High resolution multislice CT of the lung: Comparison to sequential HRCT slices

Purpose: To compare the image quality of high-resolution (HR) spiral CT sca ns from a multislice CT scanner with sequential HRCT scans from a singlesli ce CT scanner. Materials and Methods: 20 patients with diffuse lung disease received a high-resolution spiral CT on a multislice scanner (4 slices) an d 5 HRCT single slices (1 mm) on a singleslice scanner. Scan parameters of the multislice scanner were: Collimation 4 x 1 mm, pitch 6, slice thickness 1 mm. 5 HRCT slices were compared to the corresponding HR spiral CT slices using a 5-point scale by 5 radiologists with regard to the image quality a nd the number of artifacts. The evaluation was performed with a multivariat e analysis (MANOVA test). Results: Overall impression of image quality, noi se, central vessels and bronchi, and all pathological changes were not sign ificantly different between the two CT methods. Sequential HRCT scans were considered to be significantly better than HR spiral CT scans for spatial r esolution (p=0.02), depiction of peripheral vessels (p=0.02), and of small bronchi (p=0.05), and significantly worse for depiction of interlobar septa (p<0.001). Diagnostically relevant differences were found in only 2.2%. Br eathing and heartbeat artifacts each were 3 times higher in the sequential HRCT technique than in the multislice-spiral technique (p<0.0001). Conclusi on: HR spiral CT scans performed on a multislice CT scanner provide signifi cantly less artifacts and an equal diagnostic image quality compared to seq uential HRCT scans performed on a singleslice CT scanner. Multislice spiral CT in HR technique may replace the common scanning technique with conventi onal spiral CT and additional HRCT scans for diffuse lung diseases.