Performance of an Open-Source Large Language Model in Extracting Information from Free-Text Radiology Reports.

Purpose To assess the performance of a local open-source large language model (LLM) in various information extraction tasks from real-life emergency brain MRI reports. Materials and Methods All consecutive emergency brain MRI reports written in 2022 from a French quaternary center were retrospectively reviewed. Two radiologists identified MRI scans that were performed in the emergency department for headaches. Four radiologists scored the reports' conclusions as either normal or abnormal. Abnormalities were labeled as either headache-causing or incidental. Vicuna (LMSYS Org), an open-source LLM, performed the same tasks. Vicuna's performance metrics were evaluated using the radiologists' consensus as the reference standard. Results Among the 2398 reports during the study period, radiologists identified 595 that included headaches in the indication (median age of patients, 35 years [IQR, 26-51 years]; 68% [403 of 595] women). A positive finding was reported in 227 of 595 (38%) cases, 136 of which could explain the headache. The LLM had a sensitivity of 98.0% (95% CI: 96.5, 99.0) and specificity of 99.3% (95% CI: 98.8, 99.7) for detecting the presence of headache in the clinical context, a sensitivity of 99.4% (95% CI: 98.3, 99.9) and specificity of 98.6% (95% CI: 92.2, 100.0) for the use of contrast medium injection, a sensitivity of 96.0% (95% CI: 92.5, 98.2) and specificity of 98.9% (95% CI: 97.2, 99.7) for study categorization as either normal or abnormal, and a sensitivity of 88.2% (95% CI: 81.6, 93.1) and specificity of 73% (95% CI: 62, 81) for causal inference between MRI findings and headache. Conclusion An open-source LLM was able to extract information from free-text radiology reports with excellent accuracy without requiring further training. Keywords: Large Language Model (LLM), Generative Pretrained Transformers (GPT), Open Source, Information Extraction, Report, Brain, MRI Supplemental material is available for this article. Published under a CC BY 4.0 license. See also the commentary by Akinci D'Antonoli and Bluethgen in this issue.

Pediatric cervical spine clearance after blunt trauma and negative CT: What is the role of MRI?

BACKGROUND AND PURPOSE: The cervical spine in children has marked anatomical and biomechanical differences compared to adults, leading to significantly different patterns and incidence of spinal injury, and consequently to different X-ray and computed tomography (CT) imaging recommendations. Magnetic resonance imaging (MRI) has been validated to clear cervical spine trauma in adults, but not in pediatric patients. We hypothesized that MRI findings have a low probability to change management in children with spine trauma and negative CT findings. MATERIALS AND METHODS: We reviewed records for admitted pediatric patients due to blunt trauma from January 2011 to May 2021, and identified 212 patients who underwent MRI within 3 days of a negative CT. Two neuroradiologists independently reviewed all CT and MRI images for the following categories: fracture, subluxation, spinal canal compromise, ligamentous injury, spinal canal hemorrhage, cord contusion and soft tissue hemorrhage. We identified follow-up MRI examinations as negative or positive for the above categories, and calculated the prevalence of each category as a percentage of cases with negative CT. We also evaluated whether negative and positive MRI groups differed significantly with respect to age and sex of the patients. RESULTS AND CONCLUSIONS: In our study of 212 children with cervical spine trauma and a negative CT, most follow-up MRI scans were found to be negative (79.9 %). Positive MRI findings consisted mainly of ligamentous sprain without disruption (15.1 %). Ligamentous disruption and epidural or soft tissue hemorrhage were found in 4.5 %, and focal cord contusion in 0.5 %. There was no statically significant difference between negative and positive MRI groups with respect to age (P = 0.45) and sex (P = 0.52). CONCLUSION: In our patient group with a negative CT, MRI did not significantly impact management nor contribute to cervical spine clearance in children.

Shift Volume Directly Impacts Neuroradiology Error Rate at a Large Academic Medical Center: The Case for Volume Limits.

