Faculty Profiles - TAOKA Toshiaki

Papers - TAOKA Toshiaki

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[Evaluation of appearance with high-speed CE-3dMRDSA in brain].

Doi T, Nogi A, Taoka T, Hirohashi S

Nihon Hoshasen Gijutsu Gakkai zasshi Vol. 58 ( 12 ) page： 1615 - 21 2002.12

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society of Radiological Technology

We evaluated the fitting scan technique for CE-3dMRDSA, and found common ground that determines spatial resolution and time resolution (slab thickness and partition number). We also examined the relation between appearance and time resolution (volume of contrast medium and injection speed). To obtain good image contrast, the volume of contrast medium needs to be at least 7 ml and suitable for an injection speed of 3-5 ml/sec. However, when we increased the volume of contrast medium and decreased injection speed, changes in MRDSA images with time became worse. The measure of the bolus with contrast medium was found to determine image contrast. When contrast medium is injected earlier, it circulates earlier within the brain. If the scan time is not short enough, it is not possible to observe changes in MRDSA images. And when spatial resolution is improved, time resolution becomes worse. Therefore, it is important to find the point of compromise between spatial resolution and time resolution. If we look for anterior MIP images, the CNR in the spatial resolusion didn't change, when the slice thickness is more than 3 mm. Because, the partial volume effect decide the image contrast. However, unless the view is from the front, slice thickness influences spatial resolution. Therefore, when we view MIP images from the lateral direction, slice thickness must be set at less than 2 mm. Results indicated that, in CE-3dMRDSA with the fitting technique, slice thickness should be less than 3 mm, partition number 16-20, slab thickness 48 mm, contrast medium volume 7-10 ml, and injection speed 3-5 ml.

DOI： 10.6009/jjrt.kj00000921540

PubMed

CiNii Books

Method and timing of tumor volume measurement for outcome prediction in cervical cancer using magnetic resonance imaging.

Mayr NA, Taoka T, Yuh WT, Denning LM, Zhen WK, Paulino AC, Gaston RC, Sorosky JI, Meeks SL, Walker JL, Mannel RS, Buatti JM

International journal of radiation oncology, biology, physics Vol. 52 ( 1 ) page： 14-22 2002.1

Method and timing of tumor volume measurement for outcome prediction in cervical cancer using magnetic resonance Imaging Reviewed

NA Mayr, T Taoka, WTC Yuh, LM Denning, WNK Zhen, AC Paulino, RC Gaston, JI Sorosky, SL Meeks, JL Walker, RS Mannel, JM Buatti

INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS Vol. 52 ( 1 ) page： 14 - 22 2002.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

Purpose: Recently, imaging-based tumor volume before, during, and after radiation therapy (RT) has been shown to predict tumor response in cervical cancer. However, the effectiveness of different methods and timing of imaging-based tumor size assessment have not been investigated. The purpose of this study was to compare the predictive value for treatment outcome derived from simple diameter-based ellipsoid tumor volume measurement using orthogonal diameters (with ellipsoid computation) with that derived from more complex contour tracing/region-of-interest (ROI) analysis 3D tumor volumetry.
Methods and Materials: Serial magnetic resonance imaging (MRI) examinations were prospectively performed in 60 patients with advanced cervical cancer (Stages IB2-IVB/recurrent) at the start of RT, during early RT (20-25 Gy), mid-RT (45-50 Gy), and at follow-up (1-2 months after RT completion). ROI-based volumetry was derived by tracing the entire tumor region in each MR slice on the computer work station. For the diameter-based surrogate "ellipsoid volume," the three orthogonal diameters (d(1), d(2), d(3)) were measured on film hard copies to calculate volume as an ellipsoid (d(1) x d(2) x d(3) x pi/6). Serial tumor volumes and regression rates determined by each method were correlated with local control, disease-free and overall survival, and the results were compared between the two measuring methods. Median post-therapy follow-up was 4.9 years (range, 2.0-8.2 years).
Results: The best method and time point of tumor size measurement for the prediction of outcome was the tumor regression rate in the mid-therapy MRI examination (at 45-50 Gy) using 3D ROI volumetry. For the pre-RT measurement both the diameter-based method and ROI volumetry provided similar predictive accuracy, particularly for patients with small (<40 cm(3)) and large ( &GE;100 cm(3)) pre-RT tumor size. However, the pre-RT tumor size measured by either method had much less predictive value for the intermediate-size (40-99 cm(3)) tumors, which accounted for the majority of patients (55%). Tumor regression rate (fast vs. slow) obtained during mid-RT (45-50 Gy), which could only be appreciated by 3D ROI volumetry, had the best outcome prediction rate for local control (84% vs. 22%, p < 0.0001) and disease-free survival (63% vs. 20%, p = 0.0005). Within the difficult to classify intermediate pre-RT size group, slow ROI-based regression rate predicted all treatment failures (local control rate: 0% vs. 91%,p < 0.0001; disease-free survival: 0% vs. 73%, p < 0.0001). Mid-RT regression rate based on simple diameter measurement did not predict outcome. The early-RT and post-RT measurements were least useful with either measuring method.
Conclusion: Our preliminary data suggest that for the prediction of treatment outcome in cervical cancer, initial tumor volume can be estimated by simple diameter-based measurement obtained from film hard copies. When initial tumor volume is in the intermediate size range, ROI volumetry and an additional MRI during RT are needed to quantitatively analyze tumor regression rate for the prediction of treatment outcome. (C) 2002 Elsevier Science Inc.

