T1-weighted Postgadolinium Research Articles

Asymmetric Myocardial Involvement as an Early Indicator of Cardiac Dysfunction in Pediatric Dystrophinopathies: A Study on Cardiac Magnetic Resonance (CMR) Parametric Mappings.

Dystrophinopathies, such as Duchenne and Becker muscular dystrophy, frequently lead to cardiomyopathy, being its primary cause of mortality. Detecting cardiac dysfunction early is crucial, but current imaging methods lack insight into microstructural remodeling. This study aims to assess the potential of cardiac magnetic resonance (CMR) parametric mappings for early detection of myocardial involvement in dystrophinopathies and explores whether distinct involvement patterns may indicate impending dysfunction. In this prospective study, 23 dystrophinopathy patients underwent CMR with tissue mappings. To establish a basis for comparison, a control group of 173 subjects was analyzed. CMR protocols included SSFP, T2-weighted and T1-weighted sequences pre and post gadolinium, and tissue mappings for native T1 (nT1), extracellular volume (ECV), and T2 relaxation times. The difference between the left ventricular posterior wall and the interventricular septum was calculated to reveal asymmetric myocardial involvement. Significant differences in LV ejection fraction (LVEF), myocardial mass, and late gadolinium enhancement confirmed abnormalities in patients. Tissue mappings: nT1 (p < 0.001) and ECV (p = 0.002), but not T2, displayed substantial variations, suggesting sensitivity to myocardial involvement. Asymmetric myocardial involvement in nT1 (p = 0.01) and ECV (p = 0.012) between septal and LV posterior wall regions was significant. While higher mapping values didn't correlate with dysfunction, asymmetric involvement in nT1 (ρ=-0.472, p = 0.023) and ECV (ρ=-0.460, p = 0.049) exhibited a significant negative correlation with LVEF. CMR mappings show promise in early myocardial damage detection in dystrophinopathies. Although mapping values may not directly correspond to dysfunction, the negative correlation between asymmetric involvement in nT1 and ECV with LVEF suggests their potential as early biomarkers. Larger, longitudinal studies are needed for a comprehensive understanding and improved risk stratification in dystrophinopathies.

Imaging of Pancreatitis, Panniculitis, and Polyarthritis Syndrome

HomeRadiologyVol. 307, No. 4 PreviousNext Reviews and CommentaryFree AccessImages in RadiologyImaging of Pancreatitis, Panniculitis, and Polyarthritis SyndromeLakhdeep Singh Brar , Yatin ChadhaLakhdeep Singh Brar , Yatin ChadhaAuthor AffiliationsFrom the Schulich School of Medicine and Dentistry, Western University, 1151 Richmond St, London, ON, Canada N6A 3K7 (L.S.B.); and Department of Medical Imaging, North York General Hospital, Toronto, Canada (Y.C.).Address correspondence to L.S.B. (email: [email protected]).Lakhdeep Singh Brar Yatin ChadhaPublished Online:May 2 2023https://doi.org/10.1148/radiol.222426MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In A 64-year-old man initially presented with pancreatitis that required hospitalization. Several months later, he developed knee pain and a fluctuant soft tissue mass at the lateral aspect of the left knee. Rheumatologic and metabolic workups (serum calcium and phosphate, and parathyroid hormone) were negative. Radiography performed 10 months after the initial onset of pancreatitis (Figure, A) showed bilateral symmetric osteopenia involving the knees with a permeative appearance of the bones. Subsequent bilateral knee MRI scans (Figure, B and C) demonstrated bilateral multifocal osteonecrosis with rim enhancement in the soft tissues of the left knee, supporting panniculitis. Subsequent imaging showed improvement of all imaging findings. The patient was referred to orthopedic oncology at a tertiary care center as a precaution. The diagnosis of pancreatitis, panniculitis, and polyarthritis (PPP) syndrome was made based on the clinical and imaging findings.Images in a 64-year-old man presenting with knee pain 10 months after hospitalization for pancreatitis. (A) Anteroposterior radiograph of both knees shows a permeative appearance of the bones (arrows). (B) Coronal T1-weighted knee MRI scan shows osteonecrosis. (C) Coronal T1-weighted postgadolinium MRI scan shows bilateral multifocal osteonecrosis (arrowheads) and panniculitis (rim enhancing) in the lateral soft tissues of the left knee (arrow).Download as PowerPointOpen in Image Viewer PPP syndrome is rare and occurs in the setting of pancreatitis or an underlying pancreatic mass (1). Patients may report mild or absent abdominal symptoms, making it difficult to diagnose. It has been reported to occur in all age groups, with a mean age ± SD of 51 years ± 16, and has a higher prevalence rate in men than in women (2:1 ratio) (2). While any joint may be involved, it most commonly affects the knees, ankles, and wrists (2). The pathophysiology is thought to result from the release of pancreatic lipase into the circulation, causing lipolysis and inflammation (2). The clinical symptoms and imaging findings can be transient or persist over time (3). Treatment involves addressing the underlying pancreatitis (3).Disclosures of conflicts of interest: L.S.B. No relevant relationships. Y.C. No relevant relationships.

