Shigemi Futami

Time sequential single photon emission computed tomography studies in brain tumour using thallium-201

Time sequential single photon emission computed tomography (SPECT) studies using thallium-201 were performed in 25 patients with brain tumours to evaluate the kinetics of thallium in the tumour and the biological malignancy grade preoperatively. After acquisition and reconstruction of SPECT data from 1 min post injection to 48 h (1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 15–20 min, followed by 4–6, 24 and 48 h), the thallium uptake ratio in the tumour versus the homologous contralateral area of the brain was calculated and compared with findings of X-ray CT, magnetic resonance imaging, cerebral angiography and histological investigations. Early uptake of thallium in tumours was related to tumour vascularity and the disruption of the blood-brain barrier. High and rapid uptake and slow reduction of thallium indicated a hypervascular malignant tumour; however, high and rapid uptake but rapid reduction of thallium indicated a hypervascular benign tumour, such as meningioma. Hypovascular and benign tumours tended to show low uptake and slow reduction of thallium. Long-lasting retention or uptake of thallium indicates tumour malignancy.

Technetium-99m tetrofosmin for parathyroid scintigraphy: a direct comparison with 99mTc-MIBI, 201Tl, MRI and US

The aim of this study was to evaluate the efficacy and role of technetium-99m tetrofosmin for the detection of abnormal parathyroid glands to be referred for surgical treatment. Twenty-eight consecutive patients, including 25 primary and 3 secondary cases of hyperparathyroidism, were evaluated. 99mTc-tetrofosmin/99mTc-pertechnetate subtraction scintigraphy (TF/Tc) was performed on all patients, and the results were directly compared with those of 99mTc-methoxyisobutylisonitrile (MIBI)/99mTc-pertechnetate subtraction scintigraphy (MIBI/Tc), 201Tl/99mTc-pertechnetate subtraction scintigraphy (Tl/Tc), magnetic resonance imaging (MRI) and ultrasonography (US). In cases of single-gland disease, the sensitivities of TF/Tc, MIBI/Tc, Tl/Tc, MRI and US were 63.2%, 68.4%, 57.9%, 55.6% and 63.2%, respectively. In cases of multi-gland disease, the sensitivities of TF/Tc, MIBI/Tc, Tl/Tc, MRI and US were 41.7%, 41.7%, 37.5%, 58.3% and 54.2%, respectively. In cases of parathyroid adenoma, the sensitivities of TF/Tc, MIBI/Tc, Tl/Tc, MRI and US were 68.8%, 75.0%, 68.8%, 62.5% and 75.0%, respectively. In cases of parathyroid hyperplasia, the sensitivities of TF/Tc, MIBI/Tc, Tl/Tc, MRI and US were 40.7%, 40.7%, 33.3%, 53.8% and 48.1%, respectively. It is concluded that, for the detection of abnormal parathyroid glands, 99mTc-tetrofosmin is as useful as 99mTc-MIBI and is more useful than 201Tl.

Regional cerebral blood flow in diabetic patients: evaluation by N-isopropyl-123I-IMP with SPECT

Regional cerebral blood flow (rCBF) was measured using N-isopropyl-123I-iodoamphetamine (123I-IMP) with single photon emission computed tomography (SPECT) in 27 patients with diabetes mellitus with an average age of 64.1 years and with an average fasting plasma glucose of 145 mg dl-1. Their data were compared with those of 12 non-diabetic subjects with an average age of 64.6 years. None had cerebral infarction on computed tomographic (CT) studies. There were no significant differences in the physiological or laboratory data between the diabetic and non-diabetic groups except for their fasting plasma glucose and HbA1c levels. A reference sampling method using continuous arterial blood sampling was employed to quantify the rCBF. The average rCBF in each region of the cerebrum and cerebellum was significantly lower in the diabetic group than in the non-diabetic group (P<0.01). Although a definite cause was obscure, the rCBF of the diabetic patients was reduced even in the absence of findings indicative of cerebral infarction on a CT study.

Usefulness of rCBF analysis in diagnosing Parkinson’s disease: supplemental role with MIBG myocardial scintigraphy

