Distribution and variability study of the femur cortical thickness from computer tomography.

In the context of patient-specific 3D bone reconstruction, enhancing the surface with cortical thickness (COT) opens a large field of applications for research and medicine. This functionality calls for database analysis for better knowledge of COT. Our study provides a new approach to reconstruct 3D internal and external cortical surfaces from computer tomography (CT) scans and analyses COT distribution and variability on a set of asymptomatic femurs. The reconstruction method relies on a short (∼5 min) initialisation phase based on 3D reconstruction from biplanar CT-based virtual X-rays and an automatic optimisation phase based on intensity-based cortical structure detection in the CT volume, the COT being the distance between internal and external cortical surfaces. Surfaces and COT show root mean square reconstruction errors below 1 and 1.3 mm. Descriptions of the COT distributions by anatomical regions are provided and principal component analysis has been applied. The first mode, 16-50% of the variance, corresponds to the variation of the mean COT around its averaged shape; the second mode, 9-28%, corresponds to a fine variation of its shape. A femur COT model can, therefore, be described as the averaged COT distribution in which the first parameter adjusts its mean value and a second parameter adjusts its shape.

Robust femur condyle disambiguation on biplanar X-rays.

Three-dimensional (3D) reconstruction of the skeleton from biplanar X-rays relies on scarce information digitalised by an operator on both frontal and lateral radiographs. In clinical routine, difficulties occur for non-skilled operators to discriminate the medial from the lateral femur condyle on the lateral view. Our study proposes an algorithm able to detect automatically a possible inversion of the two condyles by the operator at an early stage of the reconstruction process. It relies on the computation of two 3D femur surfaces, one directly from the operator digitalisation and the other from the same digitalisation with medial and lateral condyles automatically swapped. Pairs of virtual biplanar X-rays are computed for both reconstructions and the closest pair to the original X-rays is selected on the basis of similarity measures, pointing the correct 3D surface. The algorithm shows a success rate higher than 85% for both asymptomatic and pathological femurs whatever the initial condyle digitalisation of the operator, bringing automatically non-skilled operators acting in clinical routine to the level of skilled operators. This study validates moreover the proof-of-concept of automatic shape adjustments of a 3D surface on the basis of similarity measures in the process of 3D reconstruction from biplanar X-rays.

Bocio Cervicotorácico ¿De qué depende el abordaje torácico?

Antecedentes: No hay una norma definida sobre qué enfermos requieren abordaje torácico. La experiencia basada en evidencia V, indica que la mayoría de los cirujanos lo realiza solo en el 2% de los enfermos. Objetivo: Descubrir factores clínicos, radiológicos y patológicos que pueden predecir la necesidad de un abordaje combinado o torácico puro en los bocios cervicotorácicos. Diseño: Retrospectivo. Observacional. Lugar de aplicación: Hospital Público de atención terciaria de tumores. Población: 54 enfermos, (51.8%) masculinos, con una relación 1/1. La edad media fue 57.8 años. 16/54 (29.6%) eran recidivados. 44 (81.5%) portaban tumores benignos y el resto malignos. Métodos: En 29.6% fue necesario ingresar al tórax. Se efectuó esternotomía en 10, manubriotomía en 4 y toracotomía lateral en 2. Se efectuó tiroidectomía total en 72.2%. Resultados: Se registraron complicaciones en 10/54 (18.5%) y secuelas en 8/54 (14.8%). Entre las primeras, la más frecuente fue la hipocalcemia en 6 (11.1%), seguida por sangrado en 2 (3.7%). Entre las secuelas, se registra hipocalcemia definitiva en 5, secuela recurrencial en 2. La supervivencia global a 5 años de los enfermos portadores de patología maligna fue 25%. Conclusiones: El término cervicotorácico parece ser el más abarcativo. Los pacientes que requirieron abordaje torácico fueron adultos de ambos géneros. El abordaje cervical resolvió la mayoría de los casos. Pero el 90% de las neoplasias malignas necesitó alguna forma de abordaje torácico expresada con significación estadística. Los bocios extendidos a la carina, aberrantes o del mediastino posterior, requirieron siempre abordaje torácico. La toracotomía lateral quedó reservada para bocios aberrantes y mediastinales posteriores.

Background: Only 2% of cervicothoracic goiters are resected through a thoracic approach. There are no strict guidelines that dictate the need for this surgical approach. Objective: Investigate clinical, radiographic factors associated with the need for a thoracic approach in cervicothoracic goiters. Design: Retrospective - Observational. Setting: Public tertiary care head and neck referral center. Population: 54 patients, 51.8 male with a rate 1/1. mean age was 57.8 years, 29.6% recurred goiters, 81.5% was benign and hte rest malign tumours. Methods: In 29.6% a thoracic approach was needed: sternotomy in 10, manubriotomy in 4 and lateral thoracotomy in 2. Total thyroidectomy was used i n72.2%. Results: There were complications in 10 and sequelas in 8. 5 years overall survival in malignant tumors was 25%. Conclusions: Cervicothoracic seems to be most appropriate term. Patients who needed thoracic approach were adult of both genders. Cervical approach solve most of cases. But 90% of malignant tumours needed any type of thoracic approach statiscally significant expressed. Carinal extension, aberrant or posterior goiters, always needed a thoracic approach. Lateral thoracotomy was reserved only for the last two types of goiters.