Usefulness of scintimammography as an adjunct to mammography and ultrasound in the diagnosis of breast diseases.

This study was undertaken to evaluate the diagnostic efficacy of 99mtechnetium methoxyisobutylisonitrile scintimammography (SM) and combined use of mammography and ultrasound in the detection of the breast lesions in the symptomatic breast. Histopathological findings were the gold standard. Eighty patients with symptomatic breasts underwent mammography and/or ultrasound breast followed by SM. In 25 patients there were 27 lesions that were malignant and 55 patients had 65 lesions that were benign. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of SM were found to be 92, 72, 58, 96 and 78%, respectively, as compared with the combined use of mammography and ultrasound, which showed these parameters to be 89, 94, 86, 95 and 92%, respectively. In this study, SM showed slightly better sensitivity than combined mammography and ultrasound, whereas the specificity was clearly shown as higher in the latter.

Role of iodine-131 MIBG scanning in the management of paediatric patients with neuroblastoma.

OBJECTIVES: To evaluate the role of iodine-131 metoiodobenzylguanidine (iodine-131 MIBG) scanning in the management of paediatric patients with neuroblastoma. SUBJECTS AND METHODS: Forty-three iodine-131 MIBG scans were performed on 26 children, 18 male and 8 female, ranging in age from 8 months to 11 years. Bone scan, computed tomography (CT) images and findings of bone marrow biopsy were compared with the iodine-131 MIBG scan findings. RESULTS: Of the 26 patients, 18 (69%) showed abnormal iodine-131 MIBG avidity and were proven to have a neural crest tumour on histology. The remaining 8 (31%) patients had normal iodine-131 MIBG scans, and histology showed a malignancy other than a neural crest tumour. Iodine-131 MIBG scans showed the primary site in 16 of 17 patients while CT showed 14 primary sites. In follow-up studies, the results were as follows: iodine-131 MIBG showed no evidence of disease in 4 compared with 3 on CT, persistent disease in 2 on iodine-131 MIBG and 4 on CT; recurrence in 1 on iodine-131 MIBG and 0 on CT; MIBG scans detected double the number of bony lesions compared with bone scans. The findings on iodine-131 MIBG scans and bone marrow biopsy were in agreement in 16/18 cases. Patients in whom iodine-131 MIBG scans showed disease resolution had better clinical outcomes. CONCLUSION: The findings indicate that iodine-131 MIBG scanning is useful for the diagnosis, staging, evaluation of response to therapy and detection of recurrences in patients with neuroblastoma. It exhibited a clear advantage over CT in detecting the primary site and soft issue metastases and was also superior to bone scanning in detecting skeletal metastases. It also reliably demonstrated bone marrow involvement.

Pretherapy Gallium-67 scanning in paediatric patients with Hodgkin's disease.

OBJECTIVE: To investigate the correlation between gallium-67 (67Ga) uptake and histological subtypes of Hodgkin's disease (HD) in paediatric patients. SUBJECTS AND METHODS: Fifty-eight patients (45 males and 13 females aged 9.2 +/- 4 years, range 1.5-17 years) with histologically diagnosed HD underwent pretherapy 67Ga scanning on days 2, 5, 12 or 14 days after intravenous administration of 25-50 MBq (0.7-1.4 mCi) of 67Ga citrate. The scans were evaluated both visually and quantitatively using the activity of 67Ga in the liver as a reference. Clinical outcome of 11 patients with high diffuse 67Ga skeletal uptake was compared with that of 17 patients showing normal distribution of 67Ga in the skeleton. RESULTS: Of the 58 patients, the 67Ga scans were positive in 47 patients with 117 lesions. Visual analysis did not differentiate between the histological variants of HD. However, quantitative analysis of lesion-to-liver ratios showed significantly higher values of 67Ga uptake in the mixed cellularity type than in the nodular sclerosis type (t = -3.7, p < 0.001). Patients with high skeletal uptake had a higher relapse rate (6/11) than those with normal skeletal uptake (3/17). CONCLUSION: The findings show that quantitative analysis of 67Ga uptake can differentiate between the two main subtypes of HD (mixed cellularity and nodular sclerosis). Further diffuse skeletal uptake of 67Ga indicates a higher relapse rate.

