Language lateralization from task‐based and resting state functional MRI in patients with epilepsy

We compared resting state (RS) functional connectivity and task‐based fMRI to lateralize language dominance in 30 epilepsy patients (mean age = 33; SD = 11; 12 female), a measure used for presurgical planning. Language laterality index (LI) was calculated from task fMRI in frontal, temporal, and frontal + temporal regional masks using LI bootstrap method from SPM12. RS language LI was assessed using two novel methods of calculating RS language LI from bilateral Broca's area seed based connectivity maps across regional masks and multiple thresholds (p < .05, p < .01, p < .001, top 10% connections). We compared LI from task and RS fMRI continuous values and dominance classifications. We found significant positive correlations between task LI and RS LI when functional connectivity thresholds were set to the top 10% of connections. Concordance of dominance classifications ranged from 20% to 30% for the intrahemispheric resting state LI method and 50% to 63% for the resting state LI intra‐ minus interhemispheric difference method. Approximately 40% of patients left dominant on task showed RS bilateral dominance. There was no difference in LI concordance between patients with right‐sided and left‐sided resections. Early seizure onset (<6 years old) was not associated with atypical language dominance during task‐based or RS fMRI. While a relationship between task LI and RS LI exists in patients with epilepsy, language dominance is less lateralized on RS than task fMRI. Concordance of language dominance classifications between task and resting state fMRI depends on brain regions surveyed and RS LI calculation method.     

YouTube videos as a teaching tool and patient resource for infantile spasms

The purpose of this study was to assess YouTube videos for their efficacy as a patient resource for infantile spasms. Videos were searched using the terms infantile spasm, spasm, epileptic spasm, and West syndrome. The top 25 videos under each term were selected according to set criteria. Technical quality, diagnosis of infantile spasms, and suitability as a teaching resource were assessed by 2 neurologists using the Medical Video Rating Scale. There were 5858 videos found. Of the 100 top videos, 46% did not meet selection criteria. Mean rating for technical quality was 4.0 of 5 for rater 1 and 3.9 of 5 for rater 2. Raters found 60% and 64% of videos to accurately portray infantile spasms, respectively, with significant agreement (Cohen κ coefficient = 0.75, P < .001). Ten videos were considered excellent examples (grading of 5 of 5) by at least 1 rater. YouTube may be used as an excellent patient resource for infantile spasms if guided search practices are followed.     

Language lateralization in left-handed and ambidextrous people: fMRI data

BACKGROUND: It is generally accepted that most people have left-hemispheric language dominance, though the actual incidence of atypical language distribution in non-right-handed subjects has not been extensively studied. The authors examined language distribution in these subjects and evaluated the relationships between personal handedness, family history of sinistrality, and a language laterality index (LI) measured with fMRI. METHODS: The authors used whole-brain fMRI to examine 50 healthy, non-right-handed subjects (Edinburgh Handedness Inventory quotient between -100 and 52) while they performed language activation and nonlinguistic control tasks. Counts of active voxels (p < 0.001) were computed in 22 regions of interest (ROI) covering both hemispheres and the cerebellum. LI were calculated for each ROI and each entire hemisphere using the formula [L - R]/[L + R]. RESULTS: Activation was predominantly right hemispheric in 8% (4/50), symmetric in 14% (7/50), and predominantly left hemispheric in 78% (39/50) of the subjects. Lateralization patterns were similar for all hemispheric ROI. Associations were observed between personal handedness and LI (r = 0.28, p = 0.046), family history of sinistrality and LI (p = 0.031), and age and LI (r = -0.49, p < 0.001). CONCLUSIONS: The incidence of atypical language lateralization in normal left-handed and ambidextrous subjects is higher than in normal right-handed subjects (22% vs 4-6%). These whole-brain results confirm previous findings in a left-handed cohort studied with fMRI of the lateral frontal lobe. Associations observed between personal handedness and LI and family history of handedness and LI may indicate a common genetic factor underlying the inheritance of handedness and language lateralization.     

