ABSTRACT
Placenta accreta spectrum disorders are characterized by abnormal adhesion of the placenta that can be subdivided into three categories according to degree of invasion: placenta accreta (passing through the decidua basalis and adhering to the myometrium); placenta increta (penetrating the myometrium); and placenta percreta (invading the uterine serosa or adjacent tissues or organs). The incidence of placenta accreta has increased significantly in recent decades, mainly because of an increase in the rates of cesarean section, which is its main risk factor. Accurate prenatal identification makes it possible to institute the ideal treatment with a multidisciplinary team, significantly minimizing maternal morbidity and mortality. The examinations of choice are ultrasound and magnetic resonance imaging (MRI). When the ultrasound evaluation is inconclusive, as well as when the patient has risk factors for the condition or the placenta is in a posterior location, MRI is indicated. In cases of placental invasion of the adjacent pelvic organs, MRI is also preferable because it provides a broader field of view, which improves surgical planning. Numerous features of placenta accreta spectrum disorders are discernible on MRI, including dark intraplacental bands, uterine bulging, and heterogeneous placenta. Knowledge of these findings and the combination of two or more of them increase confidence in the diagnosis.
Acretismo placentário é uma condição caracterizada pela implantação anormal da placenta, que pode ser subdividida em três espectros de acordo com o seu grau de invasão: placenta acreta (ultrapassa a decídua basal e adere ao miométrio), placenta increta (penetra o miométrio) e placenta percreta (invasão da serosa uterina ou de tecidos/órgãos adjacentes). A incidência de acretismo placentário aumentou significativamente nas últimas décadas, principalmente em função da elevação das taxas de cesarianas, sendo este o seu principal fator de risco. A sua identificação pré-natal precisa permite um tratamento ideal com equipe multidisciplinar, minimizando significativamente a morbimortalidade materna. Os exames de escolha são a ultrassonografia e a ressonância magnética (RM), sendo a RM um método complementar indicado quando a avaliação ultrassonográfica é duvidosa, para pacientes com fatores de risco para acretismo placentário ou quando a placenta tem localização posterior. A RM é preferível também para avaliar invasão de órgãos adjacentes, oferecendo um campo de visão mais amplo, o que melhora o planejamento cirúrgico. Diversas características na RM são descritas no acretismo placentário, incluindo bandas hipointensas em T2 intraplacentárias, protuberância uterina anormal e heterogeneidade placentária. O conhecimento desses achados e a combinação de mais de um critério aumentam a confiabilidade do diagnóstico.
ABSTRACT
Resumo Acretismo placentário é uma condição caracterizada pela implantação anormal da placenta, que pode ser subdividida em três espectros de acordo com o seu grau de invasão: placenta acreta (ultrapassa a decídua basal e adere ao miométrio), placenta increta (penetra o miométrio) e placenta percreta (invasão da serosa uterina ou de tecidos/órgãos adjacentes). A incidência de acretismo placentário aumentou significativamente nas últimas décadas, principalmente em função da elevação das taxas de cesarianas, sendo este o seu principal fator de risco. A sua identificação pré-natal precisa permite um tratamento ideal com equipe multidisciplinar, minimizando significativamente a morbimortalidade materna. Os exames de escolha são a ultrassonografia e a ressonância magnética (RM), sendo a RM um método complementar indicado quando a avaliação ultrassonográfica é duvidosa, para pacientes com fatores de risco para acretismo placentário ou quando a placenta tem localização posterior. A RM é preferível também para avaliar invasão de órgãos adjacentes, oferecendo um campo de visão mais amplo, o que melhora o planejamento cirúrgico. Diversas características na RM são descritas no acretismo placentário, incluindo bandas hipointensas em T2 intraplacentárias, protuberância uterina anormal e heterogeneidade placentária. O conhecimento desses achados e a combinação de mais de um critério aumentam a confiabilidade do diagnóstico.
