scholarly journals Lateral Trochlear Inclination Angle: Measurement via a 2-Image Technique to Reliably Characterize and Quantify Trochlear Dysplasia

2020 ◽  
Vol 8 (10) ◽  
pp. 232596712095841
Author(s):  
Sheeba M. Joseph ◽  
Chris Cheng ◽  
Matthew J. Solomito ◽  
J. Lee Pace
Keyword(s):  
Measurement Technique ◽  
Trochlear Dysplasia ◽  
Intraclass Correlation ◽  
Single Image ◽  
Image Measurement ◽  
Mri Scan ◽  
Morphologic Characteristics ◽  
Mri Scans ◽  
Image Technique ◽  
Dejour Classification

Background: Trochlear dysplasia (TD) is a risk factor for patellar instability (PI). The Dejour classification categorizes TD but has suboptimal reliability. Lateral trochlear inclination (LTI) is a quantitative measurement of trochlear dysplasia on a single axial magnetic resonance imaging (MRI) scan. Hypothesis: A modified LTI measurement technique using 2 different axial MRI scans that reference the most proximal aspect of the trochlear cartilage on 1 image and the fully formed posterior condyles on the second image would be as reliable as and significantly different from the single-image measurement technique for LTI. Further, the 2-image LTI would adequately represent overall proximal trochlear morphologic characteristics. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Patients aged 9 to 18 years treated for PI between 2014 and 2017 were identified. The Dejour classification was radiographically determined. Single-image LTI was measured on a single axial MRI scan at the most proximal aspect of visible trochlear cartilage. A 2-image LTI was measured from 2 separate MRI scans: 1 at the most proximal aspect of trochlear cartilage and the second at the fully formed posterior condyles. This 2-image LTI was repeated at 3 subsequent levels (the first measurement is referred to as LTI-1; repeated measurements are LTI-2, LTI-3, and LTI-4, moving distally). In total, 65 patients met the inclusion criteria, and 30 were randomly selected for reliability analysis. Results: Inter- and intrarater reliability trended toward more variability for single-image LTI (intraclass correlation coefficient [ICC], 0.86 and 0.88, respectively) than for 2-image LTI (ICC, 0.97 and 0.96, respectively). The Dejour classification had lower intra- and interrater reliability (ICC, 0.31 and 0.73, respectively). Average single-image LTI (9.2° ± 12.6°) was greater than average 2-image LTI-1 (4.2° SD ± 11.9°) ( P = .0125). Single-image LTI classified 60% of patients with PI as having TD, whereas the 2-image LTI classified 71% as having TD. The 2-image LTI was able to capture 91% of overall proximal trochlear morphologic characteristics. Conclusion: LTI has higher reliability when performed using a 2-image measurement technique compared with single-image LTI and Dejour classification. The strong correlation between 2-image LTI and average LTI shows that 91% of TD is represented on the most proximal axial image. Because the single-image measurement appears to underestimate dysplasia, previously described thresholds should be reexamined using this 2-image technique to appropriately characterize TD.

scholarly journals Reliability of the Oswestry-Bristol Classification for trochlear dysplasia

2020 ◽  
Vol 1 (7) ◽  
pp. 355-358
Author(s):  
Christian Konrads ◽  
Christoph Gonser ◽  
Sufian S. Ahmad
Keyword(s):  
Classification System ◽  
Trochlear Dysplasia ◽  
Kappa Statistic ◽  
Daily Practice ◽  
Intraobserver Reliability ◽  
Grading System ◽  
Intraobserver Agreement ◽  
Mri Scans ◽  
Classification Tool ◽  
Dejour Classification

Aims The Oswestry-Bristol Classification (OBC) was recently described as an MRI-based classification tool for the femoral trochlear. The authors demonstrated better inter- and intraobserver agreement compared to the Dejour classification. As the OBC could potentially provide a very useful MRI-based grading system for trochlear dysplasia, it was the aim to determine the inter- and intraobserver reliability of the classification system from the perspective of the non-founder. Methods Two orthopaedic surgeons independently assessed 50 MRI scans for trochlear dysplasia and classified each according to the OBC. Both observers repeated the assessments after six weeks. The inter- and intraobserver agreement was determined using Cohen’s kappa statistic and S-statistic nominal and linear weights. Results The OBC with grading into four different trochlear forms showed excellent inter- and intraobserver agreement with a mean kappa of 0.78. Conclusion The OBC is a simple MRI-based classification system with high inter- and intraobserver reliability. It could present a useful tool for grading the severity of trochlear dysplasia in daily practice. Cite this article: Bone Joint Open 2020;1-7:355–358.

