ABSTRACT
A study was undertaken to determine the ability to characterize benign and malignant masses with unenhanced and contrast material-enhanced fast low-angle shot and fat-suppressed spin-echo magnetic resonance (MR) imaging. Thirty patients with adrenal masses detected at computed tomography (CT) underwent MR imaging within 14 days after CT. CT and MR images were interpreted in a prospective, blinded fashion. Sixteen patients had 20 benign adrenal masses, and 14 patients had 18 malignant masses. Quantitative measurements included percentage of contrast enhancement on immediate postcontrast dynamic images and periphery--center signal-to-noise ratio (S/N) on gadolinium-enhanced fat-suppressed images. Qualitative evaluation included determination of the regularity of lesion margins, homogeneity of signal intensity, and local extension. MR imaging depicted all adrenal masses discovered at CT examinations. Lesions ranged in diameter from 1 to 15 (mean, 4.4) cm. No significant difference was observed in percentage of contrast enhancement between benign (90.5% +/- 59.0 [standard deviation]) and malignant (110.5% +/- 116.4) masses. A difference was observed between periphery--center S/N for benign (-.05 +/- 1.5) and malignant (7.7 +/- 9.8) masses; overlap between the two, however, occurred. Qualitative evaluation allowed correct characterization of 32 of 38 masses, comparing favorably with CT, which allowed characterization of 30 lesions.
Subject(s)
Adrenal Gland Neoplasms/diagnosis , Contrast Media , Magnetic Resonance Imaging , Organometallic Compounds , Pentetic Acid , Adenoma/diagnosis , Adenoma/diagnostic imaging , Adrenal Gland Neoplasms/diagnostic imaging , Adrenal Glands/pathology , Adult , Aged , Aged, 80 and over , Female , Gadolinium DTPA , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Prospective Studies , Tomography, X-Ray ComputedABSTRACT
To examine the pattern of immediate enhancement with gadopentetate dimeglumine on dynamic magnetic resonance (MR) images of the spleen, this study was divided into two parts: In the first part, the authors retrospectively reviewed the dynamic MR images obtained with a fast low-angle shot (FLASH) sequence in the abdomen immediately after injection of gadopentetate dimeglumine in 137 patients. In the second part, dynamic gadolinium-enhanced FLASH images were prospectively compared with contrast material-enhanced computed tomographic (CT) scans in 17 patients with focal splenic lesions discovered on CT scans. In the first part, 108 patients (79%) had an arciform pattern of contrast enhancement; 22 patients (16%), a uniform pattern of high signal intensity; and seven patients (5%), a uniform pattern of low signal intensity. Most patients had arciform enhancement of the spleen; uniform enhancement occurred in some patients with underlying malignant or inflammatory disease. In the second part, all focal lesions seen on CT scans were seen on dynamic MR images (75 lesions), significantly more than were seen on FLASH images (15 lesions) (P < .001).
