Objective:

Our aim was to determine the contribution of diffusion weighted MRI (DWI) to abdominal MRI in detecting peritoneal implants in patients with oncologic diagnosis.

Materials and methods:

Thirty-five patients operated for a malignant tumor and one patient for unknown primary malignant tumor were enrolled in this prospective, observational study. Thirty-six oncology patients underwent abdominal and pelvic MRI, diffusion weighted MRI with b value of 0-500-1000 s/mm2. All MRI images were independently evaluated by two radiologists. Peritoneal implants were divided into five categories (0-0,5cm; 0,5-1cm; 1-2cm; 2-3cm and larger than 3cm ) according to lesion sizes. Nine patients’ results were compared with surgery or laparotomy. Remaining 27 patients were evaluated with follow-up MRI or CT at a varying time between 2 and 12 months from the initial MRI, and moreover they were also evaluated with laboratory values and clinical outcomes at the 12 to 36th month from the initial MRI.

Results:

Radiologist 1 detected 78 lesions with MRI, 136 lesions with DWI and 110 lesions with MRI+DWI. Radiologist 2 detected 89 lesions with MRI, 125 lesions with DWI and 113 lesions with MRI+DWI. Peritoneal carcinomatosis was confirmed in 4 patients and 9 patients were negative for carcinomatosis with all imaging modalities. On a patient-based analysis, sensitivity and specificity for radiologist 1 were respectively 92%, 100% for MRI and 96%, 100% for MRI+DWI. Also for the radiologist 2 overall sensitivity and specificity of MRI and MRI+DWI were similar to the radiologist 1.

Conclusion:

In our study we found that the sensitivity for contrast enhanced MRI+DWI was higher than MRI.

Keywords: Malignancy, diffusion magnetic resonance imaging, peritoneal neoplasms