Atsushi K. Kono

Comparison of Regional Brain Volume and Glucose Metabolism Between Patients with Mild Dementia with Lewy Bodies and Those with Mild Alzheimer's Disease

The aim of this study was to investigate regional differences between morphologic and functional changes in patients with mild dementia with Lewy bodies (DLB) compared with those with Alzheimers disease (AD). Methods: Twenty patients with very mild DLB (mean age, 74.5 y; mean Mini-Mental State Examination [MMSE] score, 24.0), 20 patients with very mild AD (mean age, 74.1 y; mean MMSE score, 24.0), and 20 age- and sex-matched healthy volunteers (normal controls [NC]) underwent both 18F-FDG PET and 3-dimensional spoiled gradient echo MRI. Fully automatic volumetry of the MRI data was used to obtain whole brain, hippocampal, occipital, and striatal volumes, which were compared with the results of a similar analysis of glucose metabolic data. Results: In DLB patients, volumetric data indicated a significant volume decrease in the striatum, whereas 18F-FDG PET showed significant glucose metabolic reductions in the temporal, parietal, and frontal areas—including in the occipital lobe—compared with those in the NC group. In contrast, in AD patients, both the hippocampal volume and glucose metabolism were significantly decreased, whereas the occipital volume and metabolism were preserved. Conclusion: Comparison of very mild DLB and AD revealed different morphologic and metabolic changes occurring in the medial temporal lobes and the occipital lobe, demonstrating characteristic pathophysiologic differences between these 2 diseases.

Preoperative Visualization of the Artery of Adamkiewicz by Intra-Arterial CT Angiography

BACKGROUND AND PURPOSE: CT and MR angiographies have been reported to visualize the artery of Adamkiewicz (AKA) noninvasively to prevent spinal cord ischemia in surgery of thoracic descending aortic aneurysms. The purpose of this work was to compare the usefulness of CT angiography (CTA) with intra-arterial contrast injection (IACTA) with that of conventional CTA with intravenous contrast injection (IVCTA). MATERIALS AND METHODS: We enrolled 32 consecutive patients with thoracic or thoracoabdominal aortic aneurysms who were scheduled for surgical repair or endovascular stent-graft treatment. All of the CTA images were obtained using a 16-detector row CT scanner and 100 mL of contrast material (370 mg/mL) injected at a rate of 5 mL/s. Contrast was injected via the antecubital veins of 15 patients and via a pig-tail catheter placed at the proximal portion of the descending aorta in 17 patients who underwent IVCTA and IACTA, respectively. Two datasets were reconstructed from 2 consecutive scans. The AKA was identified as a characteristic hairpin curved vessel in the anterior midsagittal surface of the spine and by the absence of further enhancement in the second rather than in the first phase. Continuity between the AKA and aorta was confirmed when the vessel could be traced continuously by paging the oblique coronal multiplanar reconstruction or original axial images. RESULTS: Intra-arterial contrast injection was significantly more sensitive in identifying the AKA than IVCTA: 16 (94.1%) of 17 versus 9 (60.0%) of 15 (P = .033). Continuity between the AKA and aorta through intercostal or lumbar artery was confirmed in 14 (87.5%) of 16 and 5 (55.6%) of 9 of the IACTA and IVCTA groups, respectively. CONCLUSION: Intra-arterial contrast injection detected the AKA at a high rate and verified continuity from the aorta to the AKA.

Utility of phase contrast MR imaging for assessment of pulmonary flow and pressure estimation in patients with pulmonary hypertension: Comparison with right heart catheterization and echocardiography

To compare the utility of phase contrast MR imaging (PC‐MRI) for assessment of pulmonary flow and pressure estimation with that of right heart catheterization and echocardiography (cardiac US) in patients with pulmonary arterial hypertension (PAH).