BACKGROUND AND PURPOSE: Unlike in Europe and Japan, guidelines or recommendations from specialized radiological societies on workflow management and adaptive intervention to reduce error rates are currently lacking in the United States. This study of neuroradiologic reads at a large US academic medical center, which may hopefully contribute to this discussion, found a direct relationship between error rate and shift volume. MATERIALS AND METHODS: CT and MR imaging reports from our institution's Neuroradiology Quality Assurance database (years 2014-2020) were searched for attending physician errors. Data were collected on shift volume specific error rates per 1000 interpreted studies and RADPEER scores. Optimal cutoff points for 2, 3 and 4 groups of shift volumes were computed along with subgroups' error rates. RESULTS: A total of 643 errors were found, 91.7% of which were clinically significant (RADPEER 2b, 3b). The overall error rate (errors/1000 examinations) was 2.36. The best single shift volume cutoff point generated 2 groups: ≤ 26 studies (error rate 1.59) and > 26 studies (2.58; OR: 1.63, P < .001). The best 2 shift volume cutoff points generated 3 shift volume groups: ≤ 19 (1.34), 20-28 (1.88; OR: 1.4, P = .1) and ≥ 29 (2.6; OR: 1.94, P < .001). The best 3 shift volume cutoff points generated 4 groups: ≤ 24 (1.59), 25-66 (2.44; OR: 1.54, P < .001), 67-90 (3.03; OR: 1.91, P < .001), and ≥ 91 (2.07; OR: 1.30, P = .25). The group with shift volume ≥ 91 had a limited sample size. CONCLUSIONS: Lower shift volumes yielded significantly lower error rates. The lowest error rates were observed with shift volumes that were limited to 19-26 studies. Error rates at shift volumes between 67-90 studies were 226% higher, compared with the error rate at shift volumes of ≤ 19 studies.

Targeted magnetic resonance imaging (tMRI) of small changes in the T1 and spatial properties of normal or near normal appearing white and gray matter in disease of the brain using divided subtracted inversion recovery (dSIR) and divided reverse subtracted inversion recovery (drSIR) sequences.

This review describes targeted magnetic resonance imaging (tMRI) of small changes in the T1 and the spatial properties of normal or near normal appearing white or gray matter in disease of the brain. It employs divided subtracted inversion recovery (dSIR) and divided reverse subtracted inversion recovery (drSIR) sequences to increase the contrast produced by small changes in T1 by up to 15 times compared to conventional T1-weighted inversion recovery (IR) sequences such as magnetization prepared-rapid acquisition gradient echo (MP-RAGE). This increase in contrast can be used to reveal disease with only small changes in T1 in normal appearing white or gray matter that is not apparent on conventional MP-RAGE, T2-weighted spin echo (T2-wSE) and/or fluid attenuated inversion recovery (T2-FLAIR) images. The small changes in T1 or T2 in disease are insufficient to produce useful contrast with conventional sequences. To produce high contrast dSIR and drSIR sequences typically need to be targeted for the nulling TI of normal white or gray matter, as well as for the sign and size of the change in T1 in these tissues in disease. The dSIR sequence also shows high signal boundaries between white and gray matter. dSIR and drSIR are essentially T1 maps. There is a nearly linear relationship between signal and T1 in the middle domain (mD) of the two sequences which includes T1s between the nulling T1s of the two acquired IR sequences. The drSIR sequence is also very sensitive to reductions in T1 produced by Gadolinium based contrast agents (GBCAs), and when used with rigid body registration to align three-dimensional (3D) isotropic pre and post GBCA images may be of considerable value in showing subtle GBCA enhancement. In serial MRI studies performed at different times, the high signal boundaries generated by dSIR and drSIR sequences can be used with rigid body registration of 3D isotropic images to demonstrate contrast arising from small changes in T1 (without or with GBCA enhancement) as well as small changes in the spatial properties of normal tissues and lesions, such as their site, shape, size and surface. Applications of the sequences in cases of multiple sclerosis (MS) and methamphetamine dependency are illustrated. Using targeted narrow mD dSIR sequences, widespread abnormalities were seen in areas of normal appearing white matter shown with conventional T2-wSE and T2-FLAIR sequences. Understanding of the features of dSIR and drSIR images is facilitated by the use of their T1-bipolar filters; to explain their targeting, signal, contrast, boundaries, T1 mapping and GBCA enhancement. Targeted MRI (tMRI) using dSIR and drSIR sequences may substantially improve clinical MRI of the brain by providing unequivocal demonstration of abnormalities that are not seen with conventional sequences.

Autoimmune diseases of the spine and spinal cord.

Magnetic resonance imaging (MRI) and clinicopathological tools have led to the identification of a wide spectrum of autoimmune entities that involve the spine. A clearer understanding of the unique imaging features of these disorders, along with their clinical presentations, will prove invaluable to clinicians and potentially limit the need for more invasive procedures such as tissue biopsies. Here, we review various autoimmune diseases affecting the spine and highlight salient imaging features that distinguish them radiologically from other disease entities.

