MRI Findings Research Articles

Can multiparametric MRI clear cell likelihood scores differentiate fat-Poor AML from CcRCC in subcentimeter lesions?

To investigate the potential of multiparametric MRI clear cell likelihood scores (ccLS) for differentiating between fat-poor angiomyolipoma (AML) and clear cell renal cell carcinoma (ccRCC) in subcentimeter Lesions (1cm or smaller). This retrospective study included consecutive patients with subcentimeter renal masses who underwent multiparametric MRI between September 2009 and September 2022 across three hospitals. Clinical and MRI findings were analyzed to differentiate between fat-poor AML and ccRCC. Lesions were categorized using the ccLS and receiver operating characteristic curve analysis was performed to assess ccLS performance. Thirty-eight patients (mean age: 52 years ± 12; 19 women) with 39 lesions were included. Of the 39 lesions [mean size: 9.1mm ± 1.0 (range, 6.0-10.0mm)], 20 (51%) were ccRCC and 19 (49%) were fat-poor AML. Compared to the ccRCC, subcentimeter fat-poor AMLs were more likely to show hypointensity on T2WI (P < 0.001), homogeneous enhancement (P = 0.010), the presence of microscopic fat (P = 0.036), and the absence of a pseudocapsule (P = 0.020). The diagnostic percentage of fat-poor AML was 47% for a ccLS of 1 or 2, and ccRCC accounted for 75% in the ccLS 4 or 5 category. The AUC for discrimination was 0.846 (95% CI: 0.695-0.941, P < 0.001), with a sensitivity of 75.00% (95% CI: 50.9-91.3) and a specificity of 89.47% (95% CI: 66.9-98.7). Multiparametric MRI clear cell likelihood scores can potentially be used to differentiate between fat-poor AML and ccRCC in lesions 1cm or smaller.

Neuroimaging predictors of favorable outcomes after shunting procedures in patients with Hakim-Adams syndrome: a pilot prospective randomized trial

To evaluate diagnostic properties of MRI data comprehensive assessment model compared to traditional invasive diagnostic method (spinal tap test) in prospective randomized trial. MRI data and postoperative outcomes in patients diagnosed with idiopathic normal pressure hydrocephalus who underwent ventriculoperitoneal shunting between September 2022 and April 2024 were analyzed in prospective randomized study. In the study group, surgical decisions were based on MRI data, while the control group followed an algorithm incorporating invasive diagnostic method (spinal tap-test). Ventriculoperitoneal shunting with constant-pressure valve implantation was performed in all patients selected for surgery. The study included 54 patients (25 ones in the study group and 29 ones in the control group). Surgery was performed in 21 and 20 patients, respectively. We found no advantages of invasive diagnostic methods over comprehensive assessment of MRI data in predicting the effectiveness of surgical treatment. Comprehensive assessment of MRI findings allows for avoiding invasive diagnostic procedures in decision-making on cerebrospinal fluid shunting surgery in some patients with idiopathic normal pressure hydrocephalus.

Acquired Hepatocerebral Degeneration in a Septic Patient: Hospital Course and MRI Findings

Acquired Hepatocerebral Degeneration in a Septic Patient: Hospital Course and MRI Findings

Analysis of the Effectiveness of Platelet-Rich Plasma in the Treatment of Discogenic Pain Syndrome of the Lumbar Spine

