Short-Ti inversion-recovery pulse sequence: analysis and initial experience in cancer imaging.

Abstract

Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy.

A Hippocampal Lesion Detected by High-Field 3 Tesla Magnetic Resonance Imaging in a Patient with Temporal Lobe Epilepsy

“…Thus, assuming that each study reflected a common condition, we considered that the hippocampal lesion was too small to be detected by 1.5 T MRI. In MRI studies using the 3 T unit, we routinely adopt fast STIR images instead of T2-weighted images, because, on the former images, spin density, and T1 and T2 relaxations synergistically affect image contrast, improving the gray matter-white matter and brain-CSF contrast (Dwyer et al 1988).…”

Echo-train STIR MRI of the liver: Comparison of breath-hold and non-breath-hold imaging strategies

“…The STIR sequence is useful for detection of hepatic neoplasms and has demonstrated greater sensitivity than other non-enhanced MR sequences in some studies (1)(2)(3)(4)(5)(6). STIR uses combined T1 and T2 contrast with a non-specific form of fat suppression (16).…”

“…SHORT INVERSION-TIME inversion recovery (STIR) magnetic resonance (MR) is a sensitive technique for detection of hepatic lesions that may be performed as part of hepatic MR protocols (1)(2)(3)(4)(5)(6). STIR sequences provide fat-suppressed images with additive T1 and T2 contrast.…”

“…STIR sequences provide fat-suppressed images with additive T1 and T2 contrast. Since both primary and secondary hepatic malignancies typically demonstrate prolongation of both T1 and T2, STIR sequences have theoretical advantages for detection of pathology, despite an intrinsically low signal-to-noise ratio (1)(2)(3)(4)(5)(6). Previous studies have demonstrated that STIR MR images have a higher sensitivity than other non-enhanced MR sequences and similar sensitivity as computed tomography (CT) during arterial portography (CTAP) for detection of hepatic lesions (5,6).…”

Diagnostic evaluation of cancer patients with pelvic pain: comparison of scintigraphy, CT, and MR imaging.

“…2-4) soft-tissue or bone lesions may be image. Thus, bone marrow and retroperitoneal fat are low in signal intensity on STIR images [7,8]. Areas of malignancy, in general, are high in signal and conspicuous against the fatsuppressed background [9].…”