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.
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.



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.



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.



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.



4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1001-1006.
Ataturk University, Faculty of Medicine, Department of Radiology, Erzurum, Turkey.
Adem
A
Karaman
Diskapi Yildirim Beyazit Training and Research Hospital, Clinic of Radiology, Ankara, Turkey.
Irmak
I
Durur-Subasi
Ataturk University, Faculty of Medicine, Department of Radiology, Erzurum, Turkey.
Fatih
F
Alper
Istanbul Medipol University, Faculty of Medicine, Department of Radiology, Istanbul, Turkey.
Afak
A
Durur-Karakaya
Turkiye Yuksek Ihtısas Training and Research Hospital, Clinic of Thoracic Surgery and Lung Transplantation, Ankara, Turkey.
Mahmut
M
Subasi
Ataturk University, Faculty of Medicine, Department of Chest Diseases, Erzurum, Turkey.
Metin
M
Akgun
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000473:pathology*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
diffusion; lung; magnetic resonance imaging; neoplasms