Fully automatic differential diagnosis system for dementia with Lewy bodies and Alzheimer’s disease using FDG-PET and 3D-SSP

PurposeTo evaluate a fully automatic computer-assisted diagnostic system for mild dementia with Lewy bodies (DLB), permitting distinction from mild Alzheimer’s disease (AD).MethodsUsing 18F-fluorodeoxyglucose and positron emission tomography (FDG-PET), glucose metabolic images were obtained from mild DLB and mild AD patients. Two groups consisting of 16 mild DLB patients and 21 mild AD patients were recruited for diagnostic evaluation between mild DLB and mild AD. The mean age ± SD of the mild DLB group and the mild AD group was 74.3 ± 4.9 and 71.7 ± 2.1 years, respectively, and the mean scores of the MMSE for the mild DLB and the mild AD group were 21.7 ± 1.9 and 23.1 ± 2.1, respectively. A receiver operating characteristic (ROC) analysis was performed to compare the diagnostic performance, in terms of discrimination between DLB and AD, of conventional axial FDG-PET images inspected visually by experts and beginners with that of our fully automatic diagnosis system using the statistical brain mapping method and Z scores obtained with the DLB template.ResultsThe diagnostic performance of the automatic system was comparable to that of visual inspection by experts. The area under the ROC curve for the automatic diagnosis system was 0.77. The mean area under the ROC curve for visual inspection by experts and beginners was 0.76 and 0.65, respectively.ConclusionThe fully automatic differential diagnosis system for distinction between mild DLB and AD showed a similar diagnostic accuracy to visual inspection by experts. It would be a useful diagnostic tool to distinguish mild DLB from mild AD in clinical practice.

Cerebral perfusion pattern of idiopathic normal pressure hydrocephalus studied by SPECT and statistical brain mapping.

Objectives: To investigate the specific pattern of cerebral blood flow (CBF) in subjects with idiopathic normal pressure hydrocephalus (iNPH) using voxel-based analysis.Methods:N-isopropyl-p-[123I]iodoamphetamine (IMP) single photon emission computed tomography (SPECT) images were performed in 30 iNPH patients, who met probable iNPH criteria, 30 Alzheimer disease (AD) patients and 15 normal control (NC) subjects. Inter-group comparisons between iNPH patients and NC subjects and between AD patients and NC subjects were performed using three-dimensional stereotactic surface projection (3D-SSP) analysis. Individual 3D-SSP images of the iNPH patients were assessed by visual inspection.Results: On the Z-score maps, areas of relative hypoperfusion were recognized around the corpus callosum in all 30 iNPH patients, as well as in the Sylvian fissure regions in 19 of 30 iNPH patients which included artifacts by dilated ventricles and the Sylvian fissures. Ten frontal dominant, eight parietotemporal dominant, and 12 diffuse hypoperfusion types were demonstrated. Inter-group comparison between iNPH and NC subjects showed relative hypoperfusion in the frontal and parietotemporal areas and severe hypoperfusion around the corpus callosum and Sylvian fissure regions, while parietotemporal and posterior cingulate CBF reduction was demonstrated between the AD and NC groups.Conclusion: Voxelbased analysis showed a characteristic pattern of regional CBF reduction with frontal dominant or diffuse cerebral hypoperfusion accompanying severe hypoperfusion around the corpus callosum and Sylvian fissures with artifacts.

Automatic volumetric measurement of segmented brain structures on magnetic resonance imaging.

PurposeThe purpose of this study was to produce a fully automatic volumetric segmented brain image system (AVSIS) and to evaluate its utility for measuring hippocampal volumes and total intracranial volume (TIV).Materials and methodsWe developed a combination technique comprising an anatomical standardization technique to measure TIV, whole brain volume (WBV), and hippocampal volume obtained by magnetic resonance (MR) imaging. Altogether, 15 healthy volunteers and 15 patients with Alzheimers disease (AD) underwent three-dimensional spoiled gradient echo (3D-SPGR) imaging. Three measurements were performed by manual volumetry as the gold standard, a previous semiautomatic method, and our new method, AVSIS.ResultsWBV and hippocampal volume in the AD group were significantly smaller than those in the healthy volunteer group measured by the semiautomatic method, manual method, and AVSIS. Each volume measured by AVSIS or semiautomatic method correlated with that measured by the manual method. The correlation coefficients between TIVs, WBVs, or hippocampal volumes measured by AVSIS and the manual method were 0.910, 0.902, and 0.918, respectively; the correlation coefficients between TIVs, or WBVs, measured by the previous semiautomatic method and the manual method were 0.875, and 0.886, respectively.ConclusionWe developed a system for a fully automatic measurement of segmented brain structures and obtained good results.

Dynamic late gadolinium enhancement simply quantified using myocardium to lumen signal ratio: normal range of ratio and diffuse abnormal enhancement of cardiac amyloidosis.

