Presence Of Contrast Enhancement Research Articles

Prognosis assessment in metastatic gastrointestinal stromal tumors treated with tyrosine kinase inhibitors based on CT-texture analysis

Purpose: Identification of prognostic CT-textural features in patients with gastrointestinal stromal tumors undergoing tyrosine kinase inhibitor (TKI) therapy.Methods and materials: We identified 25 GIST patients (mean age, 70.58 ± 9.7 years; range, 41.25–84.08 years; 20 males, 5 females) with a total of 123 scans, each examined with a standardized CT protocol between 1/2014−7/2018. 92 texture features, based on pyradiomics library, were extracted and correlated to response categories; evaluated with help of modified Choi criteria. All patients underwent therapy with imatinib in the first line and different tyrosine kinase inhibitors after disease progression. KIT and PDGFR-mutations were registered in all patients as well as the number of previous treatment regimens, patient’s age as well as gender and the presence of contrast enhancement (vitality) in tumor. The lesion with the largest diameter was chosen and contoured using the spherical VOI tool. Inter-rater testing was performed by a second experienced radiologist. Regression and AUC analysis was performed.Results: Ten variables could be confirmed to be significantly associated with disease progression. Of them, four textural parameters were significantly positively associated with disease progression and negatively with progression free survival (Glcm Id [grey-level co-occurrence matrix inverse difference], p = 0.012, HR 3.83; 95% CI 1.697–8.611, Glcm Idn [grey-level co-occurrence matrix inverse difference normalized], p = 0.045, HR 2.06, 95% CI 1.015–4.185, Glrlm [grey-level run length matrix] normalized, p = 0.005, HR 3.181; 95% CI 1.418–7.138 and Ngtdm [neighboring grey-tone difference matrix] coarseness, p < 0.001, HR 3.156, 95% CI 1.554–6.411). Single variables were shown to be significantly inferior to the combination of all variables. After 6 months, 90% of patients with 0–1 risk factors (group 1), 64.4% with 2–3 risk variables and 38.1% of patients presenting > 3 structural risk variables showed stable disease. Gclm Id, Gclm Idn and Glrlm non-uniformity were associated with the number of previous treatments, Glrlm non-uniformity also with tumor vitality (enhancement), whereas Gclm Idn and Ngtdm coarseness were associated with the number of tumor mutations.Conclusion: Some of the CT-textural features correlate with disease progression and the progressive free survival as well as with the number of gene mutations and the number of treatment regimens the patients were exposed to as well as with the tumor enhancement. All these features reflect tumor homogeneity.

Differentiating atypical lipomatous tumors from lipomas with magnetic resonance imaging: a comparison with MDM2 gene amplification status

BackgroundTo evaluate the diagnostic value of MR imaging for the differentiation of lipomas and atypical lipomatous tumors (ALT) in comparison with histology and MDM2 amplification status.MethodsPatients with well-differentiated lipomatous tumors (n = 113), of which 66 were diagnosed as lipoma (mean age 53 years (range, 13–82); 47% women) and 47 as atypical lipomatous tumor (ALT; mean age 60 years (range, 28–88); 64% women), were included into this study using histology and MDM2 amplification status by fluorescence in situ hybridization (FISH) as standard of reference. Preoperative MR images were retrospectively assessed by two radiologists for the following imaging features: maximum tumor diameter (mm) as well as the affected compartment (intramuscular, intermuscular or subcutaneous), septa (absent, thin (< 2 mm) or thick septa (> 2 mm) with nodular components); contrast enhancing areas within the lipomatous tumor (< 1/3 of the tumor volume, > 1/3 of the tumor volume);ResultsOf the 47 patients with ALT, 40 (85.1%) presented thick septa (> 2 mm) and this finding significantly increased the likelihood of ALT (OR 6.24, 95% CI 3.36–11.59; P < 0.001). The likelihood of ALT was increased if the tumor exceeded a maximum diameter of 130.0 mm (OR 2.74, 95% CI 1.82–4.11, P < 0.001). The presence of contrast enhancement in lipomatous tumors significantly increased the likelihood of ALT (Odds ratio (OR) 2.95, 95% confidence interval (CI) 2.01–4.31; P < 0.001). Of the lipomas, 21.1% were located subcutaneously, 63.6% intramuscularly and 15.2% intermuscularly. On the other hand, none of the ALTs were located subcutaneously, the majority was located intermuscularly (87.3%) and a small number of ALTs was located intramuscularly (12.7%).ConclusionsOur results suggest that using specific morphological MR imaging characteristics (maximum tumor diameter, thick septa and contrast enhancement) and the information on the localization of the lipomatous tumor, a high sensitivity and substantial specificity can be achieved for the diagnosis of lipomas and ALTs.

