Mitsue Miyazaki

Toshiba America Medical Systems, Inc., Tustin, California, United States

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Publications (60)122.02 Total impact

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    ABSTRACT: Magnetic resonance imaging (MRI) cardiac gated phase contrast (PC) cine techniques have non-invasively shown the effect of the cardiac pulse on cerebrospinal fluid (CSF) movement. Echo planar imaging (EPI) has shown CSF movement as influenced by both cardiac pulsation and respiration. Previously, it has not been possible to visualize CSF movement in response to respiration non-invasively. The present study was undertaken to do so. The effect of respiration on CSF movement was investigated using a non-contrast time-spatial labeling inversion pulse (Time-SLIP) with balanced steady-state free precession (bSSFP) readout. CSF movement was observed in the intracranial compartment in response to respirations in ten normal volunteers. To elucidate the respiration effect, the acquisition was triggered at the beginning of deep inhalation, deep exhalation and breath holding. By employing this respiration-induced spin labeling bSSFP cine method, we were able to visualize CSF movement induced by respiratory excursions. CSF moved cephalad (16.4 +/- 7.7 mm) during deep inhalation and caudad (11.6 +/- 3.0 mm) during deep exhalation in the prepontine cisternal area. Small but rapid cephalad (3.0 +/- 0.4 mm) and caudad (3.0 +/- 0.5 mm) movement was observed in the same region during breath holding and is thought to reflect cardiac pulsations. The Time-SLIP bSSFP cine technique allows for non-invasive visualization of CSF movement associated with respiration to a degree not previously reported.
    Fluids and barriers of the CNS. 12/2013; 10(1):36.
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    ABSTRACT: PURPOSE To compare Fresh blood imaging (FBI), a noncontrast MRA method, using a 3T MR equipment (3T-FBI) with that at 1.5 T (1.5T-FBI) in the evaluation of the iliac and lower extremity arterial system. METHOD AND MATERIALS Peripheral pulse gated FBI was performed for 6 healthy volunteers (5 male, 1 female, mean age 24.8 y.o.) using both 3T and 1.5T with optimized parameters for each equipment. The iliac and lower extremity arteries were divided into four groups; group A was relatively larger arteries which included common iliac, external iliac, superficial femoral, and popliteal arteries. Group B contained arteries with small branches which included internal iliac and deep femoral arteries. Group C included anterior tibial, peroneal, and posterior tibial arteries, Group D contained arteries of foot which included dorsal, plantar, and metatarsal arteries. Visualization of each artery by 3T-FBI and 1.5T-FBI was graded separately with 5-point scale (5; excellent, 4; good, 3; fair, 2; poor, 1; none). Contrast-to-noise ratio (CNR) and full width at half maximum (FWHM) were calculated using an ROI method at subtracted images between systolic and diastolic acquisitions for the common iliac, external iliac, superficial femoral, and popliteal arteries. The Mann-Whitney U test and the paired t-test were used for statistical analysis. RESULTS In all groups, arterial visualization of 3T-FBI was significantly superior to those of 1.5T-FBI; in Group A, average score was 3T=4.77, 1.5T=4.04 (p<0.001); in Group B; 3T=4.67, 1.5T=3.04 (p<0.001); in Group C, 3T=4.63, 1.5T=3.75 (p<0.001); and in Group D, 3T=4.04, 1.5T=2.21 (p<0.001). CNR of 3T-FBI was significantly higher than that of 1.5 T (83.0 ± 19.8, 48.3 ± 18.5, respectively, p<0.001). FWHM of 3T-FBI was slightly larger than that of 1.5T-FBI (p<0.05), which may be caused by a longer echo space of fast spin echo of 3T (5msec) than that of 1.5 T (4msec). CONCLUSION FBI at 3T clearly demonstrated lower extremity arteries with higher CNR, especially in the smaller and more peripheral arteries which could not be depicted well at 1.5T-FBI CLINICAL RELEVANCE/APPLICATION FBI examined at 3T is significantly superior to that at 1.5T, especially for peripheral and smaller arteries which could not be well demonstrated at 1.5T-FBI.