To detect abnormal myocardial tissue in patients with diffuse myocardial disease, we propose a simple technique of late gadolinium enhancement (LGE) using routine myocardial imaging modalities.

3D automatic exposure control for 64-detector row CT: Radiation dose reduction in chest phantom study

PURPOSE The purpose of this study was to determine the utility of three-dimensional (3D) automatic exposure control (AEC) for low-dose CT examination in a chest phantom study. MATERIALS AND METHODS A chest CT phantom including simulated focal ground-glass opacities (GGOs) and nodules was scanned with a 64-detector row CT with and without AEC. Performance of 3D AEC included changing targeted standard deviations (SDs) of image noise from scout view. To determine the appropriate targeted SD number for identification, the capability of overall identification with the CT protocol adapted to each of the targeted SDs was compared with that obtained with CT without AEC by means of receiver operating characteristic analysis. RESULTS When targeted SD values equal to or higher than 250 were used, areas under the curve (Azs) of nodule identification with CT protocol using AEC were significantly smaller than that for CT protocol without AEC (p < 0.05). When targeted SD numbers at equal to or more than 180 were adapted, Azs of CT protocol with AEC had significantly smaller than that without AEC (p < 0.05). CONCLUSION This phantom study shows 3D AEC is useful for low-dose lung CT examination, and can reduce the radiation dose while maintaining good identification capability and good image quality.

Clinical Structural Anatomy of the Inferior Pyramidal Space Reconstructed Within the Cardiac Contour Using Multidetector‐Row Computed Tomography

Although many studies have described the detailed anatomy of the inferior pyramidal space, it may not be easy for cardiologists who have few chances to study cadaveric hearts to understand the correct morphology of the structure. The inferior pyramidal space is the part of extracardiac fibro‐adipose tissue wedging between the 4 cardiac chambers from the diaphragmatic surface of the heart. Many cardiologists have interests in pericardial adipose tissue, but the inferior pyramidal space seems to have been neglected. A number of important structures, including the coronary sinus, atrioventricular node, atrioventricular nodal artery, membranous septum, muscular atrioventricular sandwich (previously called the “muscular atrioventricular septum”), atrial septum, ventricular septum, aortic valvar complex, mitral valvar attachment, and tricuspid valvar attachment are associated with the inferior pyramidal space. We previously revealed its 3‐dimensional live anatomy using multidetector‐row computed tomography. Moreover, the 3‐dimensional understanding of the anatomy in association with the cardiac contour is important from the viewpoints of clinical cardiac electrophysiology. The purpose of this article is to demonstrate extended findings regarding the clinical structural anatomy of the inferior pyramidal space, which was reconstructed in combination with the cardiac contour using multidetector‐row computed tomography, and discuss the clinical implications of the findings.

Optimal angulations for obtaining an en face view of each coronary aortic sinus and the interventricular septum: Correlative anatomy around the left ventricular outflow tract

An optimal image intensifier angulation used for obtaining an en face view of a target structure is important in electrophysiologic procedures performed around each coronary aortic sinus (CAS). However, few studies have revealed the fluoroscopic anatomy of the target area. This study investigated the optimal angulation for each CAS and the interventricular septum (IVS). The study included 102 consecutive patients who underwent computed tomography coronary angiography. The optimal angle for each CAS was determined by rotating the volume‐rendered image around the vertical axis. The angle formed between the anteroposterior axis and IVS was measured using the horizontal section. The frontal direction was defined as zero, positive, or negative if the en face view of the target CAS was obtained in the frontal view, left anterior oblique (LAO) direction, or right anterior oblique (RAO) direction, respectively. The optimal angles for the left, right, and non‐CASs were 120.3 ± 10.5°, 4.8 ± 16.3°, and −110.0 ± 13.8°, respectively. The IVS angle was 42.6 ± 8.5°. Accordingly, the optimal image intensifier angulations for the left, right, and non‐CASs and the IVS were estimated to be RAO 60°, LAO 5°, LAO 70°, and RAO 50°, respectively. The IVS angle was the most common independent predictor of the optimal angle for each CAS. Differences in the optimal angulations for each CAS and the IVS are demonstrated. The biplane angulation needs to be tailored according to the individual patients and target structures for electrophysiologic procedures. Clin. Anat. 28:494–505, 2015.