Localization of the ilioischial line on axial computed tomography images for preoperative planning of total hip arthroplasty.

BACKGROUND: If the bony region indicating the ilioischial line is established on the preoperative axial computed tomography (CT) image, the distance between the simulated cup and the ilioischial line can be measured on this image so that the surgeon can use these data to define a more accurate preoperative two-dimensional (2D) template of total hip arthroplasty (THA). This study aimed to verify the hypothesis that on the CT axial image, the cortical bone area, indicated by the superimposition of a line (line α) with a perspective projection angle to the ilioischial line on radiography and tangent to the medial acetabular wall, is the cortical bone that represents the ilioischial line on radiography. METHODS: Study 1: If the two measured distances (distance A' and distance B) are sufficiently equal, then the hypothesis can be supported. Distance A' was calculated by multiplying the distance A, between the ilioischial line and the medial margin of the metal cup after THA measured at the level of the hip joint center on the pelvic radiograph, by 0.91 to correct for radiographic magnification. Distance B was defined as the distance between the medial margin of the metal cup and line α on the axial CT image at the level of the hip joint center. These two distances were measured for all 51 hip joints included in the study. Study 2: The difference between distance A and distance A# (distance A on the 2D template) was compared between the group containing 59 primary THAs in which distance B' was measured (distance B in the simulation) and the control group containing 59 primary THAs. RESULTS: Study 1: The average distance for A' was 4.5 ± 2 mm, and the average distance for B was 4.7 ± 2.1 mm. The difference between distances A and B was 0.2 ± 0.2 mm. Study 2: The mean difference between distance A and distance A# for the measurement and control groups was 1.8 ± 1.3 mm and 3.7 ± 2.4 mm, respectively (P < 0.001). CONCLUSIONS: The ilioischial line is located in the bony region where line α intersects the medial acetabular wall with a maximum overlap on axial CT images.

Valor de la tomografía abdominal para el diagnóstico del fibroleiosarcoma yeyunal / Abdominal tomography importance on the Leiomyosarcoma of jejunum diagnosis

RESUMEN Se presentó el caso de un paciente de 49 años de edad, que acudió a la consulta de Medicina Interna del Hospital General Docente "Dr. Agostinho Neto" por perder unas 20 libras de peso en dos meses y presentar heces fecales con aspecto aparente a "borra de café". El examen físico reveló desnutrición ligera y mucosas hipocoloreas. El ultrasonido abdominal mostró en hipocondrio y flanco izquierdo una imagen hipoecogénica heterogénea polilobulada que midió 68x61 mm con aspecto de paquete adenomegálico. En la tomografía computarizada de abdomen se identificó una imagen con densidad entre 33 y 57 UH, de 100 x 80 mm, polilobulada en topografía del yeyuno, que con el estudio contrastado realzó hasta 67 UH con aspecto tumoral. Se realizó resección quirúrgica del tumor con anastomosis termino-terminal. La biopsia informó fibroleiomiosarcoma. Se concluye que el estudio de las imágenes resulta útil para el diagnóstico de esta enfermedad.

ABSTRACT A 49-year-old patient presented to the internal medicine consultation office at the "Dr. Agostinho Neto" General teaching Hospital because of weight loss (20 pounds) and black stools in a period of 2 months before the evaluation. The physical examination revealed mild malnutrition and hypochlorous mucous membranes. The abdominal ultrasound image in the left hypochondrium showed a heterogeneous - polylobate - hypoechogenic mass measuring 68 x 61 mm with appearance of an adenomelagia. Computed tomography (CT) scan of the abdomen revealed an image with a density of 33 and 57 Hounsfield units (HU), measured 100 mm by 80 mm, polylobulated in jejunum topography, which with the contrasted study enhanced up to 67 UH with a tumor appearance. Surgical resection of the tumor with termino-terminal anastomosis was performed. Tumor biopsy diagnosed leiomyosarcoma. It was concluded that the study of the images was useful for the diagnosis of this disease.