Abstract123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy is a useful tool for differentiating idiopathic Parkinson’s disease (PD) from parkinsonism (PS) caused by other disorders. However, cardiac MIBG uptake is affected by various causes. Alternatively, hypoperfusion in the occipital lobe of PD is reported recently.ObjectiveThe objective is to clarify the correlation between regional cerebral blood flow (rCBF) alteration and cardiac MIBG uptake in PD. In addition, we examined whether additional brain perfusion analysis improved the differential diagnostic ability for PD from PS when compared with MIBG scintigraphy alone.MethodsForty-nine patients with PD (27 mild groups: Hoehn and Yahr stages I, II; 22 severe groups: Hoehn and Yahr stages III, IV) and 28 patients with PS participated. We compared absolute rCBF values between PD and PS. In addition, we determined correlation between MIBG parameters and each rCBF value. Finally, we compared the diagnostic ability for the differentiation of PD from PS between two diagnostic criteria, each MIBG index abnormality alone [heart-to-mediastinum ratio, H/M (E) < 1.9, H/E (D) < 1.7, washout rate > 40%] and each MIBG index abnormality or occipital lobe hypoperfusion (<36 ml/100 g per min).ResultsAbsolute rCBF value of occipital lobe was significantly lower in severe PD as compared with PS or mild PD. In the correlation analysis, rCBF of occipital lobe correlated positively with MIBG parameters (H/M). Regarding the diagnostic ability, sensitivity improved by accounting for occipital hypoperfusion as compared with MIBG indices alone. In contrast, neither specificity nor accuracy improved by adding occipital lobe analysis.ConclusionsMIBG parameters (H/M) correlated positively with occipital hypoperfusion in PD. In the differential diagnosis between PD and PS, although its usefulness might be limited, analysis of rCBF in the occipital lobe added to 123I-MIBG myocardial imaging can be recommended.

Cerebral blood flow abnormalities induced by transient hypothyroidism after thyroidectomy —Analysis by Tc-99m-HMPAO and SPM96—

The current study is an investigation of alterations in regional cerebral blood flow (rCBF) distribution in patients with transient hypothyroidism after thyroidectomy. In addition, the effects of thyroxine treatment on rCBF changes were studied.MethodsNoninvasive rCBF measurements using99mTc-HMPAO SPECT were performed on 24 post-thyroidectomy patients who were in a hypothyroidic state. The measurements were conducted before131I therapy and after thyroid hormone (thyroxine) replacement. We used adjusted rCBF images (normalization of global CBF for each subject to 50 m//100 g/min with proportional scaling) to compare these data with age-matched normal control groups (n=15) using SPM96. We also compared the absolute rCBF value of hypothyroidic patients with those of normal control groups. In addition, the association between rCBF alteration and the severity of depression was also analyzed. Finally, the effect of thyroid hormone replacement on rCBF was investigated individually using the Jack-knife test, in which patient data were compared with those from healthy volunteers. According to the result of this test, all cases were categorized into three subgroups, namely, improved, unchanged group and normal. To prove the reversibility of rCBF alteration after thyroid hormone replacement, a group comparison test between the normal controls and the improved group was done before and after thyroid hormone replacement. Similarly a group comparison test between the unchanged group and normal controls was also performed.ResultsIn the hypothyroidic condition, there was a significant decrease in the posterior part of the bilateral parietal lobes and in part of the bilateral occipital lobes, including the cuneus. These decreased rCBF areas extended to the bilateral prefrontal cortices as deterioration became more profound. On individual analysis, 16 of 24 patients (66.7%) demonstrated rCBF reduction, while 8 patient did not show significant rCBF change (33.3%, the normal group). After thyroxine replacement, improvement of rCBF was noted in nine of 16 patients (56.3%, the improved group). In seven of 16 patients (43.7% the unchanged group), the significant low rCBF area remained unchanged. Compared with the normal controls, the improved group showed significantly decreased rCBF of the bilateral parietal lobe and the occipital lobe in the hypothyroic condition. After thyroid hormone replacement, these abnormal rCBF areas disappeared. In contrast, in the unchanged group, the significant hypoperfusion area became localized but remained.Conclusion99mTc-HMPAO SPECT and SPM96 analysis demonstrated a significant rCBF decrease in the parietal lobe and part of the occipital lobe in patients with induced transient hypothyroidism after thyroidectomy. This phenomenon might contribute to understanding of the depressive state. Recovery of rCBF after thyroid hormone replacement was confirmed in some patients. However, rCBF improvement did not always occur in every patient during the follow up period. The reversibility of rCBF in transient hypothyroidism may be dependent on individual characteristics during a short-term period.

123I-MIBG myocardial scintigraphy in diabetic patients: Relationship with201Tl uptake and cardiac autonomic function

