Clinical evaluation of thallium-201 single photon emission computed tomography in equivocal neuroradiological supratentorial lesions

BACKGROUND: We performed cerebral 201Tl SPECT study on 38 presurgical patients with equivocal neuroradiological supratentorial lesions to detect differences in 201Tl uptake index between tumor/non-tumor and high-grade/low-grade samples. METHODS: Authors identified 38 cases with presurgical equivocal neuroradiological supratentorial mass lesions. All cases were submitted to histological confirmation of the lesion by biopsy, sub-total or gross-total removal of the tumor. Between 23 patients suffering from gliomas, 13 were histologically classified as being of low-grade malignant tumors and 10 were classified as being of high-grade malignancy. Fifteen non-tumor histopathological specimens were also detected. The 201Tl index was defined as the ratio of average counts per pixel in the lesion to these in the opposite region. Analysis of variance (ANOVA) and unpaired Student's OtO-test statistical methods were applied. Actuarial survival time from the date of diagnosis was calculated using the Kaplan-Meier method. Follow-up evaluation and survival time were obtained through referring physicians. Cerebral CT or MR images were obtained every three months after discharged, or more often if indicated. RESULTS: Results showed that the 201Tl uptake index ranged from 1.10 to 3.00 in the tumors lesions (mean+/-SD: 1.68+/-0.51) and from 0.80 to 1.40 in the non-tumors lesions (mean+/-SD: 1.07+/-0.17), (alpha < 0.0006 percent;). The 201Tl uptake index ranged from 1.10 to 2.30 in 13 patients with low-grade tumors (mean+/-SD: 1.45+/-0.34) and from 1.30 to 3.00 in 10 patients with high-grade tumors (mean+/-SD: 1.98+/-0.55), (alpha < 0.5 percent;). CONCLUSIONS: Our results demonstrate the clinical utility of 201Tl brain SPECT to differentiate equivocal neuroradiological supratentorial lesions and to correlate relationship between preoperative diagnosis, histological tumor grade and prognosis.     

Usefulness of thallium-201 chloride single photon emission computed tomography for the preoperative diagnosis of fourth ventricle meningioma--case report

A 51-year-old woman presented with a fourth ventricle meningioma manifesting as a 2-week history of dizziness and vomiting. Computed tomography (CT) and magnetic resonance (MR) imaging revealed a round mass lesion in the fourth ventricle. Thallium-201 chloride single photon emission computed tomography (201TlCl SPECT) showed high and rapid uptake on the early image and rapid washout on the delayed image. The preoperative diagnosis of meningioma could be established based on these findings. Total removal of the tumor was successfully performed. 201TlCl SPECT is useful for the preoperative diagnosis of fourth ventricle meningioma combined with CT, MR imaging, and angiography.     

Cortical dysplasia and epilepsy: functional imaging using single photon emission computed tomography and positron emission tomography.

Functional imaging using single photon emission CT and positron emission tomography have made important contributions to the evaluation of patients with medically intractable epilepsy and cortical dysplasia by identifying patients who previously were not considered surgical candidates. This article reviews the role of functional imaging in the presurgical evaluation of this patient population.     

Identification of clinically significant skeletal muscle necrosis by single photon emission computed tomography

Ischemia-reperfusion damage to skeletal muscle may cause serious local as well as systemic complications, its impact predominantly related to the quantity of ischemic muscle in the lower extremity. To date, there has been no noninvasive method of estimating that quantity. The authors used single photon emission computed tomography (SPECT) to quantify the volume of muscle that takes up technetium-99 pyrophosphate above a baseline threshold. Compared with the standard technique of staining slices of the muscle with nitroblue tetrazolium they found a close correlation using SPECT (r = 0.88, p less than 0.01, n = 19) in the canine model. In humans, this clinically applicable noninvasive technique may allow the surgeon to document accurately the extent of muscle necrosis in the lower extremity, to anticipate the impact of an ischemia-reperfusion injury and evaluate methods of reducing the extent of post-ischemic skeletal muscle necrosis.     

Sestamibi/iodine subtraction single photon emission computed tomography in reoperative secondary hyperparathyroidism

