Perilesional Signal Research Articles

NIMG-101. COMPARISON OF PRE-SURGICAL MRI FINDINGS FROM LONG-TERM (≥ 3 YRS) VERSUS SHORT-TERM (< 3 YRS) GLIOBLASTOMA SURVIVORS: A BLINDED, CASE-CONTROL REVIEW

Abstract BACKGROUND The median overall survival of patients with glioblastoma (GBM) is 10-12 months and the five-year survival ranges from 5-10%. Favorable clinical and molecular prognostic markers have been described in the literature, although an individual patient’s prognosis cannot easily be predetermined on these features as shown in the NOB-LTS project by Briceno et al. (SNO 2021). Until now, no radiologic characteristics have been correlated with better patient outcomes. We reviewed eighteen MRI features to determine if these could aid the identification of long-term survivors (LTS). METHODS From the NOB-LTS cohort of our Natural History Study, 16 long-term survivals (LTS; ≥ 3 years survival post-diagnosis) were matched based on sex, age, and extent of resection to 32 control (STS, < 3 years survival post-diagnosis) patients with NGS-confirmed IDH-wt glioblastoma. Pre-surgical MRIs (T1, T1 post-contrast, T2, T2/FLAIR, DWI, ADC) were reviewed by three blinded reviewers and analyzed based on pre-set criteria. RESULTS T1 hypointensity occurred commonly in the LTS (71%) vs STS (29%) while central heterogeneous signal occurred commonly in the STS (73%) vs LTS (50%) patients. Restricted diffusion was seen in 82% of STS and 70% of LTS cases. No difference was seen in irregular enhancement, peripheral and grey matter enhancement on T1 post-contrast images. Evaluation of T2/FLAIR images showed no difference in the number of lobes involved, presence of mass effect, heterogeneity of the signal or the perilesional signal abnormality or involvement of grey matter. CONCLUSION Our results suggest that pre-surgical MRI might be a useful prognostic tool as T1 hypointensity more frequently, and T1 central heterogeneity less commonly seen in the LTS group. These imaging findings may provide additional insights regarding the differences in tumor biology between LTS and STS. Further validation and correlation with histological/molecular characteristics are planned to better predict patient outcomes with newly diagnosed glioblastoma.

Differentiating Between an Atypical Hepatic Abscess and Tumor Metastasis Using Magnetic Resonance Imaging and Hepatobiliary Phase Imaging.

ObjectiveTo identify diffusion-weighted imaging (DWI) patterns and conspicuity discrepancies on hepatobiliary phase imaging (HBPI) to distinguish atypical hepatic abscesses from hepatic metastases.Materials and MethodsThis retrospective study recruited 31 patients with 43 atypical hepatic abscesses and 32 patients with 35 hepatic metastases who underwent gadobenate dimeglumine-enhanced magnetic resonance imaging. All lesions were confirmed by pathological or clinical diagnosis. For the qualitative and quantitative analyses, the signal intensity, DWI pattern, apparent diffusion coefficient, degree of perilesional edema, perilesional hyperemia, perilesional signal on HBPI, conspicuity, size discrepancy between sequences, contrast-to-noise ratio, signal-to-noise ratio, and relative enhancement ratio on dynamic phases were independently assessed by two radiologists. Significant findings for differentiating the two groups were identified via univariate and multivariate analyses with a nomogram for predicting atypical hepatic abscesses. The interobserver agreement was also analyzed for each variable.ResultsThe multivariate analysis revealed that the conspicuity discrepancy (odds ratio [OR] 34.78, 95% confidence interval [CI] 2.09–579.47, p = 0.013) and non-peripheral high signal intensity (SI) rim on DWI (OR 67.46, 95% CI 2.64, 1723.20, p = 0.011) were significant independent factors for predicting atypical hepatic abscesses. They were also shown to be high predictor points on the nomogram. When any of the set criteria were satisfied, 97.7% of atypical hepatic abscesses were correctly identified, with a specificity of 65.7%. When both criteria were combined, the specificity was up to 100%, with a sensitivity of 44.9%.ConclusionConspicuity discrepancy and a non-peripheral high SI rim on DWI are reliable and meaningful features that can distinguish atypical hepatic abscesses from hepatic metastases.

