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Biomedical subjects

Kunihiro Yoshioka

Publications and source records attributed to Kunihiro Yoshioka.

At least 19 recordsLinked to original sources
PubMed2006

MR angiography and CT angiography of the artery of Adamkiewicz: state of the art.

It is very important to assess the artery of Adamkiewicz before repair of the thoracoabdominal or descending thoracic aorta. Several studies have demonstrated the feasibility and advantages of noninvasive assessment of the artery of Adamkiewicz with magnetic resonance (MR) angiography and multi-detector row computed tomographic (CT) angiography. Recent advances in MR angiography and CT angiography have led to changes in the detectability of this artery. In the present study, both MR angiography and CT angiography were performed without complications for preoperative evaluation of 30 patients who underwent repair of the thoracoabdominal or descending thoracic aorta. MR angiography provided detection rates as high as 93% and 80% with the morphologic "hairpin turn" criterion and the anatomic "continuity" criterion, respectively. Sixteen-detector row CT angiography provided detection rates as high as 83% and 60%, respectively. Use of both MR angiography and CT angiography provided higher detection rates of 97% and 90%, respectively. The collateral pathways were depicted in seven cases (23%). MR angiography is superior for depiction of the artery of Adamkiewicz, especially when it arises from the false lumen of a dissecting aneurysm. CT angiography has a wide field of view and allows depiction of significant collateral pathways associated with the internal thoracic artery and intercostal arteries.

Adult↗
PubMed2006

Magnetic resonance angiography in coronary artery bypass grafting.

An attempt was made to reduce the incidence of perioperative stroke by detecting cerebrovascular disease with preoperative head and neck magnetic resonance angiography and by selecting the coronary artery bypass grafting technique. This strategy was used in 268 patients with ischemic heart disease who had undergone both head and neck magnetic resonance angiography before elective coronary artery bypass in our hospital between May 1997 and April 2001. In patients with significant stenosis or obstruction detected by head and neck magnetic resonance angiography, the findings were evaluated and cerebral blood flow was examined using brain single-photon emission computed tomography. In those with a high risk of cerebrovascular ischemia, off-pump coronary artery bypass was performed to maintain cerebral blood flow. No stroke occurred during surgery, and hemodynamic cerebrovascular ischemia was prevented in all 268 patients. Postoperative stroke occurred in 3 patients (1.1%), but the incidence of perioperative stroke was reduced.

Adult↗
PubMed2006

Dynamic morphologic changes in the normal aortic annulus during systole and diastole.

BACKGROUND AND AIM OF THE STUDY: The three-dimensional motion of semilunar attachment of the leaflet 'annulus' remains obscure. It has been suggested that the aortic root is distensible and moves during the cardiac cycle. In the present study, the aortic root was evaluated using two dimensions. The aortic root, notably motion of the aortic annulus, was evaluated using multidetector computed tomography (MDCT), and a three-dimensional reconstruction of the aortic annulus was performed. METHODS: Twenty-five patients (17 males, eight females) underwent MDCT. None of the patients had aortic root disease, aortic valve disease, bicuspid valve, myocardial infarction or atrial fibrillation. The aortic annulus was measured in systole and diastole, and divided into three parts: the right coronary cusp (RCC), left coronary cusp (LCC) and non-coronary cusp (NCC). The lengths of the aortic annulus, sinus of Valsalva and sinotubular junction (STJ) were also measured in systole and diastole on longitudinal views. RESULTS: The lengths of each aortic annulus part in systole and diastole were as follows. In systole: RCC 41.8 +/- 8.1 mm; LCC 39.3 +/- 5.9 mm; NCC 43.7 +/- 7.1 mm. In diastole: RCC 42.4 +/- 7.0 mm; LCC 38.6 +/- 7.8 mm; NCC 41.5 +/- 7.8 mm. No statistically significant differences were observed between lengths in systole and diastole. The longitudinal lengths of aortic annulus, sinus of Valsalva and STJ at each period were as follows. In systole: aortic annulus 22.5 +/- 2.2 mm; sinus of Valsalva 34.9 +/- 4.3 mm; STJ 28.1 +/- 3.2 mm. In diastole: aortic annulus 22.1 +/- 2.2 mm; sinus of Valsalva 34.4 +/- 4.7 mm; STJ 27.2 +/- 3.1 mm. The length of the STJ in systole was significantly greater than that in diastole. CONCLUSION: In the normal aortic root, no part of the aortic annulus changed length during the cardiac cycle. According to changes in aortic root dimensions, the commissures move outwards during the systolic phase.

