Better visualization of transbronchial biopsy using CT fluoroscopy

Computed tomography fluoroscopy (CTF) provides the capability for continuous CT imaging and has been increasingly used in interventional procedures. Our objective was to assess the usefulness of CTF in the monitoring of transbronchial biopsy procedures.

We evaluated nine patients in whom yield of "conventional" transbronchial biopsies had failed. CTF was performed on a Somatom Plus 4 Power scanner (CARE Vision CT, Siemens, Forchheim, Germany) using 120 kV, 50 mA at a frame rate of eight images per second on a matrix of 256 x 256. Image reconstruction was based on a partial scan with an acquisition time of 0.5 sec. The maximal time without interruption was 79 sec; after stopping for a few seconds a new period of 79 sec was available. The number of biopsies, procedure times, applied dose, and histologic results were documented.

With CTF-guided transbronchial biopsy, the yield of the biopsies was improved. In seven patients biopsy yielded bronchial cancer; in one patient histopathologic examination showed tuberculosis. Only in one patient did CTF-guided transbronchial biopsy fail. The mean number of biopsies was four in each patient. Mean fluoroscopy time was 165 +/- 92 sec (range 111-272 sec) and mean procedure time was 800 +/- 302 sec (range 480-1081 sec). The applied dose ranged between 500 and 1224 mSv; the mean applied dose was 743 +/- 414 mSv. There were no fatal complications.

Computed tomography fluoroscopy appears to facilitate visualization of transbronchial biopsy procedures, with the drawback of increased radiation exposure. To compare the "conventional" method versus CTF a randomized prospective study is necessary.