Lateral Patellar Inclination Angle Measured via a Two-Image Technique on Axial Magnetic Resonance Imaging

2021 ◽  
Author(s):  
James Lee Pace ◽  
Sheeba M. Joseph ◽  
Christopher Cheng ◽  
Matthew J. Solomito
Keyword(s):  
Magnetic Resonance ◽  
Intraclass Correlation ◽  
Threshold Values ◽  
Single Image ◽  
Patellar Tilt ◽  
Rater Reliability ◽  
X Ray ◽  
Image Technique ◽  
The One ◽  
Maximum Threshold

AbstractLateral patellar inclination (LPI) measures patellar tilt and is historically described on axial X-ray or a single magnetic resonance image (MRI). Given the variability in patellar height, LPI may be better represented by performing this measurement on two separate axial MRI images. We hypothesized that a two-image LPI measurement would be different from the current single-image LPI and have similar, if not superior reliability. Sixty-five patients treated for patellar instability (PI) between 2014 and 2017 were identified. Single image and two-image LPI were measured on axial MRI images. All measurements were performed by two independent observers. Reliability analysis was based on three observers' measurements of 30 randomly selected patients. Both the one image and two image LPI showed good inter-rater reliability (intraclass correlation coefficient [ICC] = 0.71 and 0.89, respectively), although the two image LPI had less variability. Both single image and two image LPI had near perfect intra-rater reliability (ICC = 0.98 and 0.98, respectively). Average single image LPI (14.6 ± 9.9 degrees) was 6.1 ± 3.4 degrees less than the average two image LPI (19.6 ± 9.4 degrees) (p = 0.037). Referencing a previously described 13.5 degrees maximum threshold, 54% of the patients had excessive patellar tilt based on single image LPI, while 73% had pathologic patellar tilt based on two image LPI. Two image LPI has similar reliability with less inter-rater variability compared with the historical single image LPI measurement. Significantly greater patellar tilt was identified with two image LPI that was found with single image LPI. A larger percentage of patients were classified as having pathologic patellar tilt based on two image LPI than single image LPI. The two image LPI provides more consistent and representative measurements of patellar tilt. Previously described threshold values for patellar tilt should be re-examined using this new measurement technique to appropriately risk stratify patients with PI and patellofemoral pain.

scholarly journals Reliability of the Oswestry-Bristol Classification for trochlear dysplasia

2020 ◽  
Vol 1 (7) ◽  
pp. 355-358
Author(s):  
Christian Konrads ◽  
Christoph Gonser ◽  
Sufian S. Ahmad
Keyword(s):  
Classification System ◽  
Trochlear Dysplasia ◽  
Kappa Statistic ◽  
Daily Practice ◽  
Intraobserver Reliability ◽  
Grading System ◽  
Intraobserver Agreement ◽  
Mri Scans ◽  
Classification Tool ◽  
Dejour Classification

Aims The Oswestry-Bristol Classification (OBC) was recently described as an MRI-based classification tool for the femoral trochlear. The authors demonstrated better inter- and intraobserver agreement compared to the Dejour classification. As the OBC could potentially provide a very useful MRI-based grading system for trochlear dysplasia, it was the aim to determine the inter- and intraobserver reliability of the classification system from the perspective of the non-founder. Methods Two orthopaedic surgeons independently assessed 50 MRI scans for trochlear dysplasia and classified each according to the OBC. Both observers repeated the assessments after six weeks. The inter- and intraobserver agreement was determined using Cohen’s kappa statistic and S-statistic nominal and linear weights. Results The OBC with grading into four different trochlear forms showed excellent inter- and intraobserver agreement with a mean kappa of 0.78. Conclusion The OBC is a simple MRI-based classification system with high inter- and intraobserver reliability. It could present a useful tool for grading the severity of trochlear dysplasia in daily practice. Cite this article: Bone Joint Open 2020;1-7:355–358.