BACKGROUND: Sestamibi/iodine subtraction single photon emission computed tomography (SPECT) has been used successfully for the preoperative localization of adenomatous and hyperplastic parathyroid tissue in primary hyperparathyroidism, but the clinical usefulness of this technique in secondary hyperparathyroidism remains uncertain. The purpose of this study was to evaluate parathyroid localization that uses sestamibi/iodine subtraction SPECT in patients with secondary hyperparathyroidism before reoperative parathyroid surgery. METHODS: Fourteen consecutive patients with chronic renal failure and secondary hyperparathyroidism who had previously undergone total parathyroidectomy combined with parathyroid autotransplantation in a sternocleidomastoid muscle were studied. Before reoperation, each patient received 400 microCi of sodium iodide I 123 orally and 20 to 25 mCi of technetium Tc 99m ((99m)Tc)-sestamibi intravenously, followed by sestamibi/iodine subtraction SPECT of the neck and chest. At surgery, the location, weight, and histopathologic results of all identified parathyroid tissue were recorded. RESULTS: At surgery, 1 hyperplastic parathyroid gland was resected from each of 13 patients; including 1 undescended gland, 6 parathyroid autotransplants, and 5 mediastinal glands. The mean weight of the resected parathyroid glands was 1707 mg (range, 85-5300 mg). Sestamibi/iodine subtraction SPECT correctly identified and localized all 13 parathyroid glands (100% sensitivity) and was negative in the 1 patient whose surgery was unsuccessful. CONCLUSIONS: The (99m)Tc-sestamibi/(123)I subtraction SPECT is able to correctly localize hyperplastic parathyroid tissue in patients with secondary hyperparathyroidism who have previously undergone parathyroid surgery and is a clinically useful study before reoperation.     

The value of combining single photon emission computerised tomography and computerised tomography in the investigation of spondylolysis

The aim of this study was to assess the diagnostic value of combining single photon emission computerised tomography (SPECT) with reverse gantry computerised tomography (rg-CT) in the investigation of spondylolysis. Patient characteristics and imaging results in 118 patients, aged 8–44 years, with low back pain (LBP) were analysed. SPECT showed increased scintigraphic uptake in 80 patients, and spondylolysis was identified on rg-CT in 53. The Cohen Kappa ratio of 0.362 (95% CI: 0.198–0.526) suggests only fair agreement for the result of increased scintigraphic activity with the finding of spondylolysis on rg-CT. We conclude that these investigations give mutually exclusive information, which leads to four diagnostic categories. When there was increased scintigraphic activity on SPECT, 58.8% (95% CI: 48.0–69.5%) of patients had spondylolysis on rg-CT. With rest from provoking activities, these lesions may heal. We interpret the findings of increased scintigraphic activity, but no spondylolysis demonstrated on rg-CT as indicating a bone stress response. These also require rest from provoking activity to prevent a stress fracture developing. In this study, 84.2% (95% CI: 72.67–95.8%) of those patients without increased activity on SPECT had no spondylolysis identified on rg-CT. These patients may need further investigations such as magnetic resonance imaging (MRI) to diagnose pathology, which typically does not involve the posterior elements—but rest from sport may not be so important. There were five patients in our study, without increased scintigraphic activity, but in whom bilateral chronic-appearing (wide separation, smooth sclerotic bone margins) spondylolyses were identified at L5. These all were anticipated from previous plain radiographs or MRI. This group will almost certainly not heal, and if the spondylolyses are the cause of pain these vertebrae will need stabilisation by surgery if physiotherapy fails.     

The investigation of dementia syndromes by133Xenon dynamic single photon emission computed tomography

The patterns of regional cerebral blood flow (rCBF) in patients with dementia caused by Alzheimer's disease is compared with that of patients with dementia caused by multiple cerebral infarctions. A total of 47 patients were examined with¹³³Xenon SPECT. The results show that the global CBF correlates with the severity of dementia caused by Alzheimer's disease and that the two forms of dementia show two different patterns of disturbances.     

Validation of ictal single photon emission computed tomography with depth encephalography and epilepsy surgery

Many centers have reported that ictal single photon emission computed tomography (SPECT) localizes regions of seizure onset with greater sensitivity and specificity than interictal SPECT. Here we report interictal and ictal SPECT scan results in both lesional and nonlesional cases. Using technetium hexamethyl propylamenamine oxide (HMPAO) or ethyl cysteinate dimer (ECD), these scans were done in 52 patients with partial and secondarily generalized seizures. Twenty-five had normal MRI and 27 showed structural lesions. None had mesial temporal sclerosis clearly identified on MRI. All 52 subsequently had interictal and ictal intracranial EEG studies that appeared to localize the seizure focus. Thirty-nine patients had surgery and have been followed for 2 or more years. Interictal SPECT scans showed focal hypoperfusion consistent with intracranial EEG localization of the seizure focus in 29% of patients. In another 13%, there was correct lateralization but not localization. Ictal SPECT scans showed focal hyperperfusion consistent with intracranial EEG localization of the seizure focus in 52% of patients. In another 25%, there was correct lateralization but not localization. The presence or absence of structural lesions on MRI did not affect ictal hyperperfusion or its correlation with intracranial EEG. Thirty-nine patients had resective surgery, of whom 62% had class I outcomes. There was a trend towards better outcome when ictal SPECT data were concordant with intracranial EEG data. The presence or absence of structural lesions on MRI did not affect the likelihood of class I outcome. Ictal SPECT is superior to interictal SPECT in localizing and lateralizing seizure foci. Its results correlate well with intracranial EEG, but in more than one third of cases, the latter shows focal seizure onset in areas that do not show focal hyperperfusion. Surgical outcome tends to be better when the two modalities give concordant results.     

