UTILITY OF ROUTINE CHEST RADIOGRAPHS IN KENYA.

BACKGROUND: Many otherwise healthy Kenyans are required to obtain chest radiographs as part of routine medical examination to exclude pulmonary TB, a condition of significant public health concern. Many of these people are required to have these radiographs taken yearly as part of routine check-up. No local data is available to support this practice. Though a quick procedure to perform and readily available throughout the country, chest radiograph exposes the individual to a dose of ionising radiation. Ionising radiation is associated with increased risk of malignancy. The cost is also substantial. OBJECTIVE: To determine the prevalence of radiological findings consistent with PTB among routine medical examination chest radiographs. DESIGN: A cross-sectional descriptive study. SETTINGS: Department of Radiology Kenyatta National Hospital, Department of Imaging and Radiation Medicine, University of Nairobi, Plaza Imaging Solutions, a private radiology practice in Nairobi and Department of Radiology, the Nairobi Hospital. SUBJECTS: Four hundred and two chest radiographs of patients presenting for routine medical examinations were analysed. RESULTS: Sixty three radiographs had abnormal but clinically insignificant findings (16%). Only one radiograph (0.25%) had radiological features of PTB. The rest were reported as normal (84%). CONCLUSION: In this study, the diagnostic yield for the intended purpose (to include/ exclude PTB) was extremely low (0.25%). It is recommended that routine chest radiographs as screening tools for active pulmonary tuberculosis be reconsidered due to poor diagnostic yield. The authors propose a bigger nation wide study before a policy decision can be proposed.

Utility of Routine Chest Radiographs in Kenya

Background: Many otherwise healthy Kenyans are required to obtain chest radiographs as part of routine medical examination to exclude pulmonary TB; a condition of significant public health concern. Many of these people are required to have these radiographs taken yearly as part of routine check-up. No local data is available to support this practice. Though a quick procedure to perform and readily available throughout the country; chest radiograph exposes the individual to a dose of ionising radiation. Ionising radiation is associated with increased risk of malignancy. The cost is also substantial. Objective: To determine the prevalence of radiological findings consistent with PTB among routine medical examination chest radiographs. Design: A cross-sectional descriptive study. Settings: Department of Radiology Kenyatta National Hospital;Department of Imaging and Radiation Medicine; University of Nairobi; Plaza Imaging Solutions; a private radiology practice in Nairobi and Department of Radiology; the Nairobi Hospital. Subjects: Four hundred and two chest radiographs of patients presenting for routine medical examinations were analysed. Results: Sixty three radiographs had abnormal but clinically insignificant findings (16). Only one radiograph (0.25). Only one radiograph (0.25) had radiological features of PTB. The rest were reported as normal (84). Conclusion: In this study; the diagnostic yield for the intended purpose (to include/ exclude PTB) was extremely low (0.25). It is recommended that routine chest radiographs as screening tools for active pulmonary tuberculosis be reconsidered due to poor diagnostic yield. The authors propose a bigger nation wide study before a policy decision can be proposed

CLINICAL FEATURES AND PATTERNS OF IMAGING IN CEREBRAL VENOUS SINUS THROMBOSIS AT KENYATTA NATIONAL HOSPITAL.

BACKGROUND: Cerebral venous sinus thrombosis (CVST) is an uncommon neurological deficit. It shows a wide range of clinical manifestations that may mimic many other neurological disorders and lead to misdiagnosis. Imaging plays a key role in the diagnosis. OBJECTIVE: To evaluate the clinical characteristics and patterns of neuroimaging findings in patients with radiologically confirmed CVST. DESIGN: A retrospective study. SETTING: Kenyatta National Hospital, a tertiary referral and teaching hospital in Nairobi Kenya. SUBJECTS: Fifty one patients treated for CVST in the hospital were studied. RESULTS: Fifty one patients with CVST were seen over the last five years. The median age of 30 years. The most common age group affected was 25-34 years. Females were more affected (n=38, 74.5%) than males (n=13, 25.5%). The most common presenting clinical features documented were headache, seizures and neurological deficits. Aetiological factors commonly seen included infection (n=20, 39.2%), pregnancy and puerperium (n=7, 13.7%) and oral contraceptive use (n=2, 3.9%). The most common NECT scan findings were hyperdense sinus and parenchymal changes. MRI showed loss of signal void in the sinus, gyral swelling and parenchymal signal change. CONCLUSION: CVST is most commonly seen in young adult females due to infection, pregnancy, puerperium and oral contraceptive use. The most common clinical finding in patients with CVST is headache, followed by seizures, neck pain, neurological deficits and visual disturbance. Infective cause is much more common in our population and other developed countries compared to the developed world.