Atrophy patterns in early clinical stages across distinct phenotypes of Alzheimer's disease

Alzheimer's disease (AD) can present with distinct clinical variants. Identifying the earliest neurodegenerative changes associated with each variant has implications for early diagnosis, and for understanding the mechanisms that underlie regional vulnerability and disease progression in AD. We performed voxel‐based morphometry to detect atrophy patterns in early clinical stages of four AD phenotypes: Posterior cortical atrophy (PCA, “visual variant,” n = 93), logopenic variant primary progressive aphasia (lvPPA, “language variant,” n = 74), and memory‐predominant AD categorized as early age‐of‐onset (EOAD, <65 years, n = 114) and late age‐of‐onset (LOAD, >65 years, n = 114). Patients with each syndrome were stratified based on: (1) degree of functional impairment, as measured by the clinical dementia rating (CDR) scale, and (2) overall extent of brain atrophy, as measured by a neuroimaging approach that sums the number of brain voxels showing significantly lower gray matter volume than cognitively normal controls (n = 80). Even at the earliest clinical stage (CDR = 0.5 or bottom quartile of overall atrophy), patients with each syndrome showed both common and variant‐specific atrophy. Common atrophy across variants was found in temporoparietal regions that comprise the posterior default mode network (DMN). Early syndrome‐specific atrophy mirrored functional brain networks underlying functions that are uniquely affected in each variant: Language network in lvPPA, posterior cingulate cortex‐hippocampal circuit in amnestic EOAD and LOAD, and visual networks in PCA. At more advanced stages, atrophy patterns largely converged across AD variants. These findings support a model in which neurodegeneration selectively targets both the DMN and syndrome‐specific vulnerable networks at the earliest clinical stages of AD. Hum Brain Mapp 36:4421–4437, 2015. © 2015 Wiley Periodicals, Inc .     

Functional connectivity maps based on hippocampal and thalamic dynamics may account for the default‐mode network

The default‐mode network (DMN) has been reported to comprise a set of inter‐connected transmodal cortical areas, including the posterior cingulate cortex (PCC), medial prefrontal cortex, posterior inferior parietal lobule, lateral temporal region and others. However, the subcortical constituents of the DMN are still not clear. This study aimed to examine whether the correlation maps derived from subcortical structures may also account for neural pattern of the DMN. Structural magnetic resonance imaging (MRI) and resting‐state functional MRI scans of 36 subjects were selected from the Rockland sample (Nathan Kline Institute). The hippocampus and thalamus were chosen as subcortical regions of interest (ROIs). Each ROI was partitioned into composite modules which in turn provided simplified and representative dynamics of blood‐oxygen‐level‐dependent (BOLD) signals. PCC‐seeded and ROI‐based correlation maps were compared by conjunction analyses and paired t‐tests (corrected P < 0.05). Our results unveiled that the hippocampus‐, thalamus‐ and PCC‐centred correlation patterns actually overlapped to a substantial degree. Integrating the signals in the thalamus and hippocampus altogether fully explained the PCC‐seeded DMN. Supplementary analyses based on the BOLD dynamics in several subcortical nuclei (caudate, putamen and globus pallidus) were dissimilar to the DMN. The DMN derived from the ROI/seed‐based approach may represent combined limbic and region‐specific informatics (and their closely interacting neural substrates). The possible causes for previous methods of task‐induced deactivation and seed‐based correlation that failed to depict the holistic limbic picture are discussed. The neocortical manifestation of DMN may reflect the limbic information in the transmodal brain regions.     

Integration of routine QA data into mega‐analysis may improve quality and sensitivity of multisite diffusion tensor imaging studies

A novel mega‐analytical approach that reduced methodological variance was evaluated using a multisite diffusion tensor imaging (DTI) fractional anisotropy (FA) data by comparing white matter integrity in people with schizophrenia to controls. Methodological variance was reduced through regression of variance captured from quality assurance (QA) and by using Marchenko–Pastur Principal Component Analysis (MP‐PCA) denoising. N = 192 (119 patients/73 controls) data sets were collected at three sites equipped with 3T MRI systems: GE MR750, GE HDx, and Siemens Trio. DTI protocol included five b = 0 and 60 diffusion‐sensitized gradient directions (b = 1,000 s/mm²). In‐house DTI QA protocol data was acquired weekly using a uniform phantom; factor analysis was used to distil into two orthogonal QA factors related to: SNR and FA. They were used as site‐specific covariates to perform mega‐analytic data aggregation. The effect size of patient‐control differences was compared to these reported by the enhancing neuro imaging genetics meta‐analysis (ENIGMA) consortium before and after regressing QA variance. Impact of MP‐PCA filtering was evaluated likewise. QA‐factors explained ～3–4% variance in the whole‐brain average FA values per site. Regression of QA factors improved the effect size of schizophrenia on whole brain average FA values—from Cohen's d = .53 to .57—and improved the agreement between the regional pattern of FA differences observed in this study versus ENIGMA from r = .54 to .70. Application of MP‐PCA‐denoising further improved the agreement to r = .81. Regression of methodological variances captured by routine QA and advanced denoising that led to a better agreement with a large mega‐analytic study.     

