Hepatic tumors: differentiation by transverse relaxation time (T2) of magnetic resonance imaging.

Abstract

Fifty-three patients who had hepatic tumors (24 hepatomas, ten metastases, and 19 cavernous hemangiomas) underwent MR imaging using a 0.35-T superconducting imager. The transverse relaxation time (T2) was calculated from a pair of spin echo images (repetition time [TR] of 1600 msec) with echo delay times (TE) of 35 and 70 msec. The computed T2 value was obtained in a fashion similar to that used to obtain CT numbers with region-of-interest cursors. The mean T2 was 59 +/- 9 msec in hepatomas, 64 +/- 15 msec in metastases, and 100 +/- 30 msec in hemangiomas. The difference between the T2 of hemangioma and that of liver malignancies was statistically significant (P less than .001); however, differentiation between hepatoma and metastases was not possible. The T2 was shorter than 80 msec in all 24 hepatomas and in nine of ten metastases, and was longer than 80 msec in 16 of 19 hemangiomas. Forty-nine of 53 cases (92%) were correctly classified when the borderline of T2 between hemangioma and hepatic malignancies was set at 80 msec. MR with T2 calculation was valuable in differentiating between hemangioma and hepatic malignancies.

Differentiation between small hepatic hemangiomas and metastases on MR images: importance of size-specific quantitative criteria.

“…Studies have indicated that differentiation between hepatic cavernous hemangioma and liver cancer with MR imaging may be done by calculating lesion/liver signal-intensity ratio (SIR) [2,3], or lesion-to-liver contrastto-noise ratio (CNR) [4], or lesion T2 relaxation times [5,6], or by subjectively comparing signal intensities of lesion and CSF [2,4,5,7]. In emphasizing the usefulness of hepatic MR imaging for distinguishing hemangiomas from metastases, most studies have included lesions that were more than several centimeters in size.…”

A modified signal intensity equation of carr-purcell-meiboom-gill pulse sequence for MR imaging.

“…The differences between the two values were less than 15.6% (10.4±4.8%) under the experimental concentrations except 8 mM solution whose image T 1 value (122 msec) was 48.8% longer. Graif et al 1985 ;Ohtomo et al 1985). A two-point curve fit used for calculating T2 value generally does not bring a high accuracy when the spacing of echo times is either too long or too short for the slope of the fitted line, or the data is noisy, or both.…”

“…T1 and T2 relaxation times in nuclear magnetic resonance give the useful information for the tissue characterization of the pathological instances (Damadian 1971;Graif et al 1985;Ohtomo et al 1985). Carr-PurcellMeiboom-Gill (CPMG) pulse sequence, which is a multiple Spin-Echo (MSE) pulse sequence, has produced the accurate T2 value in clinical magnetic resonance imaging (MRI) (Gersonde et al 1984; Rinck et al 1985).…”

Ressonância magnética dos hemangiomas hepáticos: avaliação das características morfológicas e quantitativas

“…Ressonância magnética dos hemangiomas hepáticos normal (relação intensidade de sinal lesão/ fígado [RLF]) (16,17) , os tempos de relaxação T2 (10,11,18,19) e o índice simplificado T2 (índice T2) (20,21) . A alta resolução espacial da RM cada vez mais possibilita a detecção de pequenas lesões (22) .…”