The usefulness of fully three-dimensional OSEM algorithm on lymph node metastases from lung cancer with 18F-FDG PET/CT

• DOI: 10.1007/s12149-010-0462-y
• Publication Date: 2011-01-14T02:26:07Z
• Authors: Kazumasa Inoue; Etsuo Moriya; Takayuki Suzuki; Yoshiko Ohnuki; Takashi Sato; Hideaki Kitamura; Tatsuya Sasaki; Masahiro Fukushi; Noriyuki Moriyama; Hirofumi Fujii
• Keywords: Aged, 80 and over; Male; Lung Neoplasms; Phantoms, Imaging; Middle Aged; 3. Good health; 03 medical and health sciences; Imaging, Three-Dimensional; 0302 clinical medicine; Fluorodeoxyglucose F18; Lymphatic Metastasis; Positron-Emission Tomography; Humans; Female; Tomography, X-Ray Computed; Algorithms; Aged; Retrospective Studies

This work assessed the usefulness of fully three-dimensional ordered subset expectation maximization (3D-OSEM) algorithm for lymph node (LN) metastases from lung cancer. 3D-OSEM images were evaluated by comparing them with those reconstructed by conventional algorithms, such as conventional OSEM algorithm (2D-OSEM) for 2D acquisition and Fourier rebinning plus conventional OSEM algorithm (FORE + OSEM) for 3D acquisition.In a phantom study, the contrast ratio, the image noise and the signal-to-noise ratio (SNR) were calculated, and the detectability and the image quality of these images were visually evaluated. In a clinical study, 14 patients suffering from lung cancer with LN metastases were evaluated. The image quality and the malignancy, and the detectability were visually evaluated.The contrast ratio was significantly improved using 3D-OSEM as compared with FORE + OSEM, and it was similar to 2D-OSEM. The image noise and SNR in 3D-OSEM images were significantly improved compared with those by other algorithms (p < 0.001). In the visual assessment, the image quality was significantly improved in 3D-OSEM images compared with those by 2D-OSEM and FORE + OSEM (p < 0.001, p = 0.001, respectively). In the clinical study, the image quality and the detectability of LN metastases were improved in 3D-OSEM images compared with those by FORE + OSEM (p < 0.001, p = 0.006, respectively), and image quality and detectability were similar to those of 2D-OSEM images.3D-OSEM algorithm successfully improved the diagnostic accuracy of LN metastases in 3D-PET tests.