Do we really need CT or CEMRA for the evaluation of renal arteries? Morphologic and functional MRI with Phase Contrast and Inflow balanced-SSFP with IR saturation sequences

Congress:

ECR 2019

Poster Number:

C-2832

Type:

Educational Exhibit

Keywords:

Haemodynamics / Flow dynamics, Imaging sequences, MR-Angiography, Vascular, MR physics, Kidney

Authors:

P. Rossi, F. P. Tarantino, G. Aringhieri, M. Marletta, V. Zampa, D. Caramella; Pisa/IT

DOI:

10.26044/ecr2019/C-2832

DOI-Link:

https://dx.doi.org/10.26044/ecr2019/C-2832

Fig. 1: Male 77 years old, with typical findings suggestive for atherosclerosis a)...

Fig. 2: Female 45 years old, with typical findings suggestive for fibromuscular...

Fig. 3: Male of 60 years old that underwent CT for the evaluation of an abdominal aorta...

Fig. 4: Standard MR protocol used in our department to evaluate renal arteries: (a)...

Fig. 14: Male, 77 years old. IFIR images (a-b) show bilateral ostial narrowing (arrow...

Fig. 15: Male, 73 years old. IFIR images (a-b) show bilateral ostial narrowing (arrow...

Learning objectives

- To explain the advantages compared to other diagnostic techniques of phase contrast (PC) and inflow balanced-SSFP with IR saturation (IFIR) sequences in the renal artery stenosis (RAS) diagnosis. - To review MRI semeiotics of these two sequences.

Background

RAS refers to a narrowing of one or both renal arteries leading to impaired blood flow to the kidneys and represents the most common cause of reno-vascular hypertension, accounting for 1-10% of the 50 million cases of hypertension in the US in 2018 with prevalence of unilateral stenosis (compared to bilateral stenosis) approximately from 50 % to 80% [1-3]. RAS etiopathogenesis is heterogeneous and the two most common causes are represented by atherosclerosis (60-90%) and fibro-muscular dysplasia (10-30%). Atherosclerosis primarily affects males over the age...

Findings and procedure details

From 2014 to 2017 in our department 150 patients underwent renal arteries MR evaluation with a 3T scanner using no contrast MRA sequences, as a second line exam after suspicious findings at Duplex-US. The standard protocol we use (fig.4) include an axial steady state free procession sequence, beneficial to set the further sequences, and coronal single shot fast spin echo sequence in order to visualize kidneys and to detect eventual collateral findings. Then, 3D-IFIR and 3D-PC sequences are acquired both using respiratory gating. IFIR sequence...

Conclusion

Unenhanced MRA represents a valid alternative to CEMRA and CTA in order to diagnose RAS with high spatial resolution morphological and functional evaluation. In case of doubtful US exams, it can differentiate haemo-dynamically significant from non-significant stenoses, providing the best patient care allowing to discriminate who may benefit from invasive treatment or conservative management.

Personal information

Piercarlo Rossi, Francesco Paolo Tarantino, Giacomo Aringhieri, andDavide Caramellawork at theUniversity of PisaDiagnostic and Interventional Radiology. Virna Zampa andMassimo Marlettawork at the Radiodiagnostica 1 of theUniversity Hospital of Pisa.

References

[1] Bokhari MR, Bokhari SRA. Renal Artery Stenosis. [Updated 2018 Oct 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018 Jan-. [2] Weber BR, Dieter RS. Renal artery stenosis: epidemiology and treatment. Int J Nephrol Renovasc Dis. 2014 May 13;7:169-81. doi: 10.2147/IJNRD.S40175. eCollection 2014. Review. PubMed PMID: 24868169; PubMed Central PMCID: PMC4027852. [3] Zhang HL, Sos TA, Winchester PA, Gao J, Prince MR. Renal artery stenosis: imaging options, pitfalls, and concerns. Prog Cardiovasc Dis. 2009 Nov-Dec;52(3):209-19. doi: 10.1016/j.pcad.2009.10.003. Review. PubMed PMID: 19917332. [4] Parienty...