Shinichiro Seki1, Hisanobu Koyama2, Yoshiharu Ohno3, Mizuho Nishio4, Daisuke Takenaka5, Yoshimasa Maniwa6, Tomoo Itoh7, Yoshihiro Nishimura8, Kazuro Sugimura9. 1. Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: klfsiena@yahoo.co.jp. 2. Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: hkoyama@med.kobe-u.ac.jp. 3. Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: yosirad@kobe-u.ac.jp. 4. Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan; Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: nmizuho@med.kobe-u.ac.jp. 5. Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan; Department of Diagnostic Radiology, Hyogo Cancer Center, Hyogo, Japan. Electronic address: daisuket@hp.pref.hyogo.jp. 6. Division of Thoracic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: maniwa@med.kobe-u.ac.jp. 7. Division of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: tomitoh@med.kobe-u.ac.jp. 8. Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: nishiy@med.kobe-u.ac.jp. 9. Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: sugimura@med.kobe-u.ac.jp.
Abstract
PURPOSE: To evaluate and compare the capability of diffusion-weighted MR imaging (DWI) and CT for assessment of management needs for anterior mediastinal solitary tumors. MATERIALS AND METHODS: Thirty-five patients with pathologically confirmed anterior mediastinal tumors were enrolled. The tumors were divided into two groups according to need for management: tumors not needing further intervention or treatment (group A; thymoma type A, AB and B1) and tumors needing further intervention and treatment (group B; other thymoma types and malignancies). The apparent diffusion coefficient (ADC) of each tumor was measured, and probabilities of malignancy and need for further intervention and treatment were visually assessed on CT. The differences in ADCs between group A and B and between malignancies and thymomas in group B were evaluated with the Mann-Whitney's U-test. Feasible threshold values for differentiation of group B from group A and distinguishing malignancies from thymomas assessed as group B were determined by the ROC-based positive test, and McNemar's test was used for comparing diagnostic capabilities of DWI with those of CT. RESULTS: ADCs for the two groups were significantly different (p<0.001). Application of the threshold value for differentiation of group B from A showed no significant difference (p>0.05). Application of the feasible threshold value for distinguishing malignant from thymomas assessed as group B showed that specificity (76.9%) and accuracy (85.2%) of DWI were significantly better than those of visual score (p<0.05). CONCLUSION: DWI has useful potential for the assessment of management needs for anterior mediastinum solitary tumors as well as CT.
PURPOSE: To evaluate and compare the capability of diffusion-weighted MR imaging (DWI) and CT for assessment of management needs for anterior mediastinal solitary tumors. MATERIALS AND METHODS: Thirty-five patients with pathologically confirmed anterior mediastinal tumors were enrolled. The tumors were divided into two groups according to need for management: tumors not needing further intervention or treatment (group A; thymoma type A, AB and B1) and tumors needing further intervention and treatment (group B; other thymoma types and malignancies). The apparent diffusion coefficient (ADC) of each tumor was measured, and probabilities of malignancy and need for further intervention and treatment were visually assessed on CT. The differences in ADCs between group A and B and between malignancies and thymomas in group B were evaluated with the Mann-Whitney's U-test. Feasible threshold values for differentiation of group B from group A and distinguishing malignancies from thymomas assessed as group B were determined by the ROC-based positive test, and McNemar's test was used for comparing diagnostic capabilities of DWI with those of CT. RESULTS: ADCs for the two groups were significantly different (p<0.001). Application of the threshold value for differentiation of group B from A showed no significant difference (p>0.05). Application of the feasible threshold value for distinguishing malignant from thymomas assessed as group B showed that specificity (76.9%) and accuracy (85.2%) of DWI were significantly better than those of visual score (p<0.05). CONCLUSION: DWI has useful potential for the assessment of management needs for anterior mediastinum solitary tumors as well as CT.
Authors: Lisa P Lavelle; Darragh Brady; Sinead McEvoy; David Murphy; Brian Gibney; Annika Gallagher; Marcus Butler; Fionnula Shortt; Marie McMullen; Aurelie Fabre; David A Lynch; Michael P Keane; Jonathan D Dodd Journal: Diagn Interv Radiol Date: 2017 Mar-Apr Impact factor: 2.630