Objective. This study aims to evaluate the effectiveness of intradiscal injection of platelet-rich plasma (PRP) in the treatment of discogenic pain syndrome of the lumbar spine. Materials and Methods. The study was conducted from July 2022 to September 2024 at the SI “Institute of Traumatology and Orthopedics of NAMS of Ukraine.” Patients diagnosed with discogenic pain syndrome received intradiscal PRP injections. The effectiveness was assessed at 1 and 6 months post-treatment using the Visual Analog Scale (VAS), the Oswestry Disability Index (ODI), and MRI findings (Pfirrmann classification). Results. One month after the injection, VAS scores decreased by more than 3 points in 21.2% of patients, by 2 points in 18.1%, and by 1 point in 39.3%. Six months after the injection, VAS scores decreased by more than 3 points in 54.5% of patients, by 2 points in 12.2%, and by 1 point in 21.2%. On average, VAS scores decreased by 30% one month after injection and by 46% six months after treatment compared to baseline. The average ODI scores decreased to 8.06% one month after injection and to 6.67% six months after injection, respectively. MRI evaluation of intervertebral disc changes using the Pfirrmann classification did not reveal statistically significant differences but showed a tendency toward a reduction in degenerative changes 6 months after the injection. Conclusions. The use of platelet-rich plasma significantly reduced pain and improved quality of life in patients with discogenic pain syndrome who participated in the study 6 months after treatment initiation. It is also important to note that PRP therapy is safe due to the autologous nature of the product. Additionally, no clinically significant side effects or complications were observed. The results allow us to conclude that PRP therapy is effective in treating discogenic pain syndrome.

Theta-Alpha Variability on EEG Is Associated With Acute Brain Injury in Children and Young Adults With Liver Failure.

Patients with liver failure experience long hospitalizations and acute neurologic complications. Encephalopathy limits the bedside examination, rendering presenting signs of acute brain injury less specific. Seizures are common. Brain MRI is the gold standard for detecting acute brain injury, but intensive medical needs may preclude immediate transfer for imaging. EEG is a bedside test applied in cases of seizure or encephalopathy. We hypothesized that EEG variables can predict MRI signs of acute brain injury in children hospitalized with liver failure. In this retrospective cohort analysis, records were collected for patients admitted to a MedStar hospital between 2014 and 2022 with ICD-9/10 codes related to liver failure, who underwent brain MRI and EEG testing during the same admission. Exclusion criteria included age older than 24 years and >7 days elapsing between EEG and MRI testing. Clinical data of interest from chart review, reinterpreted MRI scans, reinterpreted EEG tracings, and quantitative EEG variables were compiled into a database. Quantitative EEG variables were processed using MNE-Python. Of 746 records screened, 52 patients met inclusion criteria comprising 63 EEG-MRI pairs. Univariate analysis of all quantitative EEG variables of interest showed depressed theta-alpha variability (TAV) when paired MRI involved abnormal restricted diffusivity in cortical or deep gray matter structures (TAV 0.705, SD 0.310; p < 0.001) compared with MRI with no abnormal restricted diffusivity (TAV 0.895, SD 0.095). Multilinear regression analysis including potential confounders demonstrated independent association of depressed TAV with this MRI finding, with an odds ratio of 4.0317 (95% CI 1.3868-11.7165; AUROC 0.83). Depressed TAV on EEG is associated with increased odds of abnormal restricted diffusivity in gray matter on brain MRI in children and young adults hospitalized with liver failure. This MRI finding is seen in scenarios where changes to medical management are time-sensitive (i.e., acute stroke and PRES) or where prognostic discussion may be influenced by MRI findings (hypoxic-ischemic injury). TAV thus has a potential role as an automated, bedside decision support tool for clinicians deciding on the urgency of brain MRI in critically ill patients.

P53 status combined with MRI findings for prognosis prediction of single hepatocellular carcinoma

ObjectTo develop and validate a nomogram for predicting recurrence in individuals suffering single hepatocellular carcinoma (HCC) after curative hepatectomy. Material and methodsA retrospective analysis was conducted on 189 patients with single HCC undergoing curative resection in our center were randomized into training and validation cohorts. P53 status was determined using immunohistochemistry. Clinical data, such as age, and gender were collected. MRI findings, such as tumor size, intratumoral arteries, the presence of peritumoral enhancement and intratumoral necrosis were also recorded. Nomograms were established based on the predictors selected in the training cohort, and receiver operating characteristic (ROC) curve analyses were used to compare the predictive ability among single predictors and nomogram model. The Kaplan-Meier method were used to assess the impact of each predictor and nomogram model on HCC recurrence. The results were validated in the validation cohort. ResultsMultivariate Cox regression analysis showed that P53 (P < 0.001), tumor size (P = 0.009), and intratumoral artery (P = 0.026) were the independent risk factors for HCC recurrence. The nomogram model demonstrated favorable C-index of 0.740 (95 %CI:0.653–0.826) and 0.767 (95 %CI: 0.633–0.900) in the training and validation cohorts, and the area under the curve was 0.740 and 0.752, which was better than the performance of P53 and MR factors alone. Calibration curves indicated a good agreement between observed actual outcomes and predicted values. Kaplan-Meier curves indicated that nomogram model was powerful in discrimination and clinical usefulness. ConclusionsThe integrated nomogram combining P53 status and MRI findings can be a valuable prognostic tool for predicting postoperative recurrence of single HCC.