Differentiation of hemorrhagic infarction from primary intracerebral hemorrhage in the chronic period

Regarding incidentally found old hemorrhagic foci on gradient-echo magnetic resonance imaging (GRE), it is difficult to distinguish whether the foci are the consequence of hemorrhagic infarction (HI) or primary intracerebral hemorrhage (PICH). We analyzed the radiological characteristics of patients with a definite history of HI or PICH by reviewing long-term follow-up GRE. We retrospectively enrolled patients with HI or PICH, verified by clinical history and radiological findings, who had undergone follow-up GRE at least 3 months after the first imaging. The shape of the hemorrhagic lesion was classified as “cavitation” or “no cavitation.” The shape of the hemosiderin rim was classified as total dark rim and partial dark rim. Hyperintense perilesional signal was determined when an obvious hyperintensity on T2-weighted image was present. Further, we compared the radiological characteristics between HI and PICH. In total, 69 patients (38 with HI and 31 with PICH) were enrolled, of whom 45 (65%) were men. The mean patient age was 65.5 ± 12.7 years. The mean time interval from the initial stroke onset to the follow-up image was 56.2 months. Hyperintense perilesional signal was observed in 38 patients; it was associated with HI (33/38 vs. 5/31, p < 0.001). Furthermore, partial dark rim was associated with HI (34/40 vs. 4/29, p < 0.001). Cavitation was more frequently observed in patients with HI than in those with PICH (36/60 vs. 2/9, p = 0.068). Presence of hyperintense perilesional signal and partially encasing dark hemosiderin rim suggest that chronic hemorrhagic foci are the sequelae of HI, not PICH.

3D-Double-Inversion recovery detects perilesional gliosis better than 3D-FLAIR and postcontrast T1 imaging in calcified neurocysticercosis.

Perilesional gliosis is an important substrate for seizures in patients harboring a calcified neurocysticercosis (NCC) lesion and magnetic resonance imaging (MRI) is useful for evaluating gliosis. The purpose of this study was to evaluate the usefulness of double-inversion recovery (DIR) sequence for identifying perilesional gliosis. Hospital-based cross-sectional study. Forty-five patients with seizures were included in this study and a total of 88 calcified lesions identified on susceptibility weighted imaging (SWI) were evaluated on 3D-fluid attenuating inversion recovery (FLAIR), 3D-DIR, and 3D-postcontrast T1-weighted imaging on a 3T MRI for the presence of perilesional signal changes/enhancement. Perilesional signal was rated on a semiquantitative scale from grade 0 to 2 by independent raters. Friedman, Wilcoxon signed rank, and Kappa tests were used. 3D-DIR sequence performed better than both 3D-FLAIR and postcontrast 3D-T1W sequences as more number of lesions showed perilesional signal change on DIR sequence. DIR sequence showed perilesional signal abnormality in 24 lesions in which 3D-FLAIR was normal, whereas in another 18 lesions, it demonstrated perilesional signal changes better than 3D-FLAIR. In only three lesions, FLAIR was found to be superior to DIR sequence, whereas postcontrast T1W images showed rim enhancement in five cases where no perilesional signal change was seen on FLAIR/DIR sequences. Combining 3D-DIR with 3D-FLAIR, and postcontrast 3D-T1W sequences is beneficial for evaluation of calcified NCC lesions and 3D-DIR sequence is better than other two sequences for perilesional signal abnormalities.

