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Aldhufian M, Sheinis Pickovsky J, Alfaleh H, Melkus G, Schieda N. Prevalence of 'Fat-Poor' Adrenal Adenomas at Chemical-Shift MRI. Can Assoc Radiol J 2024; 75:98-106. [PMID: 37335612 DOI: 10.1177/08465371231179881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023] Open
Abstract
OBJECTIVE : To determine the prevalence of 'fat-poor' adrenal adenomas at chemical-shift-MRI. MATERIALS AND METHODS : This prospective IRB approved study identified 104 consecutive patients with 127 indeterminate adrenal masses that underwent 1.5-T chemical-shift-MRI between 2021-2023. Two blinded radiologists independently measured: 1) 2-Dimensionsal (2D) chemical-shift signal intensity (SI)-index on 2D Chemical-shift-MRI (SI-index >16.5% diagnosed presence of microscopic fat), 2) unenhanced CT attenuation (in cases where unenhanced CT was available). RESULTS : From 127 adrenal masses, there were 94% (119/127) adenomas and 6% (8/127) other masses (2 pheochromocytoma, 5 metastases, 1 lymphoma). 98% (117/119) adenomas had SI-Index >16.5%, only 2% (2/119) adenomas were 'fat-poor' by MRI. SI-Index >16.5% was 100% specific for adenoma, all other masses had SI-Index <16.5%. Unenhanced CT was available in 43% (55/127) lesions (50 adenomas, 5 other masses). 34% (17/50) adenomas were lipid-poor (>10 HU). Percentage of adenomas with SI-Index >16.5% were: 1) ≤10 HU, 100% (33/33), 2) 11-29 HU, 100% (12/12), 3) ≥30 HU, 60% (3/5). No other masses had attenuation ≤10 HU (0/5). CONCLUSION : Fat-poor adrenal adenomas are uncommon using 2D chemical-shift signal intensity index >16.5% at 1.5-T, occurring in approximately 2% of adenomas in this large prospective series.
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Affiliation(s)
- Meshary Aldhufian
- Department of Medical Imaging, The Ottawa Hospital, Ottawa, ON, Canada
| | | | - Hana Alfaleh
- Department of Medical Imaging, The Ottawa Hospital, Ottawa, ON, Canada
| | - Gerd Melkus
- Department of Medical Imaging, The Ottawa Hospital, Ottawa, ON, Canada
| | - Nicola Schieda
- Department of Medical Imaging, The Ottawa Hospital, Ottawa, ON, Canada
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Abstract
Due to the widespread use of imaging, incidental adrenal masses are commonly encountered. A number of pitfalls can result in misdiagnosis of these lesions, including inappropriate choice of imaging technique, presence of pseudolesions, and overlap of imaging features of different adrenal lesions. This article explores the potential pitfalls in imaging of the adrenal glands, on computed tomography and magnetic resonance imaging, that can lead to misinterpretation. Clues to correct diagnoses are provided to evade potential misinterpretation.
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Shi B, Zhang GMY, Xu M, Jin ZY, Sun H. Distinguishing metastases from benign adrenal masses: what can CT texture analysis do? Acta Radiol 2019; 60:1553-1561. [PMID: 30799636 DOI: 10.1177/0284185119830292] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Bing Shi
- Department of Radiology, Fuwai Hospital, Chinese Academy of Medical Sciences, Shenzhen, PR China
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, PR China
| | - Gu-Mu-Yang Zhang
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, PR China
| | - Min Xu
- CT Scientific Collaboration, Siemens Healthcare Limited, Shanghai, PR China
| | - Zheng-Yu Jin
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, PR China
| | - Hao Sun
- Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, PR China
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Update on Gadolinium-Based Contrast Agent-Enhanced Imaging in the Genitourinary System. AJR Am J Roentgenol 2019; 212:1223-1233. [PMID: 30973785 DOI: 10.2214/ajr.19.21137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE. The purpose of this article is to review gadolinium-based contrast agent (GBCA)-enhanced MRI applications in the genitourinary system. CONCLUSION. Nephrogenic systemic fibrosis is rare or nonexistent with standard dosing of group II GBCAs. Gadolinium retention, cost, and examination times are emerging considerations affecting GBCA use. GBCA is unnecessary to diagnose adrenal adenomas, simple cysts, and some Bosniak category II cysts; however, it is required to determine solid or septal renal mass enhancement. Biparametric prostate MRI requires high-quality and reproducible DWI; therefore, dynamic contrast-enhanced MRI remains valuable in selected prostate MRI examinations.