Pituitary abscess showing high uptake of thallium-201 on single photon emission computed tomography--case report

A 32-year-old female presented with a rare case of pituitary abscess manifesting as homonymous hemianopsia. Serum prolactin level was slightly high (40.8 ng/ml). Magnetic resonance (MR) imaging showed the content of the lesion as homogeneously isointense on the T1-weighted images and hyperintense on the T2-weighted images. The capsule of the lesion, which appeared thin and smooth, was enhanced by gadolinium. Dural enhancement around the sella turcica was also recognized. Thallium-201 single photon emission computed tomography (201Tl SPECT) showed homogeneous high accumulation in the pituitary region on both the early and delayed images. The lesion was treated via a transnasaltranssphenoidal approach. The cystic lesion contained pus and the capsule consisted of normal pituitary gland with inflammatory changes. The patient was treated with antibiotics for 3 weeks and the pituitary abscess was cured completely. Pituitary abscess can be differentiated from pituitary adenoma as lesion with a homogeneous high uptake on 201Tl SPECT on both the early and delayed images, and no enhancement of the central portion on MR images.     

Experience with single photon emission computerized tomography (SPECT) in follow-up of sternotomy healing

Single photon emission computerized tomography (SPECT) was performed thrice in ten patients undergoing open-heart surgery--preoperatively and 2 and 12 weeks postoperatively. The operations were done for ischemic heart disease (5), aortic valvular stenosis (2), aortic valvular insufficiency (1), leaking mitral prosthetic valve (1) and combined aortic and mitral valvular stenosis and insufficiency (1). The healing process in the longitudinally divided sternum was evaluated from the SPECT study. Four conventional static images in two dimensions were registered in anteroposterior, posteroanterior and left and right lateral projections. A tomographic study was done. Quantitative analyses were performed. The ratio of the sternal counts to the counts from a thoracic vertebra was calculated for use as a reference. The activity ratios showed a similar pattern in six cases, with initial increases and at 12 weeks slight decrease compared with the preoperative values. In two cases the activity was still increasing after 12 postoperative weeks. One patient, with sternotomy also one year previously, showed only slightly increased activity. The activity at the areas of the sternal wires was increased in six cases. The study thus revealed differing patterns of isotope uptake, although recovery was uneventful in all patients. The differences may reflect the possibility that the operative course and the preoperative clinical status can influence the healing mechanisms.     

Evaluation of cerebral vasospasm in patients with subarachnoid hemorrhage using single photon emission computed tomography

Cerebral vasospasm (CVS) occurs as a result of the breakdown in cerebral autoregulation mechanisms. Because cerebral vasospasm can occur after subrachnoid hemorrhage (SAH), it is important to evaluate borderline perfusion. Evaluation of borderline vascular insufficiency is important to reduce ischemic complications. In this study 25 patients with SAH were investigated by somatosensory evoked potentials (SEP), computed tomography (CT), digital subtraction angiography (DSA) and single photon emission computed tomography (SPECT) in order to predict borderline ischemic areas. Clinical grades were also correlated with these investigations. Thirteen patients had symptomatic vasospasm and 15 patients had angiographic vasospasm. SPECT showed hypoperfusion in 22 out of 25 patients. CT predicted CVS in 8 of these 22 patients. Our study shows that brain perfusion SPECT is a non-traumatic, non-invasive, non-allergic, inexpensive method for the prediction of cerebral vasospasm. We conclude that brain SPECT with Tc-99m HM-PAO is an accessible technique that can demonstrate varying degrees of regional tissue hypoperfusion in patients with delayed ischemic deficits due to CVS following SAH.     

Experimental evaluation of retrograde cerebral perfusion by single photon emission computed tomography technique (SPECT).

BACKGROUND: Protection of the brain is of vital importance during aortic arch aneurysms. In this study efficiency of retrograde cerebral perfusion was evaluated with the use of single photon emission computed tomography technique (SPECT) by using 99mTc hexamethylpropylene amine oxime (HMPAO). METHODS: Four animals were used. The internal maxillary vein was the site of retrograde cerebral perfusion. The animals were studied after the heart rate and respiration were stopped with the use of the high dose drug administration and the brain was perfused with cold Ringer's lactated solution. After this procedure, 99mTc HMPAO-SPECT study was performed. RESULTS: In one animal we did not get any cerebral image because of the competent venous valve in the internal maxillary vein. In the remaining animals, normal brain perfusion was achieved. CONCLUSIONS: 99mTc HMPAO-SPECT study documented that blood flow via the retrograde way meets the metabolic demand of the brain. Retrograde delivery of 99mTc HMPAO did not conclude any poorly perfused area in the brain when in given both sides and all parts of the brain can be effectively perfused by cerebral venous system in hypothermic conditions.     