Changes in regional cerebral blood flow due to cognitive activation among patients with schizophrenia.

BACKGROUND: The regional cerebral blood flow (rCBF) response to the Wisconsin Card Sort Test (WCST) has been used to assess the functional integrity of the prefrontal cortex in patients with schizophrenia. AIMS: In this study, patients were divided into two groups according to whether they had made few or many perseverative errors on a modified version of the WCST. A control group consisted of normal volunteers. The groups were then compared with respect to rCBF response to WCST activation. METHOD: rCBF was measured during administration of a modified version of the WCST and during a card sorting control task, using single photon emission computerised tomography (SPECT). RESULTS: Performance of the modified WCST was associated with a widespread and substantial increase in rCBF, particularly in the frontal region. The poorly performing group of patients with schizophrenia showed only a modest increase in rCBF in the left anterior cingulate region. CONCLUSION: Subjects with schizophrenia are able to respond to specific neuropsychological challenge with activation of the frontal regions.

Effective and economical option for pain palliation in prostate cancer with skeletal metastases: 32P therapy revisited.

The role of phosphorus-32 (32P) was evaluated in patients experiencing pain due to skeletal metastases from prostate cancer and refractory to other modes of treatment. Twenty patients received 185 MBq (5 mCi)32P intravenously; 12 patients received a single dose each, five patients were injected twice and three patients three times at 3-month intervals. A blood count and clinical assessment for bone pain, tender sites, mobility and analgesic intake were performed before and 4, 8 and 12 weeks after the administration of 32P. A bone scan was performed before and 12 weeks after therapy. The results showed a significant decrease in pain at 4 weeks and a palliative response persisted for up to 12 weeks. Analgesic medication intake decreased significantly (F = 13.2213, P < 0.0001) and mobility improved after therapy. Quantitative analysis of the bone scans showed a statistically significant reduction in osteoblastic activity in metastatic lesions after therapy (t = -3.80, P < 0.001). Transient myelosuppression after 4 weeks, which was statistically significant for WBC and platelet counts only (F = 3.0226, P = 0.0358; F = 6.2514, P = 0.0009 respectively), returned within normal limits by 8 weeks. We conclude that 32P is an effective and safe therapy for pain palliation.

Improved assessment of inferior left ventricular wall motion using biplane equilibrium radionuclide ventriculography.

Equilibrium radionuclide ventriculography is often restricted to the left anterior oblique projection. The differential sensitivity of left anterior oblique amplitude and phase images for anterior and inferior infarction was evaluated using quantitative analysis, and the role of left posterior oblique images assessed. Twenty anterior infarcts, 20 inferior infarcts and 20 normal controls were studied. Left anterior oblique amplitude and phase abnormalities were seen in 100% (20) and 85% (17) of anterior infarcts but only 55% (11) and 50% (10) of inferior infarcts. Left posterior oblique amplitude and phase abnormalities were seen in 95% (19) of anterior infarcts and 75% (15) and 85% (17) of inferior infarcts. Left anterior oblique standard deviation of phase differed from normal only for anterior infarction (P < 0.01); both anterior and inferior (P < 0.05) infarction differed from normal in the left posterior oblique projection. Left anterior oblique images are therefore insensitive for inferior infarction. An accurate description of regional ventricular wall motion requires biplane radionuclide ventriculography.

Neural correlates of planning ability: frontal lobe activation during the Tower of London test.

Single-photon emission computerised tomography (SPECT) was used to investigate whether pre-frontal cerebral blood flow in normal adults is increased during planning activity. A subtraction technique was used in which regional cerebral blood flow (rCBF) was measured in subjects during a computerised version of the Tower of London task. Both rCBF and performance on this task were compared to a motor control condition requiring the same responses and using the same visual display. The level of rCBF was significantly increased in the left pre-frontal cortex during the Tower of London task. In addition, subjects who took more time planning their moves, and less moves to complete a problem had a significantly higher level of rCBF in the left pre-frontal cortex. Subsequent execution latencies for the task were correlated negatively with both left and right rCBF.

A pilot study of schizophrenia-like psychosis in epilepsy using single-photon emission computerised tomography.