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Schieda N, Davenport MS, Pedrosa I, Shinagare A, Chandarana H, Curci N, Doshi A, Israel G, Remer E, Wang J, Silverman SG. Renal and adrenal masses containing fat at MRI: Proposed nomenclature by the society of abdominal radiology disease-focused panel on renal cell carcinoma. J Magn Reson Imaging 2019; 49:917-926. [PMID: 30693607 DOI: 10.1002/jmri.26542] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 09/16/2018] [Accepted: 09/17/2018] [Indexed: 12/15/2022] Open
Abstract
This article proposes a consensus nomenclature for fat-containing renal and adrenal masses at MRI to reduce variability, improve understanding, and enhance communication when describing imaging findings. The MRI appearance of "macroscopic fat" occurs due to a sufficient number of aggregated adipocytes and results in one or more of: 1) intratumoral signal intensity (SI) loss using fat-suppression techniques, or 2) chemical shift artifact of the second kind causing linear or curvilinear India-ink (etching) artifact within or at the periphery of a mass at macroscopic fat-water interfaces. "Macroscopic fat" is most commonly observed in adrenal myelolipoma and renal angiomyolipoma (AML) and only rarely encountered in other adrenal cortical tumors and renal cell carcinomas (RCC). Nonlinear noncurvilinear signal intensity loss on opposed-phase (OP) compared with in-phase (IP) chemical shift MRI (CSI) may be referred to as "microscopic fat" and is due to: a) an insufficient amount of adipocytes, or b) the presence of fat within tumor cells. Determining whether the signal intensity loss observed on CSI is due to insufficient adipocytes or fat within tumor cells cannot be accomplished using CSI alone; however, it can be inferred when other imaging features strongly suggest a particular diagnosis. Fat-poor AML are homogeneously hypointense on T2 -weighted (T2 W) imaging and avidly enhancing; signal intensity loss at OP CSI is uncommon, but when present is usually focal and is caused by an insufficient number of adipocytes within adjacent voxels. Conversely, clear-cell RCC are heterogeneously hyperintense on T2 W imaging and avidly enhancing, with the signal intensity loss observed on OP CSI being typically diffuse and due to fat within tumor cells. Adrenal adenomas, adrenal cortical carcinoma, and adrenal metastases from fat-containing primary malignancies also show signal intensity loss on OP CSI due to fat within tumor cells and not from intratumoral adipocytes. Level of Evidence: 5 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;49:917-926.
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Affiliation(s)
- Nicola Schieda
- Department of Medical Imaging, From the University of Ottawa, Ottawa Hospital, Ottawa, Ontario, Canada
| | | | - Ivan Pedrosa
- Department of Radiology, UT Southwestern, Dallas, Texas, USA
| | - Atul Shinagare
- Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Hersch Chandarana
- Department of Radiology, NYU School of Medicine, New York, New York, USA
| | - Nicole Curci
- Department of Radiology, Michigan University, Ann Arbor, Michigan, USA
| | - Ankur Doshi
- Department of Radiology, NYU School of Medicine, New York, New York, USA
| | - Gary Israel
- Department of Radiology, Yale University, New Haven, Connecticut, USA
| | - Erick Remer
- Department Radiology and Diagnostic Imaging, Cleveland Clinic, Cleveland, Ohio, USA
| | - Jane Wang
- Department of Radiology, UCSF, San Francisco, California, USA
| | - Stuart G Silverman
- Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts, USA
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Utility of MRI to Differentiate Clear Cell Renal Cell Carcinoma Adrenal Metastases From Adrenal Adenomas. AJR Am J Roentgenol 2017; 209:W152-W159. [DOI: 10.2214/ajr.16.17649] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Abstract
OBJECTIVE The objective of this article is to review the current role of CT and MRI for the characterization of adrenal nodules. CONCLUSION Unenhanced CT and chemical-shift MRI have high specificity for lipid-rich adenomas. Dual-energy CT provides comparable to slightly lower sensitivity for the diagnosis of lipid-rich adenomas but may improve characterization of lipid-poor adenomas. Nonadenomas containing intracellular lipid pose an imaging challenge; however, nonadenomas that contain lipid may be potentially diagnosed using other imaging features. Multiphase adrenal washout CT can be used to differentiate lipid-poor adenomas from metastases but is limited for the diagnosis of hypervascular malignancies and pheochromocytoma.
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