Contrast enhancement is a prognostic factor in IDH1/2 mutant, but not in wild-type WHO grade II/III glioma as confirmed by machine learning

BackgroundMutation of the isocitrate dehydrogenase (IDH) gene and co-deletion on chromosome 1p/19q is becoming increasingly relevant for the evaluation of clinical outcome in glioma. Among the imaging parameters, contrast enhancement (CE) in WHO II/III glioma has been reported to indicate poor outcome in the past. We aimed at reassessing the prognostic value of CE in these tumours within the framework of molecular markers using a machine learning approach (random survival forests [RSF]) as well as conventional Cox regression modelling. Methods301 patients with WHO grade II (n = 181) or grade III glioma (n = 120) were stratified according to their molecular profile. Pre-operative magnetic resonance imaging (MRI) was reviewed and volumetric analyses of CE and T2 volumes were performed followed by conventional univariate and multivariate Cox analyses. Furthermore, the dataset was split into discovery and validation datasets, and RSFs were trained on the discovery dataset to predict the individual risk of each patient. Concordance indices for Cox and RSF models were determined and the variable importance of explanatory variables was assessed using the minimal-depth concept. ResultsIn IDH mut tumours only, both conventional Cox regression modelling and RSF analyses showed that CE on initial MRI is a prognostic factor for survival with dependence on volume (p < 0.05). In contrast, presence of CE on initial MRI was not associated with outcome in IDH wt tumours. ConclusionsIn patients with diffuse IDH wt gliomas WHO grade II/III, CE is not associated with survival, whereas in tumours with an IDH mutation, presence of CE on initial MRI is linked to inferior survival.

Molecular profiles of tumor contrast enhancement: A radiogenomic analysis in anaplastic gliomas

The presence of contrast enhancement (CE) on magnetic resonance (MR) imaging is conventionally regarded as an indicator for tumor malignancy. However, the biological behaviors and molecular mechanism of enhanced tumor are not well illustrated. The aim of this study was to investigate the molecular profiles associated with anaplastic gliomas (AGs) presenting CE on postcontrast T1‐weighted MR imaging. In this retrospective database study, RNA sequencing and MR imaging data of 91 AGs from the Cancer Genome Atlas (TCGA) and 64 from the Chinese Glioma Genome Atlas (CGGA) were collected. Gene set enrichment analysis (GSEA), significant analysis of microarray, generalized linear models, and Least absolute shrinkage and selection operator algorithm were used to explore radiogenomic and prognostic signatures of AG patients. GSEA indicated that angiogenesis and epithelial‐mesenchymal transition were significantly associated with post‐CE. Genes driving immune system response, cell proliferation, and focal adhesions were also significantly enriched. Gene ontology of 237 differential genes indicated consistent results. A 48‐gene signature for CE was identified in TCGA and validated in CGGA dataset (area under the curve = 0.9787). Furthermore, seven genes derived from the CE‐specific signature could stratify AG patients into two subgroups based on overall survival time according to corresponding risk score. Comprehensive analysis of post‐CE and genomic characteristics leads to a better understanding of radiology‐pathology correlations. Our gene signature helps interpret the occurrence of radiological traits and predict clinical outcomes. Additionally, we found nine prognostic quantitative radiomic features of CE and investigated the underlying biological processes of them.

New insights into neurocutaneous melanosis.

Neurocutaneous melanosis is a rare disorder in which children with large cutaneous melanotic nevi have associated melanosis in the brain. Although many affected children have structurally normal brains, some have associated developmental disorders or brain anomalies. To determine the range of extent of brain melanosis as assessed by magnetic resonance imaging (MRI) and to investigate the frequency and types of associated brain anomalies. We retrospectively reviewed brain and spine MRIs of 80 patients with congenital melanocytic nevi (range: 1 day to 22 years of age) affiliated with Nevus Outreach Inc. from 1998 to 2017. Central nervous system (CNS) melanosis was diagnosed when a mass with abnormal parenchymal T1 hyperintensity was seen. The locations of abnormal signal, associated malformations, the presence of contrast enhancement and, in patients with more than one MRI, changes over time were recorded. Associations among findings were analyzed using chi-square test or Fisher exact test. Brain abnormalities were identified in 33 patients. The most common finding was melanosis in the amygdala, which was found in 31 patients (an isolated finding in 14 patients). Nineteen patients had melanosis in the brainstem, cerebellum, cerebral cortex or thalamus. Cerebral and/or spinal leptomeningeal enhancement was uncommon (five patients). Hindbrain melanosis was associated with cerebellar and pontine hypoplasia (P=0.012). Brain melanosis was most easily seen on T1 images prior to myelination; reduced/loss of visibility was noted as the CNS matured. Brain melanosis is a common manifestation in children with large cutaneous melanotic nevi, most commonly found in the anterior temporal lobes (amygdala), brainstem, cerebellum and cerebral cortex. Hindbrain melanosis is associated with hypoplasia of the affected structures. Early imaging is optimal to provide the greatest sensitivity for diagnosis and to guide proper management.