In a pilot study, SPECT was used to explore differences in rCBF between a group of patients with schizophrenia-like psychoses of epilepsy (SLPE) and a matched group of epileptic controls. Five patients in each group were investigated and those with SLPE showed significant reductions in the index of rCBF in the left medial temporal region. These differences are being investigated further.

Cortical activation during a cognitive challenge in patients with chronic temporal lobe epilepsy-a dynamic SPECT study.

In a pilot group of six patients suffering from chronic temporal lobe epilepsy, single photon emission computerized tomography (SPECT) has been used to image the changes in relative cerebral blood flow between rest (static scan) and conditions of cognitive activation (activated scan). The cognitive challenge used during activation comprised a test of word memory, and the performance was expressed as a word memory score (WMS) for each individual. An activation index (AI) was calculated from the mean normalized density counts in specific regions of interest (ROIs), and values obtained were analysed for correlation with the WMS. The mean AI was increased significantly in the right lateral temporal cortex, the right and left inferior frontal regions, the left temporal pole, and the right medial temporal cortex. A positive correlation with the WMS was found in the medial temporal cortices, and this relationship was significant for the right medial temporal ROI.

A study of regional cerebral blood flow and cognitive performance in Alzheimer's disease.

Thirty five patients with dementia of the Alzheimer type (DAT) and 35 controls matched for age, sex and handedness were investigated using single photon emission computer tomography (SPECT) with 99m technetium HMPAO. Regional cerebral blood flow (rCBF) was assessed semi-quantitatively in 18 cortical and 4 subcortical areas by normalising mean information density in each region to cerebellar mean information density. Analysis revealed significantly reduced rCBF to temporal, parietal, frontal and left occipital cortex in the patients whilst blood flow to subcortical areas showed no differences between the 2 groups. In addition, significant left-sided cortical hypoperfusion was seen in the DAT group but not in controls. When patients were sub-divided on the basis of disease severity, those with mild disease showed temporal, parietal and left frontal changes with more severely affected patients also showing right frontal and left occipital involvement. rCBF patterns did not distinguish between presenile and senile onset cases once duration and severity of illness were controlled. Eight cortical areas were also rated visually for perfusion deficits on a simple 4 point scale. Perfusion deficits were detected in 34 of 35 patients but in only 4 of 35 controls. In the DAT group significant correlations were found between many of the neuropsychological tests used and rCBF. Memory correlated with left temporal activity, praxis, perception, object assembly and block design with right parietal activity and language with activity throughout the left hemisphere. Significant correlations were also seen between subcortical and cortical blood flow, possibly explaining the correlations observed between many of the neuropsychological tests and thalamic blood flow.

What does rCBF-SPECT offer in schizophrenia?

Schizophrenia is a major psychiatric problem common in the younger population. Structural imaging and findings on autopsy have not yet revealed a specific deficit in these patients. Uncertainty in clinical diagnosis based on a set of signs and symptoms is another drawback in the management of this patient population. Regional cerebral blood flow studies (rCBF) using single photon emission computed tomography (SPECT) offers the opportunity to study the underlying phenomenon and to detect the specific functional deficits in schizophrenia.

Ventricular size and regional cerebral blood flow in schizophrenia: an attempted replication.

We attempted to replicate the finding of Berman et al. (1987) that frontal cortical blood flow correlated inversely with ventricular size in schizophrenia. Computed tomography and high-resolution 99m-Tc-HMPAO single photon emission computed tomography were performed in 25 right-handed chronic schizophrenic men engaged in a word-fluency task. Weak, nonstatistically significant inverse correlations were found between the ventricle-brain ratio (VBR) and frontal cortical blood flow. The VBR was significantly inversely correlated with the ratio of left to right medial frontal blood flow.

Quantification of regional cerebral blood flow (rCBF) using 99Tcm-HMPAO and SPECT: choice of the reference region.

