CHANGES IN LUNG-VOLUME AND VOLUME OF EMPHYSEMA AFTER UNILATERAL LUNG REDUCTION SURGERY - ANALYSIS WITH CT LUNG DENSITOMETRY

PURPOSE: To evaluate changes in volume of the lungs and volume of emph ysema after unilateral lung reduction surgery (ULRS) by using computed tomographic (CT) lung densitometry. MATERIALS AND METHODS: Twenty-eig ht patients underwent CT before and 3 months after ULRS. With use of a density mask software program and a three-dimensional graphics workst ation, CT scans were analyzed to define the volume of the lungs and th e volume of emphysema. Pre- and postoperative mean CT numbers were det ermined. RESULTS: After ULRS, the surgically reduced lung volume decre ased 22%, and the intact opposite lung volume increased 4%. Emphysema in the surgically reduced lung decreased 14% and was unchanged in the intact opposite lung. Mean CT numbers in the surgically reduced lung i ncreased 26 HU but were unchanged in the intact opposite lung. CONCLUS ION: The effects of ULRS on each lung can be evaluated by using CT lun g densitometry and a three-dimensional graphics workstation. ULRS redu ces emphysema and lung volume in the surgically reduced lung without s tatistically significant worsening of contralateral emphysema at 3 mon ths.