Kiyosumi Maeda

Publications (3)8.11 Total impact

• Article: How accurate is CT morphometry of airway? Phantom and clinical validation study.

  Masashi Takahashi, Hiroki Okada, Naoko Oguni, Kiyosumi Maeda, Koji Segawa, Norihisa Nitta, Kiyoshi Murata
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  ABSTRACT: To assess the reliability of CT airway measurement using phantom and to evaluate its reproducibility using clinical chest CT images. The phantom consisted of six tubes with different diameters and wall thicknesses was used. The wall area ratio (%WA) and wall thickness ratio (%WT) were calculated and the difference from the actual value (error ratio) was assessed. In vivo validation was performed with MDCT data of consecutive 10 patients and inter- and intra-rater agreements of the measurement were evaluated. The error ratio of %WA and %WT increased for the phantom tube with a 1mm or thinner wall thickness. The FOV size has an influence on the airway measurement especially for the tube with 1mm wall thickness. Inter-rater reliabilities between two observers for %WA and %WT were excellent and good intra-class correlation coefficient for %WA and %WT were obtained as 0.825 and 0.811, respectively. Intra-rater reliabilities of measurement also showed good intra-class correlation coefficient for %WA and %WT as 0.822 and 0.800, respectively. Although the phantom study showed there is a tendency to overestimate the wall area of an airway with a thickness 1mm or less, the software has a potential to be used in assessing longitudinal observation of the same patient, as well as, comparison among different patients due to good intra- and inter-rater reliability.
  European journal of radiology 01/2011; 80(3):e524-30. · 2.65 Impact Factor
• Article: Percutaneous transluminal angioplasty for Brescia-Cimino hemodialysis fistula dysfunction: technical success rate, patency rate and factors that influence the results.

  Kiyosumi Maeda, Akira Furukawa, Michio Yamasaki, Kiyoshi Murata
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  ABSTRACT: To evaluate the initial clinical success and long-term patency rates of percutaneous transluminal angioplasty (PTA) using a venous approach for dysfunctional Brescia-Cimino fistula and to identify factors that may affect initial success and long-term patency. A total of 99 PTA procedures were performed in retrograde fassion for 60 mature Brescia-Cimino shunts with dysfunction caused by anastomotic or peripheral outflow vein stenosis or occlusion. The initial clinical success rates were compared between stenosis and occlusion using Fisher's exact test. The Kaplan-Meier method was used to calculate the primary and secondary cumulative patency rates, and the log-rank test was used for comparison. Relative risks of patency loss according to clinical characteristics were determined with multivariate Cox models. Results: The initial clinical success rate of all interventions was 92%, and the rates for stenosis and occlusion were 99 and 65%, respectively (P < 0.0001). The primary and secondary cumulative patency rates for fistulas (excluding initial failure) at 12 months were 53 and 84%, respectively. The relative risks were 5.2 (P = 0.004) for longer lesions and 4.5 (P = 0.007) for younger fistulas. The primary cumulative patency rate of four patients with a younger fistula and a longer stenosis at 4 months was 0%. Favorable primary and secondary cumulative patency rates are obtained in most patients. Long lesion length and younger age of fistulas were the two factors that reduced the patency rate after PTA.
  European Journal of Radiology 06/2005; 54(3):426-30. · 2.61 Impact Factor
• Article: Cross-sectional imaging in Crohn disease.

  Akira Furukawa, Takao Saotome, Michio Yamasaki, Kiyosumi Maeda, Norihisa Nitta, Masashi Takahashi, Tomoyuki Tsujikawa, Yoshihide Fujiyama, Kiyoshi Murata, Tsutomu Sakamoto
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  ABSTRACT: The role of cross-sectional imaging in the diagnosis of Crohn disease has expanded with recent technologic advances in computed tomography (CT) and magnetic resonance (MR) imaging that allow rapid acquisition of high-resolution images of the intestines. To acquire images of diagnostic quality, administration of a fairly large amount of intraluminal contrast agent prior to examination and scanning with intravenous contrast material injection are necessary. Both CT and MR imaging are reported to have a sensitivity of over 95% for the detection of Crohn disease; however, they may not allow early diagnosis. Colonoscopy and conventional enteroclysis studies are indicated for patients with early-stage disease. At more advanced stages, CT and MR imaging can help identify and characterize pathologically altered bowel segments as well as extraluminal lesions (eg, fistulas, abscesses, fibrofatty proliferation, increased vascularity of the vasa recta, mesenteric lymphadenopathy). These modalities can also clearly depict inflammatory lesion activity and conditions that require elective gastrointestinal surgery, thereby aiding in treatment planning. In the clinical setting, CT is currently the imaging modality of choice at most institutions; however, it is expected that MR imaging will soon play a comparable role. CT or MR imaging should be included in a comprehensive evaluation of patients with Crohn disease, along with conventional imaging and clinical and laboratory tests.
  Radiographics 24(3):689-702. · 2.85 Impact Factor