Adult↗
PubMed2005

Three-dimensional recovery time dispersion map by 64-channel magnetocardiography may demonstrate the location of a myocardial injury and heterogeneity of repolarization.

BACKGROUND: QT dispersion reveals heterogeneities in the repolarization time in the three-dimensional (3D) structure of the ventricular myocardium. In this study, we report on a 3D function map of recovery time (RT) dispersions as measured by 64-channel magnetocardiography (MCG). METHODS: MCG were simultaneously recorded in 29 controls and 21 patients with previous myocardial infarction (MI). The 3D current density was calculated from 64-channel MCG data in the Bz component using a space filter. The heart outline, reconstructed from the integrated the current density, revealed both the atrium and ventricle. The RT for the intervals between QRS onset and the time of the maximum dT/dt of T wave, and the peak to the end of the T wave (T(peak)-negative dT/dt) were automatically measured by means of a computer from 3D MCG data. The corrected RT (RTc) and corrected T(peak)-negative dT/dt were then calculated using Bazett's formula. The 3D RTc and the corrected T(peak)-negative dT/dt dispersion map were superimposed on the heart outline generated by MCG. RESULTS: The RTc was significantly longer for the MI group than in the control group (67+/-25 ms1/2 vs. 16+/-6 ms1/2) (p<0.0001). The corrected T(peak)-negative dT/dt dispersions in each patient was also significantly longer for the MI group than in the control group (35+/-27 ms1/2 vs. 10+/-5 ms1/2) (p<0.0001). Furthermore, the 3D RTc and T(peak)-negative dT/dt dispersion maps corresponded with the space location of MI, as defined by Tc-99m tetrofosmin myocardial imaging CONCLUSIONS: 3D RTc and T(peak)-negative dT/dt dispersion maps in the ST segment, obtained by 64-channel MCG may be used demonstrate the location of a myocardial injury and heterogeneities of repolarization.

Adult↗
PubMed2005

Influence of gelatin-resorcin-formalin glue on mid-term redissection after aortic repair.

PURPOSE: To determine whether the development of mid-term redissection after surgery for acute type A aortic dissection using gelatin-resorcin-formalin (GRF) glue could be prevented by applying less formalin. METHODS: Between 1995 and 1999, 59 patients underwent surgery with GRF glue to repair acute type A aortic dissection. Forty-one patients underwent surgery before October 1998, and 18 patients underwent surgery after November 1998. An excessive amount of formalin was used in the former period and less was used in the latter period. RESULTS: Follow-up computed tomography was done for 34 patients in the former period (Former group) and for 16 patients in the latter period (Latter group). This showed redissection in 19 of the 34 patients in the Former group and in 6 of the 16 patients in the Latter group. There was no significant difference in the frequency of mid-term redissection between the two groups. CONCLUSION: The development of mid-term redissection of the aortic root was not prevented by applying less formalin in the GRF glue. Thus, we conclude that the cause of redissection is not entirely the result of too much formalin.

Aged↗
PubMed2005

Head and neck magnetic resonance angiography before coronary artery bypass grafting.

PURPOSE: To evaluate the incidence of vascular lesions in the head and neck by magnetic resonance angiography (MRA), and investigate the factors correlated with severe stenosis. METHODS: Elective coronary artery bypass grafting (CABG) was performed in 413 patients at our center between May 1997 and April 2001. We used MRA to detect head and neck vascular lesions, then evaluated the occlusive lesions and determined their prevalence. RESULTS: Neck MRA was performed in 335 patients and head MRA was performed in 335 patients. We found > or = 60% stenosis or total occlusion of the extracranial carotid and vertebral artery in 43 patients (12.8%) and > or = 60% stenosis or occlusion of the intracranial carotid and basilar artery, or stenosis accompanied by poor peripheral perfusion or occlusion of the cerebral arteries in 45 patients (13.4%). Occlusive lesions of the neck were significantly correlated with mean age, peripheral vascular disease (PVD), and old myocardial infarction. Occlusive lesions of the brain were significantly correlated with age, hypertension, PVD, and left main trunk disease. CONCLUSIONS: We found an equal incidence of intracranial and extracranial vascular lesions. Thus, searching for intracranial lesions is just as important as searching for extracranial lesions before CABG.

Adult↗
PubMed2005

Late complications following surgery for type A acute aortic dissection using gelatin-resorcin-formaldehyde glue: report of two cases.

Gelatin-resorcin-formaldehyde (GRF) glue has been widely applied during operations for acute aortic dissection (AAD). At our institution, GRF glue was applied in 40 patients who underwent surgical procedures for AAD from 1995, two of whom needed a reoperation because of the development of a redissection and/or a pseudoaneurysm at the anastomotic sites. The operative findings and histological examinations suggested that the application of GRF glue during the initial operations might be related to the development of a redissection and/or a pseudoaneurysm.