Perfusion and diffusion MRI signatures in histologic and genetic subtypes of WHO grade II–III diffuse gliomas

The value of perfusion and diffusion-weighted MRI in differentiating histological subtypes according to the 2007 WHO glioma classification scheme (i.e. astrocytoma vs. oligodendroglioma) and genetic subtypes according to the 2016 WHO reclassification (e.g. 1p/19q co-deletion and IDH1 mutation status) in WHO grade II and III diffuse gliomas remains controversial. In the current study, we describe unique perfusion and diffusion MR signatures between histological and genetic glioma subtypes. Sixty-five patients with 2007 histological designations (astrocytomas and oligodendrogliomas), 1p/19q status (+ = intact/- = co-deleted), and IDH1 mutation status (MUT/WT) were included in this study. In all patients, median relative cerebral blood volume (rCBV) and apparent diffusion coefficient (ADC) were estimated within T2 hyperintense lesions. Bootstrap hypothesis testing was used to compare subpopulations of gliomas, separated by WHO grade and 2007 or 2016 glioma classification schemes. A multivariable logistic regression model was also used to differentiate between 1p19q+ and 1p19q- WHO II-III gliomas. Neither rCBV nor ADC differed significantly between histological subtypes of pure astrocytomas and pure oligodendrogliomas. ADC was significantly different between molecular subtypes (p = 0.0016), particularly between IDHWT and IDHMUT/1p19q+ (p = 0.0013). IDHMUT/1p19q+ grade III gliomas had higher median ADC; IDHWT grade III gliomas had higher rCBV with lower ADC; and IDHMUT/1p19q- had intermediate rCBV and ADC values, similar to their grade II counterparts. A multivariable logistic regression model was able to differentiate between IDHWT and IDHMUT WHO II and III gliomas with an AUC of 0.84 (p < 0.0001, 74% sensitivity, 79% specificity). Within IDHMUT WHO II-III gliomas, a separate multivariable logistic regression model was able to differentiate between 1p19q+ and 1p19q- WHO II-III gliomas with an AUC of 0.80 (p = 0.0015, 64% sensitivity, 82% specificity). ADC better differentiated between genetic subtypes of gliomas according to the 2016 WHO guidelines compared to the classification scheme outlined in the 2007 WHO guidelines based on histological features of the tissue. Results suggest a combination of rCBV, ADC, T2 hyperintense volume, and presence of contrast enhancement together may aid in non-invasively identifying genetic subtypes of diffuse gliomas.

GENT-02. GENETIC ALTERATIONS ASSOCIATED WITH RADIOGRAPHIC FEATURES OF PROGRESSION OF IDH-MUTANT/1p19q CO-DELETED GLIOMAS

Lower-grade gliomas with IDH-mutations and 1p/19q co-deletion, or oligodendroglioma, represent an important subset with unpredictable clinical courses. Disease progression can be monitored with magnetic resonance imaging (MRI), most notably by the presence of contrast-enhancement and radiographic necrosis. We investigated molecular markers associated with radiographic features of disease progression in oligodendroglioma to help explain variations in clinical course. Fifty-five patients with oligodendroglioma were selected from The Cancer Genome Atlas with pre-operative MRIs available from The Cancer Imaging Archive. MRIs were reviewed for unequivocal contrast enhancement (CE+) and radiographic necrosis (rNec). Statistical analysis was performed to identify relationships between CE and rNec and WHO histological grade, cellular proliferation (based on Ki-67 expression), key genetic alterations, and copy number events (CNE). Patients with CE+ (n=35) outnumbered those non-CE (n=20) patients; 10 CE+ tumors demonstrated rNec. Distribution of WHO grade was nearly even (grade II n= 29; grade III n=25). CE+ and rNec were associated with higher WHO histological grade (p<0.001), increased Ki-67 expression (p=0.003), and worse overall survival (log-rank p=0.04). Tumors with NOTCH1 mutations were almost exclusively CE+ (13 of 14). 77.8% (14 of 18) of tumors with PI3K mutations and 82.4% (14 of 17) with FUBP1 mutations were CE+. CIC mutations were evenly distributed in both CE+ (n=16) and non-CE (n=9) groups. Key CNEs included gain of chromosomes 7p (n=7), 11p (n=9), and loss of chromosome 15q (n=9). Tumors with these CNEs were exclusively CE+. The use of radiographic contrast-enhancement as a surrogate for disease progression in this investigation revealed key genetic alterations and copy number variations that may help predict aggressive behavior in oligodendroglioma. These genetic signatures can better inform prognostication and may contain potential progression-related targets for future drug therapies.

