ABSTRACT
PURPOSE: To evaluate interobserver agreement in the interpretation of different MRI features of uterine leiomyomas (UL) according to observers' experience, and to assess the inter-method reproducibility (MRI versus surgery) regarding the International Federation of Gynecology and Obstetrics (FIGO) classification. METHODS: Retrospective study including UL patients who underwent MRI and surgical treatment. Four blinded observers (2 vs >10 years of experience) assessed UL regarding dimensions and volume; inner and outer mantles; FIGO classification; vascularization; degeneration; and diffusion-weighted imaging features. Uterine dimensions and volume were calculated. FIGO classification as ascertained by observers was compared to surgical findings. Intraclass correlation coefficient (ICC) estimates were used for interobserver comparison of numerical variables, and kappa statistic for categorical variables. RESULTS: Thirty-five patients (26y-73y) with 61 UL were included in the interobserver analyses, and 31 patients (54 UL) had available data allowing retrospective surgical FIGO classification for assessment of inter-method reproducibility. Both groups of observers had good to excellent agreement in assessing UL (ICC = 0.980-0.994) and uterine volumes (ICC = 0.857-0.914), mantles measurement (ICC = 0.797-0.920), and apparent diffusion coefficient calculation (ICC = 0.787-0.883). There was substantial agreement for both groups regarding FIGO classification (κ = 0.645-0.767). Vascularization, degeneration and restricted diffusion had lower agreement, varying from reasonable to moderate. Inter-method agreement was reasonable (κ = 0.341-0.395). CONCLUSIONS: Interobserver agreement of MRI for UL was higher for quantitative than qualitative features, with a little impact of observers' experience for most features. MRI agreement with surgery was reasonable. Further efforts should be taken to improve interobserver and inter-method reproducibility for MRI in this scenario.
Subject(s)
Leiomyoma , Magnetic Resonance Imaging , Female , Humans , Leiomyoma/diagnostic imaging , Leiomyoma/surgery , Magnetic Resonance Imaging/methods , Observer Variation , Pregnancy , Reproducibility of Results , Retrospective StudiesABSTRACT
OBJECTIVE: To evaluate the accuracy of steady-state free precession (SSFP) unenhanced magnetic resonance angiography (MRA) at 1.5 T for the identification of multiple renal arteries, using computed tomography angiography (CTA) as the reference standard. MATERIALS AND METHODS: This was a prospective study involving 39 patients (26 males; mean age, 62.6 years) who underwent CTA and unenhanced MRA to evaluate the proximal and middle segments of the renal arteries. The analysis was performed in two phases: the quality of unenhanced MRA images was classified as diagnostic or nondiagnostic for the presence of multiple renal arteries by two independent readers; two other independent readers then evaluated the images previously classified as being of diagnostic quality. The sensitivity, specificity, and overall accuracy of unenhanced MRA were calculated, CTA being used as the reference standard. The kappa statistic was used in order to calculate interobserver agreement. RESULTS: The image quality of unenhanced MRA was considered diagnostic in 70-90% of the extrarenal arterial segments. The CTA examination revealed 19 multiple renal arteries (8 on the right and 11 on the left). The accuracy of unenhanced MRA for the identification of multiple renal arteries was greater than 90%, with a sensitivity of 72.7-100% and a specificity of 96.3-100%. CONCLUSION: Unenhanced MRA provides high quality imaging of the extrarenal segments of renal arteries. This method may be used as an alternative for the evaluation of the renal arteries, given that it has an accuracy comparable to that of CTA.
OBJETIVO: Avaliar, prospectivamente, a acurácia da angiografia por ressonância magnética (angio-RM) sem contraste, com a sequência steady-state free precession (SSFP) 1,5 T, para a identificação de artérias renais múltiplas, usando para isso a angiografia por tomografia computadorizada (angio-TC) como padrão de referência. MATERIAIS E MÉTODOS: Trinta e nove pacientes (26 do sexo masculino; idade média de 62,6 anos) foram submetidos a angio-TC e angio-RM para avaliação dos segmentos proximais e médios das artérias renais. A análise dividiu-se em duas partes: inicialmente, a qualidade das imagens de angio-RM foi classificada como diagnóstica ou não diagnóstica por dois avaliadores independentes; posteriormente, outros dois avaliadores analisaram as imagens consideradas diagnósticas quanto à presença de múltiplas artérias renais. Sensibilidade, especificidade e acurácia da angio-RM foram calculadas utilizando-se a angio-TC como referência. Estatística kappa foi utilizada para cálculo da concordância interobservador. RESULTADOS: A qualidade das imagens de angio-RM foi considerada diagnóstica em 70-90% dos segmentos arteriais extrarrenais. A angio-TC revelou 19 artérias renais múltiplas (8 direitas e 11 esquerdas). A acurácia da angio-RM para identificação de artérias renais múltiplas foi maior que 90%, com sensibilidade variando de 72,7% a 100% e especificidade variando de 96,3% a 100%. CONCLUSÃO: A angio-RM sem contraste proporciona imagens de alta qualidade dos segmentos extrarrenais das artérias renais. Este método pode ser alternativamente utilizado para avaliação renal, com acurácia comparável à da angio-TC.
