A review of clinical and MR imaging features of renal lipid-poor angiomyolipomas
- PDF / 805,091 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 71 Downloads / 138 Views
REVIEW
A review of clinical and MR imaging features of renal lipid‑poor angiomyolipomas Mitchell P. Wilson1 · Deelan Patel1 · Prayash Katlariwala1 · Gavin Low1 Received: 14 July 2020 / Revised: 13 October 2020 / Accepted: 20 October 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract Background Lipid-poor angiomyolipomas (lpAMLs) constitute up to 5% of renal angiomyolipomas and are challenging to differentiate from malignant renal lesions on imaging alone. This review aims to identify clinical and MRI features which can be utilized to improve specificity and diagnostic accuracy for detecting lpAMLs in patients being considered for active surveillance rather than intervention. Findings Young age, female sex, and small lesion size are associated with lpAMLs in studies evaluating indeterminate renal lesions. The accuracy of criteria using T2-weighted imaging, diffusion-weighted imaging, chemical shift imaging, dynamic contrast enhancement, multiparametric imaging, and radiomics are reviewed. Low T2 signal intensity is a particularly important MRI feature for lpAML. In studies with low T2 signal intensity, homogeneous early enhancement is a typical feature with an arterial-to-delay enhancement ratio > 1.5. Intratumoral hemorrhage with decrease in signal intensity on in-phase chemical shift imaging may be particularly useful for differentiating papillary renal cell carcinomas from lpAMLs in low T2 signal intensity lesions. Combining clinical and multiparametric MRI features can result in near-perfect specificity for lpAML. Summary In select patients, clinical and MRI features can result in a high specificity and diagnostic accuracy for lpAMLs. These lesions can be considered for active surveillance rather than invasive diagnostic and therapeutic procedures such as biopsy or surgery. Keywords MRI · Kidney · Renal · Angiomyolipoma · Lipid-poor · Fat-poor · Fat-invisible
Introduction Angiomyolipomas (AMLs) are the most common benign incidental solid renal lesion identified on imaging, with the majority representing solitary sporadic lesions [1, 2]. Approximately 5–10% of renal lesions are multiple and as many as 20% of lesions are associated with tuberous sclerosis complex or other syndromes such as * Mitchell P. Wilson [email protected] Deelan Patel [email protected] Prayash Katlariwala [email protected] Gavin Low [email protected] 1
Department of Radiology and Diagnostic Imaging, University of Alberta, 2B2.41 WMC, 8440‑112 Street NW, T6G 2B7 Edmonton, AB, Canada
lymphangioleiomyomatosis [3, 4]. Small solitary AMLs identified incidentally do not typically require follow-up imaging once a diagnosis is made [5]. As many as 5% of AMLs do not demonstrate typical macroscopic fat on imaging [1, 2]. This subtype is most typically described as a lipid-poor angiomyolipoma (lpAML), although other terms including fat-poor AML, AML without visible fat, fat-invisible AML, and minimal-fat AML have been used [6–8]. Contrary to AMLs with macroscopic fat, these lesions have not been tra
Data Loading...