Health-related quality of life in patients with high-risk low-grade glioma (EORTC 22033-26033): a randomised, open-label, phase 3 intergroup study

Temozolomide chemotherapy versus radiotherapy in patients with a high-risk low-grade glioma has been shown to have no significant effect on progression-free survival. If these treatments have a different effect on health-related quality of life (HRQOL), it might affect the choice of therapy. We postulated that temozolomide compromises HRQOL and global cognitive functioning to a lesser extent than does radiotherapy. We did a prospective, phase 3, randomised controlled trial at 78 medical centres and large hospitals in 19 countries. We enrolled adult patients (aged ≥18 years) with histologically confirmed diffuse (WHO grade II) astrocytoma, oligodendroglioma, or mixed oligoastrocytoma, with a WHO performance status of 2 or lower, without previous chemotherapy or radiotherapy, who needed active treatment other than surgery. We randomly assigned eligible patients (1:1) using a minimisation technique, stratified by WHO performance status (0-1 vs 2), age (<40 years vs ≥40 years), presence of contrast enhancement on MRI, chromosome 1p status (deleted vs non-deleted vs indeterminate), and the treating medical centre, to receive either radiotherapy (50·4 Gy in 28 fractions of 1·8 Gy for 5 days per week up to 6·5 weeks) or temozolomide chemotherapy (75 mg/m2 daily, for 21 of 28 days [one cycle] for 12 cycles). The primary endpoint was progression-free survival (results published separately); here, we report the results for two key secondary endpoints: HRQOL (assessed using the European Organisation for Research and Treatment of Cancer's [EORTC] QLQ-C30 [version 3] and the EORTC Brain Cancer Module [QLQ-BN20]) and global cognitive functioning (assessed using the Mini-Mental State Examination [MMSE]). We did analyses on the intention-to-treat population. This study is closed and is registered at EudraCT, number 2004-002714-11, and at ClinicalTrials.gov, number NCT00182819. Between Dec 6, 2005, and Dec 21, 2012, we randomly assigned 477 eligible patients to either radiotherapy (n=240) or temozolomide chemotherapy (n=237). The difference in HRQOL between the two treatment groups was not significant during the 36 months' follow-up (mean between group difference [averaged over all timepoints] 0·06, 95% CI -4·64 to 4·75, p=0·98). At baseline, 32 (13%) of 239 patients who received radiotherapy and 32 (14%) of 236 patients who received temozolomide chemotherapy had impaired cognitive function, according to the MMSE scores. After randomisation, five (8%) of 63 patients who received radiotherapy and three (6%) of 54 patients who received temozolomide chemotherapy and who could be followed up for 36 months had impaired cognitive function, according to the MMSE scores. No significant difference was recorded between the groups for the change in MMSE scores during the 36 months of follow-up. The effect of temozolomide chemotherapy or radiotherapy on HRQOL or global cognitive functioning did not differ in patients with low-grade glioma. These results do not support the choice of temozolomide alone over radiotherapy alone in patients with high-risk low-grade glioma. Merck Sharp & Dohme-Merck & Co, National Cancer Institute, Swiss Cancer League, National Institute for Health Research, Cancer Research UK, Canadian Cancer Society Research Institute, National Health and Medical Research Council, European Organisation for Research and Treatment of Cancer Cancer Research Fund.

P07.16 Prognostic value of contrast enhancement and histopathological grading in diffuse gliomas depends on IDH1/2 mutation

AbstractBackground:Contrast enhancement (CE) and anaplasia have been reported to indicate poor outcome in diffuse glioma. Recently, mutational status of the IDH1/2 gene and loss of heterozygosity on chromosome 1p/19q (LOH1p/19q) have gained relevance for the evaluation of clinical outcome. Currently, a three-way classification based on IDH1/2 mutation and LOH 1p/19q has gained further importance and will eventually supersede the current WHO grading system in terms of risk stratification and treatment planning. Thus, we aimed in the present study to re-evaluate CE and histopathological WHO grading as risk factors for survival within the framework of these molecular markers.Methods:332 patients with diffuse glioma WHO grade II (n=189) or grade III (n=143) were stratified into 3 groups: IDH1/2 wild type (n=118), IDH1/2 mutated with (n=123) and without (n=91) LOH1p/19q. Preoperative magnetic resonance (MR) imaging was reviewed for presence of CE. Univariate and multivariate analyses were conducted taking into account CE, WHO grading, molecular as well as age, Karnofsky performance status, surgical procedure and adjuvant therapy.Results:In multivariate analysis, CE was not associated with OS in IDH1/2 wild type tumors whereas histopathological WHO grading had a strong independent prognostic value on OS in (p=0.001). In gliomas with IDH1/2 mutation, CE independently predicts shorter survival (p=0.04) and this effect seems to be especially pronounced in the IDH1/2 mutated group without LOH 1p/19q.Conclusions:In patients with diffuse gliomas WHO grade II/III and IDH1/2 wildtype, CE is not associated with survival in contrast to WHO grading. In patients with an IDH1/2 mutation, presence of CE on initial MRI is linked to inferior survival while grading is not.

