Proposed Topic (Most preferred): :
HA Young Investigators Session (Projects to be presented by HA staff who had joined HA for 10 years or less)
Proposed Topic (Second preferred): :
Clinical Safety and Quality Service III (Projects aiming at quality service to patients and their carers)
Authors (including presenting author) :
Kwok HM(1), YT Lit(1), KF Chan(1), WC Hon(1), A Law(2), WY Fung(1), HC Lee(1), NY Pan(1), LF Cheng(1), KFJ Ma(1)
Affiliation :
(1)Department of Diagnostic and Interventional Radiology, Princess Margaret Hospital (2)Clinical Research Center, Kowloon West Cluster
Introduction :
Renal artery stenosis remains one of the reversible causes of hypertension. Early detection is crucial to timely management, preventing irreversible progression into renal impairment. Inflow-dependent Inversion recovery (IFIR) MRA technique (NATIVE® TrueFISP, Siemens Healthcare, Erlangen, Germany) is a novel technique which is highly sensitive and specific compared with contrast enhanced MRA [1].
Objectives :
- To evaluate the diagnostic performance of the MRI examination using IFIR MRA with reference to contrast enhanced MRA.
Methodology :
A retrospective comparative diagnostic study was carried out in PMH during the period of 1st May 2023 to 31st Dec 2023. Patient’s data was extracted from electronic patient record system from Radiology Information System. All radiological exams conducted with 1.5T MR scanner (MAGNETOM Aera, Siemens) using a protocol using a coronal T2-weighed Half Fourier Single-shot Turbo spine-Echo (HASTE) sequence, an axial fat suppressed T2-weighed HASTE sequence and a 3D fat-suppressed inflow inversion recovery balanced steady state free precession (SSFP) sequence using respiratory triggered approaches (NATIVE® TrueFISP) and a 3D T1-weighed contrast-enhanced sequence with inline subtraction. All patient’s MRI examinations with and without MR contrast were reviewed. Stenosis was graded as grade 1 (Normal), 2 (<50% narrowing), 3 (50-75% narrowing) and 4 (>75% narrowing to total occlusion). Grade 2 to 4 were classified as abnormal.
Result & Outcome :
Results During the study period, 26 patients were identified (52 renal arteries) with mean age +/- SD of 40.7 +/- 15.0 years (range 14-71) and male-to-female ratio of 2.3:1. IFIR MRA correctly identifies abnormal cases in 3 patients (3 renal arteries) and correctly identify normal cases in 26 patients (49 renal arteries) with reference to contrast-enhanced MRA. The sensitivity, specificity, positive predicative value and negative predicative values are all 100%. Area under curve of receiver operating curve (AUC-ROC) is 1. IFIR MRA showed significant agreement with contrast-enhanced MRA at right kidney with Kappa for overall stenosis, ostium stenosis and peripheral stenosis being 1.00, 0.73 and 0.83 (p<0.001) and at left kidney with Kappa for overall stenosis and ostium stenosis being 1.00 and 1.00 (p<0.001). Accessory renal arteries were present in 15.4% (4/26) and all were normal. No adrenal mass was detected in all cases. Mean +/- SD of the examination time for the non-contrast protocol was about 14.9 +/- 3.9 minutes. Conclusion: Non-contrast screening protocol using IFIR MRA in 1.5T MRI produced highly sensitive and specific results relative to contrast-enhanced MRA for renal artery stenosis in native kidneys.
