Helito Paulo Victor Partezani, Rocha Stephano Raydan Ramalho, Ortiz Rafael Trevisan, Cerri Giovanni Guido, Leite Claudia da Costa, Rodrigues Marcelo Bordalo
Hospital Sírio-Libanês, São Paulo, SP, Brazil.
Instituto de Ortopedia e Traumatologia da Faculdade de Medicina da Universidade de São Paulo (IOT-FMUSP), São Paulo, SP, Brazil.
Radiol Bras. 2020 Mar-Apr;53(2):81-85. doi: 10.1590/0100-3984.2019.0054.
To assess the accuracy of magnetic resonance imaging (MRI) for the diagnosis of hallux valgus using radiography during weight bearing as the gold standard.
This was a retrospective analysis of all patients undergoing MRI of the foot and radiography of the foot during weight bearing at our institution between January and June of 2015. The hallux valgus angle (HVA) was measured on MRI and radiography. The Wilcoxon signed-rank test and simple linear regression were used in order to compare measurements. Patients were divided into two groups according to the HVA determined on radiography: > 15° (hallux valgus) and ≤ 15° (control). Qualitative and quantitative assessments of MRI scans were performed. For quantitative assessment, receiver operating characteristic curves were used in order to determine the HVA cutoff with the highest accuracy.
A total of 66 MRI scans were included, 22 in the hallux valgus group and 44 in the control group. Wilcoxon signed-rank tests indicated a significant difference between the radiography and MRI measurements. Simple linear regression showed a nonlinear relationship between the measurements and values did not present a strong correlation. In comparison with the radiography measurements, MRI with an HVA cutoff of 16.4° exhibited the highest accuracy (86%). The accuracy of the subjective (qualitative) assessment was inferior to the objective assessment (measurement of the HVA).
Hallux valgus can be diagnosed by measuring the HVA on MRI, satisfactory accuracy being achieved with an HVA cutoff of 16.4°.
以负重位X线摄影作为金标准，评估磁共振成像（MRI）诊断拇外翻的准确性。
这是一项对2015年1月至6月期间在本机构接受足部MRI检查及负重位足部X线摄影检查的所有患者的回顾性分析。在MRI和X线摄影上测量拇外翻角（HVA）。采用Wilcoxon符号秩检验和简单线性回归来比较测量结果。根据X线摄影确定的HVA将患者分为两组：>15°（拇外翻组）和≤15°（对照组）。对MRI扫描进行定性和定量评估。对于定量评估，使用受试者工作特征曲线来确定具有最高准确性的HVA临界值。
共纳入66例MRI扫描，拇外翻组22例，对照组44例。Wilcoxon符号秩检验表明X线摄影和MRI测量结果之间存在显著差异。简单线性回归显示测量值之间呈非线性关系，且相关性不强。与X线摄影测量相比，HVA临界值为16.4°的MRI表现出最高的准确性（86%）。主观（定性）评估的准确性低于客观评估（HVA测量）。
通过在MRI上测量HVA可诊断拇外翻，HVA临界值为16.4°时可获得满意的准确性。