Optimizing MRI-based brain tumor classification and detection using AI: A comparative analysis of neural networks, transfer learning, data augmentation, and the cross-transformer network

Early detection and diagnosis of brain tumors are crucial to taking adequate preventive measures, as with most cancers. On the other hand, artificial intelligence (AI) has grown exponentially, even in such complex environments as medicine. Here it’s proposed a framework to explore state-of-the-art deep learning architectures for brain tumor classification and detection. An own development called Cross-Transformer is also included, which consists of three scalar products that combine self-care model keys, queries, and values. Initially, we focused on the classification of three types of tumors: glioma, meningioma, and pituitary. With the Figshare brain tumor dataset was trained the InceptionResNetV2, InceptionV3, DenseNet121, Xception, ResNet50V2, VGG19, and EfficientNetB7 networks. Over 97 % of classifications were accurate in this experiment, which provided a network’s performance overview. Subsequently, we focused on tumor detection using the Brain MRI Images for Brain Tumor Detection and The Cancer Genome Atlas Low-Grade Glioma database. The development encompasses learning transfer, data augmentation, as well as image acquisition sequences; T1-weighted images (T1WI), T1-weighted post-gadolinium (T1-Gd), and Fluid-Attenuated Inversion Recovery (FLAIR). Based on the results, using learning transfer and data augmentation increased accuracy by up to 6 %, with a p-value below the significance level of 0.05. As well, the FLAIR sequence was the most efficient for detection. As an alternative, our proposed model proved to be the most effective in terms of training time, using approximately half the time of the second fastest network.

Radiomic Analysis of Tumour Heterogeneity Using MRI in Head and Neck Cancer Following Chemoradiotherapy: A Feasibility Study.

ObjectivesTo evaluate interval changes in heterogeneity on diffusion-weighted apparent diffusion coefficient (ADC) maps and T1-weighted post-gadolinium (T1w post gad) MRI in head and neck carcinoma (HNSCC), with and without chemo-radiotherapy (CRT) response.MethodsThis prospective observational cohort study included 24 participants (20 men, age 62.9 ± 8.8 years) with stage III and IV HNSCC. The primary tumour (n = 23) and largest lymph node (n = 22) dimensions, histogram parameters and grey-level co-occurrence matrix (GLCM) parameters were measured on ADC maps and T1w post gad sequences, performed pretreatment and 6 and 12 weeks post CRT. The 2-year treatment response at primary and nodal sites was recorded. The Wilcoxon signed-rank test was used to compare interval changes in parameters after stratifying for treatment response and failure (p < 0.001 statistical significance).Results23/23 primary tumours and 18/22 nodes responded to CRT at 2 years. Responding HNSCC demonstrated a significant interval change in ADC histogram parameters (kurtosis, coefficient of variation, entropy, energy for primary tumour; kurtosis for nodes) and T1w post gad GLCM (entropy and contrast in the primary tumour and nodes) by 6 weeks post CRT (p < 0.001). Lymph nodes with treatment failure did not demonstrate an interval alteration in heterogeneity parameters.ConclusionsADC maps and T1w post gad MRI demonstrate the evolution of heterogeneity parameters in successfully treated HNSCC by 6 weeks post CRT; however, this is not observed in lymph nodes failing treatment.Advances in KnowledgeEarly reduction in heterogeneity is demonstrated on MRI when HNSCC responds to CRT.

A 17-Year-old Boy With Nodular Lesions in the Thyroid and Lymphadenopathy.

A 17-Year-old Boy With Nodular Lesions in the Thyroid and Lymphadenopathy.