Chondrosarcomas of the hands and feet: A case series and systematic review of the literature

ObjectiveTo review the imaging features of chondrosarcomas (CS) of the hands and feet, with pathologic correlation. Materials and methodsFor 24 histologically-confirmed CS of the hands (n=14) and feet (n=10), 23 studies were retrospectively reviewed by two musculoskeletal radiologists in consensus. Radiographs (n=23), bone scintigrams (n=2), and magnetic resonance (MR) (n=7) images were evaluated for lesion location, cortical and medullary involvement, presence of perilesional signal abnormalities and soft tissue masses (STM). Pathologic specimens were reviewed for tumor grade (grade 1–3). Descriptive statistics were reported. ResultsCS occurred in adults (age range 32–92) and most were located in the digits (22/23 (95.6%)) rather than tarsal/carpal bones (1/23 (4.4%)). For digital CS, 21/22 (95.45%) involved the epiphysis in addition to the metadiaphysis, 22/23 (95.6%) exhibited >2/3 endosteal scalloping, and 16/23 (69.5%) were expansile (>50% of the bone width). Pathologic fractures (7/23 (30.4%)) and STMs (16/23 (69.6%)) were frequent. By MR, perilesional abnormalities were common (bone marrow edema in 6/7 (85%), soft tissue edema in 5/7 (71.4%), STM in 7/7 (100%)). Following contrast administration (n=6), there was solid (3/6 (50%)) or lobular (3/6 (50%)) enhancement. Bone scintigrams showed increased uptake on all phases (>anterior superior iliac spine (ASIS)). Pathology specimens revealed 17 grade 2 and 7 grade 3CS, with increased cellularity, necrosis and myxoid features. ConclusionCS of the hands and feet have common distinctive features, including involvement of the end-of-bone, significant endosteal scalloping, expansile appearance, a frequent STM, and intermediate to high grade histologic features. Additional aggressive imaging features are identified by MR (perilesional signal abnormalities) and bone scintigraphy (increased uptake>ASIS) that may be helpful clues to the diagnosis.

Comparative studies of the diagnosis and treatment of cerebral cavernous malformations in adults: systematic review

Cerebral cavernous malformation (CCM) management decisions are usually made after CCM diagnosis is suspected or definitively diagnosed on axial imaging by indirectly comparing a surgeon's estimate of operative morbidity and mortality against published estimates of CCM untreated clinical course. We used comprehensive electronic strategies to search OVID Medline and EMBASE for original studies published before 2011 of ≥20 adults with CCM that (a) evaluated diagnostic test accuracy, or (b) compared treatment with microsurgery or stereotactic radiosurgery against conservative management in a concurrent or historical control group and reported clinical outcome(s). We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group's approach to identify level 1 or level 2 studies according to the Oxford Centre for Evidence-Based Medicine's 2011 criteria. We found one eligible diagnostic test accuracy study of 72 patients with brain masses accompanied by vasogenic edema and substantial amounts of blood, which found that hyperintense perilesional signal on T1-weighted magnetic resonance imaging could differentiate CCM from other causes with excellent specificity (98 %) and reasonable sensitivity (62 %). We found five potentially eligible observational studies of adults with a CCM that had already bled, but none met level 2 criteria for a "dramatic" effect (the conventionally calculated probability of the two groups of observations coming from the same population should be less than 0.01 and a rate ratio greater than 10). We found 11 potentially eligible observational studies of adults with CCM and epilepsy, but nine studies did not demonstrate dramatic effects and the remaining two studies showed dramatic effects, but they were at high risk of bias. To address the absence of level 1 or 2 evidence to support CCM treatment decisions, there is a need for large studies of CCM treatment with a concurrent control group, ideally with randomized treatment allocation.

A T1 Hyperintense Perilesional Signal Aids in the Differentiation of a Cavernous Angioma from Other Hemorrhagic Masses