    5T. Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
  • Mitsue Miyazaki, Andrew Wheaton, Shinichi Kitane
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    ABSTRACT: PURPOSE: To evaluate a new fat suppression technique using multiple fat suppression pulses intended for breast dynamic contrast-enhanced (DCE) imaging using segmented three-dimensional fast field echo (FFE). MATERIALS AND METHODS: The effect of multiple spectrally-selective fat suppression radiofrequency pulses was modeled using numerical Bloch-equation solutions for the following fat suppression techniques: spectral-selective inversion recovery (SPIR: one pulse), double fat suppression (DFS: two pulses, combining one SPIR pulse and one CHESS pulse), and triple fat suppression (TFS: three pulses, combining one SPIR pulse and two CHESS pulses). The simulation data were evaluated in terms of fat suppression performance, scan time, and specific absorption rate (SAR) relative to the SPIR technique. The DFS technique was selected as the optimal technique based on the efficacy of fat suppression versus the costs of scan time and SAR. The DFS technique was compared with SPIR in six volunteer studies using segmented T(1) -weighted three-dimensional FFE. RESULTS: The DFS technique produced sufficient fat suppression using only two segments (two fat suppression shots). Breast DCE precontrast images using DFS presented uniform fat suppression compared with SPIR in both axial and sagittal scans in all six volunteers. CONCLUSION: DFS is a promising fat suppression technique for breast imaging even in regions with B 1+ inhomogeneity. J. Magn. Reson. Imaging 2013;. © 2013 Wiley Periodicals, Inc.
    Journal of Magnetic Resonance Imaging 11/2012; · 2.57 Impact Factor
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    Andrew J Wheaton, Mitsue Miyazaki
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    ABSTRACT: Noncontrast-enhanced magnetic resonance angiography (NCE-MRA) methods have been demonstrated in anatomies throughout the body. Previously established NCE-MRA techniques suffered from long scan times or low sensitivity. Advances in hardware and software have made NCE-MRA scan times clinically feasible. Recent concerns over the safety of gadolinium-based contrast material combined with the expense of the material and its administration have generated a demand for NCE-MRA. In response, several new NCE-MRA methods have been developed. The physical mechanisms underlying five general classes of NCE-MRA methods (inflow effect, flow-dependency on cardiac phase, flow-encoding, spin labeling, and relaxation) are explained. The original techniques of time-of-flight (TOF) and phase contrast MRA (PC-MRA) are briefly introduced. New developments in NCE-MRA, including hybrid of opposite-contrast (HOP-MRA), four dimensional PC-MRA (4D Flow), cardiac-gated 3D fast-spin-echo, flow-sensitive dephasing (FSD), arterial spin labeling (ASL), and balanced steady-state free-precession (bSSFP) are highlighted. The primary applications, advantages, and limitations of established and emerging NCE-MRA techniques are discussed.
    Journal of Magnetic Resonance Imaging 08/2012; 36(2):286-304. · 2.57 Impact Factor
  • Mitsue Miyazaki, Masaaki Akahane
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    ABSTRACT: Until recently, time-of-flight (TOF) and phase contrast (PC) were the only non-contrast MR angiography (NC-MRA) techniques practically used in clinical. In the decade, NC-MRA have been gained a revival of an interest among the MR researchers and scientists, in part because of safety concerns related to the possible link between gadolinium-based contrast agents and nephrogenic systemic fibrosis (NSF). This article introduces other established NC-MRA techniques, such as ECG-gated partial Fourier fast spin echo (FSE) and balanced steady-state free precession (bSSFP), both with and without arterial spin labeling. Then, the article focuses on two main applications: peripheral run-off and renal MRA. Recently, both applications have achieved remarkable advancements and have become a viable clinical option as an alternative to contrast-enhanced (CE)-MRA. In addition, developments on the horizon including whole body MRA applications and further advancement at 3 Tesla are discussed.