DOI： 10.1016/S0360-3016(01)01808-9

Web of Science

Palmaz stent deployment for subclavian and brachiocephalic arterial occlusive disease. Factors predictive of restenosis.

Nakagawa H, Kichikawa K, Takayama K, Sakamoto M, Wada T, Taoka T, Fukusumi A, Iwasaki S, Uchida H, Sakaki T

Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences Vol. 7 ( Suppl 1 ) page： 49 - 52 2001.12

Detection of early venous filling in gliomas on MRI: Preliminary study by 2D time-resolved dynamic contrast-enhanced MR angiography with echo-sharing technique

Sakamoto M., Taoka T., Iwasaki S., Fukusumi A., Nakagawa H., Hirohashi S., Takayama K., Wada T., Kichikawa K., Uchida H., Ohishi H., Murata K., Okamoto J.

Magnetic Resonance Imaging Vol. 19 ( 9 ) page： 1193 - 1201 2001.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Magnetic Resonance Imaging

We evaluated the detection of early venous filling of gliomas by 2D time resolved dynamic contrast enhanced MR digital subtraction angiography (MR-DSA) with echo-sharing technique and compared the results with those of conventional contrast digital subtraction angiography (C-DSA). C-DSA and MR-DSA examinations were performed in eight patients with malignant gliomas and compared with regard to the visualization of early filling veins; time intensity curves of arteries, early filling veins and normal veins were made, and rise time and time to peak were evaluated. MR-DSA visualized 12 out of 17 early filling veins depicted on C-DSA. The failure of five veins to be depicted may be due to the overlapping of other structures, such as other vessels and tumor stain. On time intensity curves, the mean difference in rise time was 0.9 sec between the artery and early filling vein, and the mean difference of time to peak was 1.6 sec. C-DSA has been the modality of choice in demonstrating early venous filling, a useful finding in the differential diagnosis of gliomas. However the high temporal resolution of MR-DSA with echo-sharing technique provides sufficient visualization of early venous filling of gliomas. Additional information for precise differential diagnosis may be obtained by adding MR-DSA to the imaging protocol for gliomas. © 2001 Elsevier Science Inc. All rights reserved.

DOI： 10.1016/S0730-725X(01)00450-7

Scopus

Palmaz Stent deployment for subclavian and brachiocephalic arterial occlusive disease - Factors predictive of restenosis Reviewed

H Nakagawa, K Kichikawa, K Takayama, M Sakamoto, T Wada, T Taoka, A Fukusumi, S Iwasaki, H Uchida, T Sakaki

INTERVENTIONAL NEURORADIOLOGY Vol. 7 page： 49 - 52 2001.12

Language：English Publishing type：Research paper (scientific journal) Publisher：EDIZIONI CENTAURO

Palmaz stent deployment is a useful method for subclavian and brachiocephalic arterial occlusive disease. We evaluated restenosis or intimal thickening after Palmaz stent deployment for nine lesions of subclavian or brachiocephalic arterial occlusive disease focusing on stent diameter, atheroma thickness near the stent, and degree of coverage for the lesion. Follow up DSA and IVUS at 5-14 months (mean 9) after therapy showed no significant changes in the size or shape of the stent itself There were two lesions of thin in-stent intimal hyperplasia and five lesions of thick hyperplasia.
There was no close relationship between intimal hyperplasia and stent diameter or atheroma size (relative thickness). There was some relationship between the degree of coverage of the lesion by the stent and degree of intimal hyperplasia, but to determine statistical significance, accumulation of a greater number of cases is necessary.