Abstract Placenta accreta spectrum disorders are characterized by abnormal adhesion of the placenta that can be subdivided into three categories according to degree of invasion: placenta accreta (passing through the decidua basalis and adhering to the myometrium); placenta increta (penetrating the myometrium); and placenta percreta (invading the uterine serosa or adjacent tissues or organs). The incidence of placenta accreta has increased significantly in recent decades, mainly because of an increase in the rates of cesarean section, which is its main risk factor. Accurate prenatal identification makes it possible to institute the ideal treatment with a multidisciplinary team, significantly minimizing maternal morbidity and mortality. The examinations of choice are ultrasound and magnetic resonance imaging (MRI). When the ultrasound evaluation is inconclusive, as well as when the patient has risk factors for the condition or the placenta is in a posterior location, MRI is indicated. In cases of placental invasion of the adjacent pelvic organs, MRI is also preferable because it provides a broader field of view, which improves surgical planning. Numerous features of placenta accreta spectrum disorders are discernible on MRI, including dark intraplacental bands, uterine bulging, and heterogeneous placenta. Knowledge of these findings and the combination of two or more of them increase confidence in the diagnosis.
ABSTRACT
Objective: To assess interobserver agreement among radiologists regarding the current Fleischner Society diagnostic criteria for usual interstitial pneumonia (UIP) patterns on computed tomography (CT). Materials and Methods: Using the Fleischner Society criteria for UIP CT patterns, five raters, working independently, categorized the high-resolution CT (HRCT) scans of 44 patients with interstitial lung disease who underwent lung biopsy. The raters also evaluated the presence, extent, and distribution of the most relevant imaging findings, as well as indicating their level of confidence in the most likely diagnosis and in up to three diagnostic hypotheses. Results: There was moderate to substantial interobserver agreement regarding the UIP patterns on HRCT-kappa statistic (κ) = 0.59-0.61. Interobserver agreement for the binary scores was substantial (κ = 0.77-0.79), whereas that for the presence of honeycombing was almost perfect (κ = 0.81-0.96). There was agreement regarding at least one of the three diagnostic hypotheses in only 36.4% of the cases. For the level of confidence in the most likely diagnosis, there was only slight to fair agreement (κ = 0.19-0.21). Conclusion: Interobserver agreement regarding the current Fleischner Society CT criteria for UIP was moderate to substantial among raters with varying levels of experience. There was only slight to fair agreement regarding the diagnostic hypotheses and for the level of confidence in the most likely diagnosis.
Objetivo: Avaliar a concordância interobservador entre radiologistas para os critérios atuais da Fleischner Society para categorias diagnósticas de pneumonia intersticial usual (PIU) em tomografia computadorizada (TC). Materiais e Métodos: Cinco observadores categorizaram independentemente as imagens de TC de 44 pacientes com doença pulmonar intersticial que foram submetidos a biópsia pulmonar empregando as últimas categorias de diagnóstico da Sociedade Fleischner para UIP. Também foram avaliadas presença, extensão e distribuição dos achados de imagem mais relevantes, bem como a confiança no diagnóstico mais provável e em até três hipóteses diagnósticas. Resultados: Houve concordância moderada a alta para as categorias diagnósticas entre os observadores (κ = 0,59-0,61). A concordância interobservador para a pontuação binária foi alta (κ = 0,77-0,79), enquanto para a presença de faveolamento foi considerada de alta a muito alta (κ = 0,81-0,96). Houve concordância em uma das três hipóteses diagnósticas em apenas 36,4% dos casos. Baixa concordância foi encontrada para o diagnóstico mais provável (κ = 0,19-0,21). Conclusão: A concordância entre observadores para os critérios atuais de TC da Fleischner Society para UIP foi moderada a alta entre observadores com diferentes níveis de experiência. Houve baixa concordância nas hipóteses diagnósticas e quanto ao grau de confiança no diagnóstico primário.
ABSTRACT
Abstract Objective: To assess interobserver agreement among radiologists regarding the current Fleischner Society diagnostic criteria for usual interstitial pneumonia (UIP) patterns on computed tomography (CT). Materials and Methods: Using the Fleischner Society criteria for UIP CT patterns, five raters, working independently, categorized the high-resolution CT (HRCT) scans of 44 patients with interstitial lung disease who underwent lung biopsy. The raters also evaluated the presence, extent, and distribution of the most relevant imaging findings, as well as indicating their level of confidence in the most likely diagnosis and in up to three diagnostic hypotheses. Results: There was moderate to substantial interobserver agreement regarding the UIP patterns on HRCT—kappa statistic (κ) = 0.59-0.61. Interobserver agreement for the binary scores was substantial (κ = 0.77-0.79), whereas that for the presence of honeycombing was almost perfect (κ = 0.81-0.96). There was agreement regarding at least one of the three diagnostic hypotheses in only 36.4% of the cases. For the level of confidence in the most likely diagnosis, there was only slight to fair agreement (κ = 0.19-0.21). Conclusion: Interobserver agreement regarding the current Fleischner Society CT criteria for UIP was moderate to substantial among raters with varying levels of experience. There was only slight to fair agreement regarding the diagnostic hypotheses and for the level of confidence in the most likely diagnosis.
