title: Using the MDCT thick slab MinIP method for the follow-up of pulmonary emphysema.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the usefulness of thick slab minimum intensity projection (MinIP) as a follow-up method in patients with pulmonary emphysema. This method was used to determine the presence or absence of changes over time in the lung field based on multi-detector-row CT (MDCT) data.
  
  
  METHODS
  Among patients diagnosed with pulmonary emphysema who underwent 16-MDCT (slice thickness, 1 mm) twice at an interval of 6 months or more, 12 patients without changes in the lung field and 14 with clear changes in the lung field were selected as subjects. An image interpretation experiment was performed by five image interpreters. Pulmonary emphysema was followed up using two types of thick slab MinIP (thick slab MinIP 1 and 2) and multi-planar reformation (MPR), and the results of image interpretation were evaluated by receiver operating characteristic (ROC) analysis. In addition, the time required for image interpretation was compared among the three follow-up methods.
  
  
  RESULTS
  The area under the ROC curve (Az) was 0.794 for thick slab MinIP 1, 0.778 for the thick slab MinIP 2, and 0.759 for MPR, showing no significant differences among the three methods. Individual differences in each item were significantly more marked for MPR than for thick slab MinIP. The time required for image interpretation was around 18 seconds for thick slab MinIP 1, 11 seconds for thick slab MinIP 2, and approximately 127 seconds for MPR, showing significant differences among the three methods.
  
  
  CONCLUSIONS
  There were no significant differences in the results of image interpretation regarding the presence or absence of changes in the lung fields between thick slab MinIP and MPR. However, thick slab MinIP showed a shorter image interpretation time and smaller individual differences in the results among image interpreters than MPR, suggesting the usefulness of this method for determining the presence or absence of changes with time in the lung fields of patients with pulmonary emphysema.
authors.affiliation: Department of Radiology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Hai
authors.initials: H
authors.lastname: Lan
authors.forename: Hiromu
authors.initials: H
authors.lastname: Nishitani
authors.forename: Sadamitsu
authors.initials: S
authors.lastname: Nishihara
authors.forename: Junji
authors.initials: J
authors.lastname: Ueno
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Takao
authors.forename: Seiji
authors.initials: S
authors.lastname: Iwamoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawanaka
authors.forename: Mawlan
authors.initials: M
authors.lastname: Mahmut
authors.forename: Si
authors.initials: S
authors.lastname: Qingge
mesh_terms: D005500:Follow-Up Studies; D006801:Humans; D061330:Multidetector Computed Tomography / Q000379:methods*; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*