Yasunari Fujinaga

Shinshu University, Shonai, Nagano, Japan

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Publications (48)77.65 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to evaluate the impact of the pancreatic signal intensity (SI) on magnetic resonance imaging (MRI) findings for predicting the development of pancreatic fistula (PF) after a distal pancreatectomy (DP) involving a triple-row stapler closure. A multivariate logistic regression analysis was used to identify risk factors for clinical PF, as defined by the International Study Group on Pancreatic Fistula grade B or C. The pancreas-to-muscle SI ratio was evaluated using fat-suppressed T1-weighted MRI. Of the 41 enrolled patients, 8 (19.5%) developed clinical PF. The pancreatic thickness (≥15 mm) and SI ratio (≥1.3) were identified as independent predictors of clinical PF in a multivariate analysis. Clinical PF was observed in one patient with a thick pancreas and a low SI ratio (14.3%), whereas it was observed in 60% of the patients with a thick pancreas and a high SI ratio. The area under the receiver operating characteristic curve for a predictive model consisting of the two factors was 0.87 (95% confidence interval, 0.75 to 0.99), the level of which tended to be greater than that for pancreatic thickness alone (0.81, p = 0.09). The SI ratio as evaluated using MRI might be useful for predicting clinical PF in patients with the pancreatic thickness ≥15 mm after DP involving a stapler closure. Copyright © 2015. Published by Elsevier B.V.
    Pancreatology 06/2015; DOI:10.1016/j.pan.2015.05.479 · 2.50 Impact Factor
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    ABSTRACT: The purpose of this study was to improve the reliability and validity of skeletal age assessment using an open and compact pediatric hand magnetic resonance (MR) imaging scanner. We used such a scanner with 0.3-tesla permanent magnet to image the left hands of 88 healthy children (aged 3.4 to 15.7 years, mean 8.8 years), and 3 raters (2 orthopedic specialists and a radiologist) assessed skeletal age using those images. We measured the strength of agreement in ratings by values of weighted Cohen's κ and the proportion of cases excluded from rating because of motion artifact and inappropriate positioning. We compared the current results with those of a previous study in which 93 healthy children (aged 4.1 to 16.4 years, mean 9.7 years) were examined with an adult hand scanner. The κ values between raters exceeded 0.80, which indicates almost perfect agreement, and most were higher than those of the previous study. The proportion of cases excluded from rating because of motion artifact or inappropriate positioning was also reduced. The results indicate that use of the compact pediatric hand scanner improved the reliability and validity of skeletal age assessments.
    Magnetic Resonance in Medical Sciences 07/2014; 13(3). DOI:10.2463/mrms.2013-0098 · 1.04 Impact Factor
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    ABSTRACT: Purpose: We aimed to clarify the usefulness of free-breathing readout-segmented echo-planar imaging (RESOLVE), which is multi-shot echo-planar imaging based on a 2D-navigator-based reacquisition technique, for detecting malignant liver tumor. Materials and methods: In 77 patients with malignant liver tumors, free-breathing RESOLVE and respiratory-triggered single-shot echo-planar imaging (SS-EPI) at 3-T MR unit were performed. We set a scan time up to approximately 5 min (300 s) before examination, measured actual scan time and assessed (1) susceptibility and (2) motion artifacts in the right and left liver lobes (3, no artifact; 1, marked), and (3) detectability of malignant liver tumors (3, good; 1, poor) using a 3-point scale. Results: The median actual scan time of RESOLVE/SS-EPI was 3651423 s. The median scores of each factor in RESOLVE/SS-EPI were as following in this order: (1) 3/2 (right lobe); 313 (left lobe), (2) 213 (right lobe); 112 (left lobe), and (3) 313, respectively. Significant differences were noted between RESOLVE and SS-EPI in all evaluated factors (P< 0.05) except for susceptibility of left lobe and detectability of the lesions. Conclusion: Despite the effect of motion artifacts, RESOLVE provides a comparable detectability of the lesion and the advantage of reducing scanning time compared with SS-EPI.