Resumo Objetivo: Avaliar a concordância interobservador entre radiologistas para os critérios atuais da Fleischner Society para categorias diagnósticas de pneumonia intersticial usual (PIU) em tomografia computadorizada (TC). Materiais e Métodos: Cinco observadores categorizaram independentemente as imagens de TC de 44 pacientes com doença pulmonar intersticial que foram submetidos a biópsia pulmonar empregando as últimas categorias de diagnóstico da Sociedade Fleischner para UIP. Também foram avaliadas presença, extensão e distribuição dos achados de imagem mais relevantes, bem como a confiança no diagnóstico mais provável e em até três hipóteses diagnósticas. Resultados: Houve concordância moderada a alta para as categorias diagnósticas entre os observadores (κ = 0,59-0,61). A concordância interobservador para a pontuação binária foi alta (κ = 0,77-0,79), enquanto para a presença de faveolamento foi considerada de alta a muito alta (κ = 0,81-0,96). Houve concordância em uma das três hipóteses diagnósticas em apenas 36,4% dos casos. Baixa concordância foi encontrada para o diagnóstico mais provável (κ = 0,19-0,21). Conclusão: A concordância entre observadores para os critérios atuais de TC da Fleischner Society para UIP foi moderada a alta entre observadores com diferentes níveis de experiência. Houve baixa concordância nas hipóteses diagnósticas e quanto ao grau de confiança no diagnóstico primário.
ABSTRACT
OBJECTIVES: There have been no investigations on the association between previous abdominopelvic MRI experience without placental MRI experience and diagnostic accuracy of placenta accreta spectrum (PAS). To evaluate the diagnostic performance of radiologists with different experience levels in interpreting PAS-related MRI findings. METHODS: This retrospective study included 60 women who underwent MRI for placental assessment between 2016 and 2020. MR images were reviewed by four radiologists who were blinded to the clinical outcomes and had different experience levels in interpreting PAS-related MRI findings. The radiologists' diagnostic performance was evaluated according to the pathologic and surgical outcomes. Simple κ statistics were calculated to determine agreement among the radiologists. RESULTS: Of 60 women, 46 were diagnosed with PAS. The maternal age mean ± SD was 33.0 years ± 5.0 for the PAS absent group and 36.0 ± 4.3 for the PAS present group (p = 0.013). Overall, the most experienced radiologist had the highest sensitivity (100%, 95% confidence interval (CI): 92.3-100%) and NPV (100%, 95% CI: 63.1-100%) in PAS diagnoses. However, the PPV and specificity were independent of experience. The most experienced radiologist had the highest diagnostic accuracy in PAS (90%, 95% CI: 79.5-96.2%) and placenta percreta (95%, 95% CI: 86.1-99.0%). There was a strong association between definitive PAS diagnoses and the highest experience level. The κ values for the interobserver agreement regarding PAS diagnoses were 0.67 for the most experienced radiologist (p < 0.001) and 0.38, 0.40, and 0.43 for the other radiologists (p = 0.001) and regarding placenta percreta diagnoses were 0.87 for the senior radiologist (p < 0.001) and 0.63, 0.57, and 0.62 for the other radiologists (p < 0.001). CONCLUSION: Previous experience in interpreting PAS-related MRI findings plays a significant role in accurately interpreting such imaging findings. Previous abdominopelvic MRI experience without specific placental MRI experience did not improve diagnostic performance. ADVANCES IN KNOWLEDGE: We believe that our study makes a significant contribution to the literature and that this paper will be of interest to the readership of your journal because to the best of our knowledge, this study is the first in which the correlation between previous experience in abdominopelvic MRI with no specific experience in PAS-related MRI and diagnostic accuracy of radiologists has been explored. Our results could aid in setting up specialized multidisciplinary teams to assist women with PAS disorders.