NIMG-71. DETECTION OF CYSTIC GLIOBLASTOMA FROM MAGNETIC RESONANCE IMAGING USING DEEP LEARNING TECHNIQUES

Abstract Glioblastoma (GBM) is the most aggressive primary brain tumor with an average survival of 15 months with standard of care treatment. GBM patients typically present with necrosis surrounded by enhancement on T1-weighted post gadolinium magnetic resonance imaging (T1gd MRI), however some patients present with a significant cystic component. Cysts are caused by different underlying biological mechanisms to necrosis and are important to identify for future clinical investigations. These cystic components can be manually identified through MRI but this process can be time consuming for large patient cohorts. Over the last two decades, our lab has collected serial MRI data of brain tumor patients. With over 70,000 images now in the database and that number increasing daily, it is clear that we have a unique resource for clinical investigation and a need to automate this process. To this end, the aim of this work was to develop and assess the performance of a convolution neural network (CNN) model for automatic detection of cystic GBMs. In this retrospective IRB-approved work, we collected pretreatment MRIs of a patient cohort consisting of 85 patients with a significant cystic component at presentation along with 400 non-cystic GBM, both identified manually through MRI. Image slices with a view of the cystic component were used as positive samples for training. Data were randomly split into training, validation, and test sets using a 70:15:15 ratio. The proportion of positive to negative cases was comparable between sets. Prior to training, we used image augmentation techniques to compensate for the class imbalance in our data. Our results showed that deep learning networks can automatically detect cystic GBMs on MRIs with high accuracy and thus illustrates the potential use of this technique in clinically relevant settings.

Perioperative outcomes following reoperation for recurrent insular gliomas.

Greater extent of resection (EOR) improves overall survival and progression-free survival for patients with low- and high-grade glioma. While resection for newly diagnosed insular gliomas can be performed with minimal morbidity, perioperative morbidity is not clearly defined for patients undergoing a repeat resection for recurrent insular gliomas. In this study the authors report on tumor characteristics, tumor EOR, and functional outcomes in patients undergoing reoperation for recurrent insular glioma. Adult patients with insular gliomas (WHO grades II-IV) who underwent index resection followed by reoperation were identified through the University of California San Francisco Brain Tumor Center. Treatment history and functional outcomes were collected retrospectively from the electronic medical record. Pre- and postoperative tumor volumes were quantified using software with region-of-interest analysis based on FLAIR and T1-weighted postgadolinium sequences from pre- and postoperative MRI. Forty-four patients (63.6% male, 36.4% female) undergoing 49 reoperations for recurrent insular tumors were identified with a median follow-up of 741 days. Left- and right-sided tumors comprised 52.3% and 47.7% of the cohort, respectively. WHO grade II, III, and IV gliomas comprised 46.9%, 28.6%, and 24.5% of the cohort, respectively. Ninety-five percent (95.9%) of cases involved language and/or motor mapping. Median EOR of the insular component of grade II, III, and IV tumors were 82.1%, 75.0%, and 94.6%, respectively. EOR during reoperation was not impacted by Berger-Sanai insular zone or tumor side. At the time of reoperation, 44.9% of tumors demonstrated malignant transformation to a higher WHO grade. Ninety-day postoperative assessment confirmed that 91.5% of patients had no new postoperative deficit attributable to surgery. Of those with new deficits, 3 (6.4%) had a visual field cut and 1 (2.1%) had hemiparesis (strength grade 1-2/5). The presence of a new postoperative deficit did not vary with EOR. Recurrent insular gliomas, regardless of insular zone and pathology, may be reoperated on with an overall acceptable degree of resection and safety despite their anatomical and functional complexities. The use of intraoperative mapping utilizing asleep or awake methods may reduce morbidity to acceptable rates despite prior surgery.

Early detection of recurrent medulloblastoma: the critical role of diffusion-weighted imaging.

Imaging diagnosis of medulloblastoma recurrence relies heavily on identifying new contrast-enhancing lesions on surveillance imaging, with diffusion-weighted imaging (DWI) being used primarily for detection of complications. We propose that DWI is more sensitive in detecting distal and leptomeningeal recurrent medulloblastoma than T1-weighted postgadolinium imaging. We identified 53 pediatric patients with medulloblastoma, 21 of whom developed definitive disease recurrence within the brain. MRI at diagnosis of recurrence and 6 months prior was evaluated for new lesions with reduced diffusion on DWI, contrast enhancement, size, and recurrence location. All recurrent medulloblastoma lesions demonstrated reduced diffusion. Apparent diffusion coefficient (ADC) measurements were statistically significantly lower (P = .00001) in recurrent lesions (mean=0.658, SD=0.072) as compared to contralateral normal region of interest (mean=0.923, SD=0.146). Sixteen patients (76.2%) with disease recurrence demonstrated contrast enhancement within the recurrent lesions. All 5 patients with nonenhancing recurrence demonstrated reduced diffusion, with a mean ADC of 0.695 ± 0.101 (normal=0.893 ± 0.100, P = .0027). While group 3 and group 4 molecular subtypes demonstrated distal recurrence more frequently, nonenhancing metastatic disease was found in all molecular subtypes. Recurrent medulloblastoma lesions do not uniformly demonstrate contrast enhancement on MRI, but all demonstrate reduced diffusion. Our findings support that DWI is more sensitive than contrast enhancement for detection of medulloblastoma recurrence, particularly in cases of leptomeningeal nonenhancing disease and distal nonenhancing focal disease. As such, recurrent medulloblastoma can present as a reduced diffusion lesion in a patient with normal postgadolinium contrast MRI.

