The benefit of SPECT when added to planar scintigraphy in patients with bone metastases in the spine.

PURPOSE: This study compared the efficiency of SPECT with planar bone scans in differentiating malignant from benign lesions and in detecting metastases to the spine. METHODS: Planar scintigraphy and SPECT were performed in 37 patients with low back pain without known malignancy and in 38 patients with confirmed malignancy. The type, location, and intensity of tracer accumulation were compared on the planar and SPECT scans. The malignant or benign nature of lesions was proved by radiologic methods, histologic findings, 6 month follow-up, or all of these. RESULTS: More metastases were detected by SPECT (SPECT, 58 of 64; planar, 42 of 64; P < 0.01). In three of seven patients with known malignancy who had a normal result of planar scan, only SPECT detected metastases. Fifty-nine metastases were radiologically mainly osteolytic, one was osteoblastic and four were mixed. Most lesions showed increased radioactivity (40 of 42 on planar scans vs. 45 of 58 on SPECT) and 2 of 42 (5%) vs. 12 of 58 (21%) were cold with marginally increased uptake. One of 58 metastases was a cold lesion seen on SPECT only. Lesions were more often malignant than benign when seen on SPECT in a pedicle (n = 5; malignant = 3, benign = 2), in the body and pedicle (n = 22; malignant = 14, benign = 8), within the vertebral body (n = 5; malignant = 4, benign = 1) and in the whole vertebra (n = 6; malignant = 4, benign = 2). The lesion to background ratio was higher on SPECT than on planar scans (SPECT, 2.26; planar scans, 1.86; P < 0.05 in malignant lesions). CONCLUSIONS: SPECT of the spine improved the diagnostic accuracy of bone scans when added to a planar scan in patients with known malignancy and clinical suspicion of spinal metastases when the planar scan was borderline abnormal. It helps in differentiating between benign and malignant lesions of the spine.

Evaluation of brain perfusion with technetium-99m bicisate single-photon emission tomography in patients with depressive disorder before and after drug treatment.

Depression is one of the most common psychiatric illnesses. Its influence on brain perfusion has been demonstrated, but conflicting data exist on follow-up after drug treatment. The aim of our study was to evaluate the effects of antidepressant drugs on regional cerebral blood flow (rCBF) in patients with depression after 3 weeks and 6 months of drug therapy. Clinical criteria for depression without psychosis were met according to psychiatric evaluation. Severity of depression was evaluated with the Hamilton Depression Rating Scale (HAMD) before every scintigraphic study. rCBF was assessed using technetium-99m bicisate (Neurolite) brain single-photon emission tomography in nine patients with severe depression before the beginning of antidepressant drug therapy and 3 weeks and six months after initiation of therapy. Only patients with no change in antidepressant medication during the study were included. No antipsychotic drugs were used. Cerebellum was used as the reference region. rCBF was evaluated for eight regions in each study in three consecutive transversal slices. Follow-up studies were compared with the baseline study. The mean HAMD score was 25.5 points initially, 16 at the second examination and 8.8 after 6 months. Global CBF was decreased compared with the reference region in drug-free patients. Perfusion of left frontal and temporal regions was significantly lower (P < 0.005) in comparison with the contralateral side. After therapy, a moderate decrease in perfusion was seen in the right frontal region (P < 0.05). Perfusion decreased further after 6 months in the right frontal (P < 0.005) and temporal regions (P < 0.01). The highly significant asymmetry in perfusion between the left and right frontal and temporal lobes almost disappeared during treatment. Our findings implicate dysfunction of the frontal and temporal cortex in clinically depressed patients before specific drug treatment. Clinical improvement and decreases in HAMD score after 3 weeks and after 6 months reflect the treatment effect on mood-related rCBF changes.

Separation and technetium labeling of autologous polyclonal immunoglobulin G.

Autologous IgG were separated from rabbit sera and radiolabeled to perform scintigraphy. The IgG separation was accomplished with fast protein liquid chromatography. IgG were directly labeled with 99mTc using stannous tartrate as reducing agent, sterilized with membrane filter and injected into rabbits. The method can be adopted for use in humans. It is suitable for repeated use as there is no danger of allergic reaction in the recipient.

Tachycardia induced cardiomyopathy in dogs; relation between chronic supraventricular and chronic ventricular tachycardia.

Long-standing ventricular tachycardia (VT) and supraventricular tachycardia (SVT) can produce a reversible left ventricular dysfunction. The onset of cardiomyopathy and the severity of posttachycardic changes depend at least on three parameters of tachycardia, including its type (VT or SVT), rate and duration. Ten dogs (beagles) were paced at 180 beats/min for 3 weeks. Two pacing modalities, supraventricular and ventricular, were used in each dog. In half of them, the study was started by ventricular, and in the other half by supraventricular high-rate pacing. The alternate pacing modality was applied after complete recovery of left ventricular function. Ventricular function and morphology were evaluated by radionuclide ventriculography, echocardiography and Swan-Ganz catheterisation. Posttachycardic changes were studied in sinus rhythm after cessation of pacing. Left ventricular ejection fraction (LVEF) fell significantly after either type of tachycardia (SVT: 53 +/- 5%, VT: 48 +/- 7%, P < 0.05) compared with baseline values (69.5 +/- 2.3%). Significant increases (P < 0.05) in end-systolic (SVT: 2.1 +/- 0.3 cm, VT: 2.4 +/- 0.2 cm vs. 1.6 +/- 0.3 cm) and end-diastolic dimensions (SVT: 3.0 +/- 0.3 cm, VT: 3.3 +/- 0.4 cm vs. 2.7 +/- 0.3 cm) indicated ventricular dilation in paced animals. Left ventricular pulmonary capillary wedge pressure increased significantly after either type of tachycardia as compared with baseline values (SVT: 7.5 +/- 1.2 mmHg, VT: 8.4 +/- 1.1 mmHg vs. 1.9 +/- 1.5 mmHg, P < 0.05); the difference between tachycardias was not significant. The present study demonstrates that chronic SVT and VT result in left ventricular dysfunction in a relatively short time, even if the heart rate is not very high. Deterioration of left ventricular ejection fraction and dilation of the left ventricle are more marked in chronic VT than in chronic SVT.