    European Journal of Radiology 06/2014; 83(10). DOI:10.1016/j.ejrad.2014.06.013 · 2.16 Impact Factor
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    Mikiko Kobayashi · Yasunari Fujinaga · Hiroyoshi Ota
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    ABSTRACT: Pancreatic intraductal papillary mucinous neoplasms (IPMNs) are mucin-producing neoplasms of the main and/or branch pancreatic ducts. To assess differences between various IPMN subtypes, immunohistochemical markers of gastric surface mucous cells (MUC5AC), gastric gland mucous cells (MUC6 and GlcNAcα1→4Galβ→R), gastric pyloric and duodenal epithelial cells (PDX1), intestinal cells (MUC2 and CDX2), small intestinal cells (CPS1) and large intestinal cells (SATB2) were evaluated in 33 surgically treated IPMNs. MUC2 expression classified IPMNs into gastric (n=17), intestinal (n=8) and mixed gastric and intestinal type (collision=7, composite=1). No differences in age or sex were observed among these types. MUC5AC and PDX1 were expressed in all IPMNs. MUC6 expression was higher in gastric and mixed types than in intestinal type. GlcNAcα1→4Galβ→R was detected in gastric and mixed type, but not in intestinal type. MUC2 and CDX2 expression were higher in intestinal type than gastric and mixed type. CPS1 expression was higher in intestinal type than gastric type. SATB2 was not observed in any IPMNs. Frequent abrupt transition between the two IPMN types in mixed-type IPMNs was observed. Gastric pyloric and small intestinal differentiation are characteristic of gastric and intestinal type IPMN, respectively, and these two IPMN types may have distinct pathogenesis.
    Acta histochemica et cytochemica official journal of the Japan Society of Histochemistry and Cytochemistry 05/2014; 47(2):45-57. DOI:10.1267/ahc.13027 · 1.22 Impact Factor
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    ABSTRACT: BACKGROUND:Although the importance of tibial tunnel position for achieving stability after anterior cruciate ligament (ACL) reconstruction was recently recognized, there are fewer detailed reports of the anatomy of the tibial topographic footprint compared with the femoral side. HYPOTHESIS:The ACL tibial footprint has a relationship to bony prominences and surrounding bony landmarks. STUDY DESIGN:Descriptive laboratory study. METHODS:This study consisted of 2 anatomic procedures for the identification of bony prominences that correspond to the ACL tibial footprint and 3 surrounding landmarks: the anterior ridge, lateral groove, and intertubercular fossa. In the first procedure, after computed tomography (CT) was performed on 12 paired, embalmed cadaveric knees, 12 knees were visually observed, while their contralateral knees were histologically observed. Comparisons were made between macroscopic and microscopic findings and 3-dimensional (3D) CT images of these bony landmarks. In the second procedure, the shape of the bony prominence and incidence of their bony landmarks were evaluated from the preoperative CT data of 60 knee joints. RESULTS:In the first procedure, we were able to confirm a bony prominence and all 3 surrounding landmarks by CT in all cases. Visual evaluation confirmed a small bony eminence at the anterior boundary of the ACL. The lateral groove was not confirmed macroscopically. The ACL was not attached to the lateral intercondylar tubercle, ACL tibial ridge, and intertubercular space at the posterior boundary. Histological evaluation confirmed that the anterior ridge and lateral groove were positioned at the anterior and lateral boundaries, respectively. There was no ligament tissue on the intercondylar space corresponding to the intercondylar fossa. In the second investigation, the bony prominence showed 2 morphological patterns: an oval type (58.3%) and a triangular type (41.6%). The 3 bony landmarks, including the anterior ridge, lateral groove, and intertubercular fossa, existed in 96.6%, 100.0%, and 96.6% of the cases, respectively. CONCLUSION:There is a bony prominence corresponding to the ACL footprint and bony landmarks on the anterior, posterior, and lateral boundaries. CLINICAL RELEVANCE:The study results may help create an accurate and reproducible tunnel, which is essential for successful ACL reconstruction surgery.