    Journal of Magnetic Resonance Imaging 01/2012; 35(1):1-19. · 2.57 Impact Factor
  • Mitsue Miyazaki, Masaaki Akahane
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    ABSTRACT: Until recently, time-of-flight (TOF) and phase contrast (PC) were the only non-contrast MR angiography (NC-MRA) techniques practically used in clinical. In the decade, NC-MRA have been gained a revival of an interest among the MR researchers and scientists, in part because of safety concerns related to the possible link between gadolinium-based contrast agents and nephrogenic systemic fibrosis (NSF). This article introduces other established NC-MRA techniques, such as ECG-gated partial Fourier fast spin echo (FSE) and balanced steady-state free precession (bSSFP), both with and without arterial spin labeling. Then, the article focuses on two main applications: peripheral run-off and renal MRA. Recently, both applications have achieved remarkable advancements and have become a viable clinical option as an alternative to contrast-enhanced (CE)-MRA. In addition, developments on the horizon including whole body MRA applications and further advancement at 3 Tesla are discussed. J. Magn. Reson. Imaging 2012 © 2011 Wiley Periodicals, Inc.
    Journal of Magnetic Resonance Imaging 01/2012; 35(1):spcone. · 2.57 Impact Factor
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    ABSTRACT: To visualize the movement of pancreatic juice noninvasively by using an unenhanced magnetic resonance (MR) imaging technique. Institutional review board approval and informed consent were obtained for this study. A flow-out technique of time-spatial labeling inversion pulse (SLIP) technique was applied using both nonselective and selective inversion pulses to label, or tag, pancreatic juice to move out of the region. Ten normal (eight men, two women; age range, 22-61 years; mean age, 35 years) and two pathologic conditions were examined on a commercially available 1.5 Tesla MR imager with quadrature-detected phased-array coils. All images were evaluated by two radiologists to assess depiction of the pancreatic juice movement or pancreatic juice reflux as compared to the pancreatic duct or the common bile duct on MRCP obtained before time-SLIP examination. The tagged pancreatic juice was satisfactory visualized after applying the pulse labeling. Noninvasive visualization of pancreatic juice movement, including normal pancreatic juice movement and reflux from the main pancreatic duct into the common bile duct, was possible by using the unenhanced time-SLIP technique. Noninvasive visualization of pancreatic juice movement is possible by using the unenhanced MR imaging time-SLIP technique.
    Journal of Magnetic Resonance Imaging 12/2011; 35(5):1119-24. · 2.57 Impact Factor
  • Mitsue Miyazaki, Hiroyoshi Isoda
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    ABSTRACT: Non-contrast-enhanced magnetic resonance angiography (MRA) techniques have experienced a resurgence of interest in the MR community, in part because of safety concerns related to the possible link between gadolinium-based contrast agents and nephrogenic systemic fibrosis (NSF). In abdominal MRA, NSF is of particular concern, given that many of the patients may have renal disease. After introducing various non-contrast-enhanced MRA techniques, this article focuses on MRA applications in the abdomen, specifically the renal arteries and portal and hepatic veins. Developments on the horizon are discussed, including techniques that provide standardization of renal artery imaging, challenges in imaging of the hepatic arteries, and further advancement at 3T.
    European journal of radiology 02/2011; 80(1):9-23. · 2.65 Impact Factor
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    ABSTRACT: To evaluate the diagnostic performance of nonenhanced magnetic resonance (MR) angiographic flow-in technique with three-dimensional balanced steady-state free precession (SSFP) (flow-in balanced SSFP), compared with digital subtraction angiography (DSA) as reference standard, for assessment of renal artery stenosis (RAS) in chronic kidney disease (CKD) patients. Institutional review board approval and written informed consent were obtained for this prospective HIPAA-compliant study. Twenty-three patients, 13 men (mean age, 67.6 years ± 8.1 [standard deviation]; age range, 58-86 years) and 10 women (mean age 73.1 years ± 12.4; age range, 49-89 years), were evaluated with flow-in balanced SSFP and DSA. Coronal and axial flow-in balanced SSFP images were obtained with 1.5-T system, with regulated breathing (recorded voice instruction). The quality of flow-in balanced SSFP images was visually evaluated; the degree of stenosis was compared between flow-in balanced SSFP source images and DSA images by using the Wilcoxon signed-rank test. Correlation between images from both modalities was calculated as the Spearman rank-order correlation coefficient; bias was examined with Bland-Altman plots. Diagnostic images were obtained in all patients. Flow-in balanced SSFP image quality was good in 87% (20 of 23) and moderate in 13% (three of 23) of patients. Forty-five renal arteries were included in the statistical analysis. Of 36 stenoses detected with flow-in balanced SSFP, 28 were relevant (degree of stenosis, ≥ 50%). The stenosis measurements of flow-in balanced SSFP were highly correlated (ρ = 0.91, P < .001) with those of DSA. The Bland-Altman plot showed a slight overestimation of the degree of stenosis (mean bias, 2.33% ± 11.95). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of flow-in balanced SSFP relative to DSA for the diagnosis of a stenosis of 50% or greater were 93% (26 of 28), 88% (15 of 17), 93% (26 of 28), 88% (15 of 17), and 91% (41 of 45), respectively. Flow-in balanced SSFP with regulated breathing is an appropriate nonenhanced MR angiographic technique for RAS assessment in CKD patients. Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101422/-/DC1.