Multiple sclerosis lesions on magnetic resonance imaging, their characterization and pathological correlation with musculoskeletal disability in Pakistanis

Background: Multiple sclerosis (MS) is an inflammatory disease affecting movement. MS has a worldwide distribution. Objectives: Early detection of MS lesions in Pakistanis by magnetic resonance imaging (MRI); to describe characteristics and to determine the association with musculoskeletal disability. Methods: We included 100 patients (18-65 years old) diagnosed with cases of MS from March 2012 to March 2013. A detailed clinical history of the musculoskeletal system was taken and MR imaging was performed to characterize lesions acquiring T1-weighted (T1W), T2W, proton density, fluid-attenuated inversion recovery(FLAIR), and T1W postgadolinium sequences. Results: Most patients belonged to a middle-aged group (42-62 years) and MS was common in women. MS lesions were found in the deep white matter of central nervous system (95 patients), supratentorially (97), periventricularly (96), juxtacortically (62), infratentorially (16), and in the temporal lobes (9). T2W sequences (99 patients detected) were superior to T1W sequences (47). By contrast, FLAIR sequence was more accurate and 100% of these cases were detected on this sequence of MRI. Muscle spasticity was found in 10 patients, muscle weakness in 53, uncoordinated movements in 7, ataxic gait in 9, and slurred speech in 3. However, numbness remained the more common clinical history (69 patients). Muscle fatigue (19), hemiparesis (8), and monoparesis in either upper and lower limbs (5) were other clinical presentations. Conclusions: MRI plays a pivotal role in detection and characterization of MS plaques. Clinical manifestations and imaging findings are similar to those reported from other parts of the world. Keywords: Ataxia, FLAIR, MRI, multiple sclerosis, muscle weakness, spasticity, T1W1, T2WI

What predicts early volumetric edema increase following stereotactic radiosurgery for brain metastases?

A volumetric analysis of pre- and post-radiosurgery (PreSRS and PostSRS) edema in patients with cerebral metastases was performed to determine factors of a predictive model assessing the risk of developing increased edema relatively early after SRS. One-hundred-fourteen metastases in 55 patients were analyzed. Selection for this analysis required an MRI ≤ 30 days before SRS and an MRI ≤ 100 days after SRS. Tumor volumes were calculated on PreSRS, SRS, and PostSRS T1-weighted postgadolinium images while edema volumes were calculating using PreSRS and PostSRS fluid-attenuated inversion recovery MR images. An increase in edema was defined as an increase in measurable edema of at least 5%. We developed and evaluated a model predicting the relative risk (RR) of increased edema after SRS. Peritumoral edema increased in 18% (21/114) of the analyzed lesions. Melanoma/renal histology, recursive partitioning analysis class III, and prior WBRT carried RRs of developing postSRS edema increase of 2.45, 2.48, and 3.16, respectively (all P values <0.05). The PreSRS edema/tumor ratio predicted for a RR of 1.007/ratio unit, and steroid dose at time of SRS predicted for a RR of 0.89/mg (all P values <0.05). A predictive model for assessing the RR of increased edema after SRS was developed based from these data and may be useful in identifying patients who might benefit from prophylactic anti-edema therapies before, during, or after SRS. This model could be used as the basis of inclusion criteria for prospective trials investigating novel anti-edema therapies.

