Savvas Andronikou

Diagnostic accuracy of chest radiography in detecting mediastinal lymphadenopathy in suspected pulmonary tuberculosis

Objective: To estimate the diagnostic accuracy of chest radiography in the detection of chest lymphadenopathy in children with clinically suspected pulmonary tuberculosis. Methods: Design: Prospective cross sectional study. Setting: A short stay ward in a children’s hospital in South Africa. Patients: Consecutive children under 14 years of age admitted with suspected pulmonary tuberculosis. Diagnostic test: Antero-posterior and/or lateral chest x rays interpreted independently and blind to the reference standard by three primary care clinicians and three paediatricians, all with a special interest in tuberculosis. Reference standard: Spiral chest computed tomography (CT) with contrast injection. Results: One hundred children (median age 21.5 months) were enrolled. Lymphadenopathy was present in 46 of 100 reference CT scans and judged to be present in 47.1% of x ray assessments. Overall sensitivity was 67% and specificity 59%. Primary care clinicians were more sensitive (71.5% v 63.3%, p = 0.047) and less specific (49.8% v 68.9%, p<0.001) than paediatricians. Overall accuracy was higher for the paediatricians (diagnostic odds ratio 3.83 v 2.49, p = 0.008). The addition of a lateral to an antero-posterior view did not significantly increase accuracy (diagnostic odds ratio 3.09 v 3.73, p = 0.16). Chance adjusted inter-observer agreement (κ) varied widely between viewer pairs, but was around 30%. Conclusions: Detection of mediastinal lymphadenopathy on chest x ray to diagnose pulmonary tuberculosis in children must be interpreted with caution. Diagnostic accuracy might be improved by refining radiological criteria for lymphadenopathy.

Definitive neuroradiological diagnostic features of tuberculous meningitis in children.

Background: Although CT scanning is used widely for making the diagnosis and detecting the complications of tuberculous meningitis (TBM) in children, the radiological features are considered non-specific. CT is particularly suggestive of the diagnosis when there is a combination of basal enhancement, hydrocephalus and infarction, and even then the diagnosis may be in doubt. In this paper we introduce a new CT feature for making the diagnosis of TBM, namely, hyperdensity in the basal cisterns on non-contrast scans, and we assess which of the recognized CT features is most sensitive and specific. Objective: To determine the sensitivity and specificity of the presence of high-density exudates in the basal cisterns (on non-contrast CT) and basal enhancement (on contrast-enhanced CT) for the diagnosis of TBM in children, and to correlate these with the complications of infarction and hydrocephalus. Materials and methods: Retrospective review of CT scans with readers blinded to the diagnosis, which was based on a definitive culture of cerebrospinal fluid (CSF) for TBM or other bacteria. Computer-aided conversion of hard-copy film density to Hounsfield units was employed as well as a density threshold technique for determining abnormally high densities. Results: The most specific feature for TBM is hyperdensity in the basal cisterns prior to IV contrast medium administration (100%). The most sensitive feature of TBM is basal enhancement (89%). A combination of features (hydrocephalus, infarction and basal enhancement) is as specific as pre-contrast hyperdensity, but has a lower sensitivity (41%). There were statistically significant differences in the presence of hydrocephalus (p=0.0016), infarcts (P=0.0014), basal enhancement (P<0.0001) and pre-contrast density (P<0.0001) between the negative and positive TBM patient groups. The presence of granulomas was not statistically significant between the two groups (P=0.44). Conclusions: The presence of high density within the basal cisterns on non-contrast CT scans is a very specific sign for TBM in children. This will enhance diagnostic confidence, allow early institution of therapy and could reduce expenditure on contrast medium, scan time and radiation exposure. With the use of threshold techniques we believe that the pre-contrast hyperdensity may be detectable by a computer program that will facilitate diagnosis, and may also be modified to detect abnormal enhancement. Basal enhancement is a sensitive sign for the diagnosis of TBM and should be sought after contrast medium administration when no hyperdensity is seen in the basal cisterns or when this finding needs to be confirmed. The CT scan feature of hyperdense exudates on pre-contrast scans should be added to the inclusion criteria for the diagnosis of TBM in children.

