Yield of CT angiography in penetrating lower extremity trauma.

PURPOSE: CT angiography (CTA) has become a valuable tool in the assessment of suspected arterial injury in patients with penetrating lower extremity trauma. However, expensive imaging such as CTA should be judiciously utilized to ensure value-based care. We therefore assessed the yield of CTA in this setting at a level-1 trauma unit and correlated it with the clinical history provided. METHODS: A retrospective descriptive study from 1 July 2013 to 31 June 2018 at a 1386-bed, tertiary-level, public-sector teaching hospital in Cape Town, South Africa.. All patients undergoing CTA for suspected arterial injury following penetrating lower extremity trauma were included. The imaging yield of clinically significant arterial injury and the predictive value of specific clinical signs were determined. RESULTS: A total of 983 patients (median age 27 years, 91% male) were included; 90% (886/983) had gunshots, 9% (89/983) stabs, and 1% (8/983) other injuries. Despite an average 13% year-on-year increase in CTA performed, there was no change in the proportion demonstrating arterial injury. Thirty-four percent (23/68) of patients with strong (hard) signs of arterial injury (active pulsatile bleeding, rapidly expanding hematoma, absent pulse, palpable thrill, or audible bruit), 11% (49/459) with moderate (soft) signs (history of an arterial bleed, excessive non-pulsatile bleeding, large non-expanding hematoma, major neurological deficit, diminished but appreciable pulse, and arterial proximity), and 5% (24/456) with no indication for imaging had clinically significant arterial injuries. Significant positive correlations were rapidly expanding hematoma (p = 0.009), an absent pulse (p < 0.001), and a diminished pulse (p < 0.001). Significant negative correlations were proximity to a major artery (p = 0.005) and no clinical indication provided (p < 0.001). CONCLUSION: There is poor correlation between clinical details provided and the presence of arterial injury at our institution. In this context, CTA serves a pivotal role in the definitive identification of arterial injury.

Chest imaging findings of chronic respiratory disease in HIV-infected adolescents on combined anti retro viral therapy.

Early treatment with combination antiretroviral therapy (cART) has improved survival of children perinatally infected with HIV into adolescence. This population is at risk of long term complications related to HIV infection, particularly chronic respiratory disease. Limited data on chest imaging findings in HIV-infected adolescents, suggest that the predominant disease is of small and large airways: predominantly bronchiolitis obliterans or bronchiectasis. Single cases of emphysema have been reported. Lung fibrosis, lymphocytic interstitial pneumonitis, post tuberculous apical fibrocystic changes and malignancies do not feature in this population. Chest radiograph (CXR) is easily accessible and widely used, especially in resource limited settings, such as sub Saharan Africa, where the greatest burden of HIV disease occurs. Lung ultrasound has been described for the diagnosis of pneumonia in children, pulmonary oedema and interstitial lung disease [1-3]. The use of this modality in chronic respiratory disease in adolescents where the predominant finding is small airway disease and bronchiectasis has however not been described. CXR is useful to evaluate structural/post infective changes, parenchymal opacification and nodules, hyperinflation or extensive bronchiectasis. CXR however, is inadequate for diagnosing small airway disease, for which high resolution computed tomography (HRCT) is the modality of choice. Where available, low dose HRCT should be used early in the course of symptomatic disease in adolescents and for follow up in children who are non responsive to treatment or clinically deteriorating. This article provides a pictorial review of the spectrum of CXR and HRCT imaging findings of chronic pulmonary disease in perinatally HIV-infected adolescents on cART and guidelines for imaging.

Quantitative CT analysis for bronchiolitis obliterans in perinatally HIV-infected adolescents-comparison with controls and lung function data.

OBJECTIVE: To compare quantitative chest CT parameters in perinatally HIV-infected adolescents with and without bronchiolitis obliterans compared with HIV-uninfected controls and their association with lung function measurements. MATERIALS AND METHODS: Seventy-eight (41 girls) HIV-infected adolescents with a mean age of 13.8 ± 1.65 years and abnormal pulmonary function tests in the prospective Cape Town Adolescent Antiretroviral Cohort underwent contrast-enhanced chest CT on inspiration and expiration. Sixteen age-, sex-, and height-matched non-infected controls were identified retrospectively. Fifty-one HIV-infected adolescents (28 girls) displayed mosaic attenuation on expiration suggesting bronchiolitis obliterans. Pulmonary function tests were collected. The following parameters were obtained: low- and high-attenuation areas, mean lung density, kurtosis, skewness, ventilation heterogeneity, lung mass, and volume. RESULTS: HIV-infected adolescents showed a significantly higher mean lung density, ventilation heterogeneity, mass, and high- and low-attenuation areas compared with non-infected individuals. Kurtosis and skewness were significantly lower as well. HIV-infected adolescents with bronchiolitis obliterans had a significantly lower kurtosis and skewness compared with those without bronchiolitis obliterans. Lung mass and volume showed the strongest correlations with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and alveolar volume. Low-attenuation areas below - 950 HU and ventilation heterogeneity showed the strongest correlation with FEV1/FVC (range, - 0.51 to - 0.34) and forced expiratory flow between 25 and 75% of FVC (range, - 0.50 to - 0.35). CONCLUSION: Quantitative chest CT on inspiration is a feasible technique to differentiate perinatally HIV-infected adolescents with and without bronchiolitis obliterans. Quantitative CT parameters correlate with spirometric measurements of small-airway disease. KEY POINTS: • Perinatally HIV-infected adolescents showed a more heterogeneous attenuation of the lung parenchyma with a higher percentage of low- and high-attenuation areas compared with non-infected patients. • Kurtosis and skewness are able to differentiate between HIV-infected adolescents with and without bronchiolitis obliterans using an inspiratory chest CT. • Quantitative CT parameters of the chest correlate significantly with pulmonary function test. Low-attenuation areas and ventilation heterogeneity are particularly associated with spirometric parameters related to airway obstruction.