PATTERN OF INTERSTITIAL LUNG DISEASE AS SEEN BY HIGH RESOLUTION COMPUTERISED TOMOGRAPHY.

BACKGROUND: Diffuse lung diseases constitute a major cause of morbidity and mortality worldwide. High Resolution Computed Tomography (HRCT) is the recommended imaging technique in the diagnosis, assessment and followup of these diseases. OBJECTIVES: To describe the pattern of HRCT findings in patients with suspected interstitial lung disease. SETTING: Kenyatta National Hospital (KNH), Nairobi Hospital and MP Shah Hospital; all situated in Nairobi, during the period February to August 2010. SUBJECTS: One hundred and one patients sent for HRCT in the six month study period. RESULTS: A total of 101 patients were recruited with age range 18 to 100 years, with a mean age of 53.6 (SD 19.7) years and a median age of 54 years. The male-female ratio was 1.2:1. Cough [80.2% (n = 81)] was the most common presenting complaint followed by dyspnoea (53.5%, n = 53) and chest pain [24.8% (n = 25)]. Overall, the predominant pattern of involvement on chest HRCT was reticular pattern seen in 56.1% (n = 82) of patients, followed by honey-comb pattern (37.8%, n = 82). CONCLUSION: The study demonstrated marked lung parenchymal destruction in most cases; a poor prognostic indicator which could have been due to delayed referral. HRCT has a high pick up rate of subtle parenchymal lung lesions as well as defining the lesions and their distribution compared to plain chest radiography. This is important in narrowing the differential diagnosis as well as for pre-biopsy planning. The diagnosis of ILD requires a multidisciplinary approach including a detailed clinical history, physical findings, and laboratory investigations, radiological and histological assessment.

EVALUATING CHAMBERLAIN'S, McGREGOR'S, AND McRAE'S SKULL-BASE LINES USING MULTI DETECTOR COMPUTERISED TOMOGRAPHY.

BACKGROUND: Traditionally the cranio-cervical junction is assessed by lateral cervical spine and base of skull radiographs which however have diagnostic challenges due to the complexity of the anatomy. Modern day Computed Tomography (CT) offers excellent bony detail and its ability to reconstruct the acquired CT data into various imaging planes makes the assessment of the cranio-cervical junction easy and more accurate. OBJECTIVE: To evaluate the relationship of the odontoid peg of C2 to the standard skull base lines of Chamberlain's, McGregor's and McRae's on computed tomography. DESIGN: Descriptive cross-sectional study. SETTING: Kenyatta National Hospital, Nairobi, between April and September 2010. RESULTS: The mean position of the odontoid process was 2.6 mm below Chamberlain's line (median 2.7 mm, SD 2.2 mm), 1.0mm (median 0.9 mm, SD 2.1 mm) below McGregor's line and 4.7 mm (median 4.6 mm, SD 1.3 mm) below McRae's line. There was no statistically significant difference in measurements between male and female patients, the different age groups and between CT and standard plain radiograph measurements (p > 0.05). CONCLUSION: Anthropometric measurements obtained using CT were lower than those from plain radiographs. There was howeverno statistical significant difference between the two imaging modalities. CT demonstrated far much superior anatomical detail compared to plain radiographs.

Cerebral venous sinus thrombosis: a report of two cases.

Cerebral venous sinus thrombosis is an uncommon yet potentially life threatening condition which is often under-diagnosed or misdiagnosed because of the variability of the clinical signs and symptoms. The imaging findings are often subtle thus the need for a high index of suspicion. The superior sagittal and transverse sinuses are the most frequently involved. The correct diagnosis of cerebral venous thrombosis relies on neuroimaging studies. The two cases reported highlight the fact that the radiologist may be the first clinician to suspect and diagnose this condition. This ultimately affects prognosis as early diagnosis and treatment reduces morbidity and mortality.