Paroxysmal delta waves of awake EEG in childhood adrenoleukodystrophy: Possible indicator of the hematopoietic stem cell therapy (HSCT).

Childhood cerebral type of Adrenoleukodystrophy (CC-ALD) is fatal without hematopoietic stem cell transplantation (HSCT). We consider whether EEGs showing focal paroxysmal delta waves can be a candidate of early detector of the apparent ALD and HSCT therapy. Twenty-two male children with ALD (5-16years; 10.4±2.8) were evaluated. Fourteen children were diagnosed as CC-ALD and the rest 8 were yet asymptomatic both clinical and MRI findings. CC-ALD patients with frontal or occipital MRI main lesions were classified as Types F and O (4 and 10 patients). Asymptomatic patients were classified as Type A whose clinical types had not been known. Awake electroencephalogram was recorded during cognitive tasks and analyzed using fast Fourier transform (FFT). Eight children (1/4F, 3/10 O and 4/8 A patients) were evaluated pre- and post-HSCT. FFT analysis revealed the high voltage slow wave characterized by an increased delta band wave power volume (DBPV) in all children. The DBPV of Type F and O patients showed anterior and posterior dominance in 4/4 and 9/10 patients. Dominant DBPV in Type A patients were anterior and posterior in 6/8 and 1/8, respectively. We classified them as Type F' and O'. DBPV decreased in all (8/8) patients after HSCT therapy. All patients showed paroxysmal delta wave. In symptomatic patients, abnormal delta wave appeared in their corresponding cortical lesions and decreased after therapy. In asymptomatic patients it may be the first sign of the apparent ALD onset and suggesting when to consider HSCT therapy.

A rare finding of testicular epidermoid keratinized cyst in a prepubertal boy: case report and management standardization.

Testicular epidermoid cysts (TECs) are rare, benign lesions that can also mimic malignant testicular masses. Accurate preoperative diagnosis is essential for proper management. A 13-year-old male presented with a painless solid mass in the left testicle. Serum tumor markers were normal. Ultrasound, CEUS and MRI findings were consistent with TEC. Surgical enucleation of the mass was performed, after ruling out malignancy through intraoperative frozen section examination. Histopathology confirmed diagnosis of keratin-filled epidermoid cyst. At 3-month follow-up, the patient is well-being and scrotal US is normal. This case highlights the importance of considering epidermoid cysts in the differential diagnosis of testicular masses in young males. Ultrasound is the first-line imaging modality in the assessment of any testicular masses. Other imaging modalities such as CEUS, elastography and MRI can be helpful to distinguish between benign and malignant lesions. Testis-sparing surgery can be safely performed, after ruling out malignancy through intraoperative frozen-section analysis.

392 Severe MRI findings, mild clinical course: unveiling attenuated glycine encephalopathy in a newborn

392 Severe MRI findings, mild clinical course: unveiling attenuated glycine encephalopathy in a newborn

Functional Connectivity Relationships to Longitudinal Motor Outcomes Differ in Very Preterm Children With and Without Brain Injury.