Chronic fatigue syndrome in women assessed with combined cardiac magnetic resonance imaging.

ObjectiveIn chronic fatigue syndrome (CFS), only a few imaging and histopathological studies have previously assessed either cardiac dimensions/function or myocardial tissue, suggesting smaller left ventricular (LV) dimensions, LV wall motion abnormalities and occasionally viral persistence that may lead to cardiomyopathy. The present study with cardiac magnetic resonance (CMR) imaging is the first to use a contrast-enhanced approach to assess cardiac involvement, including tissue characterisation of the LV wall.MethodsCMR measurements of 12 female CFS patients were compared with data of 36 age-matched, healthy female controls. With cine imaging, LV volumes, ejection fraction (EF), mass, and wall motion abnormalities were assessed. T2-weighted images were analysed for increased signal intensity, reflecting oedema (i. e. inflammation). In addition, the presence of contrast enhancement, reflecting fibrosis (i. e. myocardial damage), was analysed.ResultsWhen comparing CFS patients and healthy controls, LVEF (57.9 ± 4.3 % vs. 63.7 ± 3.7 %; p < 0.01), end-diastolic diameter (44 ± 3.7 mm vs. 49 ± 3.7 mm; p < 0.01), as well as body surface area corrected LV end-diastolic volume (77.5 ± 6.2 ml/m2 vs. 86.0 ± 9.3 ml/m2; p < 0.01), stroke volume (44.9 ± 4.5 ml/m2 vs. 54.9 ± 6.3 ml/m2; p < 0.001), and mass (39.8 ± 6.5 g/m2 vs. 49.6 ± 7.1 g/m2; p = 0.02) were significantly lower in patients. Wall motion abnormalities were observed in four patients and contrast enhancement (fibrosis) in three; none of the controls showed wall motion abnormalities or contrast enhancement. None of the patients or controls showed increased signal intensity on the T2-weighted images.ConclusionIn patients with CFS, CMR demonstrated lower LV dimensions and a mildly reduced LV function. The presence of myocardial fibrosis in some CFS patients suggests that CMR assessment of cardiac involvement is warranted as part of the scientific exploration, which may imply serial non-invasive examinations.

High-Resolution MRI Findings following Trigeminal Rhizotomy.

Patients with trigeminal neuralgia often undergo trigeminal rhizotomy via radiofrequency thermocoagulation or glycerol injection for treatment of symptoms. To date, radiologic changes in patients with trigeminal neuralgia post-rhizotomy have not been described, to our knowledge. The aim of this study was to evaluate patients after trigeminal rhizotomy to characterize post-rhizotomy changes on 3D high-resolution MR imaging. A retrospective review of trigeminal neuralgia protocol studies was performed in 26 patients after rhizotomy compared with 54 treatment-naïve subjects with trigeminal neuralgia. Examinations were reviewed independently by 2 neuroradiologists blinded to the side of symptoms and treatment history. The symmetry of Meckel's cave on constructive interference in steady-state and the presence of contrast enhancement within the trigeminal nerves on volumetric interpolated breath-hold examination images were assessed subjectively. The signal intensity of Meckel's cave was measured on coronal noncontrast constructive interference in steady-state imaging on each side. Post-rhizotomy changes included subjective clumping of nerve roots and/or decreased constructive interference in steady-state signal intensity within Meckel's cave, which was identified in 17/26 (65%) patients after rhizotomy and 3/54 (6%) treatment-naïve patients (P < .001). Constructive interference in steady-state signal intensity within Meckel's cave was, on average, 13% lower on the side of the rhizotomy in patients posttreatment compared with a 1% difference in controls (P < .001). Small regions of temporal encephalomalacia were noted in 8/26 (31%) patients after rhizotomy and 0/54 (0%) treatment-naïve patients (P < .001). Post-trigeminal rhizotomy findings frequently include nerve clumping and decreased constructive interference in steady-state signal intensity in Meckel's cave. Small areas of temporal lobe encephalomalacia are encountered less frequently.

