Benzodiazepine receptor deficiency and tinnitus.

As regards the symptom of a predominantly central tinnitus of the severe, disabling type, it has been hypothesized that a deficiency in the benzodiazepine receptor exists in the medial temporal lobe system of brain and is directly related to affect impairments including anxiety, stress, depression, and fear. This hypothesis has been investigated with single-photon emission computed tomography using the benzodiazepine radioligand 123I Iomazenil. Visual analysis revealed preliminary results of diminished benzodiazepine-binding sites in the medial temporal cortex of all patients with severe tinnitus (N = 6), a finding that is consistent with the hypothesis implicating GABAergic mechanisms in the pathophysiology of the disorder. An abnormal gamma-aminobutyric acid--A benzodiazepine receptor density may be an objective neurochemical measure of the severity of a central-type tinnitus and a rationale for treatment. Clinical correlation with the history, clinical course of the patient, and stress questionnaire are presented.

Tc-99m MAG3 evaluation of recipients with dual adult cadaveric renal allografts. Simultaneous transplantation of both kidneys from marginal donors.

PURPOSE: The application of Tc-99m mercaptoacetyl triglycine (MAG3) renal scintigraphy in patients who had simultaneous unilateral retroperitoneal transplant of both kidneys from marginal adult cadaveric donors is assessed. METHODS: Eighteen patients who had this unusual form of kidney transplant were monitored and evaluated by Tc-99m MAG3 renal scintigraphy. More than 60 of the radioisotopic studies, including immediate postoperative and subsequent follow-up examinations, were performed among these patients. RESULTS: In all the studies, the two transplanted kidneys were not equally well visualized by this scintigraphic procedure because of the inherent difference in their depth from the body surface, a feature of this particular surgical design. Despite this limitation, the efficacy of the scintigraphic procedure for such dual renal allografts appears to be similar to that established for kidney transplants performed in the conventional manner. CONCLUSION: To use the scintigraphic procedure effectively, certain sensible and logical adjustments are needed for the comparative visual and semiquantitative assessments of the two kidneys in this special form of transplantation.

Scintigraphic demonstration of postural induced drainage stasis in an en bloc renal allograft.

Within 6 months after an en bloc transplantation of two kidneys from a cadaveric pediatric donor, the recipient was referred for further scintigraphic evaluation because of clinical suspicion of having a postural related function impairment of the grafted kidneys. Tc-99m MAG3 imaging, modified by varying the position of the patient during the procedure, resulted in detection of drainage stasis only with the patient standing. This drainage stasis had not been appreciated in the preceding routine examinations performed with the patient supine. Although the positional outflow stasis by itself may not be severe enough to cause alarming dysfunction of the grafted kidneys, it could conceivably be a significant contributing factor.

Penile scintigraphy for priapism in sickle cell disease.

UNLABELLED: Penile scintigraphy with [99mTc]pertechnetate/99mTc-RBCs was performed in patients with sickle cell disease patients who had priapism to assess the role of this imaging procedure in directing the clinical management of these patients. METHODS: Fifteen studies were performed in 13 patients who were treated according to a protocol not dependent on the imaging results. The scintigraphic findings of penile vascular perfusion (stagnant or nonstagnant patterns) were collated retrospectively with the form of treatment needed for relief of the condition. RESULTS: Four of five patients with the nonstagnant perfusion pattern responded to analgesics and intravenous hydration. Four of eight patients with the stagnant pattern did not require any aggressive interventions such as corporeal aspiration/irrigation, intracorporeal epinephrine or glans-cavernosa shunt. CONCLUSION: Whereas the nonstagnant scintigraphic finding appeared to be a favorable indicator for conservative treatment, the stagnant finding was apparently noncontributory. In addition, no correlation was found between these two types of scintigraphic patterns and the subsequent sexual potency of these patients.

Testicular scintigraphic findings two to three months after torsion. Correlation with sonography and histopathology.

A patient with a nontender testicular mass had sonographic abnormalities compatible with but not entirely typical of a chronic torsion. His scintigraphic studies, done on the same day as ultrasonography and 1 month later, revealed only findings consistent with a very mild subsiding scrotal inflammatory process. On surgical exploration and pathologic examination, it was found that he had an organizing infarct of the testicle secondary to torsion. The clinical history, diagnostic studies, and microscopic slides of the surgical specimen were reviewed. It appeared that tissue granulation and lipogranulomatous changes in the epididymis, known histologic sequelae to the unusually prolonged testicular torsion of 2-3 months, produced scintigraphic findings different from those which have been described for a late or an atrophic torsion.

Hypertrophic osteoarthropathy associated with Pneumocystis carinii pneumonia in AIDS.

Hypertrophic osteoarthropathy (HOA) is a systemic disorder primarily affecting the bones, joints, and soft tissues and developing in association with another disease process. Acute pyogenic pulmonary processes (empyema, lung abscess) are occasionally accompanied by transient HOA, but reversible HOA has not previously been reported in the setting of PCP in AIDS.

Attempts at clarification of splenic visualization on reticuloendothelial images: Tc-99m DISIDA compared with heat- denatured Tc-99m RBC imaging.

Four patients with enlarged left hepatic lobes and questionable or difficult splenic visualization on Tc-99m sulphur colloid (SC) images were further examined with additional radionuclide procedures. All four patients had Tc-99m DISIDA imaging, and three of them also had heat-denatured Tc-99m RBC imaging. The hepatobiliary images appear very effective in confirming postsplenectomy expanded enlargement of the left lobe of the liver and in refuting the presence of spleen in such cases. However, distinct visualization of the spleen in these patients can be achieved only through selective spleen imaging with heat-damaged red cells.