Relevance of Tc-99m DMSA scintigraphy in renal transplant parenchymal imaging.

Tc-99m DMSA renal scintigraphy was performed in 40 renal grafts. Cyclosporin A and glucocorticoids were given to all patients as antirejection therapy, and 11 also were given azathioprine. The kidneys were transplanted 1 to 97 months before the investigation. Seventy percent of kidneys had diffusely altered distribution of Tc-99m DMSA, and 43% had focal clear-cut parenchymal defects. The frequency of parenchymal defects observed on the DMSA scans was higher in patients who suffered manifest acute rejection episodes (8/16 versus 9/24 patients, borderline significance, P < 0.06), but had no relation to the living or cadaveric donor transplant or its function. A combination of peritubular edema and interstitial fibrosis is considered the most probable explanation of diffuse changes. The high frequency of clear-cut parenchymal defects most likely results from symptomatic or asymptomatic rejection episodes complicated by renal transplant infarcts.

Indium-111-antimyosin uptake in acute and remote myocardial infarction: comparison with pathohistologic findings.

Indium-111-Fab antimyosin antibody accumulation was studied in an 81-yr-old patient who was treated twice for unstable angina on ECG, signs of apicoseptal infarction, anterolateral and inferior ischemia without clinical evidence of an acute coronary event. During the last hospitalization, 9 and 3 mo after the previous ones, additional ischemia in the inferoposterior wall was demonstrated. Antimyosin was administered to detect acute infarction but pump failure developed and the patient died. Autopsy confirmed all stages of infarction on the anterior and lateral walls, predominant fibrosis in the apicoseptal region and predominant acute necrosis in the inferior wall. Macroscopic and scintigraphic examinations of transverse slices gave concordant results. A mixture of infarctions and normal tissue was confirmed by histologic findings. Antimyosin antibody accumulation was seen in areas of acute necrosis or bordering areas of reduced uptake in myocardium with remote damage, probably caused by prolonged episodes of unstable angina without evident acute coronary event.

Detecting vesico-ureteral reflux in asymptomatic siblings of children with reflux by direct radionuclide cystography.

The incidence of vesicoureteral reflux (VUR) among asymptomatic siblings of children with VUR is much higher than the estimated incidence in the general population. It might be expected that identifying them and keeping them under close observation and/or either surgical or conservative treatment, might reduce the risk of renal scarring. Fifty-three asymptomatic children, all under 6 years of age and all siblings of children with proven VUR, were studied and direct radionuclide voiding cystography (DRVC). There were 31 (58%) boys, and 22 (42%) girls. Nine children (17%) were younger than 1 year, 13 (25%) were between 1 and 2 years of age, while 31 (58%) were older than 2 years. VUR was detected in 22 (42%) of the 53 siblings. The incidence of VUR varied considerably according to the age, and sex of the child, the highest being in boys younger than 1 year. Most of the severe reflux was seen in children under 2 years of age. Out of 11 patients with VUR, grade 2 and 3, there were 10 younger than 2 years, whereas, only 2 of the 11 siblings with VUR, grade 1 were younger than 2 years of age. The mean age of children with VUR grades 2 and 3 was 19 months, compared to the mean age of 50 months for those with VUR grade 1. DRVC, a highly sensitive method, exposes the patient to much less radiation than X-ray voiding cystography. We believe that the benefit of detecting VUR in asymptomatic siblings with DRVC outweights the invasiveness of the procedure. The predictive value of positive family history alone in identifying VUR in our study was 42%.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term follow-up after heterotopic splenic autotransplantation for traumatic splenic rupture.

The trapping function of the heterotopic splenic autotransplants (HSA) in 13 polytraumatized patients, aged 5-38 yr, was evaluated using heat damaged technetium-99m-labeled autologous red blood cells in early (1-7 mo) and late (3-4.5 yr) period after heterotopic autotransplantation to the omentum. The intensity of tracer accumulation was graded in comparison to the liver uptake. The splenic tissue surface was calculated on anterior projection each time. The shapes of the transplants were compared and new uptake foci suggesting spontaneous splenosis were looked for on both scans. The average surface of HSA was 28.2 (+/- 14.7) cm2 on early and 44.1 (+/- 14.3) cm2 on late examination (p less than 0.003) and the increase in intensity of tracer accumulation on both occasions was significant as well (p less than 0.0001). In three patients, some additional splenotic foci were found on follow-up scans. Howell-Jolly bodies in peripheral blood were detected in six of eight patients in early and remained detectable in lower number in three of eight patients on follow-up. No serious infection was noticed in our group of patients. Our work confirmed the excellent survival rates of HSA with improving trapping function and no important spread from original implantation site on long-term follow-up.