Keita Utsunomiya

Clinical significance of thallium-201 and gallium-67 scintigraphy in pulmonary tuberculosis

One hundred and thirty-nine patients with pulmonary tuberculosis were evaluated by means of gallium-67 and thallium-201 scintigraphy. The disease was clinically active in 83 and inactive in 56. The uptake ratio between the lesion and the contralateral normal lung field was calculated. The ratio determined by67Ga scintigraphy was expressed as GR, and that determined by201Tl scintigraphy (early or delayed) as ER or DR. The201Tl retention index (RI) was calculated using the following equation: RI=DR—ER/ER×100. The sensitivity, specificity and accuracy of201Tl scintigraphy with respect to the activity of pulmonary tuberculosis were better than those of67Ga scintigraphy (the figures for201Tl scintigraphy were 88.0%, 82.1% and 85.6%, respectively, and those for67Ga scintigraphy, 83.1%, 60.7% and 74.1%).We found a significant correlation between GR and ER, but there was no significant correlation between RI and ER. When the relationships between ER, C-reactive protein and 1-h erythrocyte sedimentation rate were examined among patients with abnormal uptake, no significant relationships were noted. In the 27 patients who could be followed up, GR and ER decreased with duration of the therapy, indicating a decrease in disease activity which was consistent with clinical findings. The RI was significantly higher in the early stages of therapy than in the later stages (P<0.01), suggesting a temporary delay in201Tl washout in the early stages. The washout seemed to be promoted by the effects of the therapy. Overall, it is concluded that201Tl scintigraphy is more useful and more suitable than67Ga scintigraphy for the evaluation of disease activity and therapeutic effects in patients with pulmonary tuberculosis.

A Pilot Study for the Effects of Donepezil Therapy on Cerebral and Optic Nerve Head Blood Flow, Visual Field Defect in Normal-Tension Glaucoma

PURPOSE To evaluate the effect of donepezil hydrochloride, an agent for the treatment of Alzheimers disease (AD), on the cerebral and optic nerve head (ONH) blood flow, visual field defect in normal-tension glaucoma (NTG) patients with decreased cerebral blood flow (CBF) that demonstrates an AD-like perfusion pattern. METHODS The subjects were 5 NTG patients who exhibited AD-like decreased CBF upon (123)I-iodoamphetamine single photon emission computed tomography ((123)I-IMP SPECT). Donepezil hydrochloride (5 mg/day) was prescribed for each patient during a period of 12 months. Intraocular pressure (IOP), mean deviation (MD) of the Humphrey visual field, ONH blood flow determined by a laser speckle flowgraphy, and regional CBF (rCBF) determined by (123)I-IMP SPECT were measured before and every 6 months during the treatment. RESULTS MD, ONH blood flow, and rCBF were improved significantly after 6 months of the treatment, although IOP did not change significantly. No deterioration of NTG morbidity was found in any of the measured parameters after 12 months of the treatment. CONCLUSIONS Oral administration of donepezil hydrochloride in NTG patients might prevent deterioration of visual field defect, ONH blood flow, and rCBF in the temporal, parietal, and posterior lobes. This pilot study suggested the possibility that donepezil hydrochloride might ameliorate glaucomatous optic neuropathy in NTG.

Use of iodine-123 metaiodobenzylguanidine scintigraphy to assess cardiac sympathetic denervation and the impact of hypertension in patients with non-insulin-dependent diabetes mellitus