Arcuate fasciculus asymmetry has a hand in language function but not handedness

The importance of relationships between handedness, language lateralization and localization, and white matter tracts for language performance is unclear. The goal of the study was to investigate these relationships by examining arcuate fasciculus (AF) structural asymmetry (DTI) and functional asymmetry (fMRI) in language circuits, handedness, and linguistic performance. A large sample of right‐handed (n = 158) and atypical‐handed (n = 82) healthy adults underwent DTI at 3 T to assess number of streamlines and fractional anisotropy (FA) of the AF, and language fMRI. Language functions were assessed using standard tests of vocabulary, naming, verbal fluency, and complex ideation. Laterality indices (LIs) illustrated degree of asymmetry and lateralization patterns for the AF (streamlines and FA) and verb generation fMRI. Both handedness groups showed leftward lateralization bias for streamline and fMRI LIs and symmetry for FA LI. The proportion of subjects with left, right, or symmetric lateralization were similar between groups if based on AF LIs, but differed if based on fMRI LIs (p = 0.0016). Degree of right‐handedness was not associated with AF lateralization, but was associated with fMRI language lateralization (p = 0.0014). FA LI was not associated with performance on language assessments, but streamline LI was associated with better vocabulary and complex ideation performance in atypical‐handed subjects (p = 0.022 and p = 0.0098, respectively), and better semantic fluency in right‐handed subjects (p = 0.047); however, these did not survive multiple comparisons correction. We provide evidence that AF asymmetry is independent of hand preference, and while degree of right‐handedness is associated with hemispheric language lateralization, the majority of atypical‐handed individuals are left‐lateralized for language. Hum Brain Mapp 37:3297–3309, 2016. © 2016 Wiley Periodicals, Inc .     

The Rome II and Rome III criteria identify the same subtype-populations in irritable bowel syndrome: agreement depends on the method used for symptom report

Background For comparing trials using different classifications for irritable bowel syndrome (IBS) subtypes, it is important to know whether these identify the same sub‐populations. Our aim was to determine the agreement between Rome II and Rome III subtypes, and to explore whether agreement depends on the symptom reporting method. Methods Rome II IBS patients from two identical, randomized placebo‐controlled trials of probiotics were included. Retrospective subtypes were based on the Rome II questionnaire. Prospective subtypes were based on diary cards for 2 weeks of run‐in. Agreement was determined between: (i) retrospective Rome II and Rome III, (ii) prospective Rome II and Rome III, (iii) retrospective Rome II and prospectively Rome III, (iv) retrospective and prospective Rome II, and (v) retrospective and prospective Rome III. Key Results A total of 126 patients, 72% women, mean age 46 ± 15 years, were included. The agreement between subtypes using the same symptom reporting method was: (i) 90.3% (κ = 0.85) for retrospective subtypes, and (ii) 84% (κ = 0.76) for prospective subtypes. The agreement between subtypes using different symptom reporting methods was, (iii) 49% (κ = 0.23) for retrospective Rome II and prospective Rome III, (iv) 51% (κ = 0.26) for Rome II subtypes, and (v) 41% (κ = 0.25) for Rome III subtypes. Conclusions & Inferences Agreement between Rome II and Rome III subtypes is good to very good when using the same symptom reporting method. When mixing methods, agreement is only fair even within the same classification. This has implications for comparison of trials using different symptom reporting methods for subtyping.     