    Radiology 02/2011; 259(2):592-601. · 6.34 Impact Factor
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    ABSTRACT: Flow-spoiled fresh blood imaging, a noncontrast peripheral MR angiography technique, allows the depiction of the entire tree of peripheral arteries by utilizing the signal difference between systolic- and diastolic-triggered data. The image quality of the technique relies on selecting the right triggering delay times and flow-dependent read-out spoiler gradient pulses. ECG triggering delays were verified using manual subtraction and automated software. The read-out spoiler gradients pulses were optimized on volunteers before utilizing the flow-spoiled fresh blood imaging technique to screen for peripheral arterial disease. Thirteen consecutive patients with suspected peripheral arterial disease underwent both flow-spoiled fresh blood imaging and 16-detector-row computed tomography angiography examinations. A total of 23 segments were evaluated in the arterial vascular system. Using computed tomography angiography as the reference standard, 56 diseased segments were detected with 22 nonsignificant stenoses (<50%) and 34 significant stenoses, 15 of which were totally occluded. Flow-spoiled fresh blood imaging had a sensitivity of 97%, a specificity of 96%, an accuracy of 96%, a positive predictive value of 88%, and a negative predictive value of 99%. With such a high negative predictive value, flow-spoiled fresh blood imaging has the potential to become the safest noninvasive screening tool for peripheral arterial disease, especially for patients with impaired renal function.
    Magnetic Resonance in Medicine 02/2011; 65(2):595-602. · 3.27 Impact Factor
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    ABSTRACT: We prospectively assessed the diagnostic accuracy of non-contrast-enhanced MR venography using both the flow-refocused fresh-blood imaging (FR-FBI) and the swap phase-encode arterial double-subtraction elimination (SPADE) techniques for detecting deep vein thrombosis (DVT), as compared using conventional X-ray venography as the reference standard. Forty-one legs of 32 consecutive patients (eight men, 24 women; mean age +/- standard deviation, 69.4 +/- 15.3 years) suspected of having deep vein thrombosis and thus examined using conventional X-ray venography underwent MR FR-FBI and SPADE. Twenty-five of the 32 patients had nonmagnetizing, metal implants they had received during hip or leg surgery. Two radiologists independently assessed the MR venograms as either diagnostic or nondiagnostic and with either the presence or absence of thrombi. The sensitivities of FR-FBI and SPADE for diagnosing thrombus were 100% (53 of 53) for both reviewers. Nondiagnostic segments were excluded from this analysis. The corresponding specificities were 100% (238 of 238 for reviewer A) and 99.6% (237 of 238 for reviewer B). The interobserver agreement regarding the MR images for the assessment of thrombosis was high (kappa = 0.92). Non-contrast-enhanced MR venography using SPADE and FR-FBI is highly accurate and reproducible for diagnosing DVT. This is especially advantageous for patients who have received nonmagnetizing, metal implants during orthopedic surgery.