NIMG-03FALSE POSITIVE DETECTION OF RESIDUAL TUMOR IN THE IMMEDIATE POSTOPERATIVE PERIOD

BACKGROUND: Standards for residual tumor detection after resection of brain tumors with have not been established. In the postoperative period presence of contrast enhancement is suggestive of residual tumor. METHODS: We report a case of radiological postoperative metastatic tumor residual, which upon repeat resection was found to negative for presence of tumor. RESULTS: We report a case of a patient with metastatic tumor whose immediate postoperative MRI revealed enhancement in the peritumoral resection area which was suspicious for residual tumor. Repeat craniotomy for residual tumor was offered the following day after the first resection and the enhancing area was resected. Repeat postoperative MRI did not reveal any enhancing lesion. Final pathology revealed features of gliosis without any residual tumor. A follow up MRI 4 weeks later did not show any enhancing lesion either. This report suggests that the sensitivity of MRI may allow for detection of new lesions which are not tumor. CONCLUSIONS: Our results suggest that not all enhancing lesion in the immediate postoperative period represent tumors. Repeat surgery may be warranted only in those patients in whom the enhancement fails to subside with time.

Contrast-enhanced ultrasound (CEUS): an excellent tool in the follow-up of small renal masses treated with cryoablation.

Strict imaging follow-up is mandatory after cryoablation of small renal masses (SRMs). Although it uses ionizing radiation and nephrotoxic iodinated contrast, computed tomography (CT) is still the gold standard test. Contrast-enhanced ultrasound (CEUS) is a novel technique that informs in real time about renal perfusion avoiding radiation and nephrotoxicity. The objective of this study is to compare outcomes between CEUS and CT in the follow-up of SRMs treated with cryoablation, as well as to assess degree of agreement between them. This is a prospective observational study (May 2012 to December 2013) comparing CEUS and CT in 16 patients with SRMs cryoablated. The on-going protocol of the study includes a CT and CEUS 3 months after treatment and then every 6 months during 5 years. Local relapse was defined as the presence of contrast enhancement in the mass. All the CEUS were performed by a single experienced observer (E.S.). Degree of agreement was measured with kappa index. CEUS detected contrast enhancement in three patients (3/16, 18.8%) and CT in two patients (2/16, 12.5%). Degree of agreement between CEUS and CT, according to Landis-Koch classification, was 0.76 (CI 0.33-1.19; p = 0.0165), which is excellent and higher than expected by random. Sensitivity of the test is 93.75% (15/16). Median time of follow-up after cryoablation is 22 months (15.5-36.5). CEUS has an excellent agreement with CT and a high sensitivity in the follow-up of SRMs treated with cryosurgery, demonstrating its usefulness. Due to these encouraging results, it could become a reference test in the near future for monitoring SRMs after ablative treatment.

Clinical outcome of acute necrotizing encephalopathy in related to involving the brain stem of single institution in Korea.

PurposeAcute necrotizing encephalopathy (ANE) is a fulminant disease of the brain characterized by bilateral thalamic lesions, and is prevalent among children in East Asia. The prognosis of ANE is usually poor with a high mortality rate and neurological sequelae. This study aimed to delineate the clinical characteristics and prognostic factors of ANE.MethodsWe retrospectively analyzed clinical data of 399 pediatric patients with encephalitis who were admitted to Samsung Medical Center from December 1998 to March 2011. We enrolled ten patients (11 cases) with ANE and analyzed their demographic, clinical, and neuroimaging data. The location and extent of the brain regions were checked based on fluid-attenuated inversion recovery, T1-, and T2-weighted imaging findings; the presence of contrast enhancement, restricted diffusion, and hemorrhage.ResultsTen patients were identified, including one patient with two episodes. The median age of onset was 1.5 years (0.4-8.4 years). The mortality rate was 40%, and only 30% of patients survived without neurological sequelae. The definite involvement of the brainstem on brain magnetic resonance imaging was significantly correlated with mortality (P=0.04).ConclusionBroad and extensive brainstem involvement suggested the fulminant course of ANE. Early diagnosis of ANE before brainstem involvement, through careful identification of symptoms of brain dysfunction, may be the best way to achieve better neurological outcomes.

Multiple Sclerosis Of The Spinal Cord: Is Gadolinium Irreplaceable In Assessing Lesion Activity?

