Reliability of preoperative MRI findings in patients with lumbar spinal stenosis

Background Magnetic Resonance Imaging (MRI) is an important tool in preoperative evaluation of patients with lumbar spinal stenosis (LSS). Reported reliability of various MRI findings in LSS varies from fair to excellent. There are inconsistencies in the evaluated parameters and the methodology of the studies. The purpose of this study was to evaluate the reliability of the preoperative MRI findings in patients with LSS between musculoskeletal radiologists and orthopaedic spine surgeons, using established evaluation methods and imaging data from a prospective trial. Methods Consecutive lumbar MRI examinations of candidates for surgical treatment of LSS from the Norwegian Spinal Stenosis and Degenerative Spondylolisthesis (NORDSTEN) study were independently evaluated by two musculoskeletal radiologists and two orthopaedic spine surgeons. The observers had a range of experience between six and 13 years and rated five categorical parameters (foraminal and central canal stenosis, facet joint osteoarthritis, redundant nerve roots and intraspinal synovial cysts) and one continuous parameter (dural sac cross-sectional area). All parameters were re-rated after 6 weeks by all the observers. Inter- and intraobserver agreement was assessed by Gwet’s agreement coefficient (AC1) for categorical parameters and Intraclass Correlation Coefficient (ICC) for the dural sac cross-sectional area. Results MRI examinations of 102 patients (mean age 66 ± 8 years, 53 men) were evaluated. The overall interobserver agreement was substantial or almost perfect for all categorical parameters (AC1 range 0.67 to 0.98), except for facet joint osteoarthritis, where the agreement was moderate (AC1 0.39). For the dural sac cross-sectional area, the overall interobserver agreement was good or excellent (ICC range 0.86 to 0.96). The intraobserver agreement was substantial or almost perfect/ excellent for all parameters (AC1 range 0.63 to 1.0 and ICC range 0.93 to 1.0). Conclusions There is high inter- and intraobserver agreement between radiologists and spine surgeons for preoperative MRI findings of LSS. However, the interobserver agreement is not optimal for evaluation of facet joint osteoarthritis. Trial registration www.ClinicalTrials.gov identifier: NCT02007083, registered December 2013.

Validity of the Novel Radiological Classification System of the Distal Femur

Objective Aseptic loosening (AL) is among the most important causes of failure after total knee arthroplasty (TKA). However, while there are numerous underlying causes of AL, the morphometry of the distal femur and intramedullary canal has not been sufficiently demonstrated. This study aimed to show the interobserver and intraobserver reliability and validity of the Citak classification, which has been recently defined according to the morphometry of the distal femur and provides a risk factor definition for AL. Materials and Methods A total of 200 patients whose standardized anteroposterior (AP) and lateral images of the knee joint were obtained between October 2019 and April 2020 were retrospectively evaluated in this study. Patients with a history of extra-articular deformity and knee surgery were excluded from the study. For AL, morphologies of the distal femur were identified by two observers using the new radiological classification system of the distal femur. Mean pairwise Cronbach’s alpha coefficient was used to assess the intra- and interobserver agreement of the classification. Results There was excellent interobserver agreement for the 20 cm proximal and 2 cm proximal to the lateral joint line (PLJL) and adductor tubercle (PAD), respectively. The mean Cronbach’s alpha coefficient was 0.96 (range 0.764–0.944) for the PAD and 0.98 (range 0.734–0.929) for the PLJL. There was also an excellent intraobserver agreement, with 93% average pairwise percent agreement for the index group and 95.5% average pairwise percent agreement for the anatomical classification group. Conclusions The level of inter- and intraobserver agreement for the morphology of the distal femur was excellent in the new radiological classification system, which was shown to be beneficial in the planning of revision knee arthroplasty for AL. However, there is a need for further studies in order to make a correlation of the classification with specific intraoperative findings.

Interobserver and Intraobserver Reproducibility and Reliability of the Huashan Clinical Classification System for Hirayama Disease

Purpose: The Huashan clinical classification system for Hirayama disease has recently been proposed and has been found useful for diagnosis and treatment. So far, however, there has been little in-depth evaluation of its reliability. Thus, this study aimed to assess the reproducibility and reliability of the system.Methods: Patients diagnosed with Hirayama disease between 2019 and 2020 were recruited. Seven spine surgeons from four different institutions, including an experienced group of three and an inexperienced group of four, were trained as observers of the Huashan clinical classification system for Hirayama disease, and these surgeons classified the recruited patients using the system. Then, 2 months later, they repeated the classification on the same patients in a different order. The interobserver and intraobserver agreement between the results was analyzed using percentage agreement and weighted kappa (κ) statistics.Results: A total of 60 patients were included in the analysis. For all the observers, experienced observers, and inexperienced observers, the agreement percentages were, respectively, 78.5% (κ = 0.76), 80.0% (κ = 0.78), and 78.9% (κ = 0.77), indicating substantial interobserver reproducibility. For distinguishing typical (Types I and II) and atypical (Type III) Hirayama disease among the different groups of observers, the percentage agreement ranged from 95.6 to 98.9% (κ = 0.74–0.92), indicating substantial to nearly perfect reproducibility. For suggesting conservative treatment (Types I and III) or surgery (Type II), the percentage agreement ranged from 93.3 to 96.4% (κ = 0.81–0.90), indicating nearly perfect reproducibility. As for intraobserver agreement, the percentage agreement ranged from 68.3 to 81.7% (κ = 0.65–0.79), indicating substantial reliability.Conclusion: The Huashan clinical classification system for Hirayama disease was easy to learn and apply in a clinical environment, showing excellent reproducibility and reliability. Therefore, it would be promising to apply and promote this system for the precise and individualized future treatment of Hirayama disease.