    Magnetic Resonance in Medicine 07/2010; 64(1):88-97. · 3.27 Impact Factor
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    ABSTRACT: To evaluate the efficacy of subtracted MR images from two sets of unenhanced three-dimensional (3D) MR angiography data (tag-on and tag-off images) acquired simultaneously during a single breath-hold in assessing the intraportal venous flow distribution to the distal branches from the superior mesenteric vein (SMV) and the splenic vein (SpV). Tag-on and tag-off MR images during a single breath-hold were obtained in 25 normal subjects. Tagging pulse was placed on the SMV or SpV separately to study inflow correlation of tagged blood into the portal vein. On the MR images tagged on the SMV, the mean ratings of visibility of tagged blood flow on the subtracted images were significantly higher (P = 0.016-0.0001) than those on the source images in almost all branches except second-ordered left portal vein (P = 0.096). On the subtracted MR images tagged on SMV, the tramline (16 of the 25 subjects) was the most common distribution pattern of the tagged blood inflow in the main portal vein. Subtracted MR images from two sets of unenhanced 3D MR angiography data (tag-on and tag-off images) acquired simultaneously would be effective to show the blood flow distribution of tagged blood into the portal vein and distal branches from SMV and SpV under the physiological condition without contrast injections.
    Journal of Magnetic Resonance Imaging 05/2009; 29(5):1224-9. · 2.57 Impact Factor
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    ABSTRACT: Three noncontrast-enhanced MR venography techniques are presented for assessing deep vein thrombosis (DVT) at 0.5 T in patients with metallic implants. Two cardiac-gated 3D half-Fourier FSE fresh blood imaging sequences with flow-refocusing pulses (FR-FBI) in the read-out (RO) direction and without FR pulses (non-FR-FBI) were developed for slower-flowing blood. For faster flowing blood, a swap phase-encode arterial double-subtraction elimination (SPADE) technique was developed. The three techniques were assessed both quantitatively using signal-to-noise (SNR) and contrast-noise-ratio (CNR) measurements and qualitatively by subjective image analysis in 15 volunteers. SPADE was compared to FR-FBI in the pelvic veins and FR-FBI was compared to non-FR-FBI in the thigh and calf veins. Both SPADE and FR-FBI techniques produced significantly higher SNRs, CNRs, and image quality in each comparative study (P<0.001). Five patients with metallic implants and confirmed DVT underwent SPADE (pelvic veins) and FR-FBI (thigh and calf veins) examinations and the results were compared to conventional venography. The SPADE and FR-FBI images showed all DVTs from all five patients without interference from implant susceptibility artifacts. The excellent image quality produced by both SPADE and FR-FBI throughout peripheral vasculature demonstrates their promise for detecting DVT in postsurgery patients.
    Magnetic Resonance in Medicine 02/2009; 61(4):907-17. · 3.27 Impact Factor
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    ABSTRACT: Institutional review board approval and informed consent were obtained for this study. This study was HIPAA compliant. The purpose of this study was to visualize the movement of cerebrospinal fluid (CSF) noninvasively by using an unenhanced magnetic resonance imaging technique. A time-spatial labeling inversion pulse (SLIP) technique was applied to label, or tag, CSF in a region of interest. The tagged CSF was clearly visualized at inversion times of 1500-4500 msec after pulse labeling in both intracranial and intraspinal compartments. Noninvasive visualization of CSF movement, including bulk and turbulent flow, in normal (n = 7) and altered (n = 2) physiologic conditions was possible by using the unenhanced time-SLIP technique.
    Radiology 12/2008; 249(2):644-52. · 6.34 Impact Factor
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    ABSTRACT: The association between a gadolinium-based contrast material and nephrogenic systemic fibrosis has been discussed. The purpose of our study was to evaluate whether non-contrast enhanced magnetic resonance angiography (MRA) might provide sufficient information of renal artery stenosis. The non-contrast MRA of 26 patients with hypertension was retrospectively reviewed in the present study. The significant renal artery stenosis was visually evaluated by comparing non-contrast MRA with computed tomography or conventional angiographic finding. Difference of the intensities between the proximal and distal aorta was quantitatively evaluated. The sensitivity, specificity, positive predictive value and negative predictive value of non-contrast MRA in the evaluation of the renal artery stenosis was 78%, 91%, 64% and 96%, respectively. The distal abdominal aorta showed less signal intensity than the proximal aorta by 16.9+/-12.2%. Non-contrast MRA is a non-invasive and effective method that allows evaluation of the renal artery stenosis.
