2400. Diagnostic Performance of ACR ORADS-MRI Score: A Preliminary Revalidation Study from a Tertiary Care Institution
Authors * Denotes Presenting Author
  1. Prof Shabnam Grover; Sharda University, School of Medical Sciences and Research
  2. Hemal Grover *; Weil Cornell University, School of Medicine
  3. Sayantan Patra ; VMMC and Safdarjung Hospital
  4. Prof Pratima Mittal; Amrita Institute
  5. Prof Geetika Khanna; VMMC and Safdarjung Hospital
The ACR ORADS-MRI score is a recently proposed algorithm for accurate characterization of ovarian masses, which recommends restricted intervention in benign tumors and management only in dedicated oncology centers for malignant tumors, thus directly impacting patient prognosis. The purpose of the current study was to revalidate the ACR O-RADS MRI score by evaluating its diagnostic performance for the definitive characterization of ovarian-adnexal masses as benign or malignant, using histopathology as reference standard.

Materials and Methods:
This was a cross sectional, observational, prospective, IRB-approved study conducted during the last 2 years with application of the ORADS-MRI score to a prospectively acquired dataset of adnexal masses. 3T MRI was performed on adnexal masses using sequences as per the ACR O-RADS MRI recommendation: T2W, T1W, T1W fat-saturated, DWI, dynamic contrast-enhanced sequences and T1 postgad sequences. The study included adult women with clinically and sonographically diagnosed ovarian-adnexal masses in whom final histopathological diagnosis was available. Patients with (1) age below 18 years, (2) deranged renal parameters or (3) metallic implants were excluded. The ACR O-RADS MRI scoring system was applied with a two-reviewer consensus. Both reviewers were dedicated body imagers with over 20 years of experience, who were initially blinded to the histopathology diagnosis. Tumor diagnosis was categorized as benign for O-RADS 1 to O-RADS 3 and malignant for O-RADS 4 and O-RADS 5, with subsequent histopathologic correlation. The sensitivity, specificity, NPV, and PPV were calculated. The students t test was used for calculating statistical significance.

The sample size included 63 ovarian adnexal masses, histopathology revealed 36 benign and 27 malignant tumors. O-RADS MRI had a sensitivity of 96.3%, specificity 72.2%, PPV 72.2%, NPV 96.3% and the diagnostic accuracy was 82.5%, with a p-value of 0.02.

ORADS MRI is an accurate system for definitive characterization of ovarian adnexal tumors. NPV and PPV are advantageous for patients with both benign and malignant tumors, because recommended management is specifically stratified as minimalistic intervention in benign tumors, versus management in dedicated oncology centers for malignant tumors. Therefore, in view of the critical therapeutic and prognostic implications, the concept merits larger multicenter studies with the goal to incorporate ACR O-RADS MRI into standard imaging and reporting protocols. Since the ACR O-RADS MRI scoring algorithm not only provides early and accurate characterization of ovarian adnexal masses as benign or malignant but also recommends specifically stratified management strategies, its application directly impacts patient prognosis. Therefore, the O-RADS MRI should be recommended for a wider, more rapid and universal adoption by radiologists and clinicians alike.