The value of fast low-angle shot 2-dimensional sequence with sliding multi-slice technique in the detection of abdominal metastasis of rectal cancer

Abstract

Objective To evaluate the potential of a sliding multi-slice (SMS)fast low-angbe shot 2-dimensional (FLASH-2D) sequence for abdominal lesion detection in patients with rectal cancer.Methods Nineteen paired SMS MRI( FLASH-2D sequnce) and MSCT examinations of the whole abdomen and pelvis in 15 patients (four of them were examined twice) with rectal cancer were retrospectively analyzed by two radiologists.While the lesion-based agreement between the two methods and the diagnostic agreement between two observers were tested by means of Kappa statistics,the sensitivities of SMS FLASH-2D and MSCT to detect liver metastases,lymph node metastases and bone metastases were calculated.Standard of reference consisted of a consensus evaluation of SMS,MSCT and all available follow-up examinations after a period of 6 months.Results Using SMS FLASH-2D cumulatively,both observers detected 56 of all 60 lesions respectively resulting in same sensitivities of 93.33% (56/60).Using MSCT,both observers detected 50 lesions,resulting in same sensitivities of 83.33 % (50/60) respectively.The sensitivities of SMS FLASH-2D to detect hepatic metastases were 97.44% (38/39) and 100% (39/39) for both observers respectively,compared to 100 % (39/39)and 100% (39/39)for MSCT.The sensitivities for lymph node metastases were 85.71% (12/14) and 71.43% (10/14) for SMS FLASH-2D compared to 78.57% (11/14) and 71.43% (10/14) for MSCT.The sensitivities for bone metastases were 85.71% (6/7) and 100% (7/7) for SMS FLASH 2D compared to 0(0/7) and 14.29% (1/7) for MSCT.Conclusion SMS FLASH-2D imaging and MSCT exhibit equal ability of detecting lymph node and liver metastases,but SMS FLASH 2D seems better than MSCT in dectecting bone metastases. Key words: Colorectal neoplasms; Magnetic resonance imaging; Image processing,computer-assisted