RELIABILITY OF THE GOUTALLIER CLASSIFICATION SYSTEM IN THE EVALUATION OF THE MULTIFIDUS MUSCLE

ABSTRACT Introduction: The paravertebral musculature is essential for the biomechanics and stability of the spine, and its involvement in the pathophysiology of spinal diseases has been demonstrated. Qualitative evaluation of muscle degeneration is usually performed by analyzing the fat infiltration rate proposed by the Goutallier classification system. Objective: The objective of this study is to analyze the intra- and interobserver agreement of the Goutallier Classification for the evaluation of fatty degeneration of the multifidus muscle, using magnetic resonance imaging exams. Methods: The study included 68 patients, all diagnosed with symptomatic disc hernia and indicated for surgery. Preoperative magnetic resonance images were used for the analyses. The images were initially evaluated by two orthopedists and two medical students, and then re-evaluated after two weeks. Intra- and inter-observer reliability analysis was performed using the Fleiss Kappa test and the Landis and Koch criteria. All the analyses were performed using the R statistical environment (R Development Core Team, version 3.3.1, 2016) and the significance level was set at 5%. Results: The percentages of intra- and inter-observer agreement were 86.76% and 61.03%, respectively. The intraobserver agreement was near perfect and the interobserver agreement was moderate. Conclusion: The Goutallier Classification System showed moderate interobserver and intraobserver agreement, being a relevant tool for the evaluation of paravertebral musculature fat replacement. Level of evidence II; Prospective study for diagnostic purposes.

Inter- and intraobserver reliability of morphological Mutch classification for greater tuberosity fractures of the proximal humerus: A comparison of x-ray, two-, and three-dimensional CT imaging

Background The objective of this study was to investigate inter- and intraobserver reliability of the morphological Mutch classification for greater tuberosity (GT) fragments in consecutive proximal humerus fractures (PHF) regardless of the number of parts according to the Codman classification system for three different imaging modalities (plain radiographs, two-dimensional [2-D] computed tomography [CT], and reformatted, three-dimensional [3-D] CT reconstruction). Materials and methods One hundred thirty-eight consecutive PHF with GT involvement were identified between January 2018 and December 2018 in a supraregional Level 1 trauma center. GT morphology was classified by three blinded observers according to the morphological Mutch classification using the picture archiving and communication software Visage 7.1 (Visage Imaging Inc., San Diego, CA, USA). Fleiss’ and Cohens’ kappa were assessed for inter- and intraobserver reliability. Strength of agreement for kappa (k) values was interpreted according to the Landis and Koch benchmark scale. Results In cases of isolated GT fractures (n = 24), the morphological Mutch classification achieved consistently substantial values for interobserver reliability (radiograph: k = 0.63; 2-D CT: k = 0.75; 3-D CT: k = 0.77). Moreover, use of advanced imaging (2-D and 3-D CT) tends to increase reliability. Consistently substantial mean values were found for intraobserver agreement (radiograph: Ø k = 0.72; 2-D CT: Ø k = 0.8; 3-D CT: Ø k = 0.76). In cases of multi-part PHF with GT involvement (n = 114), interobserver agreement was only slight to fair regardless of imaging modality (radiograph: k = 0.3; 2-D CT: k = 0.17; 3-D CT: k = 0.05). Intraobserver agreement achieved fair to moderate mean values (radiograph: Ø k = 0.56; 2-D CT: Ø k = 0.61; 3-D CT: Ø k = 0.33). Conclusion The morphological Mutch classification remains a reliable classification for isolated GT fractures, even with 2-D or 3-D CT imaging. Usage of these advanced imaging modalities tends to increase interobserver reliability. However, its reliability for multi-part fractures with GT involvement is limited. A simple and reliable classification is missing for this fracture entity.

Validation of a skin and coat scoring protocol in dogs

Skin and coat scores have been used to assess changes in skin and coat quality in dogs. The aim of this study was to evaluate a skin and coat protocol in dogs of different coat types. Skin and coat of long-haired, short-haired and wire-haired dogs were scored for alopecia, glossiness, greasiness, softness, scaliness and overall skin and coat quality by ten observers. Intraobserver and interobserver agreement was assessed using kappa values. Thirty-six client-owned dogs were included in the study. The overall intraobserver agreement was moderate when assessing greasiness and glossiness and substantial when assessing alopecia, softness, scaliness and overall skin and coat quality. The overall interobserver agreement was only slight to fair for all features assessed. In conclusion, the proposed skin and coat scoring protocol assesses different aspects of the skin and coat quality in dogs and is easy and non-invasive. Scoring skin and coat quality over time is only reliable if performed by the same person.