Web of Science

Detection of early venous filling in gliomas on MRI: preliminary study by 2D time-resolved dynamic contrast-enhanced MR angiography with echo-sharing technique.

Sakamoto M, Taoka T, Iwasaki S, Fukusumi A, Nakagawa H, Hirohashi S, Takayama K, Wada T, Kichikawa K, Uchida H, Ohishi H, Murata K, Okamoto J

Magnetic resonance imaging Vol. 19 ( 9 ) page： 1193 - 201 2001.11

Detection of early venous filling in gliomas on MRI: Preliminary Study by 2D time-resolved dynamic contrast-enhanced MR angiography with echo-sharing technique Reviewed

M Sakamoto, T Taoka, S Iwasaki, A Fukusumi, H Nakagawa, S Hirohashi, K Takayama, T Wada, K Kichikawa, H Uchida, H Ohishi, K Murata

MAGNETIC RESONANCE IMAGING Vol. 19 ( 9 ) page： 1193 - 1201 2001.11

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

DOI： 10.1016/S0730-725X(01)00450-7

Web of Science

Factors influencing visualization of vertebral metastases on MR imaging versus bone scintigraphy Reviewed

T Taoka, NA Mayr, HJ Lee, WTC Yuh, TM Simonson, K Rezai, KS Berbaum

AMERICAN JOURNAL OF ROENTGENOLOGY Vol. 176 ( 6 ) page： 1525 - 1530 2001.6

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER ROENTGEN RAY SOC

OBJECTIVE. The purpose of this study was to investigate whether the location and size of vertebral body metastases influence the difference in detection rates between MR imaging and bone scintigraphy.
MATERIALS AND METHODS. We retrospectively evaluated the vertebral body lesions detected on MR imaging in 74 patients with known widely disseminated metastatic disease. Three radiologists independently reviewed the MR images and bone scintigraphs. MR imaging findings included lesion size and its spatial relationship to the bony cortex (intramedullary, subcortical, and transcortical) and results were correlated with those of planar technetium 99m bone scintigraphy.
RESULTS. Findings on bone scans were negative for all intramedullary lesions without cortical involvement shown on MR imaging, regardless of their size. Findings on bone scans (71.3% for transcortical and 33.8% for subcortical) were frequently positive for lesions with cortical involvement (trans- or subcortical), and the probability of positive findings on bone scans was also influenced by the lesion size. Statistical analysis showed a positive correlation among cortical involvement, lesion size, and positive findings on bone scintigraphy (p < 0.0001).
CONCLUSION. Location (the presence of cortical bone involvement on MR imaging) and size of the vertebral body metastases appear to be important contributing factors to the difference in detection rates between MR imaging and bone scintigraphy. Cortical involvement is likely the cause of positive findings on bone scans. Early vertebral metastases tend to be small and located in the medullary cavity without cortical involvement, and therefore, findings may be positive on MR images but negative on bone scans.

DOI： 10.2214/ajr.176.6.1761525

Web of Science

PubMed

Sulcal hyperintensity on fluid-attenuated inversion recovery MR images in patients without apparent cerebrospinal fluid abnormality Reviewed

T Taoka, WTC Yuh, ML White, JP Quets, JE Maley, T Ueda

AMERICAN JOURNAL OF ROENTGENOLOGY Vol. 176 ( 2 ) page： 519 - 524 2001.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER ROENTGEN RAY SOC

OBJECTIVE. Failure to suppress cerebrospinal fluid (CSF) signal intensity (sulcal hyperintensity) on fluid-attenuated inversion recovery (FLAIR) images has been reported in patients with abnormal CSF such as those with meningitis and subarachnoid hemorrhage. Our study investigates the clinical history and MR findings associated with sulcal hyperintensity on FLAIR images in patients without apparent CSF abnormality.
SUBJECTS AND METHODS. Three hundred consecutive MR imaging examinations were prospectively screened for patients with sulcal hyperintensity on FLAIR images. Nine patients with clinical, CT, or laboratory evidence suggesting abnormal CSF were excluded. The distribution of sulcal hyperintensity on FLAIR images and associated abnormal enhance ment were evaluated, The presence of the "dirty CSF" sign (mild increase in CSF signal on unenhanced T1-weighted images or mild decrease on T2-weighted images) in the corresponding hyperintense sulcus was also assessed.
RESULTS. Twenty-six (8.9%) of the 291 patients had sulcal hyperintensity (16 focal. 10 diffuse) associated with 18 masses (6.1%) and eight vascular abnormalities (2.7%). Sulcal hy perintensity was frequently associated with the dirty CSF sign (69.2%) and abnormal contrast enhancement (overall, 96.2%; 88.5%, leptomeningeal; 53.8%, vascular enhancement).
CONCLUSION. Our study shows that sulcal hyperintensity on FLAIR imaging can occur in patients without apparent CSF abnormality. Its frequent association with mass effect, vascular disease, abnormal vascular enhancement, and dirty CSF sign suggests that an increase in blood pool, a small amount of protein leakage, and the "flow-entering" phenomenon of the congested blood may contribute to sulcal hyperintensity on FLAIR images.

