The Predictive Value of Multidetector High Resolution Computed Tomography in Evaluation of Suspected Sputum Smear Negative Active Pulmonary Tuberculosis in Egyptian Zagazig University Hospital Patients

Abstract

SummaryThe aim of this work is to study the usage of multi-detector HRCT chest in diagnosing pulmonary TB cases whose sputum smears are negative and making a correlation between their CT features and their sputum culture results.This study was carried out from December 2014 to December 2016 at Zagazig university hospitals, Radiodiagnosis department. It included 150 patients. Their ages ranged between 10 to 70 years with a mean age 40 years. They were referred from the outpatient respiratory medicine clinic of the hospital. All patients had been presented clinically with suspicion of PTB. Their clinical features and HRCT findings were investigated to predict the risk for PTB. We then designed provisional HRCT diagnostic criteria based on the results to rank the risk of PTB.A positive tuberculin skin test alone among clinical laboratory findings was significantly associated with an increase of risk of PTB. Centrilobular nodules, large nodules, tree-in-bud appearance and the main lesion being located in S1, S2, and S6 lung segments were significantly associated with an increased risk of PTB. At HRCT 40 out of 44 patients with class III ranking showed active pulmonary TB. 12 out of 51 patients presented with class II ranking and 8 out of 40 were ranked as class I. The sensitivity, specificity and positive likelihood ratio of class I ranking HRCT criteria to diagnose active pulmonary TB were 95%, 40% and 1.4, respectively. Class II ranking results were 85%, 72%, 3, respectively. Finally class III ranking results were 45%, 90%, 11.5, respectively.Cases suspected of having active pulmonary TB whose smears are negative can benefit from MD HRCT chest findings to predict those patients of high risk with good reproducibility.

Diagnostic accuracy of CBNAAT (Gene-Xpert) Vs liquid culture in clinically diagnosed presumptive childhood tuberculosis admitted in Pt. J.N.M. Medical College & Dr. Bhim Rao Ambedkar Memorial Hospital, Raipur (C.G.)

“…Gene-Xpert has a higher sensitivity than AFB smear microscopy in respiratory samples [18]. The overall positive rate of Xpert among sputum samples was significantly higher than that of liquid culture [19].…”

Modelo predictivo clínico-radiológico para diagnosticar tuberculosis pulmonar activa

“…Alsowey et al (16) en su modelo predictivo para diagnosticar tuberculosis pulmonar en pacientes con baciloscopia negativa para BAAR demostró que los nódulos, el patrón de "árbol en brote", consolidación lobular y que la lesión principal estuviera en los segmentos pulmonares 1, 2 ó 6 se asociaba significativamente con un mayor riesgo de tuberculosis, en un estudio con pacientes entre 10 y 70 años de edad.…”

“…Los hallazgos radiológicos que mayor puntuación obtuvieron en nuestro modelo, tras el patrón miliar, fueron la masa pulmonar cavitada en radiografía simple (3 puntos) y el nódulo y la consolidación cavitada en TC (2 puntos), que coincide con los patrones de Yeh et al (13) vistos en TC y el patrón de "árbol en brote" que coincide con los hallazgos de Alsowey et al (16) y de Feng et al (17) .…”

“…A diferencia de otros estudios (13,16) , hemos considerado la edad como una variable del modelo. Esto nos ha permitido confeccionar un único modelo predictivo de tuberculosis pulmonar activa independientemente de la edad del paciente, en vez de tener varios modelos predictivos en función de la edad, con distintos patrones radiológicos en cada uno de ellos.…”

“…La tomografía computarizada (TC) es una técnica más sensible y específica que la radiografía para el diagnóstico de la tuberculosis pulmonar activa, pese a su disponibilidad es limitada en algunas regiones. La capacidad de la TC para el diagnóstico de tuberculosis ya ha sido estudiada en regiones con mayor prevalencia para la infección, principalmente en Asia, obteniéndose resultados muy prometedores (13,14,15,16,17) .…”