    The American Journal of Sports Medicine 04/2014; 42(6). DOI:10.1177/0363546514528789 · 4.70 Impact Factor
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    ABSTRACT: To determine reproducibility of the femoral condyle cartilage volume (CV) in cross-sectional and longitudinal studies using various 3D imaging techniques at 1.5 T and 3 T. In 21 subjects with osteoarthritis, magnetic resonance imaging (MRI) including four different sequences (sagittal 3D fat suppressed spoiled gradient-echo [SPGR] at 1.5 T, fat suppressed fast low angle shot [FLASH] at 3 T, water-excitation dual echo steady state [DESS] at 3 T, and water-excitation multiecho data image combination [MEDIC] at 3 T) were acquired at baseline and ∼1 year later. The CV measured using semiautomated segmentation software by three readers was analyzed. The mean of the interclass correlation coefficient between each reader from SPGR, FLASH, DESS, and MEDIC was 0.899, 0.948, 0.943, and 0.954, respectively. The mean CV (×10(4) mm(3) ) measured by each reader from SPGR/FLASH/DESS/MEDIC sequences was the following in this order: 1.34/1.52/1.50/1.35, 1.21/1.43/1.40/1.27, 1.22/1.37/1.36/1.22, and 1.17/1.36/1.35/1.21 by readers 1, 2, 3 (first analysis), and 3 (second analysis), respectively. There was no statistically significant difference in CV between any readers in any sequences. The CV measured on FLASH and DESS tended to be greater than that on SPGR or MEDIC. Inter- and intraobserver reproducibility of cartilage segmentation using semiautomated software was validated. Although there was no statistical significance, there was a tendency of under- or overestimating CV by each sequence.J. Magn. Reson. Imaging 2013. © 2013 Wiley Periodicals, Inc.
    Journal of Magnetic Resonance Imaging 04/2014; 39(4). DOI:10.1002/jmri.24217 · 2.79 Impact Factor
  • Journal of Gastroenterology 03/2014; 49(5). DOI:10.1007/s00535-014-0944-0 · 4.02 Impact Factor
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    ABSTRACT: To compare radial volumetric imaging breath-hold examination with k-space weighted image contrast reconstruction (r-VIBE-KWIC) to Cartesian VIBE (c-VIBE) in arterial phase dynamic gadoxetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (DCE-MRI) of the liver. We reviewed 53 consecutive DCE-MRI studies performed on a 3-T unit using c-VIBE and 53 consecutive cases performed using r-VIBE-KWIC with full-frame image subset (r-VIBEfull) and sub-frame image subsets (r-VIBEsub; temporal resolution, 2.5-3 s). All arterial phase images were scored by two readers on: (1) contrast-enhancement ratio (CER) in the abdominal aorta; (2) scan timing; (3) artefacts; (4) visualisation of the common, right, and left hepatic arteries. Mean abdominal aortic CERs for c-VIBE, r-VIBEfull, and r-VIBEsub were 3.2, 4.3 and 6.5, respectively. There were significant differences between each group (P < 0.0001). The mean score for c-VIBE was significantly lower than that for r-VIBEfull and r-VIBEsub in all factors except for visualisation of the common hepatic artery (P < 0.05). The mean score of all factors except for scan timing for r-VIBEsub was not significantly different from that for r-VIBEfull. Radial VIBE-KWIC provides higher image quality than c-VIBE, and r-VIBEsub features high temporal resolution without image degradation in arterial phase DCE-MRI. • Radial VIBE-KWIC minimised artefact and produced high-quality and high-temporal-resolution images. • Maximum abdominal aortic enhancement was observed on sub-frame images of r-VIBE-KWIC. • Using r-VIBE-KWIC, optimal arterial phase images were obtained in over 90 %. • Using r-VIBE-KWIC, visualisation of the hepatic arteries was improved. • A two-reader study revealed r-VIBE-KWIC's advantages over Cartesian VIBE.
