The nutcracker syndrome: The usefulness of different MRI sequences for diagnosis and follow-up

Nutcracker Syndrome (NCS) is the extrinsic compression of the left renal vein by neighboring arterial, ligamentous, muscular, or osseous structures. Diagnosis is made by Doppler ultrasonography (US), multidetector computerized tomography (MDCT), magnetic resonance imaging (MRI), phlebography. The aim of the current study is to assess the value of MRI and compare the efficiency of different sequences in diagnosis and follow up of children with NCS.

A total of 40 children (female/male ratio 3:1) with NCS were included in this prospective study. A standardized abdominal MRI protocol was used and T2-TRUFI (True Fast Imaging with Steady-State Free Precession), T2-HASTE (Half Fourier Acquisition with Single Shot Turbo Spin Echo), T1-VIBE (Volumetric Interpolated Breath Hold Examination), and out-of-phase (opposed-phase) T1 sequences were obtained. The sequences were compared according to anatomical depiction, measurability, and pulsation artifact.

A four point-scale was used to assess subjective image quality and the results were listed as: 1 = poor, 2 = fair, 3 = good, and 4 = excellent. Both in total and for each individual criterion, the highest scores were obtained with T2-TRUFI (total mean 3.74 ± 0.45, anatomical depiction 3.9 ± 0.3, measurability 3.8 ± 0.4, aortic pulsation artifact 3.52 ± 0.55).

Although Doppler US is the gold standard technique in the diagnosis of NCS, MR imaging may be used as an additional modality, as it is superior to Doppler US in terms of anatomic depiction and a lower rate of imaging artifacts. Non-contrast MR imaging, particularly TRUFI sequence, may have an incremental value in the accurate diagnosis and follow-up of these patients.