Imaging Cancer in Neuroradiology.

Neuroimaging plays a pivotal role in the diagnosis, management, and prognostication of brain tumors. Recently, the World Health Organization published the fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS5), which places greater emphasis on tumor genetics and molecular markers to complement the existing histological and immunohistochemical approaches. Recent advances in computational power allowed modern neuro-oncological imaging to move from a strictly morphology-based discipline to advanced neuroimaging techniques with quantifiable tissue characteristics such as tumor cellularity, microstructural organization, hemodynamic, functional, and metabolic features, providing more precise tumor diagnosis and management. The aim of this review is to highlight the key imaging features of the recently published CNS5, outlining the current imaging standards and summarizing the latest advances in neuro-oncological imaging techniques and their role in complementing traditional brain tumor imaging and management.

Advanced imaging in first episode psychosis: a systematic review.

First-episode psychosis (FEP) is defined as the first occurrence of delusions, hallucinations, or psychic disorganization of significant magnitude, lasting more than 7 days. Evolution is difficult to predict since the first episode remains isolated in one third of cases, while recurrence occurs in another third, and the last third progresses to a schizo-affective disorder. It has been suggested that the longer psychosis goes unnoticed and untreated, the more severe the probability of relapse and recovery. MRI has become the gold standard for imaging psychiatric disorders, especially first episode psychosis. Besides ruling out some neurological conditions that may have psychiatric manifestations, advanced imaging techniques allow for identifying imaging biomarkers of psychiatric disorders. We performed a systematic review of the literature to determine how advanced imaging in FEP may have high diagnostic specificity and predictive value regarding the evolution of disease.

Comparing the benefit of ASPECTS on maximum intensity projection images of computed tomography angiography to source images and noncontract computed tomography in predicting infarct volume and collaterals extent.

INTRODUCTION: In acute ischemic strokes (AIS), the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) and CT perfusion (CTP) are commonly used to determine mechanical thrombectomy eligibility. Prior work suggests that CTA source image (CTA-SI) ASPECTS (CTAasp) and a newly described CTA maximum intensity projection (CTA-MIP) ASPECTS (MIPasp) better predict the final infarct core. Our goal was to compare MIPasp to CTAasp and non-contrast CT ASPECTS (NCCTasp) for predicting ischemic core and collaterals established by CTP. METHODS AND MATERIALS: A single institution, retrospective database for AIS due to internal carotid artery (ICA) or proximal middle cerebral artery (MCA) occlusions between January 2016 and February 2021 was reviewed. We rated ASPECTS on NCCT, CTA-SI, and CTA-MIP at baseline, then used the automated RAPID software to measure CTP ischemic core volume. The accuracy of each ASPECTS in predicting ischemic core volume (ICV) >70 cc and Hypoperfusion intensity ratio (HIR) >0.4 was compared using the receiver operating characteristic (ROC) curve. RESULTS: 122/319 patients fulfilled the inclusion criteria. Area under the curve (AUC) for MIPasp was significantly higher than NCCTasp and CTAasp for predicting ICV >70 cc (0.95 vs. 0.89 and 0.95 vs. 0.92, P =0.03 and P = 0.04). For predicting HIR >0.4, AUC for MIPasp was significantly higher than NCCTasp and CTAasp (0.85 vs. 0.72 and 0.85 vs. 0.81, P < 0.001 and P < 0.01). CONCLUSION: The predictive accuracy of detecting ischemic stroke with ICV >70cc and HIR >0.4 can be significantly improved using the MIPasp instead of CTAasp or NCCTasp.

Combined central retinal artery and medial posterior ciliary artery occlusion: Localizing the lesion.

Purpose: To report a rare case of a combined central retinal artery (CRA) and medial posterior ciliary artery (MPCA) occlusion due to an atherosclerotic lesion in the common trunk supplying both arteries. Observations: A 75-year-old man presented with acute vision loss associated with elevated intraocular pressure in the right eye. Multi-modal imaging revealed a combined retinal and choroidal infarction in the distribution of the CRA and MPCA, localizing the lesion to the common trunk of the ophthalmic artery supplying both the CRA and MPCA. Neurovascular imaging provided supportive evidence for the diagnosis. Conclusions and importance: A simultaneous retinal and choroidal vascular occlusion is an uncommon presentation. Familiarity with the anatomy of the ophthalmic arteries and its branches facilitates localizing the lesion.

