Michael James Triolo MD, Presenter: Nothing to Disclose

Natasha Wehrli MD, Abstract Co-Author: Nothing to Disclose

Thais Andrade MD, Abstract Co-Author: Nothing to Disclose

Samir S. Taneja MD, Abstract Co-Author: Consultant, Eigen Consultant, GTx, Inc Consultant, Bayer AG Consultant, Healthtronics, Inc Speaker, Johnson & Johnson Investigator, STEBA Biotech Royalties, Reed Elsevier

Andrew B. Rosenkrantz MD, Abstract Co-Author: Nothing to Disclose

To compare the perceived complexity and Bosniak cyst classification of cystic renal lesions between 1.5T and 3T MRI.

A database search was performed to identify cystic renal lesions that underwent both 1.5T and 3T contrast-enhanced MRI within a 12 month span.  Cysts exhibiting at least minimal complexity were included.  Two radiologists (R1 and R2) independently assessed all lesions, blinded to the field strength, in terms of number of septations, septal thickening, mural thickening, presence of mural nodule, and overall Bosniak cyst category.  Readers also subjectively scored clarity of internal morphology of all lesions on a 1-5 scale.  Each reader's scores were compared between 1.5T and 3T, with differences between these for a given lesion attributed to field strength rather than interval progression of the lesion during the <12 month period given known slow growth of cystic renal lesions. Pathologic correlation was available in 2 lesions, precluding comparison of accuracy between field strengths.

33 cystic renal lesions in 26 patients were identified. R1 observed greater number of septations, increased septal thickening, increased mural thickening, and increased presence of a mural nodule at 3T in 8, 7, 4, and 2 lesions, and at 1.5T in 3, 3, 2, and 0 lesions, respectively; R2 observed greater number of septations, increased septal thickening, increased mural thickening, and increased presence of a mural nodule at 3T in 3, 4, 3, and 0 lesions, and at 1.5T in 2, 0, 0, and 0 lesions, respectively. R1 provided higher Bosniak category at 3T in 9 cases and at 1.5T in 4 cases; R2 provided higher Bosniak category at 3T in 4 cases and at 1.5T in 0 cases. The higher scores at 3T than 1.5T were associated with differences in advised clinical management in 7/9 cases for R1 and 4/4 cases for R2. Clarity of lesion morphology was significantly greater at 3T than 1.5T (R1: 4.5±0.7 vs. 3.6±0.4, R2: 4.5±0.6 vs. 3.6±0.8; p<0.001, both readers).

There was an overall tendency for both readers to upgrade renal cyst complexity and Bosniak cyst category at 3T than 1.5T, which impacted advised management. We attribute this difference to known greater conspicuity of tissue enhancement at 3T.

Given potential impact of MRI field strength on the perceived complexity of cystic renal lesions, we advise that serial MRI evaluation of cystic renal lesions be performed at constant field strength.

Triolo, M, Wehrli, N, Andrade, T, Taneja, S, Rosenkrantz, A, Complex Cystic Renal Masses: Comparison of Cyst Complexity and Bosniak Classification between 1.5T and 3T MRI.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13044254.html