Children born very preterm (VPT) have high rates of motor disability, but mechanisms for early identification remain limited, especially for children who fall behind in early childhood. This study examines the relationship between functional connectivity (FC) measured at term-equivalent age and motor outcomes at 2 and 5 years. In this longitudinal observational cohort study, VPT children (gestational age 30 weeks and younger) with and without high-grade brain injury underwent FC MRI at term-equivalent age. Motor development was assessed using the Bayley Scales of Infant Development, Third Edition, at corrected age 2 years and Movement Assessment Battery for Children, Second Edition, at age 5 years. Logistic and negative binomial/Poisson regression models examined relationships between FC measures and 5-year task scores, with and without 2-year scores as covariates. Infants were categorized as "injured" or "uninjured" based on structural MRI findings at term-equivalent age. In the injured group (n = 34), each 1 SD decrease in neonatal left-right motor cortex FC was related to approximately 4× increased odds of being unable to complete a fine motor task at age 5 (log odds = -1.34, p < 0.05). In the uninjured group (n = 41), stronger basal ganglia-motor cortex FC was related to poorer fine motor scores (Est = -0.40, p < 0.05) and stronger cerebellum-motor cortex FC was related to poorer balance and fine motor scores (Est = -0.05 to -0.23, p < 0.05), with balance persisting with adjustment for 2-year scores. In VPT children with brain injury, interhemispheric motor cortex FC was related to motor deficits at 5-year assessment, similar to previous findings at 2 years. In uninjured children, FC-measured disruption of the motor system during the neonatal period was associated with motor planning/coordination difficulties that were not apparent on 2-year assessment but emerged at 5 years, suggesting that the neural basis of these deficits was established very early in life. Subsequently, 2-year follow-up may not be sufficient to detect milder motor deficits in VPT children, and they should be monitored for motor difficulties throughout the preschool years. For all VPT children, FC at term-equivalent age has the potential to improve our ability to predict disability before it presents behaviorally.

Quantitative analysis of 123I-iomazenil single-photon emission computed tomography findings from patients with infantile epileptic spasm syndrome.

This study aimed to elucidate the distribution of intracranial gamma-aminobutyric acid (GABA) receptors in patients with infantile epileptic spasms syndrome (IESS) of normal brain MRI findings using 123I-iomazenil single-photon emission computed tomography (IMZ-SPECT). This retrospective study compared IMZ-SPECT images from 20 patients with IESS of unknown etiology with normal brain MRI (unknown IESS group) and 23 patients with developmentally normal epilepsy of the same age (developmentally normal group). A three-dimensional stereotactic region of interest (ROI) template was used to divide the brain into 24 segments (left and right callosomarginal, precentral, central, parietal, angular, temporal, posterior cerebral, pericallosal, lenticular nucleus, thalamus, hippocampus, and cerebellum), and the mean accumulation of 123I-iomazenil in each ROI was calculated. The IMZ ratio for each ROI was calculated by dividing the ROI count by the mean cerebellar count of the left and right sides for the same patient. IMZ ratios for 22 ROIs, excluding the cerebellum, between the unknown IESS group and the developmentally normal group were compared. No significant differences were observed between the background characteristics of the unknown and developmentally normal groups. Hypsarrhythmia were observed in 16 patients in the IESS group. The IMZ ratio showed no significant differences between the two groups across all 22 ROIs. The IMZ ratio of the unknown IESS group was not significantly different from that of the developmentally normal group across the 22 ROIs, suggesting that GABA receptor distribution has little effect on epileptic spasms and hypsarrhythmia, and vice versa.

Cardiac MRI findings among Fabry disease patients undergoing higher intensity therapy

Cardiac MRI findings among Fabry disease patients undergoing higher intensity therapy

Anatomic Approach to Fetal Hydrocephalus.

Hydrocephalus is an imprecise term and refers to the imbalance of brain parenchyma and cerebral spinal fluid in the cranial vault. Ventriculomegaly, or enlargement of the ventricular system, is often the more precise term and is therefore preferred. Appropriate imaging and measurement techniques are critical to detect ventriculomegaly and grade its severity. There is a broad differential diagnosis with resultant highly variable clinical outcomes. Furthermore, some causes have a substantial recurrence risk in future pregnancies. Therefore, accurate diagnosis of the underlying cause is essential for pregnancy management and patient counseling. Understanding ventricular anatomy and correct measurement technique is needed for assessing and grading ventriculomegaly. This is achieved through an anatomically based approach to reach the differential diagnosis, with a focus on key decision points for delineating causes of ventriculomegaly. In particular, the posterior fossa is first assessed for structural or developmental abnormalities; then, midline brain development abnormalities and associated pathologic conditions are reviewed; and last, the cortical mantle is assessed for developmental or destructive processes. In each category, different entities are highlighted, with a particular focus on illustrating the US and MRI findings of the underlying condition and tips to differentiate similar-appearing entities. Ultimately, the informed fetal radiologist can use the proposed algorithmic approach to hydrocephalus to narrow the differential and thus provide vital diagnostic information for pregnancy counseling and management discussions. ©RSNA, 2025.

