Hisanobu Koyama MD, Presenter: Nothing to Disclose

Yoshiharu Ohno MD, PhD, Abstract Co-Author: Research Grant, Toshiba Coporation Research Grant, Koninklijke Philips Electronics NV Research Grant, Bayer AG Research Grant, DAIICHI SANKYO Group Research Grant, Eisai Co, Ltd Research Grant, Terumo Corporation Research Grant, Covidien AG Research Grant, FUJIFILM Holdings Corporation

Shinichiro Seki, Abstract Co-Author: Nothing to Disclose

Mizuho Nishio MD, Abstract Co-Author: Research Grant, Toshiba Corporation

Sumiaki Matsumoto MD, PhD, Abstract Co-Author: Research Grant, Toshiba Corporation

Takeshi Yoshikawa MD, Abstract Co-Author: Research Grant, Toshiba Corporation

Nobukazu Aoyama RT, Abstract Co-Author: Nothing to Disclose

Kazuro Sugimura MD, PhD, Abstract Co-Author: Research Grant, Toshiba Corporation Research Grant, Koninklijke Philips Electronics NV Research Grant, Bayer AG Research Grant, Eisai Co, Ltd Research Grant, DAIICHI SANKYO Group

Masakazu Kanzawa RT, Abstract Co-Author: Nothing to Disclose

To determine the appropriate parameter for quantitative differentiation of solitary pulmonary nodules (SPNs) by means of diffusion weighted MR imaging (DWI) with multiple b values.

Thirty-two subjects (24 men and 12 women, mean age 68.2 years) with 36 SPNs (range; 5-30mm) underwent DWI with multiple b values (b=0, 50, 100, 150, 300, 500, and 1000 s/mm2). According to the results from pathological and/ or more than 2 year’s follow-up examinations, all SPNs were divided into two groups: malignant SPNs (n=27) and benign SPNs (n=9). Then, five quantitative parameters were determined from region of interest (ROI) drawn over each SPN as follows: apparent diffusion coefficient (ADC), true diffusion coefficient (D) and perfusion fraction (PF) from all b-value data, and the signal intensity ratio between SPN and spinal cord on DWI with b-value at 1000 s/mm2 (LSR1000) and 500 s/mm2 (LSR500). To compare the quantitative parameter difference between malignant SPNs and benign SPNs, all parameters were compared by using Mann-Whitney’s U-test. To determine the each feasible threshold value, ROC-based positive test was performed. Finally, sensitivity, specificity and accuracy were compared each other by means of McNemar's test.

On comparison of each parameter between malignant and benign SPNs, both LSRs had significant difference between two groups (p<0.05). When applied feasible threshold values, specificity (SP) and accuracy (AC) of LSR500 (SP: 88.9 [8/9] %, AC: 77.8 [28/36] %) were significantly higher than those of ADC (SP: 33.3 [3/9] %, p<0.05; and AC: 61.1 [22/36] %, p<0.05), D (SP: 11.1 [1/9] %, p<0.05; and AC: 55.6 [20/36] %, p<0.05), and PF (SP: 22.2 [2/9] %, p<0.05; and AC: 63.9 [23/36] %, p<0.05). AC of LSR1000 (72.2 [26/36] %) was significantly higher than that of D (p<0.05), although SP (88.9 [8/9] %) were significantly higher than that of ADC, D, and PF (p<0.05).

For quantitative differentiation of SPNs on chest DWI, LSR evaluation is more useful and practical method than ADC, D, and PF assessment in routine clinical practice. In addition, b-value at 500 s/mm2 would be better to choose than b values at 1,000 s/mm2 in this setting.

For quantitative differentiation of SPNs on chest DWI, LSR evaluation is more useful and practical method than ADC, D, and PF assessment in routine clinical practice.

Koyama, H, Ohno, Y, Seki, S, Nishio, M, Matsumoto, S, Yoshikawa, T, Aoyama, N, Sugimura, K, Kanzawa, M, Solitary Pulmonary Nodule: Which Parameters Would Be Better to Assess for Quantitative Diagnosis on Diffusion-weighted MR Imaging with Multiple b-Values?.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13010124.html