PurposeTo investigate the influence of diabetic myocardial damage (suspected myocardial damage; SMD) diagnosed by201T1-SPECT and diabetic cardiac autonomic neuropathy (AN) on myocardial MIBG uptake in patients with non-insulin-dependent diabetes mellitus (NIDDM).Subjects and MethodsEighty-seven diabetic patients divided into four subgroups: 23 with SMD (+) AN (+); 19 with SMD (+) AN (−); 27 with SMD (−) AN (+); 18 with SMD (−) AN (−), and 10 controls were studied. Both planar and SPECT images were taken at 30 minutes (early) and 3 hours (delayed) after123I-MIBG injection. The heart to mediastinum uptake ratio (H/M) and washout ratio of123I-MIBG (WR) were obtained from both planar images. On SPECT images, the total uptake score (TUS) was obtained by the 5 point score method by dividing the myocardium into 20 segments on visual analysis. Similarly, the difference between the201Tl image and the123I-MIBG image in TUS was taken as the difference in the total uptake score (ΔTUS) representing cardiac sympathetic denervation without SMD.ResultsOn both early and delayed planar images, the mean H/M value in the subgroups of diabetic patients was significantly lower in the SMD (+) AN (+) group than in the control group, but among those subgroups, there was statistically significant difference between the SMD (+) AN (+) and SMD (−) AN (−) groups only on the delayed images. Regarding the WR value, there was no statistically significant difference among subjects. On SPECT image analysis, the diabetic sub-group with AN or SMD had statistically significant lower values for TUS than those of the control group. Among diabetics, there was a statistically significant differences between SMD [+] AN [+] and SMD [−] AN [−] on both early and delayed images. Similarly, the SMD [+] AN [−] group also had significantly lower values than those of SMD [−] AN [−] on early images. Regarding ΔTUS, there was a statistically significant differences between AN [+] subgroups and controls. Similarly, the mean value for ΔTUS was much higher in AN [+] subgroups than in AN [−] subgroups with or without SMD in diabetes mellitus.Conclusion123I-MIBG myocardial uptake is affected by both SMD and cardiac autonomie neuropathy. Based on the finding that ΔTUS was much higher in AN [+] subgroups and there was no statistically significant difference between SMD [+] AN [+] and SMD [−] AN [+] subgroups, a decrease in myocardial123I-MIBG uptake might progress independently of SMD.

123I-MIBG myocardial scintigraphy in diabetic patients: Relationship to autonomic neuropathy

SummaryThe aim of this study was to investigate the relationship between autonomic nerve dysfunction and myocardial uptake of l23I-meta-iodobenzyl guanidine (MIBG) in patients with diabetes mellitus. Twenty-two non-insulin-dependent diabetic patients, 9 with autonomic neuropathy [ANP( + )] and 13 without autonomic neuropathy [ANP( -)], and 8 controls were included in the study. Both planar and single photon emission tomographic (SPET) images were obtained 30 min (early) and 3 h (delayed) after the 123I-MIBG injection. The heart-to-mediastinal uptake ratio (H/M) and the washout ratio of 123I-MIBG (%WR) were calculated from planar images. The uptake ratio of the inferior wall to the anterior wall (I/A) and the %WR of both the inferior and anterior walls were calculated from the SPET images. On the early planar images, the mean H/M ratio in the ANP( + ) group was significantly lower than that of the control group. The mean %WR on the planar images in the ANP( - ) group was significantly higher than that of the controls. The SPET images demonstrated a reduction in MIBG uptake and significantly increased clearance in the inferior wall of the ANP( - ) patients. These findings extended to other areas of the heart in the ANP( + ) patients. In the quantitative analysis of the SPET images, the ANP( + ) group had significantly lower I/A values and significantly higher %WR values in the anterior wall. The ANP( + ) group showed significantly increased clearance of 123I-MIBG in the inferior wall. We conclude that 123I-MIBG myocardial scintigraphy is a useful diagnostic tool both in the early detection and evaluation of the progression of myocardial sympathetic nerve dysfunction in patients with diabetes mellitus. Both the I/A and %WR calculated from SPET images are useful parameters.

Alteration of regional cerebral blood flow in patients with chronic pain--evaluation before and after epidural spinal cord stimulation.