Cardiac MRI in Heart Transplantation: Approaches and Clinical Insights.

Orthotopic heart transplant (OHT) is a well-established therapy for end-stage heart failure that leads to improved long-term survival rates, with careful allograft surveillance essential for optimizing clinical outcomes after OHT. Unfortunately, complications can arise after OHT that can compromise the success of the OHT. Cardiac MRI is continually evolving, with a range of advanced techniques that can be applied to evaluate allograft structure and function. Understanding the unique features of cardiac MRI in OHT recipients, identifying findings suggestive of acute or chronic complications, and recognizing the limitations of this imaging modality are essential for accurate interpretation of cardiac MRI findings and subsequent clinical reporting. The authors address the anticipated postsurgical anatomy and functionality of the OHT. Emphasis is placed on the advanced functional and tissue characterization features that can be seen in the stable OHT recipient, including global longitudinal strain, late gadolinium enhancement, native T1 and T2 mapping, and extracellular volume fraction. Subsequently, the evidence for detection of acute cardiac allograft rejection with cardiac MRI comprehensive tissue characterization techniques and the role of quantitative myocardial perfusion for cardiac allograft vasculopathy screening are discussed, with reference to their comparative standard of reference screening tests, including endomyocardial biopsy, invasive coronary angiography, and myocardial rest and stress perfusion PET/CT. Cardiac MRI has been included in contemporary OHT management guidelines and therefore can be considered a complementary tool for allograft evaluation. The authors demonstrate the complementary role cardiac MRI can play in cardiac allograft surveillance, with clinical examples. ©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Agarwal in this issue.

Functional MRI and cognition in multiple sclerosis-Where are we now?

Multiple sclerosis-related cognitive impairment (MSrCI) affects most patients with multiple sclerosis (MS), significantly contributing to disability and socioeconomic challenges. MSrCI manifests across all disease stages, mainly impacting working memory, information processing, and attention. To date, the underlying mechanisms of MSrCI remain unclear, with its pathogenesis considered multifactorial. While conventional MRI findings correlate with MSrCI, there is no consensus on reliable imaging metrics to detect or diagnose cognitive impairment (CI). Functional MRI (fMRI) has provided unique insights into the brain's neuroplasticity mechanisms, revealing evidence of compensatory mechanisms in response to tissue damage, both beneficial and maladaptive. This review summarizes the current literature on the application of resting-state fMRI (rs-fMRI) and task-based fMRI (tb-fMRI) in understanding neuroplasticity and its relationship with cognitive changes in people with MS (pwMS). Searches of databases, including PubMed/Medline, Embase, Scopus, and the Web of Science, were conducted for the most recent fMRI cognitive studies in pwMS. Key findings ifrom rs-fMRI studies reveal disruptions in brain connectivity and hub integration, leading to CI due to decreased network efficiency. tb-fMRI studies highlight abnormal brain activation patterns in pwMS, with evidence of increased fMRI activity in earlier disease stages as a beneficial compensatory response, followed by reduced activation correlating with increased lesion burden and cognitive decline as the disease progresses. This suggests a gradual exhaustion of compensatory mechanisms over time. These findings support fMRI not only as a diagnostic tool for MSrCI but also as a potential imaging biomarker to improve our understanding of disease progression.

Mastering rectal cancer MRI: From foundational concepts to optimal staging.