Test–retest repeatability of assessing environmental and lifestyle factors in Parkinson's disease

Epidemiological studies of environmental risk factors in Parkinson's disease (PD) are dependent on recollection of past exposures based on patients' self‐reports. There are limited studies that have assessed the quality of such data. We conducted a prospective study to determine the test–retest repeatability of environmental and lifestyle factors, and medical data in a PD cohort of Asian ethnicity. A total of 150 consecutive PD patients were initially screened, and 100 were recruited and completed an initial interview. Eighty‐three patients completed the second interview more than 6 months later. Lifestyle habits (such as smoking and coffee consumption) showed excellent agreement (κ > 0.90). For the amount and duration of coffee, tea, alcohol, and cigarette smoking exposure, the total agreement in the response for these factors in the repeat interview were noted in 71.4%, 73.3%, 100%, and 90%, respectively (ICC > 0.83). Medical conditions for which the patients were on treatment, such as diabetes, hypertension, and stroke, revealed very high repeatability (κ = 0.81–0.90). Environmental exposures like well‐water consumption and prior farm‐dwelling produced a moderately good repeatability (κ = 0.66–0.77). In conclusion, our study demonstrates that even over long interval period of more than half a year, self‐report lifestyle exposure information, personal and environmental exposure data can be collected with moderate‐to‐high repeatability from PD patients. © 2008 Movement Disorder Society     

A Surgical Planning Method for Functional MRI Assessment of Language Dominance: Influences from Threshold, Region-of-Interest, and Stimulus Mode

Presurgical determination of language laterality is an important step for assessing potential risk of dysfunction resulting from brain resection within or near suspected language areas. Image-based functional MRI (fMRI) methods seek to address limitations to the clinical gold-standard technique by offering a safer, less costly, and non-invasive alternative. In this study we outline a set of protocols for objective determination of langue-specific asymmetry from fMRI activation maps. We studied 13 healthy, right-handed volunteers using a vocalized antonym-generation task. Initially, using the standard threshold-dependent laterality index (LI) procedure, we demonstrated an undesirably high degree of intra-subject variability and indeterminacy in LI value. We addressed this issue by implementing a novel threshold-independent method, resulting in a single, unambiguous LI for each subject. These LIs were then averaged across the group and used to compare functional laterality within the whole hemispheric volumes and six intra-hemispheric regions-of-interest (ROIs). We noted that as a result of increased bilateral activation from vocalizations, laterality assessment calculated from the whole hemisphere resulted in insignificant asymmetry. However, by focusing the LI exclusively on the inferior frontal (IFG) and supramarginal gyri (SMG), robust leftward asymmetries were observed. We also examined the influence of stimulus mode on the group mean ROI LI, and observed an increase in IFG asymmetry using visual mode, and in SMG using the auditory mode. Based on these findings, we make recommendations for optimized presurgical protocols.     

The CSF tap test in normal pressure hydrocephalus: evaluation time,reliability and the influence of pain

Background: The cerebrospinal fluid tap test (TT) is a diagnostic tool used to select patients with idiopathic normal pressure hydrocephalus (iNPH) for shunt surgery. The procedure and the evaluation of the TT vary between centres. We aimed to describe the evaluation time after the TT, to assess the variability between repeated measurements, the interrater agreement of the gait tests chosen and finally to investigate whether pain affects the gait performance post‐TT. Methods: Forty patients (21 men and 19 women) under evaluation for iNPH underwent a TT. Standardized gait analyses were performed before and 2, 4, 6, 8 and 24 h after the TT and repeated twice on every occasion. Independent of each other, two investigators evaluated the quality of gait. At each assessment time, the patients graded headache and back pain on a visual analogue scale. Results: Twenty‐seven patients (15 men and 12 women) responded to TT. Improvements in gait speed and number of steps were significant at every assessment time post‐TT. The variability between two measurements was low (Intra class correlation coefficient = 0.97), and the inter‐rater agreement was good with a κ = 0.74. Pain correlated negatively with improvement in gait speed (r = ?0.40, P < 0.05). Conclusions: We suggest that the TT can be evaluated at any time within the first 24 h and should be repeated if the patient does not initially improve. Gait analysis appears reliable between two evaluators. Further, it is indicated that post‐lumbar puncture pain negatively affects the gait and should be minimized.     