Risk-Stratification of Children Presenting to Ambulatory Paediatrics with First-Onset Seizures: Should We Order an Urgent CT Brain?

INTRODUCTION: A computed tomography (CT) brain scan is an often-utilised emergency department imaging modality to detect emergent intra-cranial pathology in a child with a first seizure. Identifying children at low risk of having a clinically significant intra-cranial abnormality could prevent unnecessary radiation exposure and contrast/sedation-related risks. OBJECTIVES: To identify clinical variables which could predict clinically significant CT brain abnormalities and use recursive partitioning analysis to define a low-risk group of children in whom emergent CT brain can be deferred. METHODS: Retrospective cross-sectional review of 468 children who underwent emergent CT brain after presenting to a low- and middle-income paediatric emergency department following first seizure. RESULTS: In total 133/468 (28.4%) of CT brain scans had clinically significant abnormalities. Failure to return to neurological baseline and focal neurological deficit persisting >36 h had statistical significance in a multiple regression analysis. Recursive partitioning analysis, applied to a subgroup without suspected tuberculous meningitis (n = 414), classified 153 children aged between 6 months and 5 years, who had a normal neurological baseline, had returned to baseline post-seizure, and were not in status epilepticus, as non-clinically significant scans and 98% were correctly classified. CONCLUSION: Our study re-inforces the American Academy of Neurology recommendation that children with persistent post-ictal abnormal neurological status and/or post-ictal focal deficit be prioritised for emergent CT brain. Having excluded children with suspected tuberculous meningitis, the remaining subgroup aged 6 months to 5 years presenting with a non-status first seizure, normal neurological baseline and return to baseline post-seizure, are at very low risk of having a clinically significant CT brain abnormality.

High-resolution computed tomography features of lung disease in perinatally HIV-infected adolescents on combined antiretroviral therapy.

INTRODUCTION: Chronic lung disease is common in perinatally HIV-infected children as they increasingly surviving into adolescence. There are few data on the radiologic spectrum of disease in this population. METHODS: Contrasted high-resolution computed tomography (HRCT) was performed in ambulatory South African adolescents enrolled in a prospective study of perinatally-infected adolescents aged 9 to 14 years established on combined antiretroviral therapy (cART) and followed for 36 months. Consecutive participants with reduced lung function (defined by a forced expiratory volume in 1 second [FEV1] of <80% normal and/or lung diffusion capacity [DLCO] <80% normal] underwent HRCT. History, clinical, and laboratory data were collected. Two radiologists blinded to clinical data and to each other, reported scans using standardized methodology; a third radiologist resolved discrepancies. RESULTS: Amongst 100 participants undergoing HRCT, median age was 13.8 years (12.8-15.1). The median duration on cART was 8.4 years (IQR = 5.7-9.8). Mosaic attenuation was the most common finding (73%). Of these 71 (91%) demonstrated associated air trapping radiologically consistent with bronchiolitis obliterans. Bronchiectasis occurred in 39% with significant correlation between extent of bronchiectasis and mosaic attenuation (r = 0.57, P < .001). Prior hospitaliszation for childhood pneumonia at any time before enrollment was associated with mosaic attenuation (OR = 3.9, 95%CI, [1.2-12.5]); prior pulmonary tuberculosis (TB) was associated with the combination of mosaic attenuation and bronchiectasis (OR = 4.9, 95%CI, [1.6-15.7]). Most participants (86%) with mosaic attenuation had stage III or IV HIV disease at time of HIV diagnosis (OR = 3.6; [0.9-14.9]). Inter observer agreement between the two readers was good for bronchiectasis (K = 0.71) and moderate for mosaic attenuation (K = 0.51). DISCUSSION: Despite well-controlled HIV and long duration of cART, HRCT changes were common in perinatally HIV-infected adolescents. There was a high prevalence of small airways disease with and without associated bronchiectasis. These changes were associated with prior pulmonary TB or prior severe pneumonia. Strategies to prevent and treat early life respiratory infection must be strengthened to reduce the burden of chronic lung disease in HIV-infected adolescents.

Unusual Presentation of Pulmonary Hydatidosis Mimicking Thoracic Malignancy in a Paediatric South African Patient.