Factors Associated With Neuroradiologic Diagnostic Errors at a Large Tertiary-Care Academic Medical Center: A Case-Control Study.

BACKGROUND. Numerous studies have explored factors associated with diagnostic errors in neuroradiology; however, large-scale multivariable analyses are lacking. OBJECTIVE. The purpose of this study was to evaluate associations of interpretation time, shift volume, care setting, day of week, and trainee participation with diagnostic errors by neuroradiologists at a large academic medical center. METHODS. This retrospective case-control study using a large tertiary-care academic medical center's neuroradiology quality assurance database evaluated CT and MRI examinations for which neuroradiologists had assigned RADPEER scores. The database was searched from January 2014 through March 2020 for examinations without (RADPEER score of 1) or with (RADPEER scores of 2a, 2b, 3a, 3b, or 4) diagnostic error. For each examination with error, two examinations without error were randomly selected (unless only one examination could be identified) and matched by interpreting radiologist and examination type to form case and control groups. Marginal mixed-effects logistic regression models were used to assess associations of diagnostic error with interpretation time (number of minutes since the immediately preceding report's completion), shift volume (number of examinations interpreted during the shift), emergency/inpatient setting, weekend interpretation, and trainee participation in interpretation. RESULTS. The case group included 564 examinations in 564 patients (mean age, 50.0 ± 25.0 [SD] years; 309 men, 255 women); the control group included 1019 examinations in 1019 patients (mean age, 52.5 ± 23.2 years; 540 men, 479 women). In the case versus control group, mean interpretation time was 16.3 ± 17.2 [SD] minutes versus 14.8 ± 16.7 minutes; mean shift volume was 50.0 ± 22.1 [SD] examinations versus 45.4 ± 22.9 examinations. In univariable models, diagnostic error was associated with shift volume (OR = 1.22, p < .001) and weekend interpretation (OR = 1.60, p < .001) but not interpretation time, emergency/inpatient setting, or trainee participation (p > .05). However, in multivariable models, diagnostic error was independently associated with interpretation time (OR = 1.18, p = .003), shift volume (OR = 1.27, p < .001), and weekend interpretation (OR = 1.69, p = .02). In subanalysis, diagnostic error showed independent associations on weekdays with interpretation time (OR = 1.18, p = .003) and shift volume (OR = 1.27, p < .001); such associations were not observed on weekends (interpretation time: p = .62; shift volume: p = .58). CONCLUSION. Diagnostic errors in neuroradiology were associated with longer interpretation times, higher shift volumes, and weekend interpretation. CLINICAL IMPACT. These findings should be considered when designing work-flow-related interventions seeking to reduce neuroradiology interpretation errors.

Feasibility and usefulness of brain imaging in catatonia.

Catatonia is a well characterized psychomotor syndrome that has recognizable motor, affective, behavioural and vegetative manifestations. Despite recent demonstration that catatonia is often associated with brain imaging abnormalities, there is currently no consensus or guidelines about the role of brain imaging. In this study, we assessed the feasibility of brain imaging in a series of patients with catatonia in a routine clinical setting and estimated the prevalence of clinically relevant radiological abnormalities. Sixty patients with catatonia were evaluated against sixty non-healthy controls subjects with headache. The MRI reports were reviewed, and MRI scans were also interpreted by neuroradiologists using a standardised MRI assessment. In this cohort, more than 85% of brain scans of patients with catatonia revealed abnormalities. The most frequently reported abnormalities in the catatonic group were white matter abnormalities (n = 44), followed by brain atrophy (n = 27). There was no evidence for significant differences in the frequency of abnormalities found in radiology reports and standardised neuroradiological assessments. The frequency of abnormalities was similar to that found in a population of non-healthy controls subjects with headache. This study shows that MRI is feasible in patients with catatonia and that brain imaging abnormalities are common findings in these patients. Most frequently, white matter abnormalities and diffuse brain atrophy are observed.

Quantitative susceptibility mapping demonstrates different patterns of iron overload in subtypes of early-onset Alzheimer's disease.

