Chest CT findings in Hiv a descriptive cross-sectional study on the abnormal patterns encountered on chest CT scan images of adult Hiv patients at Kenyatta national hospital.

Abstract

Background Pulmonary complications of HIV are a major contributor to morbidity and mortality related to the disease as most patients with HIV encounter at least one pulmonary complication in their lifetime. Imaging plays a crucial role in the diagnosis and management of various complications. Chest CT has been shown to be more accurate than chest radiographs in making the diagnosis. Objective The main objective of this study was to determine the abnormal patterns encountered on Chest CT images of adult HIV patients at Kenyatta National Hospital. Methodology A descriptive observational study was carried out over a period of 6 months from November 2019 to March 2020. Convenient sampling technique was used to identify a total of 91 adult HIV patients who had been referred for chest CT scans. The patients were from the inpatient wards, Comprehensive Care Clinic and Chest Clinic. The patient’s demographics such as age and gender were recorded in the data collection tool after signing an informed consent. A brief history of the presenting complaint; duration of presenting illness; use of HAART; smoking history and previous history of TB or pneumonia, was taken and recorded in the data collection tool. The chest CT scan images from each of the patients were then reviewed by the researcher and a consultant radiologist. The findings were reported, and the radiographic patterns encountered were then recorded in a data collection form for each participant. Data analysis was carried out by Statistical Package for Social Science model SPSS version 23. Demographics were presented as frequency and proportions for categorical variables as well as means and medians. Chi-square test as well as Logistic Regression were used to determine the predictors of having an abnormal radiographic pattern. The findings were presented in the form of texts, charts, graphs and tables. Utility This study has great relevance and utility. No previous study has been conducted in Kenya to assess the changes seen in the lungs of HIV patients as seen on chest CT. This study can also be used to determine the predictors of having lung parenchymal changes in HIV patients. Results The total number of patients involved in the study was 91. 59.6 % were males while 40.4 % were females. The male to female ratio was 1.47:1 with a male majority of 53 patients. 25.3 % had a history of smoking while 41.8% had a history of pulmonary tuberculosis (T.B). Previous history of pneumonia was reported in 12.1% of the patients. 61% of the patients were on HAART. The majority,76.9% of the patients had abnormal patterns seen on chest CT. The most common radiographic patterns encountered were bronchiectasis (31.4%), emphysema (21.42%), and ground glass opacities (21.42%). Other patterns seen were nodules (17.1%), consolidation (15.71%) adenopathy (15.71%), tree in bud (14.28%) and cavitation (12.85%). Pleural effusion accounted for 7.14% of the abnormal patterns seen. The least common pattern was honey combing at 4.28% Age and gender were not found to be predictors of having an abnormal pattern on chest CT. History of pneumonia and use of HAART were also not found to be statistically significant predictors of having a radiographic abnormality. History of smoking (OR = 9.2, p = 0.014, 95% CI = 1.2-72.7) and history of pulmonary TB (OR = 22.4, p = 0.001, 95% CI = 2.9-176.4) were found to be significant and independent predictors of having a radiographic abnormality. Conclusion Chest CT is an effective tool in imaging patients with HIV as a wide range of imaging patterns can be detected which can significantly aid in the diagnosis of lung pathologies. HIV patients with either history of pulmonary TB or smoking have a significant and independent increased risk of developing abnormal lung patterns as seen in the above study. Study Limitations 1. The study was a hospital-based study and therefore cannot be generalized for the whole population. 2. Comparison was not done with CD4 levels as not all patients had current count. Recommendation: Future studies can correlate radiographic findings with CD4 level counts and laboratory results. This would better assess the relationship between the radiographic patterns and the level of immune suppression and further assess the pathological causes of the abnormal patterns.