Angiographic features of 26 children with Takayasu's arteritis

Abstract Background. Takayasus arteritis (TA) is a chronic idiopathic inflammatory disease affecting primarily the aorta, its proximal branches and the pulmonary arteries. Objectives. To retrospectively review the angiograms of children with TA so as to describe the patterns of vascular involvement. Patients and methods. Twenty-six children with TA who differed from most other studies in that almost all of them presented with hypertension, reflecting the incidence of abdominal aortic and renal artery involvement. Results. The most consistent finding was stenosis of the aorta. Marginal irregularity/undulation of the aorta was also a useful angiographic diagnostic feature in subtle disease. The incidence of aneurysms was high compared to other studies and both fusiform and saccular aneurysms were encountered. Percutaneous transluminal angioplasty (PTA) was successful in all eight patients in whom it was performed. MRI, CT angiography and US are discussed as less invasive imaging alternatives. TA is a significant cause of renovascular hypertension in children in South Africa where there is a high incidence of tuberculous infection. Knowledge of the angiographic features and pattern of aortic involvement is essential for diagnosis and initiation of early and appropriate treatment, including PTA.

Modern imaging of tuberculosis in children: thoracic, central nervous system and abdominal tuberculosis.

Tuberculosis (TB) can affect any organ in the body. Children are a high-risk group for contracting the disease and pose a constant challenge to clinicians with regard to making a definitive diagnosis. Radiologists are playing a more active role in diagnosing TB, and armed with more accurate diagnostic investigations such as CT and MRI, they must face the cost implications as well as technical limitations. This review aims to guide the reader through the modern imaging techniques useful for diagnosing TB of the thorax, central nervous system and abdomen in children. The more specific features of each modality in the particular anatomical regions are highlighted.

Patterns of disease on MRI in 53 children with tuberculous spondylitis and the role of gadolinium

Abstract Background. Tuberculosis (TB) of the spine is the most common site of osseous involvement and has a higher prevalence in developing nations with an increasing incidence in developed nations. There are few paediatric reports of TB spondylitis (TBS) that include MRI findings. Objective. To determine the MRI characteristics of TBS in children with special reference to gadolinium enhancement and findings on follow-up MRI. Materials and methods. A retrospective review of patient records and MRI scans by three readers using a consensus method of 53 patients below 13 years of age. Results. Seventy-nine percent presented with kyphosis. MRI showed thoracic involvement in 83%. Eighty-five percent showed contiguous involvement of two or more vertebral bodies. An intraspinal or paraspinal soft-tissue mass or abscess was present in 98%. Subligamentous extension was noted in 64% of patients. Gadolinium was administered in 26 patients. Ring enhancement of the soft-tissue mass was shown in 65% of these. Subligamentous enhancement was shown in 35% and bone enhancement was shown in 100% of patients. Follow-up MRI performed in 16 patients showed progressive bone destruction in 10 patients, progressive kyphosis in 2 patients and progression of soft-tissue disease in 4 patients. Conclusions. We have demonstrated an advanced pattern of TBS in this childhood population, which supports other reports that describe a more aggressive process in children. Kyphosis and cord compressions were the most common complications. The use of gadolinium is promising in detecting disease earlier, as it invariably results in bone enhancement and may assist in making the diagnosis when the rim-enhancing pattern of the soft-tissue mass is demonstrated. Follow-up imaging with MRI is a suitable way of assessing resolution of cord compression and decrease in size of the soft-tissue mass. Therefore, considering the pattern of involvement in children with TBS demonstrated by this study, MRI is considered an ideal modality for making the diagnosis, demonstrating the extent of disease, identifying complications and assessing response to treatment.

The CT features of abdominal tuberculosis in children

Abstract.Background: The last decade has seen a resurgence in the incidence and clinical presentation of tuberculosis (TB). Little data exist in the paediatric age group regarding abdominal tuberculosis (ATB) and limited reports of its CT features have been published. Purpose: To elucidate the CT features of ATB in children. Materials and methods: The medical records of 22 patients with ATB were reviewed. Data were extracted regarding the methods of diagnosis and HIV status. The plain chest films were examined and the CT scans were assessed for adenopathy, solid organ involvement, ascites, bowel wall and omental thickening and inflammatory masses. Results: Ten patients had biopsy-proven ATB, 11 had extra-abdominal TB with clinical suspicion of ATB and 1 had a positive trial of therapy. Five patients were tested for HIV and one tested positive. Thirteen patients had abnormal chest radiographs. The commonest CT finding was lymphadenopathy (n=17), followed by solid organ involvement (n=12), ascites (n=5), bowel wall thickening (n=5), inflammatory masses (n=2) and omental thickening (n=1). Conclusions: The clinical features of ATB are protean. This usually results in a delay in diagnosis and impacts negatively on patient morbidity and mortality. On CT, the constellation of findings is highly suggestive of the diagnosis of ATB and, used in conjunction with clinical and laboratory data, should narrow the differential considerably. Unique findings include histologically proven active TB in calcified lymph nodes and a pancreatic TB granuloma.