DOI： 10.2214/ajr.176.2.1760519

Web of Science

PubMed

Sulcal hyperintensity on fluid-attenuated inversion recovery MR images in patients without apparent cerebrospinal fluid abnormality Reviewed

T Taoka, WTC Yuh, ML White, JP Quets, JE Maley, T Ueda

AMERICAN JOURNAL OF ROENTGENOLOGY Vol. 176 ( 2 ) page： 519 - 524 2001.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER ROENTGEN RAY SOC

Web of Science

Chronic brain inflammation results in progressive MRI change and dementia in ischemic neurodegeneration Reviewed

Fujioka M, Taoka T, Matsuo Y, Mishima K, Fujiwara M, Ogoshi K, Kondo Y, Sakaki T, Park D, Siesjo B. K

Society for Neuroscience Abstracts Vol. 27 ( 2 ) page： 2304 2001

Palmaz stent deployment for subclavian and brachiocephalic arterial occlusive disease: Factors predictive of restenosis

Nakagawa H., Kichikawa K., Takayama K., Sakamoto M., Wada T., Taoka T., Fukusumi A., Iwasaki S., Uchida H., Sakaki T.

Interventional Neuroradiology Vol. 7 ( SUPPL. 1 ) page： 49 - 52 2001

Language：English Publishing type：Research paper (scientific journal) Publisher：Interventional Neuroradiology

Palmaz stent deployment is a useful method for subclavian and brachiocephalic arterial occlusive disease. We evaluated restenosis or intimal thickening after Palmaz stent deployment for nine lesions of subclavian or brachiocephalic arterial occlusive disease focusing on stent diameter, atheroma thickness near the stent, and degree of coverage for the lesion. Follow up DSA and IVUS at 5-14 months (mean 9) after therapy showed no significant changes in the size or shape of the stent itself. There were two lesions of thin in-stent intimal hyperplasia and five lesions of thick hyperplasia. There was no close relationship between intimal hyperplasia and stent diameter or atheroma size (relative thickness). There was some relationship between the degree of coverage of the lesion by the stent and degree of intimal hyperplasia, but to determine statistical significance, accumulation of a greater number of cases is necessary.

Scopus

MR imaging of pituitary morphology in idiopathic intracranial hypertension.

Yuh WT, Zhu M, Taoka T, Quets JP, Maley JE, Muhonen MG, Schuster ME, Kardon RH

Journal of magnetic resonance imaging : JMRI Vol. 12 ( 6 ) page： 808-13 2000.12

MR imaging of pituitary morphology in idiopathic intracranial hypertension Reviewed

WTC Yuh, MW Zhu, T Taoka, JP Quets, JE Maley, MG Muhonen, ME Schuster, RH Kardon

JOURNAL OF MAGNETIC RESONANCE IMAGING Vol. 12 ( 6 ) page： 808 - 813 2000.12

Language：English Publishing type：Research paper (scientific journal) Publisher：JOHN WILEY & SONS INC