The Unified Visual Function Scale assessments show inter- and intraobserver agreement and correlate with Patient Quality of Life in skullbase parasellar tumours

BACKGROUND The authors have previously described the Unified Visual Function Scale (UVFS). Here we assessed intraobserver and interobserver reliability of the scale, and investigated correlations with patient quality of life (QoL). METHODS Eight healthcare practitioners independently applied the UVFS in 20 representative cases from our parasellar meningioma series. Scoring was compared to consensus grades assigned by lead authors. Inter- and intraobserver agreement was measured using intraclass correlation coefficient (ICC), Fleiss’s , and Cohen’s  respectively. Patient QoL was assessed Visual Function Questionnaire (VFQ-25) or Activities of Daily Vision Scale (ADVS), and correlated with UVFS grades for each eye. RESULTS The interobserver ICC was 0.734 (95% CI, 0.652 to 0.811), with Fleiss’s  of 0.758, 0.691, and 0.899 for grades A, B, and C respectively. The intraobserver ICC was 0.758 (95% CI 0.638 to 0.872), and Fleiss’s  was 0.604, 0.268, and 0.910 for grades A, B, and C respectively. The Cohen’s  for agreement between UVFS category grades and consensus grades was 0.816 (95 CI, 0.698 to 0.934). Survey response rate was 51% (27/53). The UVFS demonstrated strong correlation with VFQ-25 subdivisions general vision (r = 0.7712), near activities (r = 0.7262), peripheral vision (r = 0.6722), and driving (r = 0.6608), and also demonstrated strong correlation with the overall ADVS score (r = 0.5902). CONCLUSION This study shows that the UVFS is valid within a small subset of observers, and accurately reflects patient quality of life. It is robust and practical, which make it suitable for broad implementation.

Visual Evaluation of Image Quality of a Low Dose 2D/3D Slot Scanner Imaging System Compared to Two Conventional Digital Radiography X-ray Imaging Systems

The purpose of this study was to assess the image quality of the low dose 2D/3D slot scanner (LDSS) imaging system compared to conventional digital radiography (DR) imaging systems. Visual image quality was assessed using the visual grading analysis (VGA) method. This method is a subjective approach that uses a human observer to evaluate and optimise radiographic images for different imaging technologies. Methods and materials: ten posterior-anterior (PA) and ten lateral (LAT) images of a chest anthropomorphic phantoms and a knee phantom were acquired by an LDSS imaging system and two conventional DR imaging systems. The images were shown in random order to three (chest) radiologists and three experienced (knee) radiographers, who scored the images against a number of criteria. Inter- and intraobserver agreement was assessed using Fleiss’ kappa and weighted kappa. Results: the statistical comparison of the agreement between the observers showed good interobserver agreement, with Fleiss’ kappa coefficients of 0.27–0.63 and 0.23–0.45 for the chest and knee protocols, respectively. Comparison of intraobserver agreement also showed good agreement with weighted kappa coefficients of 0.27–0.63 and 0.23–0.45 for the chest and knee protocols, respectively. The LDSS imaging system achieved significantly higher VGA image quality compared to the DR imaging systems in the AP and LAT chest protocols (p < 0.001). However, the LDSS imaging system achieved lower image quality than one DR system (p ≤ 0.016) and equivalent image quality to the other DR systems (p ≤ 0.27) in the knee protocol. The LDSS imaging system achieved effective dose savings of 33–52% for the chest protocol and 30–35% for the knee protocol compared with DR systems. Conclusions: this work has shown that the LDSS imaging system has the potential to acquire chest and knee images at diagnostic quality and at a lower effective dose than DR systems.

Intra- and Interobserver Variability in Magnetic Resonance Imaging Measurements in Rectal Cancer Patients

Colorectal cancer is the second most common cancer in Europe, and accurate lymph node staging in rectal cancer patients is essential for the selection of their treatment. MRI lymph node staging is complex, and few studies have been published regarding its reproducibility. This study assesses the inter- and intraobserver variability in lymph node size, apparent diffusion coefficient (ADC) measurements, and morphological characterization among inexperienced and experienced radiologists. Four radiologists with different levels of experience in MRI rectal cancer staging analyzed 36 MRI scans of 36 patients with rectal adenocarcinoma. Inter- and intraobserver variation was calculated using interclass correlation coefficients and Cohens-kappa statistics, respectively. Inter- and intraobserver agreement for the length and width measurements was good to excellent, and for that of ADC it was fair to good. Interobserver agreement for the assessment of irregular border was moderate, heterogeneous signal was fair, round shape was fair to moderate, and extramesorectal lymph node location was moderate to almost perfect. Intraobserver agreement for the assessment of irregular border was fair to substantial, heterogeneous signal was fair to moderate, round shape was fair to moderate, and extramesorectal lymph node location was substantial to almost perfect. Our data indicate that subjective variables such as morphological characteristics are less reproducible than numerical variables, regardless of the level of experience of the observers.