Kenta Miwa RT, Presenter: Nothing to Disclose

Masayuki Inubushi, Abstract Co-Author: Nothing to Disclose

Kei Wagatsuma, Abstract Co-Author: Nothing to Disclose

Tokuo Umeda PhD, Abstract Co-Author: Nothing to Disclose

Akiko Okawa MD, RN, Abstract Co-Author: Nothing to Disclose

Takuro Umeda, Abstract Co-Author: Nothing to Disclose

Mitsuru Koizumi, Abstract Co-Author: Nothing to Disclose

Masayuki Sasaki, Abstract Co-Author: Nothing to Disclose

The present study aimed to determine whether fractal analysis of morphological complexity and intratumoral heterogeneity of FDG uptake can help to differentiate malignant from benign pulmonary nodules.

We retrospectively analyzed data from 54 patients with suspected non-small cell lung cancer (NSCLC) who were examined by contrast-enhanced chest CT and FDG PET/CT within the same week. Pathological assessments of biopsy specimens confirmed 35 and 19 nodules as NSCLC and inflammatory lesions, respectively. The morphological fractal dimension (m-FD), maximum standardized uptake value (SUVmax) and density fractal dimension (d-FD) of target nodules were calculated from CT and PET images. Fractal dimension (FD) is a quantitative index of morphological complexity and tracer uptake heterogeneity; higher values indicate increased complexity and heterogeneity.

The m-FD, SUVmax and d-FD significantly differed between malignant and benign pulmonary nodules (p < 0.05). Although the diagnostic ability was better for d-FD than m-FD and SUVmax, the difference did not reach statistical significance. Tumor size correlated significantly with SUVmax (r = 0.51, p < 0.05), but not with either m-FD or d-FD. Furthermore, m-FD combined with either SUVmax or d-FD improved diagnostic accuracy to 92.6% and 94.4%, respectively.

The d-FD of intratumoral heterogeneity of FDG uptake can help to differentially diagnose malignant and benign pulmonary nodules. The SUVmax and d-FD obtained from FDG-PET images provide different types of information that are equally useful for differential diagnoses. Furthermore, the morphological complexity determined by CT combined with heterogeneous FDG uptake determined by PET improved diagnostic accuracy.

Combining the morphological complexity of tumors on CT images with the heterogeneity of FDG uptake on PET images can help to differentially diagnose malignant and benign pulmonary nodules.

Miwa, K, Inubushi, M, Wagatsuma, K, Umeda, T, Okawa, A, Umeda, T, Koizumi, M, Sasaki, M, FDG Uptake Heterogeneity Evaluated by Fractal Analysis Improves the Differential Diagnosis of Pulmonary Nodules.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13026250.html