Hisanobu Koyama MD

Publications (2)5.4 Total impact

• Article: Dynamic perfusion MRI: Capability for evaluation of disease severity and progression of pulmonary arterial hypertension in patients with connective tissue disease

  PhD Yoshiharu Ohno MD, Hisanobu Koyama MD, PhD Munenobu Nogami MD, Daisuke Takenaka MD, PhD Sumiaki Matsumoto MD, Yumiko Onishi MD, Keiko Matsumoto MD, Kenya Murase PhD, Kazuro Sugimura MD
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  ABSTRACT: PurposeTo prospectively evaluate the capability of dynamic perfusion MRI for assessment of disease severity and progression to pulmonary arterial hypertension (PAH) in connective tissue disease (CTD) patients.Materials and Methods In all, 18 gender- and age-matched CTD patients without and with PAH and nine healthy volunteers underwent dynamic perfusion MRI, Doppler echocardiography, and pulmonary function test. Disease severity of CTD was assessed in terms of diffusing capacity for carbon monoxide (%DLCO) and estimated systolic pulmonary arterial pressure (sPAP), and progression of PAH in terms of pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR). From calculated pulmonary perfusion parameter maps, means of pulmonary blood flow (mPBF), pulmonary blood volume (mPBV), and mean transit time (mMTT) were determined as averages of all region of interest (ROI) measurements. To determine disease severity in CTD, all parameters were statistically correlated with sPAP and %DLCO. To determine progression to PAH, all parameters were statistically correlated with mPAP and PVR.ResultsAll pulmonary perfusion parameters correlated significantly with sPAP and %DLCO (P < 0.05). mPBF and mPBV correlated significantly with mPAP and moderately with PVR (P < 0.05).Conclusion Dynamic perfusion MRI can be used for assessment of disease severity and progression of PAH in CTD patients. J. Magn. Reson. Imaging 2008;28:887–899. © 2008 Wiley-Liss, Inc.
  Journal of Magnetic Resonance Imaging 09/2008; 28(4):887 - 899. · 2.70 Impact Factor
• Article: STIR turbo SE MR imaging vs. coregistered FDG‐PET/CT: Quantitative and qualitative assessment of N‐stage in non‐small‐cell lung cancer patients

  PhD Yoshiharu Ohno MD, Hisanobu Koyama MD, Munenobu Nogami MD, PhD Daisuke Takenaka MD, Takeshi Yoshikawa MD, Masahiro Yoshimura MD, Chiho Ohbayashi MD, Kazuro Sugimura MD, Yoshiharu Ohno, Hisanobu Koyama, Munenobu Nogami, Daisuke Takenaka, Takeshi Yoshikawa, Masahiro Yoshimura, Chiho Ohbayashi, Kazuro Sugimura
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  ABSTRACT: PurposeTo conduct a prospective comparison of the accuracy of short inversion time (TI) inversion-recovery (STIR) turbo spin-echo (SE) imaging and coregistered 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG)–positron emission tomography (PET) with computed tomography (CT) (coregistered FDG-PET/CT) to assess the N-stage in non-small-cell lung cancer (NSCLC) patients.Materials and MethodsA total of 115 consecutive NSCLC patients prospectively underwent CT, STIR turbo SE imaging, and FDG-PET, as well as surgical and pathological examinations. All STIR turbo SE images were obtained with a 0.9% saline phantom, which was placed alongside the chest wall of each patient, and coregistered FDG-PET/CTs were reconstructed using commercially available software. For quantitative assessments, the ratio of signal intensity (SI) of each lymph node to that of 0.9% saline phantom (lymph node-saline ratio [LSR]) and maximal standardized uptake value (SUVmax) of each lymph node were calculated. Feasible threshold values were determined by using the receiver operating characteristic (ROC) curve-based positive test, and diagnostic capabilities of N-stage were compared by McNemar's test on a per patient basis.ResultsWhen feasible, threshold values were adopted, quantitative sensitivity (90.1%) and accuracy (92.2%) of STIR turbo SE imaging were significantly higher than those of quantitative and qualitative sensitivities (76.7% and 74.4%) and accuracies (83.5% and 82.6%) of coregistered FDG-PET/CT on a per patient basis (P < 0.05).ConclusionSTIR turbo SE imaging is at least as valid as coregistered FDG-PET/CT for quantitative and qualitative assessment of the N-stage for NSCLC patients. J. Magn. Reson. Imaging 2007;26:1071–1080. © 2007 Wiley-Liss, Inc.
  Journal of Magnetic Resonance Imaging 09/2007; 26(4):1071 - 1080. · 2.70 Impact Factor