Abstract Purpose: To evaluate the relationship between the T2 patterns of spinal cord multiple sclerosis lesions and their contrast uptake. Material and method: We retrospectively reviewed the appearance of spinal cord lesions in 29 patients (with relapsing-remitting multiple sclerosis) who had signs and symptoms of myelopathy on neurologic examination and at least one active lesion visualized on magnetic resonance examinations performed between 2004 and 2011. We correlated the T2 patterns of lesions with contrast enhancement and calculated sensitivity and specificity in predicting gadolinium enhancement. Results: Only focal patterns consisting of a lesion’s center homogenously brighter than its periphery on T2-weighed images (type I) correlated significantly with the presence of contrast enhancement (p = 0.004). Sensitivity was 0.307 and specificity 0.929. In contrast, enhancement was not significantly related to uniformly hyperintense T2 focal lesions (type II) or diffuse (type III) pattern defined as poorly delineated areas of multiple small, confluent, subtle hyperintense T2 lesions (p &gt; 0.5 for both). Conclusions: We believe that information about the activity of multiple sclerosis spinal cord lesions in patients with myelopathy may be extracted not only from contrast enhanced, but also from non-enhanced magnetic resonance images.

Magnetic resonance imaging pattern in natalizumab‐associated progressive multifocal leukoencephalopathy

Natalizumab is an effective treatment for patients with multiple sclerosis (MS) that is associated with a risk of progressive multifocal leukoencephalopathy (PML). Recommendations were published in 2006 to improve early diagnosis of PML using magnetic resonance imaging (MRI). However, due to the small number of MS patients initially diagnosed with PML, the imaging criteria could only be derived from PML lesions in patients with human immunodeficiency virus. Therefore, there is an urgent need to assess the MRI characteristics of PML in MS patients to update the existing recommendations. In this retrospective review, the first 40 natalizumab-treated MS patients diagnosed with PML in the postmarketing setting were identified, of whom 22 (10 with clinically diagnosed immune reconstitution inflammatory syndrome) fulfilled the inclusion criteria for this study. Magnetic resonance images were analyzed according to predefined criteria by 5 independent readers. The most frequent lesion pattern in early scans from PML patients was that of large (>3 cm, 15 of 18), subcortical (18 of 18), T2 or fluid-attenuated inversion recovery hyperintense (18 of 18), T1-hypointense (17 of 18), and diffusion-hyperintense (15 of 15) lesions, with a sharp border toward the gray matter and an ill-defined border toward the white matter (18 of 18) on T2-weighted images. We could detect contrast enhancement in 41% (7 of 17) of the cases on the first scan at clinical presentation. Attention to characteristic MRI patterns, especially the presence of contrast enhancement, and the subcortical location may have utility in screening and early diagnosis of PML in natalizumab-treated MS patients.

Metabolic profile of PML lesions in patients with and without IRIS

To characterize progressive multifocal leukoencephalopathy (PML) lesions by contrast-enhanced MRI and evaluate their metabolism using proton magnetic resonance spectroscopy ((1)H- MRS) in the setting of immune reconstitution inflammatory syndrome (IRIS). A total of 42 patients with PML underwent a clinical evaluation as well as brain MRI and (1)H-MRS at baseline and 3, 6, and 12 months later. The presence of IRIS was determined based on clinical and laboratory criteria. Ratios of N-acetylaspartate (NAA), choline (Cho), myo-inositol (mI), and lipid/lactate (Lip1 and Lip2) to creatine (Cr) were measured and correlated with the presence of contrast enhancement (CE) in PML lesions. IRIS occurred in 16 of 28 (57.1%) PML survivors (PML-S) and 1 of 14 (7.1%) PML progressors (PML-P). Lesions of patients with PML-IRIS showed significantly higher Cho/Cr (p = 0.0001), mI/Cr (p = 0.02), Lip1/Cr (p < 0.0001), and Lip2/Cr (p = 0.002) ratios and lower NAA/Cr (p = 0.02) ratios than patients with PML who did not have IRIS. An elevated Cho/Cr ratio was associated with CE within the (1)H-MRS voxel, whereas lipid/Cr ratios were elevated in PML-IRIS lesions independently of CE. Follow-up until 33 months from PML onset showed persistent elevation of the mI/Cr ratio in lesions of patients with PML-IRIS. A Lip1/Cr ratio greater than 1.5 combined with the presence of CE yielded a 79% probability of IRIS compared with 13% in the absence of these criteria. (1)H-MRS is a valuable tool to recognize and track IRIS in PML and may prove useful in the clinical management of these patients.

Magnetic resonance imaging volumetric assessment of the extent of contrast enhancement and resection in oligodendroglial tumors