Abstract. The objectives of this clinical study using iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy were (a) to evaluate cardiac sympathetic denervation in non-insulin-dependent diabetes mellitus (NIDDM) patients with and without hypertension and (b) to investigate the relation between cardiac sympathetic denervation and prognosis in NIDDM patients. We compared clinical characteristics and MIBG data [heart to mediastinum (H/M) ratio and % washout rate (WR)] in a control group and NIDDM patients with and without hypertension. MIBG scintigraphy was performed in 11 controls and 82 NIDDM patients without overt cardiovascular disease except for hypertension (systolic blood pressure ≥140 and/or diastolic blood pressure ≥90 mmHg). After MIBG examination, blood pressure was measured regularly in all NIDDM patients. There were significant differences between 65 normotensive and 17 hypertensive NIDDM patients with respect to age (55±11 vs 63±12 years, respectively, P<0.05), prevalence of diabetic retinopathy (12% vs 35%, respectively, P<0.05) and systolic blood pressure (120±12 vs 145±16 mmHg, respectively, P<0.001). The H/M ratio in hypertensive NIDDM patients was significantly lower than in the control group (1.81±0.29 vs 2.27±0.20, respectively, P<0.01). During the follow-up period (18± 12 months), 17 NIDDM patients newly developed hypertension after MIBG examination. There were no significant differences in their clinical characteristics compared with persistently normotensive or hypertensive NIDDM patients. %WR in patients with new onset hypertension was significantly higher than in the control group (30.88%±16.87% vs 12.89%±11.94%, respectively, P<0.05). Moreover, in these patients %WR correlated with duration from the date of MIBG scintigraphy to the onset of hypertension (r=-0.512, P<0.05). Five NIDDM patients died during the follow-up period (four newly hypertensive patients and one normotensive patient). There were significant statistical differences between the control group and non-survivors in terms of age (54±11 vs 73±11 years, respectively, P<0.01), H/M ratio (2.27± 0.20 vs 1.64±0.36, respectively, P<0.01) and %WR (12.89%±11.94% vs 42.52%±22.39%, respectively, P<0.01). In conclusion, cardiac sympathetic denervation using MIBG scintigraphy observed in hypertensive NIDDM patients, and was more profound in non-survivors. MIBG scintigraphy proved useful for the evaluation of NIDDM patients with new onset hypertension, and it was found that NIDDM patients with abnormalities on MIBG scintigraphy needed to be observe carefully.

Technetium-99m MIBI single photon emission computed tomography as an indicator of prognosis for patients with lung cancer —Preliminaly report—

Purpose: We performed technetium-99m hexakis-2-methoxyisobutylisonitrile (Tc-99m MIBI) single photon emission computed tomography (SPECT) in 23 patients with primary lung cancer between July 1993 and March 1996. We evaluated the relationships among the uptake ratio, retention index and the prognosis after radiation therapy and/or chemotherapy.Materials and Methods: Tc-99m MIBI SPECT was performed at 30 minutes and at 3 hours after intravenous injection of 600 MBq of Tc-99m MIBI with three gamma camera detectors (GCA-9300A/HG) on transverse SPECT images. Regions of interest were set in the area of abnormal uptake of Tc-99m MIBI and in the contralateral normal lung. The ratio of uptake in the lesion to that in the contralateral normal lung was obtained on early images (early ratio; ER) as well as delayed images (delayed ratio; DR). The retention index (RI) was calculated as follows: RI=(DR-ER)/ER×100. The ratio was compared with survival time and prognostic factors.Results: There was no correlation between ER and DR. The patients with high RI survived longer than those with low RI (median survival, 19.4 months vs. 9.4 months; p=0.0104 by the Mantel-Cox test).Conclusion: These results suggest that RI is the most useful among Tc-99m MIBI indices of primary lung cancer in predicting prognosis.

I-123 MIBG cardiac imaging in diabetic neuropathy before and after epalrestat therapy.

I-123 metaiodobenzylguanidine (MIBG) scintigraphy is a new method to evaluate cardiac sympathetic nerve disturbance in patients with diabetes mellitus. Epalrestat specifically inhibits aldose reductase and improves diabetic neuropathy. The authors report a case of improvement in cardiac sympathetic dysfunction using MIBG scintigraphy with epalrestat therapy. In this case, epalrestat effectively reversed diabetic neuropathy, and MIBG scintigraphy was useful to evaluate the effect of epalrestat.

Gated blood pool SPECT improves reproducibility of right and left ventricular Fourier phase analysis in radionuclide angiography

Objectives: The ventricular phase angle, a parametric method applied to Fourier phase analysis (FPA) in radionuclide ventriculography, allows the quantitative analysis of ventricular contractile synchrony. However, FPA reproducibility using gated blood pool SPECT (GBPS) has not been fully evaluated. The present study evaluates whether by using GBPS, the reproducibility of FPA could be improved over that in planar radionuclide angiography (PRNA).Methods: Forty-three subjects underwent both GBPS and PRNA, of which 10 subjects were normal controls, 25 had dilated cardiomyopathy, and 8 had various heart diseases. Interventricular contractile synchrony was measured as the absolute difference in RV and LV mean ventricular phase angle as deltaø (RV- LV). Intraventricular contractile synchrony was measured as the standard deviation of the mean phase angle for the RV and LV blood pools (RVSDø, LVSDø). Two nuclear physicians processed the same phase images of GBPS to evaluate the interobserver reproducibility of the phase angles using data from the 43 study participants. Phase images acquired from PRNA were processed in the same manner.Results: Excellent reproducibility of deltaø (RV - LV) was obtained with both GBPS (Y = -3.10 + 0.89 X; r = 0.901) and PRNA (Y = -4.51 + 0.81 -X; r = 0.834). In regard to RVSDø reproducibility was not adequate with PRNA (Y = 18.56 + 0.35.X; r = 0.424), while it was acceptable with GBPS (Y = 5.22 + 0.85.X; r = 0.864). LVSDø reproducibility was superior using both GBPS (Y = 4.15 + 0.97.X; r = 0.965) and PRNA (Y = -0.55 + 0.98.X; r = 0.910).Conclusion: Our results demonstrate FPA obtained using GBPS to be highly reproducible for evaluating deltaø (RV - LV), RVSDø and LVSDø, in comparison with the PRNA method. We thus consider GBPS appropriate for evaluating ventricular contractile synchrony.