Aged↗
PubMed2005

Construction of a three-dimensional outline of the heart and conduction pathway by means of a 64-channel magnetocardiogram in patients with atrial flutter and fibrillation.

BACKGROUND: Magnetocardiography (MCG) has the potential for collecting three-dimensional (3D) intracardiac electric information, because the magnetic field is unaffected by the shape of the lungs and torso. In the present study, we report on the generation of a 3D heart outline and conduction pathway by means of a current density map using a 64-channel SQUID system, and an evaluation of its significance in patients with atrial flutter (AFL) and atrial fibrillation (AFIB). METHODS: The subjects consisted of 20 healthy volunteers, and 3 patients with AFL and 4 patients with AFIB. A 64-channel MCG was recorded after digitization at 500 Hz, and a 3D current density was reconstructed from the magnetic fields using a space filter in conjunction with the minimum normalization method of Tikhonov. A 3D heart outline was generated from the integrated current density by the space filter. The conduction pathway was superimposed on a heart outline generated by a magnetic field. The heart outline was verified by the silhouette on the magnetic resonance (MR) images. An MCG was recorded pre- and post interventional therapy, and therapeutic efficacy was evaluated. RESULTS: The 3D heart outline of the atrium and ventricle corresponded to the silhouette of the right atrium and left ventricle, respectively, on an MR image. The serial conduction pathway of the QRS segment superimposed on the 3D heart outline map demonstrated the conduction pattern generated within the heart. The MCG revealed a counter-clockwise rotation in patients with AFL, and random micro-reentry in the case of AFIB. After interventional therapy, restoration of the sinus rhythm was verified in patients with both AFL and AFIB. CONCLUSIONS: A 64-channel MCG was used to evaluate the 3D heart outline and conduction pathway in patients with AFL and AFIB without the need for MR images. Condensed Abstract A 64-channel MCG was used to evaluate the 3D heart out line and conduction pathway in patients with AFL and AFIB.

Aged↗
PubMed2005

[Coronary sinus ostial atresia with thrombus: a case report].

An 82-year-old woman presented with mitral regurgitation and atrial fibrillation. She was hospitalized for further examination of cardiac thrombus detected by transthoracic echocardiography. No definitive diagnosis could be made based on computed tomography and magnetic resonance imaging. Intravenous contrast echocardiography suggested a coronary sinus thrombus. Coronary angiography showed coronary sinus ostial atresia. Multislice computed tomography confirmed the presence of thrombus in the enlarged coronary sinus with coronary sinus ostial atresia and persistent left superior vena cava. Persistent left superior vena cava is present in 3% of patients with congenital heart disease. Persistent left superior vena cava is detected by chance during cardiac catheterization for other conditions in patients without cardiac malformations. The present case was detected at an advanced age, and in the absence of prior symptoms.

Aged↗
PubMed2004

Three-dimensional demonstration of total anomalous pulmonary venous return with contrast-enhanced magnetic resonance angiography.

A newborn male was hospitalized for a heart murmur and severe cyanosis after his birth. Echocardiography showed an abnormal vein crossing below the diaphragm; total anomalous pulmonary venous return (TAPVR, Darling type III) was suspected. A contrast-enhanced 3-dimensional magnetic resonance angiography (MRA) was performed on the 6th day after his birth to assess pulmonary vein stenosis. The MRA was obtained with a 1.5-T superconducting imager (Signa Horizon LX EchoSpeed, with 8.3 operating system software; GE Medical Systems, Milwaukee, WI) and a 4-channel phased array coil for the brain to optimize signal detection with the image sequence from a fast-spoiled gradient-echo (fast-SPGR) with fat suppression. Contrast medium (gadopentetate dimeglumine, 0.1 mmol/kg, Magnevist, Schering, Berlin, Germany), 0.6 mL, was administered at 0.2 mL/sec using a power injector.

Cardiovascular Abnormalities↗
PubMed2004

[Diagnosis of ischemic heart disease with coronary artery calcification score by electron beam computed tomography].

Coronary artery calcification score (CACS) by electron beam computed tomography (EBT) is determined as useful to access ischemic heart disease. Our study shows the availability of CACS by EBT among Japanese population as much as previous reports from abroad. Although EBT does not spread in Japan for less multipurposeness and good cost, multi-detector row CT which enables to measure CACS spread over Japan. It may be a useful tool for diagnosis of ischemic heart disease.

Calcinosis↗