The aim of this study was to investigate the morphologic changes of the pituitary gland in patients with the clinical diagnosis of idiopathic intracranial hypertension (IIH). Qualitative and quantitative analyses of pituitary morphology were performed in normal subjects (n = 23), patients with the clinical diagnosis of IIH (n = 40), and patients with acute increased intracranial pressure (AICP; n = 37) caused by acute head trauma. The loss of pituitary height (concavity) on the sagittal T1-weighted image was classified into five categories: I = normal, II = superior concavity that was mild (< (1)/(3) the height of the sella), III = moderate (between (1)/(3) and (2)/(3) concavity of height of sells), IV = severe (> (2)/(3) concavity of height of sells), and V = empty sells. The area ratio of pituitary gland to sella turcica measured in the midsagittal plane was quantified. Clinical records were retrospectively reviewed to correlate with magnetic resonance (MR) findings. Using moderate concavity (> (1)/(3)) as the minimum criterion for abnormality, IIH patients had an 85% incidence of morphologic changes with 80% sensitivity and 92% specificity. Empty sells (almost complete concavity of the sella) was found in only 2.5% of patients with IIH. Quantitative analysis of the pituitary gland/sella turcica area ratio showed a significant decrease in patients with IIH (P < 0.0001) but no significant difference between the normal subjects and AICP patients. A posterior deviation of the pituitary stalk was seen in 43% of patients. No enlargement of the ventricles or sulcal effacement was seen in IIH patients. Routine brain MR examination of patients with IIH frequently shows morphologic changes of the pituitary gland ranging from various degrees of concavity to (rarely) the extreme case of an empty sella. The etiology is unknown and may be related to the severity and duration of elevated CSF pressure. Such findings may be useful to facilitate the diagnosis of IIH, particularly in patients with equivocal clinical findings or when IIH is not suspected. (C) 2000 Wiley-Liss, Inc.

DOI： 10.1002/1522-2586(200012)12:6<808::AID-JMRI3>3.0.CO;2-N

DOI： 10.1002/1522-2586(200012)12:6<808::aid-jmri3>3.0.co;2-n

Web of Science

Magnetic resonance imaging in the assessment of radiation response in cervical cancer: regarding Hatano K et al. IJROBP 1999; 45:399-344.

Mayr NA, Taoka T, Yuh WT, Zhen WK, Paulino AC, Sorosky JI, Buatti JM

International journal of radiation oncology, biology, physics Vol. 48 ( 3 ) page： 910-2 2000.10

Magnetic resonance imaging in the assessment of radiation response in cervical cancer: Regarding Hatano K et al. IJROBP 1999;45 : 339-344. Reviewed

NA Mayr, T Taoka, WTC Yuh, WNK Zhen, AC Paulino, JI Sorosky, JM Buatti

INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS Vol. 48 ( 3 ) page： 910 - 911 2000.10

Functional magnetic resonance imaging using iron oxide particles in characterizing head and neck adenopathy.

Hoffman HT, Quets J, Toshiaki T, Funk GF, McCulloch TM, Graham SM, Robinson RA, Schuster ME, Yuh WT

The Laryngoscope Vol. 110 ( 9 ) page： 1425-30 2000.9

Enhancement pattern of normal extraocular muscles in dynamic contrast-enhanced MR imaging with fat suppression.

Taoka T, Iwasaki S, Uchida H, Fukusumi A, Kichikawa K, Nakagawa H, Takayama K, Sakamoto M, Ohishi H

Acta radiologica (Stockholm, Sweden : 1987) Vol. 41 ( 3 ) page： 211 - 6 2000.5

Enhancement pattern of normal extraocular muscles in dynamic contrast-enhanced MR imaging with fat suppression Reviewed

T Taoka, S Iwasaki, H Uchida, A Fukusumi, K Kichikawa, H Nakagawa, K Takayama, M Sakamoto, H Ohishi

ACTA RADIOLOGICA Vol. 41 ( 3 ) page： 211 - 216 2000.5

Language：English Publishing type：Research paper (scientific journal) Publisher：MUNKSGAARD INT PUBL LTD

Purpose. To evaluate the internal structure of normal extraocular muscles on fat-suppressed dynamic contrast-enhanced MR imaging.
Material and Methods. Ten subjects were examined using fat-suppressed dynamic contrast-enhanced MR imaging. We evaluated the enhancement pattern (C-shaped or ring-like) of extraocular muscles and quantified the maximum ratios of enhancement (R-max) and maximum ratios of signal increase (V-max). We also quantified R-max and V-max in the central and peripheral portions of medial rectus muscles.
Results: in the early phase of dynamic contrast-enhanced MR imaging, a C-shaped or ring-like pattern was observed in 100% of inferior rectus, 95% of medial rectus, 55% of superior rectus, 20% of lateral rectus, and 15% of superior oblique muscles. Overall mean R-max and V-max values showed statistically significant differences to the temporal muscles. For the peripheral portion of medial rectus muscles, mean R-max and V-max values were greater than for the central portion.
Conclusion: Using fat-suppressed dynamic contrast-enhanced MR imaging, the C-shape or ring-like internal structure of the extraocular muscles could be visualized, and were considered to reflect their structure of orbital and global layers. Potential usefulness of the fat-suppressed dynamic contrast-enhanced MR imaging for detecting pathological status is suggested.

DOI： 10.1080/028418500127345361

Web of Science

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Papers - TAOKA Toshiaki