    European Radiology 03/2014; 24(6). DOI:10.1007/s00330-014-3122-0 · 4.34 Impact Factor
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    ABSTRACT: Diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) were performed on a healthy 31-year-old man with asymptomatic lumbar disc herniation. Although the left S1 nerve root was obviously entrapped by a herniated mass, neither DWI nor DTI showed any significant findings for the nerve root. Decreased apparent diffusion coefficient (ADC) values and increased fractional anisotropy (FA) values were found. These results are contrary to those in previously published studies of symptomatic patients, in which a combination of increased ADC and decreased FA seem to have a relationship with nerve injury and subsequent symptoms, such as leg pain or palsy. Our results seen in an asymptomatic subject suggest that the compressed nerve with no injury, such as edema, demyelination, or persistent axonal injury, may be indicated by a combination of decreased ADC and increased FA. ADC and FA could therefore be potential tools to elucidate the pathomechanism of radiculopathy. J. Med. Invest. 61: 197-203, February, 2014.
    The Journal of Medical Investigation 01/2014; 61(1.2):197-203. DOI:10.2152/jmi.61.197
  • S Uchiyama · T Itsubo · K Nakamura · Y Fujinaga · N Sato · T Imaeda · M Kadoya · H Kato
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    ABSTRACT: This multicentre prospective clinical trial aimed to determine whether early administration of alendronate (ALN) delays fracture healing after surgical treatment of fractures of the distal radius. The study population comprised 80 patients (four men and 76 women) with a mean age of 70 years (52 to 86) with acute fragility fractures of the distal radius requiring open reduction and internal fixation with a volar locking plate and screws. Two groups of 40 patients each were randomly allocated either to receive once weekly oral ALN administration (35 mg) within a few days after surgery and continued for six months, or oral ALN administration delayed until four months after surgery. Postero-anterior and lateral radiographs of the affected wrist were taken monthly for six months after surgery. No differences between groups was observed with regard to gender (p = 1.0), age (p = 0.916), fracture classification (p = 0.274) or bone mineral density measured at the spine (p = 0.714). The radiographs were assessed by three independent assessors. There were no significant differences in the mean time to complete cortical bridging observed between the ALN group (3.5 months (se 0.16)) and the no-ALN group (3.1 months (se 0.15)) (p = 0.068). All the fractures healed in the both groups by the last follow-up. Improvement of the Quick-Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, grip strength, wrist range of movement, and tenderness over the fracture site did not differ between the groups over the six-month period. Based on our results, early administration of ALN after surgery for distal radius fracture did not appear to delay fracture healing times either radiologically or clinically. Cite this article: Bone Joint J 2013;95-B:1544-50.
    Bone and Joint Journal 11/2013; 95-B(11):1544-50. DOI:10.1302/0301-620X.95B11.31652
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    ABSTRACT: Objective To describe the imaging findings of primary and secondary pancreatic malignant lymphoma on magnetic resonance imaging (MRI), to help differentiate lymphoma of the pancreas from primary adenocarcinoma and autoimmune pancreatitis among others, and to discuss a few atypical presentations of pancreatitis mimicking lymphoma. Conclusion Knowledge of these imaging manifestations of lymphoma may be helpful to arrive at an accurate diagnosis and avoid unnecessary morbidity and mortality from inadvertent surgery. Main Messages • Pancreatic malignant lymphoma is shown as a nodular low-density area with mild enhancement on CT. • It sometimes shows variable manifestations mimicking other tumours and inflammatory conditions. • MRI provides useful information for differentiating malignant lymphoma from other mimickers.