Usefulness of tc-99m MIBI SPECT in predicting multidrug resistance gene expression levels in non-small cell lung cancer--a preliminary report.

In this study we investigated whether Tc-99m hexakis 2-methoxy isobutyl isonitrile (Tc-99m MIBI) single-photon emission computed tomography (SPECT) has a correlation with the multidrug resistance (MDR1) and multidrug resistance-associated protein (MRP1) gene expression levels in non-small cell lung cancer (NSCLC). Fifteen patients with NSCLC were studied. SPECT images were obtained 15 (early) and 120 (delayed) min after injection of Tc-99m MIBI. We chose only one transverse section and set the region of interest over the tumor and out of the body. The mean counts in the tumor on early and delayed images were corrected by using those in the background and represented as Te and Td, respectively. Resected tumor specimens were frozen with liquid nitrogen and each positive control cell line was cultured. After the total ribonucleic acid (RNA) was extracted from specimens and cell lines, the complimentary deoxyribonucleic acid (cDNA) was amplified by the reverse transcription-polymerase chain reaction (RT-PCR) method. Each product was electrophoresed and fluorointensity was measured. The gene expression level was represented as the ratio of that of the positive control cell line. Te and Td indicated a significant correlation with the MDR1 gene expression level (p=0.015 and p=0.022), but not the gene of MRP1 (p=0.100 and p=0.145). In conclusion, Te and Td are useful parameters in predicting the MDR1 gene expression level, but not MRP1 in NSCLC.

Optimal scan delay of arterial phase scanning of hepatic CT using a real-time image reconstruction system

To optimize scan delay of arterial phase scanning of hepatic CT, 30 patients suspected of having HCC were examined using real-time image reconstruction technology (SureStart). In all cases, SureStart was successful. Despite the low dose, these images allowed adequate visualization of the abdominal aorta. The mean delay from the initiation of contrast administration to the beginning of arterial phase scanning was 29.6 +/- 5.2 sec (mean +/- SD; range, 22-51 sec).

A case of local recurrent pheochromocytoma: usefulness of I-123 MIBG early SPECT and maximum intensity projection images.

It has been reported that 10% of patients with pheochromocytoma experience recurrence despite surgery. The authors administered I-123 MIBG to patients with recurrent pheochromocytoma and found that early images are more useful than delayed images to detect recurrence. Early imaging with I-123 MIBG is useful for postoperative follow-up studies in patients with pheochromocytoma and those with possible tumor recurrence.

Evaluation of breath-hold201Tl SPECT in the differential diagnosis of solitary pulmonary nodules

The aim of this study was to evaluate the usefulness of deep inspiration breath-hold SPECT (BrST, a method for201T1 SPECT) in the diagnosis of solitary pulmonary nodules (SPN).Methods: Ten patients with malignant lesions and five with benign lesions were enrolled in this study. Early SPECT acquisition was performed 15 min after injection of201T1, while delayed SPECT images were acquired 3 h after injection. The first 15-sec acquisition was done using the BrST technique, and the second with the conventional free breathing (FB) method. We performed this technique alternately, and therefore, the odd data were from BrST and the even data were from FB. We referred to the T/N ratio of the early images as the ER and to the T/N ratio of the delayed images as the DR. To semi-quantitatively evaluate the degree of retention in the lesion, the retention index (RI) was calculated.Results: The RI of BrST indicated greater accuracy than that of FB in the differential diagnosis of SPN. For the benign and malignant lesions, the RI of BrST was -3.07 ± 31.51 and 29.86 ± 25.01, respectively (p < 0.05). The sensitivity, specificity, and accuracy of BrST (80%, 80%, and 80%, respectively) were significantly higher than those of FB (p < 0.05).Conclusion: The BrST method is more accurate than that of the conventional FB method in the differential diagnosis of SPN.