Is It Better to Include Necrosis in Apparent Diffusion Coefficient (ADC) Measurements? The Necrosis/Wall ADC Ratio to Differentiate Malignant and Benign Necrotic Lung Lesions: Preliminary Results

KARAMAN A., Durur-Subasi I., ALPER F., Durur-Karakaya A., Subasi M., Akgun M.

JOURNAL OF MAGNETIC RESONANCE IMAGING, vol.46, no.4, pp.1001-1006, 2017 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 46 Issue: 4
  • Publication Date: 2017
  • Doi Number: 10.1002/jmri.25649
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1001-1006
  • Keywords: diffusion, lung, magnetic resonance imaging, neoplasms
  • Istanbul Medipol University Affiliated: Yes


Purpose: To determine whether the use of necrosis/wall apparent diffusion coefficient (ADC) ratios in the differentiation of necrotic lung lesions is more reliable than measuring the wall alone. Materials and Methods: In this retrospective study, a total of 76 patients (54 males and 22 females, 71% vs. 29%, with a mean age of 53 ± 18 years, range, 18–84) were enrolled, 33 of whom had lung carcinoma and 43 had a benign necrotic lung lesion. A 3T scanner was used. The calculation of the necrosis/wall ADC ratio was based on ADC values measured from necrosis and the wall of the lesions by diffusion-weighted imaging (DWI). Statistical analyses were performed with the independent samples t-test and receiver operating characteristic analysis. Intraobserver and interobserver reliability were calculated for ADC values of wall and necrosis. Results: The mean necrosis/wall ADC ratio was 1.67 ± 0.23 for malignant lesions and 0.75 ± 0.19 for benign lung lesions (P < 0.001). To estimate malignancy the area under the curve (AUC) values for necrosis ADC, wall ADC, and the necrosis/wall ADC ratio were 0.720, 0.073, and 0.997, respectively. A wall/necrosis ADC ratio cutoff value of 1.12 demonstrated a 100% sensitivity and 98% specificity in the estimation of malignancy. Positive predictive value was 100%, and negative predictive value 98% and diagnostic accuracy 99%. There was a good intraobserver and interobserver reliability for wall and necrosis. Conclusion: The necrosis/wall ADC ratio appears to be a reliable and promising tool for discriminating lung carcinoma from benign necrotic lung lesions than measuring the wall alone. Level of Evidence: 4. Technical Efficacy: Stage 2. J. Magn. Reson. Imaging 2017;46:1001–1006.