OBJECTIVES: We aimed to define brain iron distribution patterns in subtypes of early-onset Alzheimer's disease (EOAD) by the use of quantitative susceptibility mapping (QSM). METHODS: EOAD patients prospectively underwent MRI on a 3-T scanner and concomitant clinical and neuropsychological evaluation, between 2016 and 2019. An age-matched control group was constituted of cognitively healthy participants at risk of developing AD. Volumetry of the hippocampus and cerebral cortex was performed on 3DT1 images. EOAD subtypes were defined according to the hippocampal to cortical volume ratio (HV:CTV). Limbic-predominant atrophy (LPMRI) is referred to HV:CTV ratios below the 25th percentile, hippocampal-sparing (HpSpMRI) above the 75th percentile, and typical-AD between the 25th and 75th percentile. Brain iron was estimated using QSM. QSM analyses were made voxel-wise and in 7 regions of interest within deep gray nuclei and limbic structures. Iron distribution in EOAD subtypes and controls was compared using an ANOVA. RESULTS: Sixty-eight EOAD patients and 43 controls were evaluated. QSM values were significantly higher in deep gray nuclei (p < 0.001) and limbic structures (p = 0.04) of EOAD patients compared to controls. Among EOAD subtypes, HpSpMRI had the highest QSM values in deep gray nuclei (p < 0.001) whereas the highest QSM values in limbic structures were observed in LPMRI (p = 0.005). QSM in deep gray nuclei had an AUC = 0.92 in discriminating HpSpMRI and controls. CONCLUSIONS: In early-onset Alzheimer's disease patients, we observed significant variations of iron distribution reflecting the pattern of brain atrophy. Iron overload in deep gray nuclei could help to identify patients with atypical presentation of Alzheimer's disease. KEY POINTS: • In early-onset AD patients, QSM indicated a significant brain iron overload in comparison with age-matched controls. • Iron load in limbic structures was higher in participants with limbic-predominant subtype. • Iron load in deep nuclei was more important in participants with hippocampal-sparing subtype.

Impact of Shift Volume on Neuroradiology Diagnostic Errors at a Large Tertiary Academic Center.

BACKGROUND AND PURPOSE: Medical errors can result in significant morbidity and mortality. The goal of our study is to evaluate correlation between shift volume and errors made by attending neuroradiologists at an academic medical center, using a large data set. MATERIALS AND METHODS: CT and MRI reports from our Neuroradiology Quality Assurance database (years 2014 - 2020) were searched for attending physician errors. Data were collected on shift volume, category of missed findings, error type, interpretation setting, exam type, clinical significance. RESULTS: 654 reports contained diagnostic error. There was a significant difference between mean volume of interpreted studies on shifts when an error was made compared with shifts in which no error was documented (46.58 (SD=22.37) vs 34.09 (SD=18.60), p<0.00001); and between shifts when perceptual error was made compared with shifts when interpretive errors were made (49.50 (SD=21.9) vs 43.26 (SD=21.75), p=0.0094). 59.6% of errors occurred in the emergency/inpatient setting, 84% were perceptual and 91.1% clinically significant. Categorical distribution of errors was: vascular 25.8%, brain 23.4%, skull base 13.8%, spine 12.4%, head/neck 11.3%, fractures 10.2%, other 3.1%. Errors were detected most often on brain MRI (25.4%), head CT (18.7%), head/neck CTA (13.8%), spine MRI (13.7%). CONCLUSION: Errors were associated with higher volume shifts, were primarily perceptual and clinically significant. We need National guidelines establishing a range of what is a safe number of interpreted cross-sectional studies per day.

Root of the Neck and Extracranial Vessel Anatomy.

The root of the neck is the junctional anatomic structure between the thoracic inlet, the axilla, and the lower neck. The detailed radiological anatomy of this critical area is discussed in this review.

High-Resolution CT Imaging of the Temporal Bone: A Cadaveric Specimen Study.

