Pattern of T2 hypointensity associated with ring-enhancing brain lesions can help to differentiate pathology

Abstract

Ring-enhancing lesions seen on MR images can occur with a variety of etiologies. Some ring-enhancing lesions have hypointense rims peripherally on T2-weighted MR images. In this study, we examined whether T2 hypointense rims were associated with specific pathologies. A search for ring-enhancing lesions on MR images obtained from 1996 to 2004 was performed, and revealed 221 patients with MRI findings of ring enhancement. The pattern of T2 hypointensity (arc or rim) corresponding with ring enhancement was recorded. In addition, we analyzed other imaging characteristics, including signal on diffusion-weighted images, central homogeneity on T2 and multiplicity of lesions. We then reviewed clinical data on the patients to ascertain the diagnosis for each examination. The most common associated pathologies in our study were gliomas (40%), metastases (30%), abscesses (8%) and multiple sclerosis (MS; 6%). Hypointense borders on T2-weighted images were present in 67% of lesions in the form of a rim in 40% and an arc in 60%. Abscesses had the highest percentage of hypointense rims. Metastases and gliomas more commonly had arcs, and MS lesions were divided between rims and arcs. Abscesses and MS lesions were more commonly homogeneous centrally, compared to gliomas and metastases. Additionally, abscesses were more often bright on diffusion imaging than the other pathologies. As expected, abscesses and MS lesions were usually multiple, whereas metastases were typically multiple in approximately 50% of the patients; gliomas were generally solitary. Trends in T2 hypointensity may aid in distinguishing among etiologies of ring-enhancing lesions, although there is overlap between the MR appearance of these various pathologies.

Cerebral lesions of multiple sclerosis: is gadolinium always irreplaceable in assessing lesion activity?

“…Both types of lesions are surrounded in most cases by a hyperintense area of edema. Type II lesions overlap with the patterns previously described by Schwartz et al (13) and Llufriu et al (12). The Type III pattern exhibits a less hyperintense pattern on T2-weighted images and is well defined and either homogeneous or inhomogeneous (small hypointense ring, arc or dot) in the center.…”

“…The other team of radiologists (C.A.T., M.M.B.) evaluated the intensity of the lesions compared with the surrounding normal white matter and with each other, the internal homogeneity of lesions, and the presence or absence of accompanying peripheral rim hypointensity, as defined by previous studies (12,13). The patterns of lesions on T2-weighted images were then classified into three types according to their morphology and signal intensity.…”

Differentiation between Brain Glioblastoma Multiforme and Solitary Metastasis: Qualitative and Quantitative Analysis Based on Routine MR Imaging

“…1 On routine MR imaging scans (precontrast T1WI and T2WI and postcontrast images), the 2 types of tumors usually demonstrate similar radiologic appearance: an obviously necrotic mass, with strong peritumoral T2 prolongation on unenhanced images, and ringlike enhancement on postcontrast images. 2,3 Therefore, it is thought to be very difficult to distinguish between these 2 types of tumors with routine MR imaging alone. [4][5][6] Many studies have focused on other advanced MR imaging modalities, such as DTI, 3,5,7,8 DWI, 9,10 PWI, 6,[11][12][13][14][15][16] and MR spectroscopy, 17 to explore the differentiating characteristics.…”

Neurotoxocariais: A Rare or Neglected Disease?

“…Concerning the neuroimaging (CT scan and MRI), neurotoxocariasis is mainly characterized by a granulomatous process leading to reversible white matter lesions and single ringenhancing ("cerebral granuloma") or multiple ring-enhancing lesions as demonstrated in biopsy-confirmed cases reported in literature [12,13]. However, ring-enhancing lesions are one of the most commonly encountered abnormalities that can be caused by a variety of infectious disease, neoplastic, inflammatory, or vascular diseases [14]. In particular, single enhancing lesions (SEL) represent a common diagnostic dilemma in tropical countries where they are generally due to infectious diseases such as neurocysticercosis (NCC) and tuberculosis.…”