Normal abdominal enhancement patterns with dynamic gadolinium-enhanced MR imaging.

Abstract

The objective of this study was to quantitatively and qualitatively determine contrast enhancement patterns of normal abdominal organs with dynamic gadolinium-enhanced magnetic resonance (MR) imaging. Dynamic gadolinium-enhanced, T1-weighted, spin-echo imaging was performed during a 23-second breath hold in 38 patients, with images acquired before, during, and at 1,2, and 5 minutes after bolus injection of gadopentetate dimeglumine. Enhancement patterns of normal liver, spleen, pancreas, adrenal gland, kidney, aorta, inferior vena cava, and fat were determined by visual evaluation and by performance of signal intensity measurements with an electronic cursor. Time-intensity curves demonstrated peak enhancement of all abdominal organs during or immediately after bolus injection of gadopentetate dimeglumine. MR enhancement patterns included visualization of renal cortical nephrogram and heterogeneous enhancement of the spleen during the bolus phase of contrast material administration. Peak enhancement of normal liver was 72%; spleen, 172%; pancreas, 82%; adrenal gland, 85%; and kidney, 291%. This study established reference data regarding abdominal organ enhancement that will be useful as dynamic gadolinium-enhanced MR imaging becomes clinically implemented.

Discriminatory power of MRI for differentiation of adrenal non-adenomas vs adenomas evaluated by means of ROC analysis: Can biopsy be obviated?

“…Fixing the ROI we took into consideration uneven position of the lesion during dynamic examination due to different diaphragm position on following breathholds, and we avoided inclusion of artifacts from aortic pulsation along phase encoding axis. The ROI did not include the enhancing marginal tumor tissue because it could be a part of normal adrenal tissue [25], which has pattern of enhancement in dynamic examination similar to the malignant adrenal masses ± flat plateau [26] and to preclude partial-volume effects.…”

Radiology of the spleen

“…4) [13]. This is assumed to be the main reason for the well-documented phenomenon of inhomogeneous enhancement of the normal splenic parenchyma during the first minute of dynamic contrastenhanced imaging [14,15]. Thus, after approximately 1 min, the splenic tissue achieves a homogeneous appearance again (Fig.…”

Discrete signal processing of dynamic contrast‐enhanced MR imaging: Statistical validation and preliminary clinical application

“…In the development of DEMRI, two distinct time intervals have been identified: (a) an early vascular phase that occurs within 120 seconds of contrast agent injection (4)(5)(6)(8)(9)(10)(12)(13)(14)(15)(16)(17) and (b) a late slow-perfusion phase that begins 120 seconds after contrast agent injection (2,4,5,9,17). Structures that enhance during the early phase correlate with viable tumor and arteries, while enhancement during the later phase correlates with inflammation and edema (17).…”

“…Structures that enhance during the early phase correlate with viable tumor and arteries, while enhancement during the later phase correlates with inflammation and edema (17). Previous methods for estimating the rate of contrast agent accumulation have calculated either overall percentage contrast agent accumulation as a ratio of the difference between the signal intensities of the pre-and postcontrast images to that of the baseline image (12)(13)(14)(15)(16)18), or the percentage rate of initial contrast agent accumulation (19)(20)(21)(22)(23). These methods frequently average contrast agent uptake over numerous observer-selected tumor regions, requiring considerable time to analyze.…”