Reversible pulmonary uptake and hypertrophic pulmonary osteoarthropathic distribution of technetium-99m methylene diphosphonate in a case of Pneumocystis carinii pneumonia.

Diffuse pulmonary deposition of [99mTc]methylene diphosphonate (MDP) as well as abnormalities characteristic of hypertrophic pulmonary osteoarthropathy have been observed in a patient with Pneumocystis carinii pneumonia (PCP). The findings of the bone scan together with those in the corresponding scintigraphy, and roentgenograms of the chest and skeletal structures are presented. Parallel reversal of [67Ga]citrate and [99mTc]MDP pulmonary uptake with specific treatment for and clinical resolution of PCP implies a causal relationship.

Paget's disease: a cause of photopenic skeletal defect in indium-111 WBC scintigraphy.

As an incidental finding in an [111In]WBC scan performed in search of an infectious focus, photon deficient areas were found in several skeletal locations, characterized by bone and gallium scintigraphy and confirmed radiographically as sites of active Paget's disease. The literature concerning cold bone defects in the [111In]WBC scintiscan is reviewed. Loss of marrow component in the bone appears to be the underlying mechanism for such an abnormality.

Gated blood pool scintigraphic monitoring of doxorubicin cardiomyopathy: comparison of camera and computerized probe results in 101 patients.

Serial gated blood pool scintigraphic monitoring of cardiac function with both a nonimaging scintillation probe and a conventional gamma camera-computer imaging system was performed in 101 patients receiving doxorubicin hydrochloride (Adriamycin) chemotherapy. Comparison of probe- and camera-derived ejection fractions (n = 287) correlated significantly (r = 0.70, p less than 0.005) as did the interstudy (n = 183) change in ejection fraction (r = 0.76, p greater than 0.005). Significant discordance in probe- and camera-derived ejection fraction change occurred in 3 (1.6%) of 183 interstudy intervals. Average intrastudy variability of absolute probe-derived ejection fraction was 2.9%. This variability was unrelated to the level of cardiac function. Thirteen patients (13%) developed clinical cardiotoxicity, including four at cumulative Adriamycin levels less than 450 mg/m2. Mean absolute camera ejection fraction decline for these patients was 21% from baseline evaluation, and mean absolute probe ejection fraction decline was 22%. The minimal absolute ejection fraction decline was 11% for patients with clinical congestive heart failure. Eight asymptomatic patients had therapy terminated before the development of clinical cardiotoxicity after a mean decline in absolute camera ejection fraction of 19 +/- 4% (SD) and in probe ejection fraction of 19 +/- 9% into abnormal ranges (a decline in magnitude equivalent to that in patients developing congestive failure). None of these five asymptomatic patients available for clinical follow-up at 6 months after termination of Adriamycin therapy subsequently developed signs of ventricular dysfunction. The majority of patients (83%) studied at 450 mg/m2 cumulative dose levels did not have a 15% or greater decline from baseline into the abnormal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Malignant external otitis: early scintigraphic detection.

Pseudomonas otitis externa in elderly diabetics may extend aggressively to adjacent bone, cranial nerves, meninges, and vessels, leading to a clinical diagnosis of "malignant" external otitis. Early diagnosis is necessary for successful treatment. This study compares the findings of initial radiographs, thin-section tomography of temporal bone, CT scans of head and neck, technetium-99m methylene diphosphonate (MDP) and gallium-67 citrate scintigraphy, and single-photon emission computed tomography (SPECT) for detection of temporal bone osteomyelitis in ten patients fulfilling the clinical diagnostic criteria of malignant external otitis. Skull radiographs were negative in all of the eight patients studied. Thin-section tomography was positive in one of the seven patients studied using this modality. CT scanning suggested osteomyelitis in three of nine patients. Both Tc-99m and Ga-67 citrate scintigraphy were positive in 10 of 10 patients. Three patients who were considered to be in clinical remission had positive Tc-99m scans and normal Ga-67 scans. These results suggest that technetium and gallium scintigraphy are more sensitive than radiographs and CT scans for early detection of malignant external otitis. Gallium scintigraphy appears to be more specific for follow-up evaluation of these patients.

Diagnosis of acute testicular torsion using radionuclide scanning.

We analyzed retrospectively 99mtechnetium scrotal scan findings in 37 patients with acute scrotal pain. Correlation between scan interpretation, and either surgical findings and/or final clinical diagnosis revealed an accuracy of 89 per cent. Only 1 false negative and 3 false positive results were recorded. Scan data revealed a positive predictive value of 75 per cent, negative predictive value of 96 per cent, sensitivity of 90 per cent and specificity of 89 per cent. An inter-institutional observer study also was conducted to assess reliability of the scan, resulting in an 88 per cent agreement. The testicular scan has been found to be an accurate and reliable method to distinguish between epididymo-orchitis and testicular torsion.

Improved renal screening on bone scans.

Intravenous injection of Tc-99m-labeled radionuclides permits angioscintigraphic and blood pool visualization of both supra- and infradiaphragmatic organs. By adding this procedure to routine bone scans an improvement in the diagnostic yield of incidentally observed renal abnormalities was achieved. Several illustrative cases involving hyper- and hypovascular lesions are presented. The authors recommended increased use of immediate postinjection blood pool studies in all routine brain and bone scans as a means of renal screening at negligible cost.