Areas activated during naturalistic reading comprehension overlap topological visual,auditory, and somatotomotor maps

Cortical mapping techniques using fMRI have been instrumental in identifying the boundaries of topological (neighbor‐preserving) maps in early sensory areas. The presence of topological maps beyond early sensory areas raises the possibility that they might play a significant role in other cognitive systems, and that topological mapping might help to delineate areas involved in higher cognitive processes. In this study, we combine surface‐based visual, auditory, and somatomotor mapping methods with a naturalistic reading comprehension task in the same group of subjects to provide a qualitative and quantitative assessment of the cortical overlap between sensory‐motor maps in all major sensory modalities, and reading processing regions. Our results suggest that cortical activation during naturalistic reading comprehension overlaps more extensively with topological sensory‐motor maps than has been heretofore appreciated. Reading activation in regions adjacent to occipital lobe and inferior parietal lobe almost completely overlaps visual maps, whereas a significant portion of frontal activation for reading in dorsolateral and ventral prefrontal cortex overlaps both visual and auditory maps. Even classical language regions in superior temporal cortex are partially overlapped by topological visual and auditory maps. By contrast, the main overlap with somatomotor maps is restricted to a small region on the anterior bank of the central sulcus near the border between the face and hand representations of M‐I. Hum Brain Mapp 37:2784–2810, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc .     

The burden of headache in Russia: validation of the diagnostic questionnaire in a population‐based sample

Background: We report validation of the Russian‐language version of the Lifting The Burden headache screening and diagnostic questionnaire in a population‐based sample of 501 individuals in four cities (Smolensk, Tchelyabinsk, Nishny Novgorod and Tver) and three rural areas (Tula, Tver and Gornyi) of Russia. Methods: The structured questionnaire, based on ICHD‐II criteria, was applied face to face by trained non‐medical interviewers calling at randomly selected households. Response rates were about 73% in cities and 80% in rural areas. Results: Of those responding, 301 reported headache in the previous year; of the total sample, 143 people with and 47 without headache according to the questionnaire were re‐interviewed by telephone by one of the two neurologists unaware of the questionnaire diagnoses. Migraine (MIG), either definite (dMIG) or probable (pMIG), was diagnosed by the questionnaire in 72 cases, and tension‐type headache (TTH), either definite (dTTH) or probable (pTTH), in 66 cases; the five others with headache were unclassifiable by questionnaire. Physicians diagnosed dMIG or pMIG in 65 cases, dTTH or pTTH in 89 cases and no headache in 31 cases; in five cases, headache was unclassifiable. The questionnaire had sensitivities and specificities of 77% and 82% for MIG (κ = 0.58) and of 64% and 91% for TTH (κ = 0.56). Conclusions: We concluded that the questionnaire can be utilized in a population‐based countrywide survey of the burden attributable to primary headache disorders in Russia.     

A new rating instrument to assess festination and freezing gait in Parkinsonian patients

Festination and freezing of gait (FOG) are sudden episodic inabilities to initiate or sustain locomotion mostly experienced during the later stages of Parkinson's disease (PD) or other higher‐level gait disorders. The aim of this study was to develop a clinical rating instrument for short‐interval rating of festination and FOG. Foot movements of 33 patients were video taped and rated during 12 episodes in a standardized course on a four‐level interval scale according to severity. Motor blocks were provoked in four situations and by three levels of dual‐tasking (tasks). Addition of the item scores produced a FOG score. The assessment requires less than 15 min. The inter‐rater and re‐test reliability of the FOG score is high (Kendall κ = 0.85–0.92, P < 0.0001). Variability of the item scale due to situations and tasks can be attributed to unidimensional group factors (Cronbach's α 0.84 and 0.94). Group comparisons and a logistic regression model show significant effects for both situations and tasks on the item scale (Friedman test: “situation”: P < 0.0001, “task”: P < 0.0001). Six patients with PD have significantly different scores during mobile (practical ON; 6.2 ± 3.9) and immobile (practical OFF; 15.8 ± 4.6) medication states (P < 0.05). The FOG score correlates with the 10 m number of steps (ρ = 0.58; P = 0.001) and with the self‐evaluation of FOG (ρ = 0.51; P < 0.01). Our results encourage the further use of the FOG score to evaluate festination and FOG. © 2010 Movement Disorder Society     

Resting‐state functional connectivity predicts the strength of hemispheric lateralization for language processing in temporal lobe epilepsy and normals