In this case report, an illustrative case of pulmonary hydatidosis in a young South African girl is presented. The acute symptomatology, rapidly worsening clinical condition and the extremely atypical appearance of the hydatid cysts on imaging were initially misleading and raised suspicion for malignant disease.

"Barbell Sign": A Diagnostic Imaging Finding in Progressive Multifocal Leukoencephalopathy.

The recently proposed diagnostic algorithm for progressive multifocal leukoencephalopathy underscores the importance of imaging and emphasizes the role of the radiologist in the diagnostic workup. We describe a case series of patients with visual symptoms and a typical pattern of brain involvement in definite progressive multifocal leukoencephalopathy, for which we have coined the term barbell sign.

Infantile intrathoracic large airway obstruction in a setting with a high prevalence of tuberculosis/HIV.

Background There has been no detailed analysis of the cause of intrathoracic large airway obstruction in infants in a resource-limited environment with a high prevalence of pulmonary tuberculosis (PTB) and human immunodeficiency virus (HIV). Aim To define the aetiology and severity of intrathoracic large airway obstruction in infants in a tertiary South African hospital with a high prevalence of PTB and HIV. Methods A retrospective study of infants was conducted with computerised tomography (CT) evidence of intrathoracic large airway obstruction from 1 January 2011 to 31 May 2014. CT scans were evaluated for the cause, site and severity of airway narrowing, with severity stratified as 'mild' (<50%), 'moderate' (51-75%) or 'severe' (>75%). Results Forty-four patients (28 males, 64%; median age 145 days, range 5-331), and 79 sites of attenuation were included. Vascular (22/44, 50%) and nodal (18/44, 41%) compressions accounted for over 90% of cases. Thirty-five patients (79.5%) had at least one site of moderate/severe attenuation, and 26 (59%) had multiple such sites. Adenopathy was the commonest cause of moderate/severe compression (18/35, 51%). All cases of nodal compression were of tuberculous origin. HIV-serology was recorded in 32 patients (73%), one of whom, with vascular compression, was HIV-infected. Half of the patients (11/22, 50%) with vascular compression had congenital abnormalities, most commonly cardiac anomalies (7/22, 32%). There were no synchronous vascular and nodal compressions. Conclusion Infantile intrathoracic large airway obstruction where there is a high prevalence of PTB and HIV is characterised by its extrinsic aetiology, severity and multicentricity, with more than half of all moderate/severe obstructions being caused by tuberculous adenopathy.

Clinicoradiologic response of neurologic tuberculous mass lesions in children treated with thalidomide.

Neurologic tuberculous pseudoabscesses that clinically progress despite conventional antituberculosis therapy may be responsive to adjuvant thalidomide, a potent tumor necrosis factor-α inhibitor. In this study, the addition of thalidomide provided substantial clinical benefit in the majority of patients, and magnetic resonance imaging evolution of lesions from early-stage "T2 bright" with edema to "T2 black" represented a marker of cure.

Central nervous system manifestations of HIV infection in children.

Vertically transmitted HIV infection is a major problem in the developing world due to the poor availability of antiretroviral agents to pregnant women. HIV is a neurotrophic virus and causes devastating neurological insults to the immature brain. The effects of the virus are further compounded by the opportunistic infections and neoplasms that occur as a result of the associated immune suppression. This review focuses on the imaging features of HIV infection and its complications in the central nervous system.

The effects of misinterpretation of an artefact on multidetector row CT scans in children.

BACKGROUND: Artefacts reflect problems with radiographic technique rather than true pathology. These may be misinterpreted as pathology with serious consequences. An artefact caused such problems in one paediatric imaging department. OBJECTIVE: To determine the incidence, and consequences of misinterpretation, of a CT artefact in a paediatric imaging department. MATERIALS AND METHODS: A retrospective review of images and reports of paediatric CT scans over a set period with a known artefact was performed. Reports were correlated with reviewers' evaluation of the presence of artefact and reviewed for correct identification of artefact, misinterpretation as pathology, and action taken as a result. RESULTS: A total of 74 CT scans had been performed over the study period and an artefact detected by reviewers on 32 (43%). Six (18.75%) of these were misinterpreted as pathology, of which three (9.4%) were reported as tuberculous granulomas, two (6.2%) as haemorrhages and one (3.1%) as an unknown hyperdensity. Two patients (6.2%) had subsequent MRI studies performed, and treatment for tuberculosis was continued in one patient (3.1%). CONCLUSION: No initial report identified the artefact. One-fifth of the scans with the artefact were misinterpreted as pathology and half of these misinterpretations led to further action. Artefacts result in false diagnoses and unnecessary investigations; vigilance is needed.

Bridging bronchus and sling left pulmonary artery: a rare entity demonstrated by coronal CT with 3-D rendering display and minimal-intensity projections.

We present a 5-month-old boy with bridging bronchus associated with a sling left pulmonary artery, both of which are rare. Coronal CT using 3-D volume rendering technique was used to delineate the abnormality and plan surgery. We propose that this technique could be used as single diagnostic tool in a child who presents, as children with this anomaly do, with chronic or recurrent lower respiratory tract infections.