BackgroundChronic pain is defined as intractable pain caused by abnormal pain transmission or impairment of the pain control system per se. Alteration of regional cerebral blood flow (rCBF) is known to occur under the presence of pain stimulation. Epidural spinal cord stimulation (SCS) is occasionally effective in relieving the symptom.ObjectiveThe aim of the current study is to investigate the alteration of rCBF in baseline condition and to find the association between the rCBF change and the efficacy of SCS in chronic pain.MethodsA total of 18 patients underwent Tc-99m-HMPAO SPECT before and after SCS. Analysis with three-dimensional stereo-tactic surface projections (3D-SSP) with stereo-tactic extraction estimation (SEE) software was adopted to evaluate the rCBF. We assessed the extent score of the abnormal region in each segment (rate of the coordinates with a Z-value that exceeds three kinds of threshold value 2.0, 2.5 and 3.0 in all coordinates within a segment). According to the therapeutic response defined by visual analogue scale, we categorized patients into two groups, the good responder (GR) group (n = 12) and poor responder (PR) group (n = 6). In the analysis, we compared the extent score in the following two conditions. (1)Comparison between the PR group and normal control group under both baseline condition and after SCS. (2)Comparison between the GR group and normal control group under both baseline condition and after SCS.Results(1)In the PR group, increased rCBF was observed in left thalamus, bilateral precuneus and bilateral cerebellum under the baseline condition. After SCS, the range of these increased rCBF areas localized but remained. Decrease of rCBF was noted in bilateral subcallosal gyrus, superior temporal gyrus (STG) and bilateral anterior cingulate gyrus (ACG). They localized after SCS, but remained. (2)In the GR group, increased rCBF areas were noted in bilateral precuneus and bilateral cerebellum under the baseline condition. After SCS, they localized in bilateral precuneus but those of bilateral cerebellum remained. Decreased rCBF area was noted in bilateral subcallosal gyrus, STG and bilateral ACG under the baseline. After SCS, they localized in bilateral subcallosal gyrus and bilateral STG. In contrast, they enlarged in bilateral ACG.ConclusionChronic pain patients demonstrated abnormal rCBF distribution on both baseline and post SCS conditions. Increased rCBF of thalamus and precuneus under both conditions in the PR group and decreased rCBF of ACG under post SCS conditions in the GR group were characteristic patterns. Tc-99m-HMPAO SPECT with 3D-SSP and SEE analysis is likely objective and effective in monitoring and evaluating therapeutic outcome by SCS in chronic pain. In addition, it provides information that is useful in the selection of SCS candidates.

Usefulness of a deep-inspiration breath-hold 18F-FDG PET/CT technique in diagnosing liver, bile duct, and pancreas tumors.

BackgroundThe deep-inspiration breath-hold 18F-fluorodeoxyglucose PET/computed tomography (DIBH 18F-FDG PET/CT) technique improves the limitations of diagnosing a lesion located in an area influenced by respiratory motion that brings about spatial misregistration caused by respiration between PET and CT. However, its clinical effectiveness with regard to abdominal lesions has not been elucidated. The influence of respiratory motion for calculating the maximal standardized uptake value (SUVmax) and metabolic volume (MV) in DIBH 18F-FDG PET/CT has not been investigated either. ObjectiveThe purpose of this study was to investigate the usefulness of the DIBH 18F-FDG PET/CT technique in diagnosing liver tumors, bile duct cancers, and pancreas tumors. In addition, we compared the values of SUVmax and MV between DIBH and nonbreath-hold (NBH). MethodsForty patients with various abdominal malignancies including liver tumors, bile duct cancers, and pancreas tumors were enrolled. In total, the patients had 47 abdominal lesions. All patients showed a misregistered image in the early whole-body image taken 50 min after intravenous 18F-FDG infusions. We added the delayed images 40 min after the first image. On the delayed image, we carried out both conventional techniques with normal respiration (NBH) and the DIBH technique. Finally, we compared two kinds of images in each patient. At the same time, we compared both SUVmax and MV of cancer obtained by the two kinds of imaging methods. ResultsIn 14 lesions (29.8%), we corrected the anatomical tumor location, from the incorrect to the correct organ, by the DIBH technique. In 22 lesions (46.8%), we corrected the tumor location within the organ. Consequently, tumor staging also changed in 11 patients (23.4%) after correction by the DIBH technique. Regarding the SUVmax value by DIBH, it showed an increase of approximately 15.0–58.6% compared with that measured by NBH. In contrast, the value of MV by DIBH showed a decrease of 20% compared with that measured by NBH. ConclusionThe DIBH 18F-FDG PET/CT technique is feasible for accurate localization when diagnosing of liver tumors, bile duct cancers, and pancreas cancers. The DIBH technique also improves the inaccurate quantification of both SUVmax and MV.

201TI SPECT for evaluating head and neck cancer

Background: Thallium-201 (201Tl) has come to be widely used in the diagnosis of several kinds of malignant tumor, but its usefulness in diagnosing head and neck cancer has not been established. Purpose: This study investigated the usefulness of201Tl SPECT imaging in patients with head and neck cancer histologically confirmed. Methods: Eighteen patients with histologically proven head and neck cancer were studied.201Tl SPECT images were obtained both 15 min and 4 hours after intravenous injection of 148 MBq of201Tl-chloride.201Tl-indices were calculated semiquantitatively to assess the tracer uptake in relation to tumor size and histological type. Results: High201Tl uptake was noted in all primary tumors and metastatic lymph nodes on the both early and delayed images, but201Tl-indices did not show any correlation with tumor size or histological type. Conclusion: Primary head and neck cancer and lymph node metastasis can be effectively visualized with201Tl SPECT. It may provide information in addition to morphological changes and may be a supplemental method to use in the evaluation of head and neck cancer.