The effects of the choice of the reference region in determining the relative regional cerebral blood flow (rCBF) using 99Tcm-hexamethylpropylene amine oxime (HMPAO) single photon emission tomography (SPECT) have been studied in order to establish or exclude it as a cause of inconsistencies in these studies. Relative rCBF was estimated by normalizing the regional count densities to two reference regions, the cerebellum and the whole slice, in 35 patients with Alzheimer's disease (AD), 25 patients with chronic schizophrenia (SCH) and the same number of matched normal volunteers. The statistical significance of the differences in rCBF between patients and their matched normals varied in the two sets of rCBF data. Smaller differences were highly significant while some larger differences were of less significance with whole slice normalization. The results suggest that the choice of reference region is one of the causes resulting in discrepancies in the results from various centres. The need to use a standard reference region is indicated.

Morphologic (CT) and functional (rCBF-SPECT) correlates in Alzheimer's disease.

Thirty-five patients with a clinical diagnosis of probable Alzheimer's disease underwent computed tomography (CT) and regional cerebral blood flow (rCBF) studies using single photon emission computed tomography (SPECT). Two sets of images in each subject were scored for the extent of structure and function changes. Thirty-four of 35 patients had various degrees of atrophy on CT, 33 of whom also had perfusion deficits of varying severity. One patient with normal CT had perfusion deficits, and another patient with a normal perfusion pattern had changes on CT. Regional perfusion deficits on SPECT were seen with and without associated changes on CT. Correlations were studied between CT and SPECT scores using Spearman's rank correlation coefficients. While regional scores on CT and SPECT did not significantly correlate, the total and left hemisphere scores on two sets of images showed fair correlations (r = 0.425 and r = 0.535, respectively, P less than 0.01). The correlations between cognitive performance in patients as assessed on Mini-Mental State Examination (MMSE) and CAM-COG and perfusion scores were highly significant while CT scores showed lower correlations. These findings suggest that the relationship between structural and functional changes in Alzheimer's disease is not straightforward and that the extent of changes in function as assessed by regional cerebral blood flow studies is a reliable measure of deficits in cognitive function.

Patterns of regional cerebral blood flow in Alzheimer's disease.

Regional cerebral blood flow was assessed in 35 patients with Alzheimer's disease and the same number of matched normal volunteers. Images were scored for regional perfusion deficits. Mildly demented patients had parietal and temporal perfusion deficits, often unilateral. Moderate to severely demented patients had bilateral temporal and parietal perfusion deficits. All severely demented patients also had involvement of both occipital regions. Frontal lobe deficits were seen in 14 patients. Left cortical perfusion deficits were more severe than the right cortical perfusion deficits in general. Patients with early onset of the disease showed left frontal deficits, more often, however, the total perfusion deficit scores in early and late onset groups were not statistically significant. Also, the cognitive performance scores were not statistically significant in these two groups. These results suggest a stage-dependent reduction in regional cerebral blood flow in patients with Alzheimer's disease.

A controlled study of 99mTc-HMPAO single-photon emission imaging in chronic schizophrenia.

Regional cerebral blood flow (rCBF) during a word fluency task was compared in twenty-five male, right-handed, medicated schizophrenic patients and twenty-five age-matched male, right-handed healthy volunteers, using 99mtechnetium-HMPAO multidetector single-photon emission tomography. Increased rCBF in caudate and thalamus was found in patients, probably secondary to neuroleptic medication. Patients showed decreased rCBF in left frontal cortical regions and increased rCBF in left posterior cortical regions, compared to controls. Patterns of left-sided frontal rCBF dominance in controls were reversed in patients, as were normal patterns of right-sided parietal rCBF dominance. Negative symptom score correlated inversely with mesial frontal rCBF, particularly on the left.

In vivo characterisation of 3-iodo-6-methoxybenzamide 123I in humans.

3-Iodo-6-methoxybenzamide (123I-IBZM), a new Dopamine D2 receptor ligand, was used in conjunction with SME 810 brain tomography to study six subjects (one normal volunteer, four schizophrenics and one DAT patient). Initial Dynamic SPET was followed by multislice SPET. High-resolution images of the D2 receptor distribution in the basal ganglia were obtained. The specific binding in D2 receptors of the basal ganglia is highest from 2-4 h p.i. Patients on anti-psychotic drugs showed significantly lower specific binding. Dopamine D2 brain receptor availability in man may now be studied with SPET. Continuous data acquisition with single slice tomography is particularly important in the study of this type of radiotracers.