There is no relevant literature documenting the additional benefit of MRI abdomen and pelvis with IV contrast in the nonexcretory phase in a patient with acute flank pain and suspicion of stone disease. MRI Abdomen and Pelvis Without IV Contrast MRI abdomen and pelvis without IV contrast is defined as any MRI protocol not specifically tailored for evaluation of the upper and lower urinary tracts, which includes precontrast imaging but does not include heavily T2-weighted images of the urinary tract. There is limited literature on the use of MRI abdomen and pelvis without and with IV Acute Onset Flank Pain-Suspicion of Stone Disease contrast in the evaluation of the patient with suspected urolithiasis; however, in one study, T2-weighted imaging has been shown to improve sensitivity of detection of perirenal fluid in the setting of acute calculus ureteric obstruction compared with fat stranding on unenhanced CT (77% versus 45%, respectively) [25]. In another study, also in the setting of acute ureteric obstruction, both excretory urography and T2-weighted MRI showed obstruction in a high percentage of cases [26]. MRU Without and With IV Contrast MRU is an alternative means of obtaining cross-sectional, excretory phase images without the use of iodinated contrast. Limited studies are available detailing the utility of contrast-enhanced MRU in the detection of urolithiasis. In a study published in 2001, the use of gadolinium-enhanced 3-D fast low-angle shot MRU was shown to provide higher sensitivity in detection of stones compared with noncontrast MR technique (heavily T2-weighted; combined thin-slice half-Fourier acquisition single-shot turbo spin-echo and thick-slab single-shot turbo spin-echo; 96%- 100% versus 54%-58%, respectively) [27].
Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . There is no relevant literature documenting the additional benefit of MRI abdomen and pelvis with IV contrast in the nonexcretory phase in a patient with acute flank pain and suspicion of stone disease. MRI Abdomen and Pelvis Without IV Contrast MRI abdomen and pelvis without IV contrast is defined as any MRI protocol not specifically tailored for evaluation of the upper and lower urinary tracts, which includes precontrast imaging but does not include heavily T2-weighted images of the urinary tract. There is limited literature on the use of MRI abdomen and pelvis without and with IV Acute Onset Flank Pain-Suspicion of Stone Disease contrast in the evaluation of the patient with suspected urolithiasis; however, in one study, T2-weighted imaging has been shown to improve sensitivity of detection of perirenal fluid in the setting of acute calculus ureteric obstruction compared with fat stranding on unenhanced CT (77% versus 45%, respectively) [25]. In another study, also in the setting of acute ureteric obstruction, both excretory urography and T2-weighted MRI showed obstruction in a high percentage of cases [26]. MRU Without and With IV Contrast MRU is an alternative means of obtaining cross-sectional, excretory phase images without the use of iodinated contrast. Limited studies are available detailing the utility of contrast-enhanced MRU in the detection of urolithiasis. In a study published in 2001, the use of gadolinium-enhanced 3-D fast low-angle shot MRU was shown to provide higher sensitivity in detection of stones compared with noncontrast MR technique (heavily T2-weighted; combined thin-slice half-Fourier acquisition single-shot turbo spin-echo and thick-slab single-shot turbo spin-echo; 96%- 100% versus 54%-58%, respectively) [27].