RESUMEN
CONTEXT AND OBJECTIVE: Recent studies have shown noncontrast computed tomography (NCT) to be more effective than ultrasound (US) for imaging acute ureterolithiasis. However, to our knowledge, there are few studies directly comparing these techniques in an emergency teaching hospital setting. The objectives of this study were to compare the diagnostic accuracy of US and NCT performed by senior radiology residents for diagnosing acute ureterolithiasis; and to assess interobserver agreement on tomography interpretations by residents and experienced abdominal radiologists. DESIGN AND SETTING: Prospective study of 52 consecutive patients, who underwent both US and NCT within an interval of eight hours, at Hospital São Paulo. METHODS: US scans were performed by senior residents and read by experienced radiologists. NCT scan images were read by senior residents, and subsequently by three abdominal radiologists. The interobserver variability was assessed using the kappa statistic. RESULTS: Ureteral calculi were found in 40 out of 52 patients (77%). US presented sensitivity of 22% and specificity of 100%. When collecting system dilatation was associated, US demonstrated 73% sensitivity, 82% specificity. The interobserver agreement in NCT analysis was very high with regard to identification of calculi, collecting system dilatation and stranding of perinephric fat. CONCLUSIONS: US has limited value for identifying ureteral calculi in comparison with NCT, even when collecting system dilatation is present. Residents and abdominal radiologists demonstrated excellent agreement rates for ureteral calculi, identification of collecting system dilatation and stranding of perinephric fat on NCT.
Asunto(s)
Tomografía Computarizada Espiral/normas , Cálculos Ureterales/diagnóstico por imagen , Enfermedad Aguda , Métodos Epidemiológicos , Hospitales de Enseñanza , Humanos , Internado y Residencia , Variaciones Dependientes del Observador , Competencia Profesional , Radiografía Abdominal , Radiología , UltrasonografíaRESUMEN
CONTEXT AND OBJECTIVE: Recent studies have shown noncontrast computed tomography (NCT) to be more effective than ultrasound (US) for imaging acute ureterolithiasis. However, to our knowledge, there are few studies directly comparing these techniques in an emergency teaching hospital setting. The objectives of this study were to compare the diagnostic accuracy of US and NCT performed by senior radiology residents for diagnosing acute ureterolithiasis; and to assess interobserver agreement on tomography interpretations by residents and experienced abdominal radiologists. DESIGN AND SETTING: Prospective study of 52 consecutive patients, who underwent both US and NCT within an interval of eight hours, at Hospital São Paulo. METHODS: US scans were performed by senior residents and read by experienced radiologists. NCT scan images were read by senior residents, and subsequently by three abdominal radiologists. The interobserver variability was assessed using the kappa statistic. RESULTS: Ureteral calculi were found in 40 out of 52 patients (77 percent). US presented sensitivity of 22 percent and specificity of 100 percent. When collecting system dilatation was associated, US demonstrated 73 percent sensitivity, 82 percent specificity. The interobserver agreement in NCT analysis was very high with regard to identification of calculi, collecting system dilatation and stranding of perinephric fat. CONCLUSIONS: US has limited value for identifying ureteral calculi in comparison with NCT, even when collecting system dilatation is present. Residents and abdominal radiologists demonstrated excellent agreement rates for ureteral calculi, identification of collecting system dilatation and stranding of perinephric fat on NCT.
CONTEXTO E OBJETIVO: Estudos atuais demonstram que a tomografia computadorizada helicoidal sem contraste (TC) apresenta maior acurácia do que a ultra-sonografia (US) no diagnóstico da ureterolitíase aguda, porém, poucos estudos a esse respeito foram realizados em atendimento radiológico de urgência de hospital universitário. Nossos objetivos foram comparar a sensibilidade diagnóstica da US com a TC realizadas por residentes no diagnóstico de ureterolitíase aguda e comparar a análise da TC interpretada por residentes e radiologistas experientes. TIPO DE ESTUDO E LOCAL: Estudo prospectivo de 52 pacientes com cólica renal aguda, que foram submetidos a exame de US seguido de TC em período máximo de oito horas no Hospital São Paulo. MÉTODOS: Os exames de US foram realizados por médicos residentes e conferidos pelos preceptores, já os de TC foram analisados por outro residente e posteriormente analisados por três radiologistas independentes. RESULTADOS: Nos 52 pacientes analisados foram encontrados 40 cálculos ureterais na TC (77 por cento). A US apresentou uma sensibilidade de 22 por cento e especificidade de 100 por cento, que aumentou para 73 por cento e 82 por cento respectivamente, quando se associou a identificação da dilatação do sistema coletor. A TC analisada pelo residente e pelos radiologistas apresentou uma excelente correlação para identificação do cálculo ureteral, para heterogeneidade da gordura peri-renal e para dilatação do sistema coletor. CONCLUSÕES: A US realizada pelos residentes tem menor sensibilidade no diagnóstico da litíase ureteral, quando comparada à TC, mesmo quando associada à presença de dilatação do sistema coletor. Residentes e radiologistas especialistas apresentaram excelente concordância no diagnóstico de litíase ureteral.
Asunto(s)
Humanos , Variaciones Dependientes del Observador , Tomografía Computarizada Espiral/normas , Cálculos Ureterales , Cálculos Ureterales , Enfermedad Aguda , Métodos Epidemiológicos , Hospitales de Enseñanza , Internado y Residencia , Médicos , Competencia Profesional , Radiografía Abdominal , RadiologíaRESUMEN
PURPOSE: To study the imaging exams more commonly used for abdominal aortic aneurysms evaluation - ultrasonography, conventional computerized tomography, helical computerized tomography and nuclear magnetic angioresonance - comparing the preoperative measurements reached by those radiological methods with the measurements made during the surgical procedures. METHODS: Patients who had indication of elective transperitoneal surgical treatment for their abdominal aortic aneurysms were included in the study. The initial diagnosis of the aortic dilatation was made by ultrasonography and, after the surgical treatment was indicated, the patient was submitted to another imaging method. Sixty patients were divided into 3 groups according to the complementary imaging method (conventional computerised tomography, helical computerized tomography, nuclear magnetic angioresonance). The ultrasonography of the first 20 patients were joined in a fourth group. There were considered in the study the measurements of the transversal diameter of the proximal neck, maximum transversal diameter of the aneurysm, straight-line length and transversal diameter of the common iliac arteries given by the imaging methods. The same measurements were made by using a caliper during the surgical procedure, and then compared to the values obtained from the radiological exams. RESULTS: The maximum transverse diameter had a range measurement variation of 4.5 to 13.6 cm in the intraoperative, with no statistically significant differences when compared with all the imaging tests. The ultrasonography, however, overestimated the measurements of the proximal neck and the common iliac arteries, in comparison with intraoperative measures. The length of the aorta aneurysm obtained by the conventional computerized tomography was significantly lower if compared to the measures done with the calliper during the operation. The helical computerized tomography and the nuclear magnetic angioresonance provided measurements with no significant differences in the statistic view when compared to the intraoperative measures. CONCLUSIONS: Ultrasonography is a reliable method for the diagnosis and follow-up of the aorta abdominal aneurysms, but insufficient for endovascular surgery planning. The conventional computed tomography can provoke distortion in the length measurements of the aorta dilatation. Helical computed tomography and nuclear magnetic angioresonance provided precise measurements of all the studied parameters, being of great utility for surgical planning.