MRI plays a critical role in the local staging, restaging, surveillance, and risk stratification of patients, ensuring they receive the most tailored therapy. As such, radiologists must be familiar not only with the key MRI findings that influence management decisions but also with the appropriate MRI protocols and structured reporting. Given the complexity of selecting the optimal therapy for each patient-which often requires multidisciplinary discussions-radiologists should be well-versed in relevant treatment strategies and surgical terms, understanding their significance in guiding patient care. In this manuscript, we review the most common treatment options for managing patients with rectal adenocarcinoma, emphasizing key MRI principles and protocol characteristics for accurate staging. We also highlight important anatomical landmarks and essential factors to be described during baseline assessment. Additionally, we discuss crucial information for restaging and surveillance.

Comparisons among radiologist, MR findings and radiomics-clinical models in predicting placenta accreta spectrum disorders: a multicenter study.

To assess and compare the diagnostic accuracy of radiologist, MR findings, and radiomics-clinical models in the diagnosis of placental implantation disorders. Retrospective collection of MR images from patients suspected of having placenta accreta spectrum (PAS) was conducted across three institutions: Institution I (n = 505), Institution II (n = 67), and Institution III (n = 58). Data from Institution I were utilized to form a training set, while data from Institutions II and III served as an external test set. Radiologist diagnosis was performed by radiologists of varying levels of experience. The interpretation of MR findings was conducted by two radiologists with 10-15years of experience in pelvic MR diagnosis, following the guidelines for diagnosis. Radiomics analysis extracted features from sagittal T2-weighted images and combined them with prenatal clinical features to construct predictive models. These models were then evaluated for discrimination and calibration to assess their performance. As measured by the area under the receiver operating characteristic curve (AUC), the diagnostic efficacy was 0.587 (0.542-0.630) for junior radiologists from Institution I, 0.568 (0.441-0.689) from Institution II, and 0.507 (0.373-0.641) from Institution III. The AUC was 0.623 (0.580-0.666) for senior radiologists from Institution I, 0.635 (0.508-0.749) from Institution II, and 0.632 (0.495-0.755) from Institution III. The diagnostic efficacy of MR findings was 0.648 (0.601-0.695) for Institution I, 0.569 (0.429-0.709) for Institution II, and 0.588 (0.442-0.735) for Institution III. The diagnostic efficacy of the radiomics-clinical model was significantly higher, with an AUC of 0.794 (0.754-0.833) for Institution I, 0.783 (0.664-0.903) for Institution II, and 0.816 (0.704-0.927) for Institution III. The diagnostic efficacy of the Fusion model was significantly higher, with an AUC of 0.867 (0.836-0.899) for Institution I, 0.849 (0.753-0.944) for Institution II, and 0.823 (0.708-0.939) for Institution III. The fusion models demonstrated superior diagnostic efficacy compared to radiologists, MR findings, and the radiomics-clinical models. Furthermore, the diagnostic accuracy of PAS was notably higher when utilizing the radiomics-clinical models than when relying solely on radiologist diagnosis or MR findings. Radiomics analysis substantially augments the diagnostic precision in PAS, providing a significant enhancement over conventional radiologist and MRI findings. The diagnostic efficacy of the fusion model is notably superior to that of individual diagnostic modalities.

Can Baseline MRI Findings Identify Who Responds Better to Early Surgery Versus Exercise and Education in Young Patients With Meniscal Tears? A Subgroup Analysis From the DREAM Trial

Can Baseline MRI Findings Identify Who Responds Better to Early Surgery Versus Exercise and Education in Young Patients With Meniscal Tears? A Subgroup Analysis From the DREAM Trial

P-91. Clinical characteristics and analysis of predictors of the outcome of septic arthritis of the shoulder : a 16-year experience

