A simple technique is described for generating ventilation/perfusion ratio and perfusion/ventilation ratio images from the posterior Tc-99m PYP aerosol inhalation and Tc-99m MAA perfusion images obtained during routine lung scintigraphy. These images highlight areas of ventilation/perfusion incongruence--mismatch or reverse mismatch--that may sometimes be difficult to detect on conventional images.

Aerosols↗

PubMed1991

Incidental detection of urinary tract abnormalities with skeletal scintigraphy.

Urinary tract abnormalities are detected as incidental findings in 15% of skeletal scintigraphic studies. Several scintigraphic patterns denote these abnormalities. Bilateral diffuse increased uptake is found in patients who have undergone chemotherapy and those with hyperparathyroidism, hypercalcemia, and sickle cell disease. Bilateral diffuse decreased uptake occurs in patients with end-stage renal disease, extensive metastatic disease to the bone, and various hematologic disorders. Focal increased activity is associated with postoperative changes and effects from radiation therapy. Focal decreased uptake is caused by space-occupying lesions such as abscesses, cysts, and neoplasms. Abnormal size, shape, and position associated with abnormalities of the kidney and bladder can also be seen. Although these scintigraphic patterns are seldom suggestive of a definitive diagnosis, they are highly specific for urinary tract disease.

Bone and Bones↗

PubMed1990

Scintigraphic measurement of oropharyngeal transit in man.

Scintigraphic studies of the oropharyngeal transit of a liquid bolus were performed in 15 healthy controls, 12 patients with symptoms of oral-pharyngeal dysphagia, and 13 patients with neuromuscular disease, who did not have dysphagia. Gamma camera imaging of the head, neck, and upper thorax was undertaken, in the lateral projection, during the swallowing of the radiolabeled bolus of water. Inspection of summed images permitted the selection of regions of interest (ROI) to represent the mouth, pharynx, and upper esophagus. Transit times between each ROI were calculated and compared. Significant prolongation of bolus transit time between the mouth and esophagus was present in both patients with and without dysphagia (0.59 +/- 0.38 sec and 0.33 +/- 0.7 sec; mean +/- SD, respectively) compared with controls (0.26 +/- 0.04 sec P less than 0.001, P less than 0.01, respectively, Mann-Whitney U test). Repeat studies in 25 individuals indicated that the transit measurements were more reproducible between swallows in normal subjects than in patients with symptoms. Deglutitive scintigraphy provides a noninvasive technique for the quantitative study of swallowing and its disorders.

Adult↗

PubMed1990

Nonosseous accumulation of bone-seeking radiopharmaceuticals.

Bone scintigrams are usually obtained for evaluation of skeletal abnormalities; soft-tissue abnormalities are often an unexpected finding. However, the recognition of specific conditions with extraskeletal accumulation of bone-seeking radiopharmaceuticals greatly enhances the diagnostic value of the study. Several examples of abnormal nonosseous uptake in both neoplastic and nonneoplastic processes involving the brain, lung, heart, breast, bowel, liver, spleen, skeletal muscle, kidney, and bladder are presented. Examples of artifactual uptake in the soft tissues are also described. Causes for nonosseous accumulation are discussed.

Bone and Bones↗