Comparison of Delayed Enhanced CT and Chemical Shift MR for Evaluating Hyperattenuating Incidental Adrenal Masses1
- 1 June 2007
- journal article
- research article
- Published by Radiological Society of North America (RSNA) in Radiology
- Vol. 243 (3), 760-765
- https://doi.org/10.1148/radiol.2433051978
Abstract
To retrospectively compare the accuracy of delayed enhanced computed tomography (CT) and chemical shift magnetic resonance (MR) imaging for characterizing hyperattenuating adrenal masses at CT, with either follow-up imaging or pathologic review as the reference standard. The institutional review board approved this retrospective study with a waiver of patient informed consent. Forty-three hyperattenuating adrenal masses (>10 HU) on unenhanced CT images were found in 34 patients (23 men and 11 women; mean age, 52.7 years) by reviewing radiologic reports. These lesions were retrospectively analyzed with delayed enhanced CT and chemical shift MR. The diagnostic accuracy of CT by using absolute percentage loss of enhancement (PLE) and relative PLE and of chemical shift MR by using adrenal-to-spleen ratio (ASR) or signal intensity index (SII) were obtained to determine which modality was more accurate for lipid-poor adenoma. For CT, an adenoma was diagnosed if a mass had an absolute PLE greater than 60% and a relative PLE greater than 40%. For MR, an adenoma was diagnosed if a mass had an ASR of 0.71 or an SII greater than 16.5%. McNemar test was used to compare diagnostic performance of CT and MR. Hyperattenuating adrenal masses included 37 adenomas and six nonadenomas. The sensitivity, specificity, and accuracy for adenoma at CT were 97% (36 of 37), 100% (six of six), and 98% (42 of 43), respectively, and at MR were 86% (32 of 37), 50% (three of six), and 49% (21 of 43), respectively. CT helped confirm five more adenomas and three more metastatic tumors than did MR. However, there was no significant difference for diagnostic accuracy between these two imaging modalities (P>.05) Delayed enhanced CT can characterize additional hyperattenuating adrenal masses that cannot be characterized with chemical shift MR.Keywords
This publication has 12 references indexed in Scilit:
- Comparison of Unenhanced CT and Chemical Shift MRI in Evaluating Lipid-Rich Adrenal AdenomasAmerican Journal of Roentgenology, 2004
- Chemical Shift MR Imaging of Hyperattenuating (>10 HU) Adrenal Masses: Does It Still Have a Role?Radiology, 2004
- Characterization of Adrenal Tumors by Chemical Shift Fast Low-Angle Shot MR Imaging: Comparison of Four Methods of Quantitative EvaluationAmerican Journal of Roentgenology, 2003
- Adrenal Masses: Characterization with Combined Unenhanced and Delayed Enhanced CTRadiology, 2002
- Characterization of Indeterminate (Lipid-poor) Adrenal Masses: Use of Washout Characteristics at Contrast-enhanced CTRadiology, 2000
- Delayed Enhanced CT of Lipid-Poor Adrenal AdenomasAmerican Journal of Roentgenology, 2000
- Adrenal masses: correlation between CT attenuation value and chemical shift ratio at MR imaging with in-phase and opposed-phase sequences.Radiology, 1996
- Characterization of adrenal masses with chemical shift and gadolinium-enhanced MR imaging.Radiology, 1995
- Incidentally Discovered Adrenal Masses*Endocrine Reviews, 1995
- Benign and malignant adrenal masses: CT distinction with attenuation coefficients, size, and observer analysis.Radiology, 1991