Local staging of rectal carcinoma and assessment of the circumferential resection margin with high-resolution MRI using an integrated parallel acquisition technique

Purpose: To assess the diagnostic accuracy of integrated parallel acquisition technique (iPAT) in local staging of rectal carcinoma in comparison to conventional high-resolution MRI. Materials and Methods: A total of 28 patients with a neoplasm of the rectum and 15 control patients underwent MRI of the pelvis. High-resolution images were acquired conventionally and with iPAT using a modified sensitivity encoding (mSENSE). Image quality, signal-to-noise and contrast-to-noise ratios (SNR. CNR), tumor extent, nodal status. and delineation of the circumferential resection margin (CRM) were compared. In 19 patients with a carcinoma. MR findings were correlated with the histopathological diagnosis. Tumor distance to the CRM was matched with resection specimen in 12 cases. Results: The comparison of both MR techniques revealed no clinically relevant differences in tumor staging and delineation of the CRM. though SNR and CNR were significantly lower in mSENSE images. Tumor stage was concordant in 17 of 19 cases compared to histopathology. In four of nine patients with T3 and T4 carcinomas, the histopathological resection margin was <= 2 mm, in five cases MRI predicted a margin of <= 2 mm. Conclusion: The application of iPAT in local staging of rectal carcinoma is time-saving and does not degrade diagnostic accuracy. Tumor stage, nodal status, and the CRM can be assessed equally compared to conventional acquisition techniques.