Aradhana Mukherjea Venkatesan MD, Presenter: Nothing to Disclose

Nagaraj Setty Holalkere MD, Abstract Co-Author: Nothing to Disclose

Peter F. Hahn MD, PhD, Abstract Co-Author: Nothing to Disclose

Susanna In-Sun Lee MD, PhD, Abstract Co-Author: Nothing to Disclose

To determine whether there are differences in apparent diffusion coefficient (ADC) values in normal female pelvic structures at field strengths commonly used for diffusion weighted imaging (DWI).

A retrospective review of 56 patients who underwent pelvic MRI with DWI at 1.5 & 3T was performed. Patients were imaged over 9 months and divided into a study group (mean age 45, range 26-69) and age-matched control group. Study patients were imaged at 3T (Trio, Siemens) using FOV= 22 x 22 cm, 5/0mm thickness/gap, 23 slices/1.9 min free breathing seq., TE/TR 89/3000, matrix 128 x 128, bandwidth +178 kHz, b=0 and 1000s/mm2. Age-matched controls were evaluated at 1.5 T (Signa Advantage; GE Medical Systems/Magnetom; Siemens) using FOV = 34 x 26 cm, 8/2mm thickness/gap, 15 slices/3.5 min free breathing seq., TE/TR 50/5000 ms, matrix 128 x 128, bandwidth +125 kHz, b = 0 and 1000 s/mm2. Quantification of ADC values (X10-3 mm2/sec) from axial and sagittal ADC maps was performed independently by 2 readers blinded to clinical data on a PACS sytem (Agfa, Impax V.4) by placing regions of interest over uterine myometrium, endometrium and ovarian stoma. ADC values were compared using unpaired t-tests.

Mean ADC values for uterine myometrium on sagittal and axial images was .78 and .83 respectively at 1.5T and .96 and 1.00 respectively at 3T. Mean ADC values for uterine endometrium on sagittal and axial images was 1.12 and 1.19 respectively at 1.5T and 1.17 and 1.15 respectively at 3T. Mean ADC values for ovarian stroma on sagittal and axial images was .78 and .83 respectively at 1.5T and 1.06 and 1.05 respectively at 3T. There was no significant difference in ADC values of myometrium (p=0.06) and endometrium (p=0.9). Ovarian ADC values were significantly different(p=0.02).

Quantitative DWI evaluation at 1.5 vs. 3T is not significantly different for uterine myometrium and endometrium. ADC values for ovarian stroma are different. Evaluation of DWI for the diagnosis of adnexal pathology will likely require separate studies at 1.5 and 3T.

ADC values for ovarian stroma are different at 1.5 & 3T; it is recommended that DWI protocols be optimized separately to evaluate adnexal pathology.

Venkatesan, A, Holalkere, N, Hahn, P, Lee, S, Diffusion-weighted MR Imaging of the Female Pelvis at 1.5 and 3.0 T: A Comparative Study of Apparent Diffusion Coefficient (ADC) Values of Normal Gynecologic Anatomy.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5013641.html