

PubMed1975

Accuracy of 99mTC-diphosphonate bone scans and roentgenograms in the detection of prostate, breast and lung carcinoma metastases.

A technetium 99m diphosphonate scan is a sensitive detector of bony metastases of breast, prostate, and lung cancer. For these particular neoplasms, a negative bone scan in an asymptomatic patient is adequate evidence for absence of bony metastases and a correlative roentgenographic examination may not be necessary. Positive studies demonstrating multiple characteristic discrete areas of increased activity should be considered strong evidence for metastases. Single equivocal lesions require roentgenographic and occasionally biopsy correlation. If roentgenography fails to reveal the source of increased uptake, (e.g., degenerative disease) the scan lesion should remain suspicious for metastases.

Biopsy↗

PubMed1974