Oligodendrogliomas that enhance on MR images are associated with poor prognosis. However, the importance of the volume of enhancing tumor tissue, and the extent of its resection, is uncertain. The authors examined the prognostic significance of preoperative and residual postoperative enhancing tissue volumes in a large single-center series of patients with oligodendroglioma. They also examined the relationship between enhancement and characteristic genetic signatures in oligodendroglial tumors, specifically deletion of 1p and 19q (del 1p/19q). The authors retrospectively analyzed 100 consecutive cases of oligodendroglioma involving patients who had undergone T1-weighted gadolinium-enhanced MRI at diagnosis and immediately after initial surgical intervention. The presence of preoperative enhancement was determined by consensus. Preoperative and residual postoperative volumes were measured using a quantitative, semiautomated method by a single blinded observer. Intrarater reliability for preoperative volumes was confirmed by remeasurement in a subset of patients 3 months later. Intrarater and interrater reliability for residual postoperative volumes was confirmed by remeasurement of these volumes by both the original and a second blinded observer. Multivariate analysis was used to assess the influence of contrast enhancement at diagnosis and the volume of pre- and postoperative contrast-enhancing tumor tissue on time to relapse (TTR) and overall survival (OS), while controlling for confounding clinical, pathological, and genetic factors. Sixty-three of 100 patients had enhancing tumors at initial presentation. Presence of contrast enhancement at diagnosis was related to reduced TTR and OS on univariate analysis but was not significantly related on multivariate analysis. In enhancing tumors, however, greater initial volume of enhancing tissue correlated with shortened TTR (p = 0.00070). Reduced postoperative residual enhancing volume and a relatively greater resection of enhancing tissue correlated with longer OS (p = 0.0012 and 0.0041, respectively). Interestingly, patients in whom 100% of enhancing tumor was resected had significantly longer TTR (174 vs 64 weeks) and OS (392 vs 135 weeks) than those with any residual enhancing tumor postoperatively. This prognostic benefit was not consistently maintained with greater than 90% or even greater than 95% resection of enhancing tissue. There was no relationship between presence or volume of enhancement and del 1p/19q. In enhancing oligodendrogliomas, completely resecting enhancing tissue independently improves outcome, irrespective of histological grade or genetic status. This finding supports aggressive resection and may impact treatment planning for patients with these tumors.

Imaging biomarkers of angiogenesis and the microvascular environment in cerebral tumours

Conventional contrast-enhanced CT and MRI are now in routine clinical use for the diagnosis, treatment and monitoring of diseases in the brain. The presence of contrast enhancement is a proxy for the pathological changes that occur in the normally highly regulated brain vasculature and blood-brain barrier. With recognition of the limitations of these techniques, and a greater appreciation for the nuanced mechanisms of microvascular change in a variety of pathological processes, novel techniques are under investigation for their utility in further interrogating the microvasculature of the brain. This is particularly important in tumours, where the reliance on angiogenesis (new vessel formation) is crucial for tumour growth, and the resulting microvascular configuration and derangement has profound implications for diagnosis, treatment and monitoring. In addition, novel therapeutic approaches that seek to directly modify the microvasculature require more sensitive and specific biological markers of baseline tumour behaviour and response. The currently used imaging biomarkers of angiogenesis and brain tumour microvascular environment are reviewed.

MRI parameters for prediction of multiple sclerosis diagnosis in children with acute CNS demyelination: a prospective national cohort study

Multiple sclerosis (MS) diagnostic criteria incorporate MRI features that can be used to predict later diagnosis of MS in adults with acute CNS demyelination. To identify MRI predictors of a subsequent MS diagnosis in a paediatric population, we created a standardised scoring method and applied it to MRI scans from a national prospective incidence cohort of children with CNS demyelination. Clinical and MRI examinations were done at the onset of acute CNS demyelination and every 3 months in the first year after that, and at the time of a second demyelinating attack. MS was diagnosed on the basis of clinical or MRI evidence of relapsing disease. Baseline MRI scans were assessed for the presence of 14 binary response parameters. Parameters were assessed with a multiple tetrachoric correlation matrix. Univariate analyses and multivariable Cox proportional hazards models were used to identify predictors of MS. Between Sept 1, 2004, and June 30, 2010, 332 children and adolescents were assessed for eligibility. 1139 scans were available from 284 eligible participants who had been followed up for 3·9 (SD 1·7) years. 57 (20%) were diagnosed with MS after a median of 188 (IQR 144-337) days. Seven of 14 binary response parameters were retained. The presence of either one or more T1-weighted hypointense lesions (hazard ratio 20·6, 95% CI 5·46-78·0) or one or more periventricular lesions (3·34, 1·27-8·83) was associated with an increased likelihood of MS diagnosis (sensitivity 84%, specificity 93%, positive predictive value 76%, negative predictive value 96%). Risk for MS diagnosis was highest when both parameters were present (34·27, 16·69-70·38). Although the presence of contrast enhancement, cerebral white matter, intracallosal, and brainstem lesions was associated with MS in the univariate analyses, these parameters were not retained in the multivariable models. Specific MRI parameters can be used to predict diagnosis of MS in children with incident demyelination of the CNS. The ability to promptly identify children with MS will enhance timely access to care and will be important for future clinical trials in paediatric MS. Canadian Multiple Sclerosis Scientific Research Foundation.