Using the MDCT thick slab MinIP method for the follow-up of pulmonary emphysema

Abstract : Purpose : The purpose of this study was to evaluate the usefulness of thick slabminimum intensity projection (MinIP) as a follow-up method in patients with pulmonaryemphysema. This method was used to determine the presence or absence of changes overtime in the lung field based on multi-detector-row CT (MDCT) data. Methods : Among patientsdiagnosed 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 lungfield and 14 with clear changes in the lung field were selected as subjects. An image interpretationexperiment was performed by five image interpreters. Pulmonary emphysemawas followed up using two types of thick slab MinIP (thick slab MinIP 1 and 2) andmulti-planar reformation (MPR), and the results of image interpretation were evaluatedby receiver operating characteristic (ROC) analysis. In addition, the time required forimage interpretation was compared among the three follow-up methods. Results : Thearea under the ROC curve (Az) was 0.794 for thick slab MinIP 1, 0.778 for the thick slabMinIP 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 thanfor thick slab MinIP. The time required for image interpretation was around 18 secondsfor thick slab MinIP 1, 11 seconds for thick slab MinIP 2, and approximately 127 secondsfor MPR, showing significant differences among the three methods. Conclusion : Therewere no significant differences in the results of image interpretation regarding the presenceor 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 individualdifferences in the results among image interpreters than MPR, suggesting the usefulnessof this method for determining the presence or absence of changes with time in the lungfields of patients with pulmonary emphysema.

The journal of medical investigation : http://medical.med.tokushima-u.ac.jp/jmi/index.html