    Insights into Imaging 03/2013; 4(3). DOI:10.1007/s13244-013-0242-z
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    ABSTRACT: Objectives: Immunoglobulin (Ig)G4-related disease is a recently proposed systemic disorder that includes autoimmune pancreatitis (AIP), Mikulicz's disease, and various other organ lesions. In the present retrospective study, we examined whether thyroid lesions should also be included in IgG4-related disease (Ig4-RD) under the new term IgG4-related thyroiditis. Method: We enrolled 114 patients with Ig4-RD, including 92 patients with AIP, 15 patients with Mikulicz's disease, and seven patients with IgG4-related cholangitis, and analysed clinical findings, function, serum values of activity markers, computed tomography (CT) images, and histology of the thyroid gland. Results: Among the 22 patients (19%) in our cohort who were found to have hypothyroidism [thyroid stimulating hormone (TSH) > 4 mIU/L], 11 patients had clinical hypothyroidism [free thyroxine (FT4) < 1 ng/dL] and 11 patients had subclinical hypothyroidism (FT4 ≥ 1 ng/dL). Serum concentrations of IgG, IgG4, circulating immune complex (CIC), and β2-microglobulin (β2-MG) were significantly higher in the hypothyroidism group compared with the remaining 92 euthyroid patients, and serum C3 concentration was significantly lower. After prednisolone treatment, TSH values had decreased significantly (p = 0.005) in this group and FT4 values had increased significantly (p = 0.047). CT images showed that the thyroid glands of patients with clinical hypothyroidism had a significantly greater volume than those of the euthyroid and other groups. Pathological analysis of one resected thyroid gland disclosed a focused lesion with infiltration of lymphocytes and IgG4-bearing plasma cells and loss of thyroid follicles. Conclusions: Thyroid lesions associated with hypothyroidism can be considered as a new disease termed IgG4-related thyroiditis. Awareness of this condition should lead to appropriate corticosteroid treatment that may prevent progression to a fibrous state.
    Scandinavian journal of rheumatology 03/2013; 42(4). DOI:10.3109/03009742.2012.761281 · 2.61 Impact Factor
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    ABSTRACT: We summarize here the consensus reached at the Symposium of the 48th Annual Meeting of the Liver Cancer Study Group of Japan held in Kanazawa on July 20th and 21st, 2012, on the role of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) in the management of hepatocellular carcinoma (HCC). Currently, dynamic CT is the first choice of imaging modality when HCC is suspected. EOB-MRI is useful for differentiation and definitive diagnosis of HCC when dynamic CT/MRI does not show conclusive findings for HCC. In addition, contrast- enhanced ultrasound with Sonazoid is useful for making a decision on whether or not to treat a hypovascular lesion <1 cm when the nodules are shown with low intensity in the hepatocyte phase of EOB-MRI. Furthermore, EOB-MRI should be performed in selected cases of HCC ultrahigh-risk groups every 3-4 months, or EOB-MRI should be performed at least once at the first visit in all HCC ultrahigh-risk groups.
    Oncology 01/2013; 84 Suppl 1:21-7. DOI:10.1159/000345885 · 2.61 Impact Factor
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    ABSTRACT: PURPOSE To determine which can more precisely predict postoperative liver reserve preoperatively, gadoxetate disodium-enhanced MR imaging or 99mTc-galactosyl serum albumin (99mTc-GSA) scintigraphy. METHOD AND MATERIALS Twelve consecutive patients (4 men, 8 women; mean age 70.3 years) who underwent gadoxetate disodium-enhanced MR imaging and 99mTc-GSA scintigraphy within 2 weeks before hepatectomy as a preoperative evaluation were included in this study. Remnant Hepatocellular Uptake Index: rHUI = rV[(rL20/S20) - 1] was determined from the future remnant liver volume (rV) and mean signal intensities of the future remnant liver (rL20) and the spleen (S20) on contrast enhanced MR images at 20 minutes after gadoxetate disodium administration. Receptor index of the future remnant liver: rLHL15 = rL%[L15/(H15 + L15)] was determined from the uptake ratio of the future remnant liver to the whole liver (rL%) on SPECT and the uptake of the liver (L15) and the heart (H15) on planar image of scintigraphy at 15 minutes after 99mTc-GSA administration. The correlation coefficients and its 95% confidence intervals (95%CIs) between indices for the segmental liver reserve (rHUI and rLHL15) and laboratory data at 1 week after hepatectomy (serum albumin, ALB; logarithm of serum total bilirubin, BIL; prothrombin time, PT) were evaluated. The significance of the correlation was evaluated by test for non-correlation. RESULTS Correlation coefficients and its probability values and 95%CIs were 0.69 (P = 0.012) [0.68, 0.71] for ALB, -0.30 (P = 0.339) [-0.32, -0.28] for BIL, and -0.69 (P = 0.024) [-0.71, -0.68] for PT in rLHL15, respectively. In rHUI, 0.21 (P = 0.508) [0.20, 0.23] for ALB, -0.59 (P = 0.045) [-0.60, -0.57] for BIL, and -0.29 (P = 0.362) [-0.30, -0.28] for PT, respectively. CONCLUSION Quantitative index for segmental liver reserve such as rHUI obtained from preoperative gadoxetate disodium-enhanced MR imaging predicts more precisely postoperative liver reserve in bilirubin metabolism, whereas rLHL15 obtained from preoperative 99mTc-GSA scintigraphy is superior to rHUI in the evaluation of postoperative liver reserve in protein synthesis. CLINICAL RELEVANCE/APPLICATION Postoperative liver failure can be avoided by quantitative indices for segmental liver reserve such as rHUI and rLHL15 obtained from gadoxetate disodium-enhanced MR imaging and 99mTc-GSA scintigraphy.
    Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
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    ABSTRACT: PURPOSE: To evaluate the difference in the time-intensity curves (TICs) of the abdominal aorta on dynamic contrast-enhanced MRI (DCE-MRI) between Gd-DTPA and Gd-EOB-DTPA. MATERIALS AND METHODS: Ten healthy volunteers underwent DCE-MRI three times with the following protocol: group A, Gd-DTPA at an injection rate of 3 ml/s; group B, Gd-EOB-DTPA, 3 ml/s; group C, Gd-EOB-DTPA, 1.5 ml/s. Signal intensities (SIs) of the abdominal aorta were measured, and the contrast enhancement ratio (CER) was calculated. Time-to-CER curves were compared among the three groups. The differences in maximum CER (CER(max)) and time-to-peak of CER were analyzed. RESULTS: The time-to-CER curve showed a double peak pattern in group A and single-peak pattern in groups B and C. The mean time between the first and the second peak was 6.2 s. The mean CER(max) of each group was 4.50, 4.52 and 4.27, respectively. In group A, B and C, the mean time-to-peak was 14.6, 10.6 and 12.6 s, respectively. There was a significant difference between group A and B (P < 0.01). CONCLUSION: To set up the optimal protocol for abdominal DCE-MRI, it should be noted that TIC in the Gd-DTPA and Gd-EOB-DTPA group showed different patterns, and a slower injection rate showed a less abrupt SI change in the Gd-EOB-DTPA group than in the Gd-DTPA group.
    Japanese journal of radiology 11/2012; 31(3). DOI:10.1007/s11604-012-0162-8 · 0.74 Impact Factor
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    ABSTRACT: AIM: We aimed to correlate the macroscopic and magnetic resonance imaging (MRI) findings of hepatocellular carcinomas (HCC). METHODS: This was a multicenter study, whose study protocol was approved by each institutional review board. One hundred and forty-six resected nodules in 124 patients who had received a preoperative hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MRI (EOB-MRI) were analyzed. In both findings, we compared the diameter of HCC and macroscopic types divided into five types: (i) small nodular type with indistinct margin (SN-IM); (ii) simple nodular type (with distinct margin) (SN-DM); (iii) simple nodular type with extranodular growth (SN-EG); (iv) confluent multinodular type (CMN); and (v) infiltrative type (IF). RESULTS: The diameters in each finding (D(surg) and D(MRI) ) were significantly correlated (R = 0.961), although D(surg) was larger than D(MRI) (P = 0.0216). There were significant differences between D(surg) in SN-IM and the other groups (P < 0.0001). Sensitivity, specificity and accuracy were 5.3, 99.2 and 87; 84.8, 62.7 and 81.4; 58.1, 91.3 and 84.2; 70.6, 91.5 and 89, in SN-IM, SN-DM, SN-EG and CMN, respectively. The kappa value of every size was as follows: all sizes, 0.45; 20 mm or less, 0.23; more than 20 mm, 0.56. CONCLUSION: EOB-MRI could predict the macroscopic pathological findings except for SN-IM. Small tumor size might be helpful to diagnose SN-IM.
