Yasuharu Ogura

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.

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.

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.

Present diagnostic strategies for acute pulmonary thromboembolism; results of a questionnaire in a retrospective trial conducted by the Respiratory Nuclear Medicine Working Group of the Japanese Society of Nuclear Medicine.

The aim of this study is to re-evaluate and clarify the diagnostic role of ventilation/perfusion lung scintigraphy in Japan, now that single-detector-row helical CT and multidetector-row CT are available in clinical practice. The Respiratory Nuclear Medicine Working Group of the Japanese Society of Nuclear Medicine distributed a questionnaire to institutions in Japan equipped with scintillation cameras as of September 2001. Of 1,222 institutions, 239 returned effective answers (19.6%). The most frequent combination for initial diagnosis of acute pulmonary thromboembolism was chest radiography, perfusion lung scintigraphy, and contrast-enhanced CT (111 institutions, 46.4%). The questionnaire revealed that the validity and usage of perfusion lung scintigraphy and those of contrast-enhanced CT were equivalent in the present clinical situation. On the other hand, the diagnostic value of ventilation lung scintigraphy in suspected pulmonary thromboembolism has not been established in Japan. Even though contrast-enhanced CT is widely used in Japan, perfusion lung scintigraphy is still required to determine disease severity and monitor its progress.

3D Imaging of the Trachea and Bronchi from Helical Scan CT.

ヘリカルCTのデータから気管・気管支系の三次元立体表示を行い, 最適な表示条件とその描出能について検討した. 対象は気管支鏡およびヘリカルCTが施行された肺病変16例である.使用装置は東芝社製Xforceで, 撮像条件はX線ビーム幅5mm, テーブル移動速度5mm/1.5秒, 1回転1.5秒で連続20回転スキャンし, 2mmピッチで横断像を画像再構成した. 得られたデータから三次元表示ソフトウエアCEMAX-VIPstationを用いて気管・気管支を立体表示し, 気管支鏡所見と対比検討した. 気管・気管支の三次元表示には, CT値の抽出閾値-650HU～-100HUが最も描出良好であった. また区域気管支まで気管支内腔の観察が可能であり, 気管支内の腫瘤は内腔狭窄, 壁肥厚として描出された. 気管・気管支の三次元表示を観察することにより病変部の全体的な把握が容易となり, また気管支壁の外方からの観察も可能であることから気管支病変の解析により有用であると考えられた.