Objective Super-high and ultra-high spatial resolution computed tomography (CT) imaging can be advantageous for detecting temporal bone pathology and guiding treatment strategies. Methods Six temporal bone cadaveric specimens were used to evaluate the temporal bone microanatomic structures utilizing the following CT reconstruction modes: normal resolution (NR, 0.5-mm slice thickness, 512 2 matrix), high resolution (HR, 0.5-mm slice thickness, 1,024 2 matrix), super-high resolution (SHR, 0.25-mm slice thickness, 1,024 2 matrix), and ultra-high resolution (UHR, 0.25-mm slice thickness, 2,048 2 matrix). Noise and signal-to-noise ratio (SNR) for bone and air were measured at each reconstruction mode. Two observers assessed visualization of seven small anatomic structures using a 4-point scale at each reconstruction mode. Results Noise was significantly higher and SNR significantly lower with increases in spatial resolution (NR, HR, and SHR). There was no statistical difference between SHR and UHR imaging with regard to noise and SNR. There was significantly improved visibility of all temporal bone osseous structures of interest with SHR and UHR imaging relative to NR imaging ( p < 0.001) and most of the temporal bone osseous structures relative to HR imaging. There was no statistical difference in the subjective image quality between SHR and UHR imaging of the temporal bone ( p ≥ 0.085). Conclusion Super-high-resolution and ultra-high-resolution CT imaging results in significant improvement in image quality compared with normal-resolution and high-resolution CT imaging of the temporal bone. This preliminary study also demonstrates equivalency between super-high and ultra-high spatial resolution temporal bone CT imaging protocols for clinical use.

Anatomy of Intracranial Veins.

The cerebral venous system is complex and sophisticated and serves various major functions toward maintaining brain homeostasis. Cerebral veins contain about 70% of cerebral blood volume, have thin walls, are valveless, and cross seamlessly white matter, ependymal, cisternal, arachnoid, and dural boundaries to eventually drain cerebral blood either into dural sinuses or deep cerebral veins. Although numerous variations in the cerebral venous anatomic arrangement may be encountered, the overall configuration is relatively predictable and landmarks relatively well defined. A reasonable understanding of cerebral vascular embryology is helpful to appreciate normal anatomy and variations that have clinical relevance. Increasing interest in transvascular therapy, particularly transvenous endovascular intervention provides justification for practitioners in the neurosciences to acquire at least a basic understanding of the cerebral venous system.

Autoimmune disease of head and neck, imaging, and clinical review.

Autoimmune disease of the head and neck (H&N) could be primary or secondary to systemic diseases, medications, or malignancies. Immune-mediated diseases of the H&N are not common in daily practice of radiologists; the diagnosis is frequently delayed because of the non-specific initial presentation and lack of familiarity with some of the specific imaging and clinical features. In this review, we aim to provide a practical diagnostic approach based on the specific radiological findings for each disease. We hope that our review will help radiologists expand their understanding of the spectrum of the discussed disease entities, help them narrow the differential diagnosis, and avoid unnecessary tissue biopsy when appropriate based on the specific clinical scenarios.

Paraspinal soft tissue edema ratio: An accurate marker for early lumbar spine spondylodiscitis on an unenhanced MRI.

PURPOSE: MRI is currently the gold standard imaging modality in the diagnosis of lumbar spine discitis/osteomyelitis. However, even with supportive clinical and laboratory data, the accuracy of MRI remains limited by several degenerative and inflammatory mimics, such that it continues to represent a challenge for radiologists. This study reports a new quantitative imaging marker of lumbar paraspinal soft tissue edema which shows significant accuracy for spondylodiscitis. METHODS: Thirty-five patients with equivocal MRI findings of lumbar discitis/osteomyelitis vs endplate degenerative changes were reviewed over a 24-month period. Patients with a history of surgery, fractures/recent trauma, signs of advanced infection such as abscesses, phlegmon or severe osseous destruction were excluded. Two ABR board certified neuroradiologists who were blinded to the final diagnosis evaluated a new marker; the superior-inferior paraspinal edema ratio (SI-PER). The SI-PER was obtained by measuring the superior-inferior extent of increased signal/edema in the paraspinal soft tissues on the paraspinal inversion recovery images divided by the vertebral body height measured at midpoint. Cases positive for spondylodiscitis were those confirmed by biopsy, aspiration/drainage, surgery, or clinical improvement following antibiotic treatment. The diagnostic sensitivity and specificity of SI-PER were determined by Receiver operating characteristic (ROC) analysis. RESULTS: In 23/35 (66%) patients, the diagnosis of discitis/osteomyelitis was confirmed. The SI-PER showed a significant association with a positive MRI diagnosis (p = 0.001). Inter-observer correlation for SI-PER was 0.92. ROC analysis showed an area under the curve of 0.84. A SI-PER of 2.5 was 96% sensitive and 75% specific for the diagnosis of discitis/osteomyelitis, with a PPV of 88% and a NPV of 90%. CONCLUSION: In this study, the superior inferior paraspinal edema ratio (SI-PER), a newly defined MRI marker, was found to have high sensitivity for differentiating spondylodiscitis from endplate degenerative changes on lumbar spine MRI.