PO31FRACTAL ANALYSIS OF PREOPERATIVE IMAGING AS A TOOL FOR PREDICTING PROGNOSIS IN GLIOBLASTOMA MULTIFORMAE – PRELIMINARY RESULTS

INTRODUCTION: The fractal analysis objectively quantifies the geometric complexity of structures in unitless measure index. We hypothesise it may reflect the degree of malignancy in glioblastoma multiformae (GBM). METHOD: A group of 33 patients with postoperative diagnosis of GBM were retrospectively enrolled into the study. Preoperative brain MR (T1-weighted post-gadolinium) were processed and analyzed to determine the average and maximum fractal dimension (FD and FDmax) of the inner and outer surface of the contrast enhancing part of the tumour. Box-count method and ImageJ 1.49 software were used. Corellations between fractal dimensions and: 1) demographics; 2) immunohistochemical characteristics; 3) progression free (PFS) and overal survival (OS); 4) tumour volume were determined by mean of nonparametric tests. RESULTS: There were 8 women and 25 men in the study group, mean age was 67 ± 10 years. Fractal analysis was possible to be perfomed in all cases with good inter-observer reproducibility (Kappa >0.80). The median FD was 1.2550 (IQR 0.0897) and FDmax 1.3848 (IQR 0.1057). There was a statisticaly significant Spearman Rank correlation between fractal dimensions and Ki-67 index (-0.44 and -0.52 for FD and FDmax respectively). Both FD and FDmax were significantly (Fi2; p < 0.05) correlated with: age, tumor volume, PFS, OS, and Phosphohistone-H3 index but not with the expression of neurofilaments, p53, GFAP, EGFR and IDH-1. CONCLUSION: Fractal analysis of the preoperative MR images may pottentially act as an adjunct in determing the degree of malignancy and prognosis in GBM. Further studies on a wider cohort of patients are warranted.

NI-67 * THE ROLE OF FLAIR VOLUME AS A PROGNOSTICATING FACTOR IN PATIENTS WITH GLIOBLASTOMA

BACKGROUND: Volumetric analysis on T1-weighted post-gadolinium (T1-PG) magnetic resonance imaging (MRI) sequence is central in managing patients with glioblastoma. It is unclear how the contrast enhancing tumor volume relates to abnormal findings in other MRI sequences such as fluid attenuated inversion recovery (FLAIR) and whether additional prognosticating information can be derived from these supplementary radiographic techniques. OBJECTIVES: To determine the relationship between volumetric measurements (T1-PG, FLAIR) and survival in patients with newly diagnosed GBM using rapid volumetric measurement (MacDonald ellipsoid method) for estimation of tumor volume. We will also compare the accuracy of rapid volumetric measurement to a manual tracing method for determination of tumor volume. METHODS: Tumor volumes of 30 patients (10 females, mean age 63 years) with diagnosis of glioblastoma were retrospectively measured using pre-operative MRI. Enhancing tumor volume on the T1-PG sequence was calculated using both a manual tracing method and the MacDonald ellipsoid method while volume of abnormal signal intensity on the FLAIR sequence was measured using the MacDonald ellipsoid method. The relationship between volumetric analyses and duration of survival were examined. RESULTS: Mean volume of enhancing tumors in the T1-PG sequence was 43.93 cm3 and 48.30 cm3 (manual and MacDonald ellipsoid method respectively), while mean volume of abnormal signal intensity in the FLAIR sequence was 147.60 cm3. There was moderate correlation between the T1-PG and FLAIR volumes (r= 0.65). Average duration of survival from surgery was 341 days. Neither tumor volume measurements correlated with duration of survival. CONCLUSIONS: Rapid measurement of tumor volume is a reasonable and accurate estimate of manually traced tumor volumes. Both T1-PG and FLAIR alone do not correlate with survival in this small group of patients.

CANINE MENINGEAL DISEASE: ASSOCIATIONS BETWEEN MAGNETIC RESONANCE IMAGING SIGNS AND HISTOLOGIC FINDINGS

In order to compare the accuracy of MR sequences for diagnosis of meningeal disease, MR images of the brain, and histopathologic specimens including the meninges of 60 dogs were reviewed retrospectively by independent observers in a cross-sectional study. MR images included T1-weighted pre- and postgadolinium images, subtraction images, T2-weighted images, and T2-weighted fluid-attenuated inversion-recovery (FLAIR) images. Pathologic changes affected the pachymeninges in 16 dogs, leptomeninges in 35 dogs, and brain in 38 dogs. The meninges were normal in 12 dogs. Meninges were classified histopathologically as normal (grade 0), slightly or inconsistently affected (grade 1), or markedly affected (grade 2). When applying relaxed pathologic criteria (grades 0 and 1 considered normal), the results of ROC analysis (area under curve, AUC) were: T1-weighted postcontrast images 0.74; subtraction images 0.7; T2-weighted images 0.68; FLAIR images 0.56. The difference in AUC between T1-weighted postgadolinium images and FLAIR images was significant (P = 0.04). AUC for FLAIR images was not significantly different from 0.5. When applying strict pathologic criteria (only grade 0 considered normal), none of the MR sequences had AUC significantly different from 0.5. On the basis of T1-weighted postgadolinium images and subtraction images, correct anatomic classification of lesions occurred more often for pachymeningeal than leptomeningeal lesions (P < 0.001). Overall, MR imaging had low sensitivity for diagnosis of meningeal pathology in dogs, particularly for changes affecting the leptomeninges. Subtraction images had similar accuracy to T1-weighted postgadolinium images for meningeal lesions in dogs. T2-weighted FLAIR images appear to have limited diagnostic utility for meningeal lesions.