    Hepatology Research 09/2012; 43(5). DOI:10.1111/j.1872-034X.2012.01089.x · 2.22 Impact Factor
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    ABSTRACT: To identify characteristic magnetic resonance (MR) features of focal autoimmune pancreatitis (f-AIP) useful for differentiation from pancreatic cancer (PC). We retrospectively analyzed MR imaging findings of 20 f-AIP lesions and 40 PC lesions smaller than 40 mm in diameter. On fat-suppressed T2-weighted images and dynamic contrast-enhanced fat-suppressed T1-weighted images (DCE-T1WI), we classified MR features of internal signal intensity for each lesion into homogeneous, speckled, or target type. We assessed the sensitivity, specificity, and accuracy of these findings in the diagnosis of f-AIP. We also investigated the incidence of previously reported findings for differentiation between f-AIP and PC. Speckled enhancement within a hypointense or isointense lesion on pancreatic phase DCE-T1WI (speckled type) was observed more frequently in f-AIP than in PC, with high sensitivity, high specificity, and high accuracy. Hypointensity to hyperintensity surrounding a less enhanced focal area on DCE-T1WIs (target type) and upper stream main pancreatic duct dilatation were observed more frequently in PC than in f-AIP. Speckled enhancement inside an f-AIP lesion on pancreatic phase DCE-T1WI was useful for differentiation from PC.
    Japanese journal of radiology 01/2012; 30(4):296-309. DOI:10.1007/s11604-011-0047-2 · 0.74 Impact Factor
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    ABSTRACT: We aimed to reveal the difference in contrast enhancement of the abdominal organs and major vessels on dynamic contrast-enhanced magnetic resonance imaging (DCM-MRI) using gadoxetic sodium (Gd-EOB-DTPA) and gadopentetate dimeglumine (Gd-DTPA) in the same patients. DCM-MRI using Gd-EOBDTPA and Gd-DTPA were performed in the same 17 patients. Precontrast and DCM-MRI images [arterial phase (AP), portal venous phase (PP), hepatic venous phase (HP)] were acquired before and after bolus injection of each contrast agent. The organ-to-muscle ratio [liver (L/M), spleen (S/M), aorta (A/M), portal vein (P/M), hepatic vein (V/M)] were calculated at each phase and analyzed statistically. There was no significant difference between Gd-EOB-DTPA and Gd-DTPA images regarding the L/M or V/M mean on precontrast images or the mean of L/M at AP and L/M at the PP. At the AP, PP, and HP, the means of S/M, A/M, P/M, and V/M with Gd-EOBDTPA were lower than those with Gd-DTPA. On HP, The mean L/M with Gd-EOB-DTPA was higher than that with Gd-DTPA. On 3-T DCM-MRI using Gd-EOB-DTPA, contrast enhancement of the organs, except for the liver, was lower than that on DCM-MRI using Gd-DTPA. The HP was already affected by hepatobiliary uptake in Gd-EOB-DTPA.