In temporal lobe epilepsy (TLE), determining the hemispheric specialization for language before surgery is critical to preserving a patient's cognitive abilities post‐surgery. To date, the major techniques utilized are limited by the capacity of patients to efficiently realize the task. We determined whether resting‐state functional connectivity (rsFC) is a reliable predictor of language hemispheric dominance in right and left TLE patients, relative to controls. We chose three subregions of the inferior frontal cortex (pars orbitalis, pars triangularis, and pars opercularis) as the seed regions. All participants performed both a verb generation task and a resting‐state fMRI procedure. Based on the language task, we computed a laterality index (LI) for the resulting network. This revealed that 96% of the participants were left‐hemisphere dominant, although there remained a large degree of variability in the strength of left lateralization. We tested whether LI correlated with rsFC values emerging from each seed. We revealed a set of regions that was specific to each group. Unique correlations involving the epileptic mesial temporal lobe were revealed for the right and left TLE patients, but not for the controls. Importantly, for both TLE groups, the rsFC emerging from a contralateral seed was the most predictive of LI. Overall, our data depict the broad patterns of rsFC that support strong versus weak left hemisphere language laterality. This project provides the first evidence that rsFC data may potentially be used on its own to verify the strength of hemispheric dominance for language in impaired or pathologic populations. Hum Brain Mapp, 36:288–303, 2015. © 2014 Wiley Periodicals, Inc.     

Comparing within‐subject classification and regularization methods in fMRI for large and small sample sizes

In recent years, a variety of multivariate classifier models have been applied to fMRI, with different modeling assumptions. When classifying high‐dimensional fMRI data, we must also regularize to improve model stability, and the interactions between classifier and regularization techniques are still being investigated. Classifiers are usually compared on large, multisubject fMRI datasets. However, it is unclear how classifier/regularizer models perform for within‐subject analyses, as a function of signal strength and sample size. We compare four standard classifiers: Linear and Quadratic Discriminants, Logistic Regression and Support Vector Machines. Classification was performed on data in the linear kernel (covariance) feature space, and classifiers are tuned with four commonly‐used regularizers: Principal Component and Independent Component Analysis, and penalization of kernel features using L₁ and L₂ norms. We evaluated prediction accuracy (P) and spatial reproducibility (R) of all classifier/regularizer combinations on single‐subject analyses, over a range of three different block task contrasts and sample sizes for a BOLD fMRI experiment. We show that the classifier model has a small impact on signal detection, compared to the choice of regularizer. PCA maximizes reproducibility and global SNR, whereas L_p‐norms tend to maximize prediction. ICA produces low reproducibility, and prediction accuracy is classifier‐dependent. However, trade‐offs in (P,R) depend partly on the optimization criterion, and PCA‐based models are able to explore the widest range of (P,R) values. These trends are consistent across task contrasts and data sizes (training samples range from 6 to 96 scans). In addition, the trends in classifier performance are consistent for ROI‐based classifier analyses. Hum Brain Mapp 35:4499–4517, 2014. © 2014 Wiley Periodicals, Inc .     

Operational definitions improve reliability of the age‐related white matter changes scale

Background and purpose: Although the age‐related white matter changes (ARWMC) scale has been advocated to be applicable to both MRI and CT for assessing the severity of WMC, its inter‐rater reliability on CT is only fair. We aimed to operationalize the ARWMC scale and investigate the effect of this operationalization on the reliability and validity on MRI and CT. Methods: Operational definitions of the ARWMC scale were derived from Erkinjuntti research criteria for subcortical vascular dementia and Scheltens scale. Using original and operationalized ARWMC scale, eight observers recorded the time for rating per MRI and per CT. We investigated the inter‐rater and intrarater reliability as well as validity against volume using data from 97 stroke patients. Results: Inter‐rater reliability of the operationalized scale on CT (0.874, 95% confidence interval [0.780–0.934]) was better than the original scale (0.569, 95% confidence interval [0.247–0.775]). Its intrarater reliability on CT (0.869) and reliability on MRI (inter‐rater: 0.860; intrarater: 0.838) was comparable with the original scale (CT intrarater: 0.750 and on MRI inter‐rater: 0.845; intrarater: 0.853). The time required to administer the operationalized scale (4′2″ for MRI and 1′18″ for CT) was similar to that of the original scale (3′56″ for MRI and 1′16″ for CT). The original scale and operationalized scale also significantly correlated with WMC volume (operationalized scale ρ = 0.613, P < 0.001, original scale ρ = 0.638, P < 0.001). Conclusion: Operational definitions improve the inter‐rater reliability of ARWMC scale on CT, and it correlates with volumetric measurement.