ABSTRACT
Abstract Objective: To evaluate the accuracy of steady-state free precession (SSFP) unenhanced magnetic resonance angiography (MRA) at 1.5 T for the identification of multiple renal arteries, using computed tomography angiography (CTA) as the reference standard. Materials and Methods: This was a prospective study involving 39 patients (26 males; mean age, 62.6 years) who underwent CTA and unenhanced MRA to evaluate the proximal and middle segments of the renal arteries. The analysis was performed in two phases: the quality of unenhanced MRA images was classified as diagnostic or nondiagnostic for the presence of multiple renal arteries by two independent readers; two other independent readers then evaluated the images previously classified as being of diagnostic quality. The sensitivity, specificity, and overall accuracy of unenhanced MRA were calculated, CTA being used as the reference standard. The kappa statistic was used in order to calculate interobserver agreement. Results: The image quality of unenhanced MRA was considered diagnostic in 70-90% of the extrarenal arterial segments. The CTA examination revealed 19 multiple renal arteries (8 on the right and 11 on the left). The accuracy of unenhanced MRA for the identification of multiple renal arteries was greater than 90%, with a sensitivity of 72.7-100% and a specificity of 96.3-100%. Conclusion: Unenhanced MRA provides high quality imaging of the extrarenal segments of renal arteries. This method may be used as an alternative for the evaluation of the renal arteries, given that it has an accuracy comparable to that of CTA.
Resumo Objetivo: Avaliar, prospectivamente, a acurácia da angiografia por ressonância magnética (angio-RM) sem contraste, com a sequência steady-state free precession (SSFP) 1,5 T, para a identificação de artérias renais múltiplas, usando para isso a angiografia por tomografia computadorizada (angio-TC) como padrão de referência. Materiais e Métodos: Trinta e nove pacientes (26 do sexo masculino; idade média de 62,6 anos) foram submetidos a angio-TC e angio-RM para avaliação dos segmentos proximais e médios das artérias renais. A análise dividiu-se em duas partes: inicialmente, a qualidade das imagens de angio-RM foi classificada como diagnóstica ou não diagnóstica por dois avaliadores independentes; posteriormente, outros dois avaliadores analisaram as imagens consideradas diagnósticas quanto à presença de múltiplas artérias renais. Sensibilidade, especificidade e acurácia da angio-RM foram calculadas utilizando-se a angio-TC como referência. Estatística kappa foi utilizada para cálculo da concordância interobservador. Resultados: A qualidade das imagens de angio-RM foi considerada diagnóstica em 70-90% dos segmentos arteriais extrarrenais. A angio-TC revelou 19 artérias renais múltiplas (8 direitas e 11 esquerdas). A acurácia da angio-RM para identificação de artérias renais múltiplas foi maior que 90%, com sensibilidade variando de 72,7% a 100% e especificidade variando de 96,3% a 100%. Conclusão: A angio-RM sem contraste proporciona imagens de alta qualidade dos segmentos extrarrenais das artérias renais. Este método pode ser alternativamente utilizado para avaliação renal, com acurácia comparável à da angio-TC.
ABSTRACT
OBJECTIVE: To assess the impact that examiner experience has on the reproducibility and accuracy of computed tomography (CT) enterography in the detection of radiological signs in patients with Crohn's disease. MATERIALS AND METHODS: This was a retrospective, cross-sectional observational study involving the analysis of CT enterography scans of 20 patients with Crohn's disease. The exams were analyzed independently by two radiologists in their last year of residence (duo I) and by two abdominal imaging specialists (duo II). The interobserver agreement of each pair of examiners in identifying the main radiological signs was calculated with the kappa test. The accuracy of the examiners with less experience was quantified by using the consensus among three experienced examiners as a reference. RESULTS: Duo I and duo II obtained a similar interobserver agreement, with a moderate to good correlation, for mural hyperenhancement, parietal thickening, mural stratification, fat densification, and comb sign (kappa: 0.45-0.64). The less experienced examiners showed an accuracy > 80% for all signs, except for lymph nodes and fistula, for which it ranged from 60% to 75%. CONCLUSION: Less experienced examiners have a tendency to present a level of interobserver agreement similar to that of experienced examiners in evaluating Crohn's disease through CT enterography, as well as showing satisfactory accuracy in identifying most radiological signs of the disease.