A cavernous angioma is a developmental vascular malformation with a high risk of hemorrhage. The purpose of this work was to retrospectively determine whether an MR sign of T1 hyperintense perilesional signal intensity is useful for the differentiation of cavernous angioma from other hemorrhagic cerebral masses. The institutional review board approved this study. We retrospectively evaluated the MR images of 72 patients with acute or subacute cerebral hemorrhagic lesions with perilesional edema (29 cavernous angiomas, 13 glioblastomas, 1 oligodendroglioma, 16 metastatic tumors, and 13 intracerebral hemorrhages) for the presence of T1 hyperintense perilesional signal intensity. In addition, T1 signal intensities of a perilesional edema were quantitatively analyzed. In cavernous angiomas, volumes of hemorrhagic lesions and perilesional edemas, lesion locations, presence of contrast enhancement, and time intervals between symptom onset and MR imaging were also assessed. Data were analyzed using unpaired t test or Fisher exact test. T1 hyperintense perilesional signal intensity sign was found in 18 (62.1%) of 29 cavernous angiomas, in 1 (6.3%) of 16 metastases, and in 0 primary brain tumors or intracerebral hemorrhages. Sensitivity, specificity, and positive predictive value of this sign for cavernous angioma were 62%, 98%, and 95%, respectively. The perilesional T1 hyperintensity was significantly higher in cavernous angiomas (P = .045) than in normal white matter. Perilesional edema volumes were larger in cavernous angiomas with the MR sign than in cavernous angiomas without the sign (P = .009). When the MR sign of T1 hyperintense perilesional signal intensity is present, there is a high probability of cavernous angioma being present in the brain, and this MR sign may be helpful for differentiating cavernous angioma from hemorrhagic tumors and intracerebral hemorrhages.

Pyogenic hepatic abscesses: MRI findings on T1- and T2-weighted and serial gadolinium-enhanced gradient-echo images.

The purpose of this study was to determine the magnetic resonance imaging (MRI) features of pyogenic hepatic abscesses on T1-weighted, T2-weighted, and serial gadolinium (Gd)-enhanced T1-weighted spoiled gradient-echo (SGE) images including images acquired in the immediate, intermediate, and late phases of enhancement. The MRI studies of 20 patients with pyogenic liver abscesses were retrospectively reviewed. All patients were examined on 1.5 (n = 19) and 1.0 (n = 1) T MR scanners. MR studies included T1-weighted, T2-weighted, and serial Gd-enhanced SGE images. The following determinations were made: signal intensity of the abscess cavity and perilesional liver tissue, and the presence of internal septations, layering material, or air in the abscess cavity. The pattern of enhancement of the abscess wall, internal septae and peri-abscess liver were evaluated on serial Gd-enhanced SGE images. A total of 53 abscesses were observed in the 20 patients. Fortyeight abscesses were hypointense on T1-weighted and hyperintense on T2-weighted images. Internal septations were present in four abscesses. Lower signal intensity material was observed in a dependent location on T2-weighted images in one abscess. Signal void foci of air located on the nondependent surface was observed in two abscesses. Two other abscesses contained signal void air that occupied the entire abscess cavity, observed on all imaging sequences. On serial gadolinium-enhanced images, all abscesses revealed early enhancement of the wall, which persisted with negligible change in degree of enhancement or thickness on delayed images. Abscess walls ranged in thickness from 2 to 5 mm. Internal septations ranged in thickness from 2 to 3 mm. Abscess walls and septations were relatively uniform in thickness with no evidence of focal nodularity. Periabscess liver tissue was mildly hypointense on T1-weighted and mildly hyperintense on T2-weighted images in 20 lesions, which were either circumferential (n = 12) or wedge-shaped (n = 8). All these regions enhanced more than the remainder of the liver on immediate post-gadolinium images and remained relatively hyperintense on late phase images. Periabscess liver parenchyma was isointense on both T1- and T2-weighted images in 18 lesions, and in these lesions wedge-shaped subsegmental (n = 6) or segmental (n = 12) enhancement was observed on immediate gadolinium-enhanced images, which faded to isointensity on intermediate phase images. No perilesional signal changes and enhancement difference was observed in 15 lesions. Characteristic features of abscesses include: intense mural enhancement on early gadolinium-enhanced images, which persists with negligible change in thickness and intensity on later post-gadolinium images, and the presence of periabscess increased enhancement on immediate post-gadolinium images. These MRI features may help to distinguish abscesses from other focal liver lesions during differential diagnosis.