MRI to demonstrate diagnostic features and complications of TBM not seen with CT.

BackgroundComputed tomography (CT) findings in children with tuberculous meningitis (TBM) often do not explain the clinical presentation and may even be normal. Magnetic resonance imaging (MRI) has the potential to diagnose TBM with greater sensitivity than CT and also to detect more infarcts.AimThe aim of this study was to determine whether MRI demonstrates features and complications of TBM not present on CT.Materials and methodsRetrospective, blinded evaluation and comparison of CT and MRI findings in children with TBM were performed.ResultsOf 30 children included, MRI demonstrated eight more with basal enhancement and four more with infarctions. Overall, MRI demonstrated an additional 104 sites of infarction (of a total 172) than CT. Of these, 89 were acute and visualized only on diffusion-weighted image. MRI showed five more patients with unilateral and two more with bilateral basal ganglia infarcts than CT as well as 19 brainstem infarcts. Hydrocephalus was equally detected by MRI and CT.ConclusionMRI is superior to CT for diagnosing TBM (by detecting basal enhancement in more patients) and prognosis (by detecting many more infarcts in strategic locations). The role of CT is defined for the acute setting in detecting hydrocephalus for surgical management.

Tuberculous Meningitis-Related Optic Neuritis: Recovery of Vision With Thalidomide in 4 Consecutive Cases

Blindness is an uncommon but devastating complication of tuberculosis meningitis. The main causes are chronically raised intracranial pressure (hydrocephalus and/or tuberculomas) or direct involvement of the optic chiasm or optic nerves by the basal arachnoiditis (inflammation and/or compression). Antituberculosis therapy combined with corticosteroids and control of intracranial pressure constitutes the mainstay of therapy for tuberculous meningitis. Despite these treatment measures, some patients develop blindness, mainly as a result of progressive optochiasmatic arachnoiditis. This led us to explore the role of adjuvant thalidomide therapy, and we describe the dramatic recovery of vision in 4 consecutive cases. Clinical recovery was accompanied by marked radiological improvement on magnetic resonance imaging (MRI) of the brain.

Advances in imaging chest tuberculosis: blurring of differences between children and adults

This article reviews the ongoing role of imaging in the diagnosis of tuberculosis (TB) and its complications. A modern imaging classification of TB, taking into account both adults and children and the blurring of differences in the presentation patterns, must be absorbed into daily practice. Clinicians must not only be familiar with imaging features of TB but also become expert at detecting these when radiologists are unavailable. Communication between radiologists and clinicians with regard to local constraints, patterns of disease, human immunodeficiency virus (HIV) coinfection rates, and imaging parameters relevant for management (especially in drug resistance programs) is paramount for making an impact with imaging, and preserving clinician confidence. Recognition of special imaging, anatomic and vulnerability differences between children and adults is more important than trying to define patterns of disease exclusive to children.

MRI findings in acute idiopathic transverse myelopathy in children

ObjectiveTo describe the clinical and MRI findings in three children with acute idiopathic myelopathy (AIM).Materials and methodsRetrospective review of the clinical presentation, MRI findings and outcome of three patients diagnosed with acute idiopathic transverse myelitis.ResultsOf note was the swift onset of symptoms in all patients, without any preceding illness or history of vaccination in two of the patients, and the rapid resolution of symptoms on steroid therapy in all the patients. MRI showed T2-weighted hyperintensity and patchy enhancement with gadolinium, but the extensive cord involvement did not correlate with the severity of presentation or outcome.ConclusionsOur findings do not support that MRI evidence alone of diffuse myelopathy is a predictor of poor outcome in childhood AIM.