    Circulation Journal 09/2008; 72(10):1627-30. · 3.58 Impact Factor
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    ABSTRACT: OBJECTIVE: Eighteen healthy persons underwent unenhanced MR angiography with a breath-hold ECG-synchronized 3D half-Fourier fast spin-echo technique to evaluate the visibility of the portal vein and its branches. CONCLUSION: Our results indicated that unenhanced MR angiography with a singlebreath-hold ECG-synchronized 3D half-Fourier fast spin-echo sequence facilitates precise visualization of the anatomic features of the portal vein and its branches without the use of contrast agents.
    American Journal of Roentgenology 08/2008; 191(2):550-4. · 2.90 Impact Factor
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    Journal of Cardiovascular Magnetic Resonance 01/2008; · 4.44 Impact Factor
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    ABSTRACT: PURPOSE To evaluate the feasibility of a non-contrast time resolved MR angiography (MRA) technique using ECG-gated two-dimensional half-Fourier FSE by measuring an arterial pulse wave velocity (PWV), which is thought as an indicator of the arterial stiffness. METHOD AND MATERIALS All MR examinations were performed using a Toshiba EXCELART 1.5T with a torso SPEEDER coil. The 2D single-shot images in multiple cardiac phases using a 5 or 10 msec interval were acquired in the coronal plane with ECG-triggered half-Fourier FSE, TR of 3- or 4RR interval, ETS of 4 ms, TEeff of 32 ms, matrix of 192x256, and a 70-mm thick slice. Signal change at two points in the lower extremity artery was measured using an ROI analysis from the time-signal intensity curve. The PWV was calculated using PWV=D/T; where T is a transit time of the signal decrease point in the signal intensity curve and D is a distance between the two ROIs manually measured on the computer screen. Twenty-five subjects include 6 normal volunteer (mean age; 27.6 y.o.), 11 patients without symptoms or past history of cardiovascular diseases (mean age; 74.1 y.o.), and 6 patients with arteriosclerosis obliterans (ASO) (mean age; 71.5 y.o.). We evaluated that 1) the relationship of PWV and age, 2) alternation of PWV in patients with atherosclerosis, and 3) the correlation between PWV and brachial - ankle PWV (baPWV). The baPWV was measured using a volume-plethymographic apparatus. RESULTS The PWV increases linearly with ages in the normal subjects (r=0.64). The PWV of the ASO patients was significantly higher than that of healthy subjects (13.6±5.4 m/sec, 8.0±2.3 m/sec, respectively; p<0.05). A well-correlated phenomenon is observed between the two measurements (r=0.58, p<0.01). Our method allows observation of the regional change of PWV. CONCLUSION The technique can be incorporated in the routine clinical study of MRA; therefore, it becomes possible to evaluate functional changes of arterial wall using PWV and morphology using non-contrast MRA. CLINICAL RELEVANCE/APPLICATION A non-contrast time resolved MR angiography technique using ECG-gated two-dimensional half-Fourier FSE allows evaluation of the change in arterial wall stiffness as well as flow dynamics.
    Radiological Society of North America 2007 Scientific Assembly and Annual Meeting; 11/2007
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    ABSTRACT: PURPOSE Fresh blood imaging (FBI) is a nonenhanced MR angiography technique, which employs arterial signal difference between systole and diastole during a cardiac cycle. Larger signal difference between two phases allows better conspicuous arterial demonstration. Cardiac output and peripheral blood flow physiologically increase after a food intake. The purpose of this study is to evaluate the effect of food intake on the visualization of peripheral arteries and the quality of the FBI images, and then determine the optimal examination timing. METHOD AND MATERIALS All MR examinations were performed using a 1.5-T system using a torso QD coil. Both diastolic and systolic 3D data were acquired with ECG-triggered half-Fourier FSE. The subtracted images between the systolic and diastolic images underwent MIP processing. Pelvic and femoral region of six normal healthy volunteers were examined at six phases as follows; phase 1, pre-food intake (about 7 hours after previous meal); phase 2, just after; phase 3, 1 hour after; phase 4, 2 hours after; phase 5, 4 hours after; phase 6, 10 hours after. The images were evaluated regarding with, A, visualization of arteries; B, separation of artery and vein; and C, an effect of peristalsis of digestive tracts on an arterial demonstration. RESULTS At phase 2, 3, 4, and 5, arterial signal was significantly higher and more conspicuous, and the visualization of small peripheral vessels got better than at phase 1 and 6 (p<0.05). Because heart rate increased and R-R interval of ECG became short at phase 2 and 3, the determination of suitable delay time for systolic or diastric acquisition was difficult, resulting poor arterio-venous separation. In pelvic examination in some cases, misregistration artifacts due to peristalsis of digestive tract make arterial demonstration poor at phase 2, 3, and 4. CONCLUSION Depiction of peripheral arteries using FBI improves after food intake, which may be reflecting the increase in peripheral blood flow. Three to five hours after food intake is thought to be optimal for FBI examination. CLINICAL RELEVANCE/APPLICATION Depiction of peripheral arteries using nonenhanced FBI improves after food intake and this exam is recommended to be performed at 3 to 5 hours after food intake.