Ressonância Magnética em Doentes Grávidas com Suspeita de Embolia Pulmonar: Steady-State Free Precession vs 3D-GRE Após Gadolínio

Pulmonary embolism is a leading cause of maternal mortality in the developed world. Ventilation-perfusion scintigraphy and Computer tomography cause ionizing radiation exposure. Gadolinium-enhanced magnetic resonance imaging is generally not indicated in pregnant patients. MRI using motion resistant techniques that do not use intravenous contrast material, such as balanced steady-state free precession may be a better approach in pregnant patients. To describe the preliminary findings of the use of SSFP for the evaluation of pregnant patients with suspected PE, and to compare with a young women population evaluated with postgadolinium 3D-gradient echo sequences for the same intention. Radiology database was searched for two groups of subjects who underwent chest MRI at 1.5T for suspected PE, between January, 2007 and June, 2010: pregnant patients with MRI including balanced SSFP (group A) and females younger than 45 years old including a T1-weighted postgadolinium 3D-GRE (group B) sequence. The final study population consisted of 21 subjects. Blind and independent evaluation of MR images was performed for image quality of the pulmonary arterial system, PE and other chest findings. Data was subject to statistical analysis. Good image quality was observed in all central and lobar arteries on both groups and in 90% (group A) and at least 83.3% (group B) of the segmental arteries. There was no significant difference between groups A and B for image quality of central and lobar pulmonary arteries (p > 0.05). SSFP can visualize central, lobar and segmental pulmonary arteries with sufficient image quality in pregnant patients, comparable to 3D-GRE.

Abstract 5561: Radiogenomic analysis indicates MR images are potentially predictive of EGFR mutation status in glioblastoma multiforme

Abstract Objective: To predict mutations of key genes in glioblastoma multiforme (GBM) from MR image features. Methods: We obtained mutational and MR image data from 35 patients in the Cancer Genome Atlas (TCGA) GBM database. T1-weighted axial images pre and post gadolinium contrast MRI were processed as follows: a board certified neuro-radiologist traced a region of interest (ROI) around the enhanced part of the largest lesion in the T1 post-contrast MRI and confirmed by comparing it with the T1 pre-contrast image. This ROI was then used to compute features that characterized the intensity of the enhanced lesion, the sharpness of lesion boundaries and the boundary shape. We used the resulting data set to build a linear regression model with regularization to predict the presence of a mutation in terms of image features. We focused on predicting mutations in EGFR because several drugs target it and because EGFR mutations are prevalent in the TCGA GBM data. We evaluated the performance of predicting EGFR mutations from MR imaging data using 5-fold cross validation (5F-CV) and the area under the ROC Curve (AUC). The optimal ROC operating point was defined as the point with the maximal sum of sensitivity and specificity when the cost of false positives and false negatives are considered equivalent. Results: We found that computationally-derived MR image features can predict the presence of EGFR mutations with an AUC of 0.80. The optimal operating point had a sensitivity and specificity of 83% and 93% respectively. The top ranked features in the image-based EGFR-predictor model suggest that EGFR-mutated tumors have blurrier edges than EGFR-wild-type tumors. Conclusion: Our preliminary radiogenomic analysis of GBM suggests MR images may be used to non-invasively determine the mutation status of EGFR, an important drug target in glioblastoma. The ability to determine important genomic aberrations based on image data suggests a increasingly important role for imaging in personalized medicine and warrants further investigation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5561. doi:1538-7445.AM2012-5561

MRI identifies plantar plate pathology in the forefoot of patients with rheumatoid arthritis