OBJETIVO: Avaliar o impacto da experiência do examinador na reprodutibilidade e na acurácia de detecção de sinais radiológicos em exames de enterografia por tomografia computadorizada (entero-TC) de pacientes portadores da doença de Crohn. MATERIAIS E MÉTODOS: Análise retrospectiva de exames de entero-TC de 20 pacientes com doença de Crohn. Os exames foram analisados, independentemente, por dois radiologistas do último ano de residência (dupla I) e dois especialistas em imagem abdominal (dupla II). A concordância interobservador de cada dupla de examinadores para a identificação dos principais sinais tomográficos foi calculada pelo teste kappa. A acurácia da dupla I foi medida usando-se como referência um consenso entre três examinadores experientes. RESULTADOS: Ambas as duplas obtiveram concordância interobservador semelhante e com correlação moderada a boa para os sinais de estratificação mural, espessamento da parede, realce mucoso, densificação da gordura e sinal do pente (kappa: 0,45-0,64). Os examinadores menos experientes apresentaram acurácia superior a 80% para os sinais, exceto para linfonodos e fístula (entre 60% e 75%). CONCLUSÃO: Examinadores menos experientes têm tendência a apresentar grau de concordância entre si semelhante à de examinadores experientes na avaliação dos principais sinais tomográficos da doença de Crohn, com acurácia considerada satisfatória, para a maioria dos sinais.
ABSTRACT
Abstract Objective: To assess the impact that examiner experience has on the reproducibility and accuracy of computed tomography (CT) enterography in the detection of radiological signs in patients with Crohn's disease. Materials and Methods: This was a retrospective, cross-sectional observational study involving the analysis of CT enterography scans of 20 patients with Crohn's disease. The exams were analyzed independently by two radiologists in their last year of residence (duo I) and by two abdominal imaging specialists (duo II). The interobserver agreement of each pair of examiners in identifying the main radiological signs was calculated with the kappa test. The accuracy of the examiners with less experience was quantified by using the consensus among three experienced examiners as a reference. Results: Duo I and duo II obtained a similar interobserver agreement, with a moderate to good correlation, for mural hyperenhancement, parietal thickening, mural stratification, fat densification, and comb sign (kappa: 0.45-0.64). The less experienced examiners showed an accuracy > 80% for all signs, except for lymph nodes and fistula, for which it ranged from 60% to 75%. Conclusion: Less experienced examiners have a tendency to present a level of interobserver agreement similar to that of experienced examiners in evaluating Crohn's disease through CT enterography, as well as showing satisfactory accuracy in identifying most radiological signs of the disease.
Resumo Objetivo: Avaliar o impacto da experiência do examinador na reprodutibilidade e na acurácia de detecção de sinais radiológicos em exames de enterografia por tomografia computadorizada (entero-TC) de pacientes portadores da doença de Crohn. Materiais e Métodos: Análise retrospectiva de exames de entero-TC de 20 pacientes com doença de Crohn. Os exames foram analisados, independentemente, por dois radiologistas do último ano de residência (dupla I) e dois especialistas em imagem abdominal (dupla II). A concordância interobservador de cada dupla de examinadores para a identificação dos principais sinais tomográficos foi calculada pelo teste kappa. A acurácia da dupla I foi medida usando-se como referência um consenso entre três examinadores experientes. Resultados: Ambas as duplas obtiveram concordância interobservador semelhante e com correlação moderada a boa para os sinais de estratificação mural, espessamento da parede, realce mucoso, densificação da gordura e sinal do pente (kappa: 0,45-0,64). Os examinadores menos experientes apresentaram acurácia superior a 80% para os sinais, exceto para linfonodos e fístula (entre 60% e 75%). Conclusão: Examinadores menos experientes têm tendência a apresentar grau de concordância entre si semelhante à de examinadores experientes na avaliação dos principais sinais tomográficos da doença de Crohn, com acurácia considerada satisfatória, para a maioria dos sinais.