Abstract Background The number of septic arthritis cases is increasing due to the increasing number of joint surgeries and lengthened life expectancy. There are few data about the characteristics and risk factors of septic arthritis of the shoulder. As timely diagnosis and treatment are essential, we aim to describe the clinical characteristics and analyze predictors of the outcome of Septic arthritis of the shoulder. Microorganisms causing septic arthritis of the shoulder Methods We performed a retrospective cohort study of patients diagnosed with septic arthritis of the shoulder between June 2007 and June 2023 at a tertiary hospital in Korea, Aged over 19. We excluded patients who did not undergo treatment in this hospital and had tuberculosis isolated from synovial culture. We analyzed demographic data, comorbidities and underlying conditions, shoulder trauma history, operation history, acupuncture history, previous steroid injection history, rotator cuff tear, clinical presentation, MRI finding, synovial findings, laboratory findings, and culture findings. We analyzed whether each characteristic was associated with unfavorable outcome. Results Among 99 patients enrolled in this study, 49 patients showed unfavorable prognosis. The most frequently identified microorganisms were Staphylococcus aureus (39 cases), 11 of which were Methicillin-resistant S. aureus (MRSA), Streptococcus, and beta-haemolytic (7 cases). The univariate analysis revealed that elevated blood WBC count at 2 weeks and CRP/Albumin ratio at 2 weeks were significant factors. Additionally, findings of positive culture, blood stream infection and MRSA isolation were statistically significant. In multivariate analysis, we identified positive culture findings (OR 3.34; 95% CI, 1.01 – 11.12; P = 0.049), the CRP/albumin ratio at 2 weeks (OR 1.07; 95% CI, 1.01 – 1.12; P = 0.012), and the Charlson calculator score (OR 0.32; 95% CI, 0.69 – 0.99; P = 0.037) as risk factors for unfavorable outcomes. Conclusion The significance of our study is that we analyzed characteristics of multiple cases for the long term and identified new predictors of the outcome for septic arthritis of the shoulder. In case of identified positive culture findings, elevated CRP/albumin ratio at 2 weeks and high Charlson calculator score, unfavorable outcome can be considered. Disclosures All Authors: No reported disclosures

P-918. Rabies encephalitis: Spectrum of MRI findings and predicted probability of abnormality detection based on symptom duration

Abstract Background Rabies is a highly lethal infectious disease and is equivalent to a death sentence for the patient. With currently available tests, the ante-mortem diagnostic sensitivity is only ∼40%. Currently, there are only isolated case reports or small case series exploring the MRI features in rabies encephalitis. T2 TSE showing hyperintensities in bilateral basal ganglia (caudate nucleus, putamen and globus pallidus) and thalamus and corresponding DWI and ADC images showing true diffusion restriction Methods A prospective observational study was designed to explore the patterns of MRI abnormalities in rabies patients. A total of 31 patients were enrolled in the study, out of which 21 underwent Contrast-Enhanced Magnetic Resonance Imaging of Brain and spinal cord. FLAIR/T2 images showing hyperintensities in dorsal brainstem, cervical spinal cord Results Overall, MRI was normal in 10(47.6%) patients, whereas 11(52.4%) patients showed abnormalities. Abnormalities were detected in various brain regions with brainstem, spinal cord and basal ganglia being the most commonly affected regions. Other regions such as the cortex, sub-cortical white matter, limbic system, internal capsule, corona radiata, thalamus, and sub-thalamic region were also involved to varying degrees. Diffusion-weighted-imaging showed typical pattern of diffusion restriction in 6 cases (28.5%). No gadolinium contrast enhancement was observed in any patient. Overall, no significant difference in neuroimaging findings were observed between encephalitic and paralytic forms of rabies. In addition, univariate logistic regression analysis revealed that the likelihood of detecting abnormalities on MRI increases with the duration from the symptom onset. T2 hyperintensity in conus medullaris with contrast enhancing cauda equina nerve roots Conclusion Till date this is the largest prospective study (21 cases) exploring the MRI findings in the patients of rabies encephalitis. The study demonstrated certain patterns of brain imaging in rabies which in the appropriate clinical context could significantly aid in establishing the ante-mortem diagnosis of rabies encephalitis. At the same time, the study also highlights the fact that a normal MRI brain does not rule out the diagnosis and that the probability of finding specific abnormalities on MRI increases as the disease progresses. Univariable logistic regression to estimate predicted probability of appearance of MRI abnormality after appearance of 1st cardinal symptom Disclosures All Authors: No reported disclosures