Previous cadaveric studies have suggested that forefoot deformities at the metatarsophalangeal (MTP) joints in patients with rheumatoid arthritis (RA) might result from the failure of the ligamentous system and displacement of the plantar plates. This study aimed to examine the relationship between plantar plate pathology and the rheumatoid arthritis magnetic resonance imaging score (RAMRIS) of the lesser (second to fifth) MTP joints in patients with RA using high-resolution 3 T magnetic resonance imaging (MRI). In 24 patients with RA, the forefoot was imaged using 3 T MRI. Proton density fat-suppressed, T2-weighted fat-suppressed and T1-weighted post gadolinium sequences were acquired through 96 lesser MTP joints. Images were scored for synovitis, bone marrow oedema and bone erosion using the RAMRIS system and the plantar plates were assessed for pathology. Seventeen females and 7 males with a mean age of 55.5 years (range 37–71) and disease duration of 10.6 years (range 0.6–36) took part in the study. Plantar plate pathology was most frequently demonstrated on MRI at the fifth MTP joint. An association was demonstrated between plantar plate pathology and RAMRIS-reported synovitis, bone marrow oedema and bone erosion at the fourth and fifth MTP joints. In patients with RA, 3 T MRI demonstrates that plantar plate pathology at the lesser MTP joints is associated with features of disease severity. Plantar plate pathology is more common at the fourth and fifth MTP joints in subjects with RA in contrast to the predilection for the second MTP reported previously in subjects without RA.

Teaching Neuro Images : Punctuate and curvilinear enhancement peppering the pons responsive to steroids

A 48-year-old man developed progressive vertigo, ataxia, and dysarthria. MRI demonstrated gadolinium-enhancing abnormalities in the pons and cerebellar peduncles (figure, A). Further investigations excluded neurosarcoidosis, CNS lymphoma, granulomatosis, and paraneoplastic or chronic infectious processes. In particular, 2 CSF examinations revealed mildly elevated protein levels (0.73 g/L, N < 0.40 g/L) without pleocytosis, tumoral cells, or oligoclonal bands. Figure Initial T1-weighted postgadolinium brain MRI (A) Symmetric enhancement of the pons and both cerebellar peduncles, with pattern highly suggestive of a perivascular distribution. (B) Near complete resolution with corticosteroids. (C) Recurrence of the same lesions without corticosteroids. The patient was treated with IV …

MR Imaging of Optic Neuropathy with Extended Echo-Train Acquisition Fluid-Attenuated Inversion Recovery

XETA, also known as Cube, is a relatively new 3D FSE sequence that can be used to perform whole-brain FLAIR T2-weighted imaging at isotropic high spatial resolution. This high-resolution volumetric imaging, coupled with both fat and fluid suppression, permits ideal evaluation of optic nerve anatomy and signal intensity; therefore, we hypothesized that XETA FLAIR would be useful for the detection of T2 signal-intensity abnormality in the optic nerve. Our purpose was to evaluate the sensitivity of XETA FLAIR for this abnormality and to compare it with the coronal FSE T2 FS. After obtaining approval of the institutional review board, 2 CAQ neuroradiologists retrospectively reviewed all patients with a clinical diagnosis of optic neuropathy who had undergone XETA FLAIR and standard orbital imaging from September 2006 to February 2009. Fifteen patients met these criteria and underwent the following sequences: XETA FLAIR, coronal FSE T2 FS, and T1-weighted postgadolinium sequences with FS. Signal-intensity abnormality was identified on the correct side of the patient's vision loss in all 15 patients on XETA but in only 11/15 patients on the coronal FSE T2-weighted imaging. Reviewer 1 perceived the signal-intensity abnormality better on the XETA versus T2-weighted imaging in 10/15 patients, and reviewer 2, in 9/15 patients. Neither reviewer visualized any of the imaging better by using the conventional coronal FSE T2 FS sequence. XETA FLAIR was more sensitive than coronal FSE T2 FS for identifying abnormal signal intensity within the optic nerves in patients with optic neuropathy.

Water excitation MPRAGE: An alternative sequence for postcontrast imaging of the abdomen in noncooperative patients at 1.5 Tesla and 3.0 Tesla MRI

To evaluate the diagnostic image quality of postgadolinium water excitation-magnetization-prepared rapid gradient-echo (WE-MPRAGE) sequence in abdominal examinations of noncooperative patients at 1.5 Tesla (T) and 3.0T MRI. Eighty-nine consecutive patients (48 males and 41 females; mean age +/- standard deviation, 54.6 +/- 16.6 years) who had MRI examinations including postgadolinium WE-MPRAGE were included in the study. Of 89 patients, 33 underwent noncooperative protocol at 1.5T, 10 underwent noncooperative protocol at 3.0T, and 46 underwent cooperative protocol at 3.0T. Postgadolinium WE-MPRAGE, MPRAGE, and three-dimensional gradient-echo sequences of these three different groups were qualitatively evaluated for image quality, extent of artifacts, lesion conspicuity, and homogeneity of fat-attenuation by two reviewers retrospectively, independently, and blindly. The results were compared using Wilcoxon signed rank and Mann-Whitney U tests. Kappa statistics were used to measure the extent of agreement between the reviewers. The average scores indicated that the images were diagnostic for WE-MPRAGE at 1.5T and 3.0T in noncooperative patients. WE-MPRAGE achieved homogenous fat-attenuation in 31/33 (94%) of noncooperative patients at 1.5T and 10/10 (100%) of noncooperative patients at 3.0T. WE-MPRAGE at 3.0T had better results for image quality, extent of artifacts, lesion conspicuity and homogeneity of fat-attenuation compared with WE-MPRAGE at 1.5T, in noncooperative patients (P = 0.0008, 0.0006, 0.0024, and 0.0042; respectively). Kappa statistics varied between 0.76 and 1.00, representing good to excellent agreement. WE-MPRAGE may be used as a T1-weighted postgadolinium fat-attenuated sequence in noncooperative patients, particularly at 3.0T MRI.