    Radiological Society of North America 2006 Scientific Assembly and Annual Meeting; 11/2006
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    ABSTRACT: PURPOSE A novel 2D non-contrast MR digital subtraction angiography (NC-MRDSA) technique using ECG-gated 2D half-Fourier FSE, employing flow void phenomenon of pulsatile flow, provides DSA-like images without contrast materials. The purpose of this study is to evaluate the feasibility of quantitative analysis of NC-MRDSA, regarding with the assessment of the severity of peripheral arterial diseases. METHOD AND MATERIALS Twenty-five consecutive patients with peripheral arterial diseases were evaluated. All MR examinations were performed using a 1.5-T system with a torso QD coil. Single-shot thick slice images in multiple cardiac phases with a 10 msec interval were acquired with 2D half-Fourier FSE. The diastolic image was subtracted from the following systolic images, resulting in obtaining the images demonstrating hemodynamic flow. The grade of stenosis was determined with using 3-point scale (grade 1, <49% stenosis; grade 2, 50%-99%; grade 3, 100%). Signal changes were measured using ROI analysis, which was placed distal to stenosis or occlusion, from the time of a trigger R wave to the starting point of signal decrease (SPD) at the systolic phase. The SPD was compared with Fontaine stages, the grade of stenosis and ankle-brachial index (ABI). RESULTS The average SPD of the grade 2 stenosis was significantly longer than that with grade 1 (115±16 msec, 78±14 msec, respectively, p<0.01). The average SPD of the grade 3 was significantly longer (170±21 msec) than that with grade 2 (p<0.01), or that with grade 1 (p<0.01). The average SPD of Fontaine stage of II, III, and IV was significantly longer than that of Fontaine I (p<0.01). There was an inverse correlation between SPD and ABI with a correlation coefficient of -0.72. CONCLUSION The delay in SPD according to the high Fontaine stage, the high grade of stenosis, and lower ABI, was thought that pulse wave transmission was delayed because of decreased pressure owing to occlusion or severe stenosis. NC-MRDSA allows flow dynamic information without contrast materials. CLINICAL RELEVANCE/APPLICATION Non-contrast MRDSA can demonstrate flow dynamic information without contrast materials and is recommended as part of MR angiography for peripheral vascular diseases.
    Radiological Society of North America 2006 Scientific Assembly and Annual Meeting; 11/2006

Publication Stats

534 Citations
122.02 Total Impact Points

Institutions

  • 2003–2012
    • Toshiba America Medical Systems, Inc.
      Tustin, California, United States
  • 2011
    • Advance MRI
      Frisco, Texas, United States
  • 2010
    • Osaka City University
      • Graduate School of Medicine
      Ōsaka-shi, Osaka-fu, Japan
  • 2009
    • Kawasaki Medical University
      Kurasiki, Okayama, Japan
    • Osaka University
      • Department of Medical Physics and Engineering
      Ōsaka-shi, Osaka-fu, Japan
  • 2002
    • Yamaguchi University
      • Division of Radiology
      Yamaguti, Yamaguchi, Japan
  • 2000
    • Nagoya University
      • Division of Radiology
      Nagoya-shi, Aichi-ken, Japan
    • Mitsubishi Nagoya Hospital
      Nagoya, Aichi, Japan
  • 1999
    • Toho University
      • Department of Radiology
      Edo, Tōkyō, Japan
  • 1998
    • Toshiba Corporation
      Edo, Tōkyō, Japan