OBJECTIVE: Our purpose was to assess the incremental effect of maximum-intensity-projection (MIP) image processing on the ability of various observers to detect small (<1 cm in diameter) central and peripheral lung nodules revealed by multidetector CT. MATERIALS AND METHODS: We retrospectively identified 25 patients with metastatic disease, each having from two to nine nodules that were 3-9 mm in diameter. Two senior and three junior reviewers interpreted all images on a workstation. The observers first reviewed axial images (3.75-mm collimation, 3-mm reconstruction interval, multidetector acquisition) in cine and sequential fashion and recorded the size, lobe, and central or peripheral (within 1 cm of the edge of lung) location of each nodule. MIP images (10-mm slab, 8-mm interval) were then reviewed, and additional nodules detected were recorded. Final counts were established by consensus. RESULTS: The reviewers found 122 nodules (71 peripheral, 51 central) in the 25 patients. The addition of MIP slabs significantly enhanced reviewer detection of central nodules (p < 0.001) and junior reviewer detection of peripheral nodules (p < 0.001). MIP slabs also reduced the effects of reviewer experience, particularly for peripheral nodules. CONCLUSION: MIP processing reduces the number of overlooked small nodules, particularly in the central lung. Observer nodule detection remains imperfect even when lesions are clearly depicted on images.
OBJECTIVE: Our purpose was to assess the incremental effect of maximum-intensity-projection (MIP) image processing on the ability of various observers to detect small (<1 cm in diameter) central and peripheral lung nodules revealed by multidetector CT. MATERIALS AND METHODS: We retrospectively identified 25 patients with metastatic disease, each having from two to nine nodules that were 3-9 mm in diameter. Two senior and three junior reviewers interpreted all images on a workstation. The observers first reviewed axial images (3.75-mm collimation, 3-mm reconstruction interval, multidetector acquisition) in cine and sequential fashion and recorded the size, lobe, and central or peripheral (within 1 cm of the edge of lung) location of each nodule. MIP images (10-mm slab, 8-mm interval) were then reviewed, and additional nodules detected were recorded. Final counts were established by consensus. RESULTS: The reviewers found 122 nodules (71 peripheral, 51 central) in the 25 patients. The addition of MIP slabs significantly enhanced reviewer detection of central nodules (p < 0.001) and junior reviewer detection of peripheral nodules (p < 0.001). MIP slabs also reduced the effects of reviewer experience, particularly for peripheral nodules. CONCLUSION: MIP processing reduces the number of overlooked small nodules, particularly in the central lung. Observer nodule detection remains imperfect even when lesions are clearly depicted on images.
Authors: Samuel G Armato; Michael F McNitt-Gray; Anthony P Reeves; Charles R Meyer; Geoffrey McLennan; Denise R Aberle; Ella A Kazerooni; Heber MacMahon; Edwin J R van Beek; David Yankelevitz; Eric A Hoffman; Claudia I Henschke; Rachael Y Roberts; Matthew S Brown; Roger M Engelmann; Richard C Pais; Christopher W Piker; David Qing; Masha Kocherginsky; Barbara Y Croft; Laurence P Clarke Journal: Acad Radiol Date: 2007-11 Impact factor: 3.173