Evaluation of volatile behaviour and the volatilization volume of molten salt in DIR-MCFC by using the image measurement technique

2005 ◽  
Vol 145 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Kimihiko Sugiura ◽  
Makoto Yamauchi ◽  
Kazumi Tanimoto ◽  
Yasumasa Yoshitani
Keyword(s):  
Molten Salt ◽  
Measurement Technique ◽  
Image Measurement

Image measurement technique on vibration amplitude of ultrasonic horn

2013 ◽  
Author(s):  
Yong-bin Zhang ◽  
Zhi-qun Wu ◽  
Jian-ping Zhu ◽  
Jian-guo He ◽  
Guang-min Liu
Keyword(s):  
Measurement Technique ◽  
Vibration Amplitude ◽  
Image Measurement

Classification of dysplasia of the femoral trochlea in patients with patellar instability depends on the evaluation plane

2019 ◽  
Vol 4 (6) ◽  
pp. 290-295
Author(s):  
Yuzo Yamada ◽  
Yukiyoshi Toritsuka ◽  
Shuji Horibe ◽  
Norimasa Nakamura ◽  
Kazuomi Sugamoto ◽  
...  
Keyword(s):  
Patellar Instability ◽  
Articular Surface ◽  
Trochlear Dysplasia ◽  
Three Dimensional ◽  
Reference Plane ◽  
Transepicondylar Axis ◽  
Predisposing Factor ◽  
Femoral Trochlea ◽  
Dejour Classification ◽  
Axial View

ObjectiveTrochlear dysplasia is a major predisposing factor of patellar instability (PI). Dysplasia types are generally evaluated using the Dejour classification, but it is unclear whether this classification covers the entire spectrum. The objective of this study was to confirm whether the trochlear types on an axial view categorised according to the classification represent the entire trochlear shape.MethodsNinety knees from 81 patients with PI and 15 knees from 10 healthy volunteers (HVs) were evaluated. Three-dimensional knee models were created by MRIs. The femoral trochlear planes (FTPs) were defined as virtual cross sections including the transepicondylar axis, closer to the perpendicular plane of the articular surface. FTP 0 was defined as the reference plane including the proximal edge of the femoral trochlea and FTP θ as the plane making optional angle θ to FTP 0. Trochlear dysplasia types according to the classification were evaluated at every 10 degrees of FTPs up to 60 degrees (FTP 10, 20, 30, 40, 50 and 60). A trochlea with a sulcus angle <145° was defined as normal. Changes in the trochlear type according to FTPs, and agreement with clinical classification were evaluated.ResultsEighty-six knees (96%) in patients with PI and 12 (80%) in HVs showed changing trochlear types in different FTPs. Patterns of change varied among patients with PI and HVs. This suggests morphological variation of dysplastic trochleae. Agreement of trochlear type on each FTP with the clinically used Dejour classification was 42% on FTP 10, 49% on FTP 20, 33% on FTP 30, 22% on FTP 40, 22% on FTP 50% and 22% on FTP 60 in patients with PI, and 20% at FTP 10, 80% at FTP 20 and 100% on FTP 30 through FTP 60 in HVs. This suggests that the trochlear types in the clinically used plane do not always match the ones on the planes describing the contact surface to the patella.ConclusionThe trochlear types on an axial view provided by the Dejour classification do not represent the entire trochlear geometry. Multiple axial planes should be clinically used to more precisely describe the entire trochlear shape.

scholarly journals The Evaluation of Trochlear Osseous Morphology: An Epidemiologic Study

2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0044
Author(s):  
Sercan Yalçin ◽  
Gabriel Onor ◽  
Scott Kaar ◽  
lee Pace ◽  
Paolo Ferrua ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Normal Population ◽  
Trochlear Dysplasia ◽  
Interobserver Reliability ◽  
Intraclass Correlation ◽  
Epidemiologic Study ◽  
Intraobserver Reliability ◽  
Severe Dysplasia ◽  
Mild Dysplasia ◽  
Study Population