Prevalence of coronary artery disease using thallium-201 single photon emission computed tomography among patients newly undergoing chronic peritoneal dialysis and its association with mortality

BACKGROUND: Previous data about the prevalence of coronary artery disease in dialysis patients were mainly based on history or electrocardiogram. METHODS: We evaluated the prevalence of coronary artery disease using routine thallium-201 single photon emission computed tomography (SPECT) in 227 patients at the start of chronic peritoneal dialysis between January 1996 and October 2003. We also analyzed its association with mortality. RESULTS: Fifty-one patients (22.5%) were positive on thallium SPECT. There were significant differences in age, underlying diabetic nephropathy, and C-reactive protein (CRP), serum albumin, total cholesterol, and prealbumin levels among patients positive and negative on thallium SPECT. Multivariate logistic regression analysis showed that age (> or =60 years), underlying diabetic nephropathy, and CRP (> or =0.5 mg/dl) were independent predictors of positive thallium SPECT, with the patients positive for all three factors having a probability for positive thallium SPECT of 43%, whereas patients negative for all three factors had a probability of only 4%. Ninety patients died, and 137 survived during the median follow-up period of 34 (range 3-99) months. Kaplan-Meier survival analysis revealed that age, underlying diabetic nephropathy, serum albumin, prealbumin, and CRP levels, positive thallium SPECT, and smoking affected survival. Survival was not different according to gender, presence of hypertension, body mass index, total cholesterol, or lipoprotein(a). Cox regression analysis showed that only underlying diabetic nephropathy and age (> or =60 years) were independent predictors of mortality. CONCLUSIONS: We found that 22.5% of the patients who started chronic peritoneal dialysis had a positive thallium SPECT. Age, underlying diabetic nephropathy, and CRP were independent predictors of a positive thallium SPECT. Underlying diabetic nephropathy and age, but not positive thallium SPECT, were independent predictors of mortality.     

单光子发射计算机断层扫描在颅脑创伤后的临床研究

目的 探索单光子发射计算机断层扫描（SPECF）在脑外伤评估及预后方面的价值的依据。方法 28例中、重度颅脑损伤患者分别于伤后3天、10天及3～4周接受SPECF、CT检查及临床评定。3个月后所有患者行脑外伤综合征的临床测试，对首检SPECF显像阳性者复查SPECF，分析首检SPECF显像阳性者与损伤程度的关系，动态观察SPECF显像与预后的关系。结果 SPECF显像阳性与脑损伤程度有关，首检SPECF显像阳性提示预后良好，复查SPECF显像阳性提示多出现脑外伤综合征。对幕上损伤患者表现的小脑症状、体征可以做出合理的解释。结论 在中至重度颅脑损伤后SPECF显像与CT扫描比较更敏感，脑SPECF具有无创性、功能性及灵敏性高等特点，是脑外伤后功能评估、预后判断及临床研究的可靠方法。     

Hemodynamic evaluation of vascular reconstructive surgery for childhood moyamoya disease using single photon emission computed tomography.

To evaluate the efficacy of vascular reconstructive surgery for childhood moyamoya disease, the cerebral blood flow (CBF) in 31 hemispheres of 16 patients was examined by single photon emission computed tomography (SPECT) using the 133Xe inhalation method. Results were divided into two groups; 17 hemispheres with superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis [A(+) group] and 14 hemispheres without anastomosis [A(-) group]. The mean hemispheric CBF (mCBF) and regional CBF (rCBF) in the frontal, temporal, occipital, and basal ganglia regions were calculated. Pre- and postoperative SPECT on the 10 hemispheres of the A(+) group showed an increase in mCBF in 6 hemispheres, the disappearance of the low perfusion area (LPA) in all 5 hemispheres where LPA was present before surgery, and an improvement in rCBF distribution (an increase in rCBF in the frontal and temporal lobes and a decrease in the basal ganglia). This suggests that vascular reconstruction is greatly effective in treating this disease. A comparison between the A(+) group and the A(-) group by postoperative SPECT, as well as the clinical outcomes and the postoperative findings of electroencephalography and angiography, revealed that the A(+) group was superior to the A(-) group in the frequency of LPA (12% and 43%, respectively) and rCBF in the frontal region where STA-MCA anastomosis was usually performed. These results indicate that STA-MCA anastomosis with indirect synangiosis is the most effective treatment of childhood moyamoya disease.