Deferasirox, an Iron-Chelating Agent, as Salvage Therapy for Rhinocerebral Mucormycosis

Iron availability is a critical factor in the growth of Mucorales (5). Here we report the novel use of deferasirox (Exjade; Novartis), an iron chelator recently approved by the U.S. Food and Drug Administration for the treatment of transfusion-related iron overload (3), as salvage therapy for a patient with progressive rhinocerebral mucormycosis. A 40-year-old man presented to an outside hospital with diabetic ketoacidosis, left retrobulbar pain, and a left cranial nerve VI palsy. The patient developed complete left ophthalmoplegia, blindness, and worsening proptosis. He received amphotericin B lipid complex, but no surgery was performed. The patient was transferred to our institution on day 14 and underwent immediate left orbital exenteration, revealing an ischemic globe with extensive necrosis of the extraocular muscles. Frozen sections revealed broad, aseptate hyphae branching at 90°, typical of Mucorales; fungal cultures were negative. The patient was started on liposomal amphotericin B (LAmB) at 15 mg/kg of body weight/day and caspofungin at 70 mg/day (based on mouse data demonstrating polyene-echinocandin synergy) (6). Postoperatively, a magnetic resonance imaging (MRI) scan confirmed the presence of left cavernous sinus thrombosis (Fig. ​(Fig.1A1A). FIG. 1. (A) T1-weighted fat-saturated postgadolinium MRI obtained after left orbital exenteration. This is an axial image through the orbits and cavernous sinus, demonstrating abnormal enhancement in the left orbit, absence of normal flow void in the left carotid ... Over the next several months, MRIs revealed new enhancement of cranial nerve V and a new lesion in the pons and left cerebellum (Fig. ​(Fig.1B).1B). Because of worsening renal insufficiency (serum creatinine of >4.5 mg/dl versus a baseline of 0.8 mg/dl), the dose of LAmB was eventually titrated down to once weekly (∼day 210). A subsequent MRI (∼day 240) showed significant increase in size and enhancement of the left cerebellar signal consistent with progressive mucormycosis (Fig. ​(Fig.1C).1C). A 7-day course of salvage deferasirox was administered orally at a dose of 1,000 mg (∼15 mg/kg) daily. Repeat MRI of the brain 1 week after conclusion of deferasirox treatment demonstrated significant improvement in cerebellar disease (Fig. ​(Fig.1D).1D). LAmB was discontinued. Four months after the end of all antifungal therapy (∼day 400), the patient has remained asymptomatic, neurologically intact, and without radiographic changes on serial MRIs of the brain. The potential therapeutic role of iron chelation therapy for mucormycosis was initially obscured by the paradoxically increased risk of developing mucormycosis during treatment with deferoxamine (1). However, Mucorales fungi are able to specifically bind to deferoxamine-iron complexes, strip the iron from the chelator through a reductive process, and facilitate iron uptake (1). Animal models have shown that other iron chelators do not act as iron siderophores for Mucorales. Specifically, treatment of mucor-infected mice (4) or guinea pigs (2) with deferiprone markedly improved survival. These data suggested that iron chelation might be useful in the treatment of refractory mucormycosis. In summary, we describe a patient with advanced brainstem and cavernous sinus mucormycosis, who had significant progression radiographically despite months of polyene treatment but had a successful outcome after salvage deferasirox was added. The precise effect of the deferasirox treatment is confounded by concurrent polyene therapy. Nevertheless, given the encouraging results in this case, additional study of iron chelation in treatment of mucormycosis is warranted. (This case was reported in part at the 16th Congress of the International Society for Human and Animal Mycology [ISHAM] meeting in Paris, France, June 2006.)