    Japanese journal of radiology 12/2011; 29(10):695-700. DOI:10.1007/s11604-011-0615-5 · 0.74 Impact Factor
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    ABSTRACT: PURPOSE The liver volume and a quantitative liver function test such as indocyanine green (ICG) clearance test have been considered to be an indicator of the liver reserve. Because the same uptake pathways by hepatocytes have been considered for ICG and gadoxetate disodium, we speculated that the segmental liver reserve can be quantitatively estimated by use of gadoxetate disodium-enhanced MR imaging. The subject of this study was to evaluate the usefulness of computerized estimation of quantitative segmental liver reserve after transcatheter arterial chemoembolization (TACE) by use of gadoxetate-enhanced MR imaging comparing to volumetry. METHOD AND MATERIALS 3D-GRE T1-weighted images with fat suppression at 20 min after gadoxetate disodium administration were obtained from 14 patients prior to TACE using ethiodized oil and gelatin sponge particle. The greatest increase of serum total bilirubin within 1 week after TACE was measured, and increase more than 1 mg/dL was regarded as a liver dysfunction. The remnant liver volume (rV) which is the unembolized liver volume, and the mean signal intensity of the remnant liver (rL20) and the spleen (S20) were retrospectively estimated by use of computerized method from gadoxetate disodium-enhanced MR images and CT during hepatic angiography (CTHA) which was obtained right before TACE procedure. The feature value rV(rL20 - S20)/S20 were determined, and ROC analysis was made between rV and rV(rL20 - S20)/S20 in the prediction of the liver dysfunction after TACE. The informed consent requirement was waived, and this retrospective study was approved by the Institutional Review Board. RESULTS A significant difference in rV(rL20 - S20)/S20 was observed between the group with (mean = 0.36, 95%CI = 0.27 - 0.44) and without (mean = 0.61, 95%CI = 0.47 - 0.75) a liver dysfunction after TACE. By ROC analysis, the Az value of rV(rL20 - S20)/S20 for the prediction of liver dysfunction after TACE was 0.91 and higher than rV (0.64). CONCLUSION The risk of a liver dysfunction after TACE can be quantitatively estimated by use of computerized method from gadoxetate disodium-enhanced MR images and CT during hepatic angiography. CLINICAL RELEVANCE/APPLICATION The risk of a liver dysfunction after TACE can be quantitatively estimated by use of computerized method from gadoxetate disodium-enhanced MR images and CT during hepatic angiography.
    Radiological Society of North America 2011 Scientific Assembly and Annual Meeting; 11/2011
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    ABSTRACT: To determine whether liver function correlating with indocyanine green (ICG) clearance could be estimated quantitatively from gadoxetate disodium-enhanced magnetic resonance (MR) images. This retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Twenty-three consecutive patients who underwent an ICG clearance test and gadoxetate disodium-enhanced MR imaging with the same parameters as were used for a preoperative examination were chosen. The hepatocellular uptake index (HUI) from liver volume (V(L))and mean signal intensity of the liver on contrast-enhanced T1-weighted images with fat suppression (L(20)) and mean signal intensity of the spleen on contrast-enhanced T1-weighted images with fat suppression (S(20)) on 3D gradient-echo T1-weighted images with fat suppression obtained at 20 minutes after gadoxetate disodium (0.025 mmol per kilogram of body weight) administration was determined with the following equation: V(L)[(L(20)/S(20)) - 1]. The correlation of the plasma disappearance rate of ICG (ICG-PDR) and various factors derived from MR imaging, including HUI, iron and fat deposition in the liver and spleen, and spleen volume (V(S)), were evaluated with stepwise multiple regression analysis. The difference between the ratio of the remnant HUI to the HUI of the total liver (rHUI/HUI) and ratio of the liver remnant V(L) to the total V(L) (rV(L)/V(L)) was evaluated in four patients who had segmental heterogeneity of liver function. HUI and V(S) were the factors significantly correlated with ICG-PDR (R = 0.87). The mean value and its 95% confidence interval were 0.18 and 0.01 to 0.34, respectively, for the following calculation: (rHUI/HUI) - (rV(L)/V(L)). The liver function correlating with ICG-PDR can be estimated quantitatively from the signal intensities and the volumes of the liver and spleen on gadoxetate disodium-enhanced MR images, which may improve the estimation of segmental liver function.
    Radiology 06/2011; 260(3):727-33. DOI:10.1148/radiol.11100586 · 6.21 Impact Factor

Publication Stats

390 Citations
77.65 Total Impact Points


  • 2003–2015
    • Shinshu University
      • Department of Radiology
      Shonai, Nagano, Japan
    • Tohoku University
      • Institute for Materials Research
      Sendai-shi, Miyagi-ken, Japan
  • 2014
    • University of California, Irvine
      • Department of Radiological Sciences
      Irvine, California, United States
  • 1997
    • Kanazawa University
      • Department of Radiology
      Kanazawa-shi, Ishikawa-ken, Japan