Objectives: The purpose of this study is to investigate the prevalence of the trochlear dysplasia in our study population. Methods: We obtained 692 skeletally mature femoral specimens from the [Blinded Institution], [Blinded Collection]. Five observers were asked to evaluate each specimen for trochlear dysplasia on a scale between 0 and 3 (0 – normal/no dysplasia; 1 – mild dysplasia; 2 – moderate dysplasia; 3 – severe dysplasia). Each observer made initial evaluations for interobserver reliability. Each observer then re-evaluated each specimen one month later to determine intraobserver reliability. We evaluated inter and intraobserver reliability utilizing intraclass correlation coefficient (ICC). All statistics were performed with SPSS v.25 (IBM, USA). Results: The interobserver ICC of first and second evaluation of all observers were found to be 0.906 [0.894-0,916] and 0.904 [0.892-0.915], respectively. The intraobserver ICC of observers were as follows: Reviewer1: 0.799 [0.771-0.825]; Reviewer2: 0.686 [0.645-0.724]; Reviewer3: 0.808 [0.781-0.832]; Reviewer4: 0.787 [0.757-0.814]; Reviewer5: 0.778 [0.747-0.806]. These results show intra and interobserver correlation was good to excellent. The percentages of normal trochlea, mild dysplasia, moderate dysplasia and severe dysplasia for first evaluation, by reviewer, are as follows: Reviewer 1: 82.7%, 12.1%, 4.0%, 1.2%; Reviewer 2: 37.3%, 26.2%, 27.5%, 9.1%; Reviewer 3: 57.9%, 28.0%, 12.1%, 1.9%; Reviewer 4: 64.2%, 25.6%, 7.7%, 2.6%; Reviewer 5: 65.6%, 14.9%, 12.3%, 7.2%. The percentages of normal trochlea, mild dysplasia, moderate dysplasia and severe dysplasia for second evaluation, by reviewer, are as follows: Reviewer 1: 78.8%, 16.6%, 3.6%, 1.0%; Reviewer 2: 40.3%, 26.4%, 23.3%, 10.0%; Reviewer 3: 42.2%,35.1%, 18.8%, 3.9%; Reviewer 4: 57.4%, 31.9%, 8.2%, 2.5%; Reviewer 5: 73.7%, 8.2%, 9.7%, 8.4%. In total, the percentages of normal trochlea, mild dysplasia, moderate dysplasia and severe dysplasia were 60.00%, 22.51%, 12.72%, 4.77%; respectively. Conclusions: This study shows that although there was no absolute criteria to grade trochlear dysplasia, observers had similar opinions on the degree of dysplasia. Also, our cohort shows that moderate to severe dysplasia is not uncommon as it is present in around 17% of knees in our cohort. This is the first epidemiologic study evaluating the prevalence of trochlear dysplasia in the normal population.

scholarly journals Idiopathic Normal Pressure Hydrocephalus: Cerebral Perfusion Measured with pCASL before and Repeatedly after CSF Removal

2014 ◽  
Vol 34 (11) ◽  
pp. 1771-1778 ◽  
Author(s):  
Johan Virhammar ◽  
Katarina Laurell ◽  
André Ahlgren ◽  
Kristina Giuliana Cesarini ◽  
Elna-Marie Larsson
Keyword(s):  
White Matter ◽  
Normal Pressure Hydrocephalus ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Regional Variability ◽  
Mri Scans ◽  
Magnetic Resonance Imaging Mri ◽  
Gait Function

Pseudo-continuous arterial spin labeling (pCASL) measurements were performed in 20 patients with idiopathic normal pressure hydrocephalus (iNPH) to investigate whether cerebral blood flow (CBF) increases during the first 24 hours after a cerebrospinal fluid tap test (CSF TT). Five pCASL magnetic resonance imaging (MRI) scans were performed. Two scans were performed before removal of 40 mL CSF, and the other three at 30 minutes, 4 hours, and 24 hours, respectively after the CSF TT. Thirteen different regions of interest (ROIs) were manually drawn on coregistered MR images. In patients with increased CBF in lateral and frontal white matter after the CSF TT, gait function improved more than it did in patients with decreased CBF in these regions. However, in the whole sample, there was no significant increase in CBF after CSF removal compared with baseline investigations. The repeatability of CBF measurements at baseline was high, with intraclass correlation coefficients of 0.60 to 0.90 for different ROIs, but the median regional variability was in the range of 5% to 17%. Our results indicate that CBF in white matter close to the lateral ventricles plays a role in the reversibility of symptoms after CSF removal in patients with iNPH.

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