Yoshiharu Ohno MD, Presenter: Nothing to Disclose

Hiroto Hatabu MD, Abstract Co-Author: Nothing to Disclose

Takanori Higashino MD, Abstract Co-Author: Nothing to Disclose

Munenobu Nogami MD, Abstract Co-Author: Nothing to Disclose

Masahiko Fujii MD, Abstract Co-Author: Nothing to Disclose

Kazuro Sugimura MD, Abstract Co-Author: Nothing to Disclose

To compare the diagnostic capability of dynamic MR imaging (MRI) with dynamic CT in solitary pulmonary nodule (SPN) patients.

187 consecutive patients with 202 SPN (less than 30 mm in diameter) underwent dynamic MRI, dynamic CT, microbacterial and pathological examinations. All dynamic MRIs were obtained by using 3D spoiled gradient echo sequence (TR 2.7ms/ TE 0.6 ms/ Flip angle 30 degree) using two 1.5 T MR scanners (Gyroscan Intera and ACS-NT, Philips Medical Systems, Best, The Netherlands). All CT examinations were performed by a 4-detector-row CT scanner (Somatom Plus 4 Volume Zoom, Siemens Medical Systems, Forchheim, germany). 202 SPNs were classified into two groups by final diagnosis: malignant SPN (n=152) and benign SPN (n=50). From signal intensity - time and attenuation-time curves, relative enhancement and slope of enhancement were calculated, and compared between two groups by using Student’s t-test. To compare the diagnostic capability between dynamic MRI and CT indexes, ROC analyses were performed. Threshold values of all MR and CT indexes were determined to maximize their accuracy. Finally, sensitivity, specificity and accuracy of each index were compared each other by using McNemar’s test.

The mean maximum relative enhancement and mean slope of enhancement of malignant SPN group were significantly higher than those of benign groups on dynamic MRI (p<0.0001, p<0.0001) and dynamic CT (p=0.0004, p=0.0004). Diagnostic capability of relative enhancement of dynamic MRI (Az=0.81) was significantly higher than that of relative enhancement (Az=0.68, p<0.05) and slope of enhancement (Az=0.67, p<0.05) of dynamic CT. Diagnostic capability of slope of enhancement of dynamic MRI (Az=0.88) was also significantly higher than that of both dynamic CT indexes (p<0.05). Specificity (78.0%) and accuracy (92.3%) of slope of enhancement of dynamic MRI were the significantly higher than those of other indexes (p<0.05).

Dynamic MR imaging is useful for more specific and accurate differentiation of malignant SPNs from benign SPNs, when compared with dynamic CT.

Ohno, Y, Hatabu, H, Higashino, T, Nogami, M, Fujii, M, Sugimura, K, Solitary Pulmonary Nodule: Comparison of Diagnostic Capability between Dynamic MR Imaging and CT.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4404957.html