People at high risk of tuberculosis should be treated with prophylactic drugs to reduce the chance of spreading the disease, propose scientists in China. Billions of people worldwide are latently infected with tuberculosis, many of whom will experience reactivation of the disease in their lifetime. However, screening methods to identify latent tuberculosis carriers and predict reactivation are still limited, and treating everyone with latent tuberculosis infection is too expensive. Wen-Hong Zhang and colleagues at Huashan Hospital in Shanghai reviewed the risk factors for tuberculosis reactivation and concluded that treatment should focus on high-risk groups such as people with HIV, organ transplant recipients, silicosis patients, or close contacts of people with pulmonary tuberculosis. For the first two groups, isoniazid monotherapy is an effective treatment, but for others, scant evidence is available to guide the best therapy.

Updates on the risk factors for latent tuberculosis reactivation and their managements.

Isoniazid (INH) has been the mainstay of treatment of latent tuberculosis infection for almost 50 years. The currently recommended preferred regimen is 9 months daily self-administered INH (9H); this has efficacy of more than 90% if completed properly. Unfortunately, INH is associated with serious adverse events, including hepatotoxicity. Although risk factors for this complication are well established, allowing for better selection of candidates for therapy, this complication still occurs, and is occasionally fatal. Hence close follow up of patients is necessary, increasing the cost and complexity of treatment. This problem, plus the lengthy duration, results in poor acceptance by patients and providers, and poor adherence by patients. As a result, many preventable cases of tuberculosis continue to occur, and the public health impact of latent tuberculosis infection treatment is suboptimal. These problems have spurred interest in finding shorter, safer and cheaper alternative regimens, with similar efficacy. Of the many regimens that have been examined, 2 months of rifampin and pyrazinamide has excellent efficacy-in experimental studies in mice and randomized trials, largely in HIV-infected persons. However, while the safety of 2 months of rifampin and pyrazinamide appears acceptable in HIV-infected persons and children, in non-HIV-infected adults this regimen is associated with an unacceptably high rate of severe liver toxicity. Three to four months of INH and rifampin has had equivalent effectiveness as 6 months INH in several randomized trials. However, completion of therapy and toxicity has been the same as with INH-possibly because two drugs are taken rather than one. The fourth commonly studied regimen is 4 months rifampin. This has been found to have significantly better completion than 9H, with significantly less toxicity, especially hepatotoxicity. However, only one trial has evaluated efficacy and effectiveness of mono-rifampin therapy. In this trial, 3 months rifampin had somewhat better efficacy than either 3 months of isoniazid and rifampin (3HR) or 6 months isoniazid. Two large scale trials are ongoing; one is comparing efficacy and effectiveness of 9H with 4 months rifampin (both daily and self-administered), while the second, which is nearing completion, compares daily self-administered 9H with 3 months directly observed once weekly INH combined with rifapentine. The results of these two trials will likely shape future recommendations substantially.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1440-1843.2010.01751.x

Treatment of latent tuberculosis infection: An update.

Background: A study was conducted to evaluate the effect of the empirical use of fluoroquinolones on the timing of antituberculous treatment and the outcome of patients with tuberculosis in an endemic area. Methods: All patients with culture confirmed tuberculosis aged ⩾14 years diagnosed between July 2002 and December 2003 were included and their medical records were reviewed. Results: Seventy nine (14.4%) of the 548 tuberculosis patients identified received a fluoroquinolone (FQ group), 218 received a non-fluoroquinolone antibiotic (AB group), and 251 received no antibiotics before antituberculous treatment. Fifty two (65.8%) experienced clinical improvement after fluoroquinolone use. In the FQ group the median interval from the initial visit to starting antituberculous treatment was longer than in the AB group and in those who received no antibiotics (41 v 16 v 7 days), and the prognosis was worse (hazard ratio 6.88 (95% CI 1.84 to 25.72)). More patients in the FQ and AB groups were aged >65 years (53.2% and 61.0% v 31.5%), had underlying disease (53.2% and 46.8% v 34.3%), and were hypoalbuminaemic (67.2% and 64.9% v 35.1%). Of the nine mycobacterial isolates obtained after fluoroquinolone use from nine patients whose initial isolates were susceptible to ofloxacin, one (11.1%) was resistant to ofloxacin (after fluoroquinolone use for 7 days). Independent factors for a poor prognosis included empirical fluoroquinolone use, age >65, underlying disease, hypoalbuminaemia, and lack of early antituberculous treatment. Conclusions: 14.4% of our patients with tuberculosis received a fluoroquinolone before the diagnosis. With a 34 day delay in antituberculous treatment and more frequent coexistence of underlying disease and hypoalbuminaemia, empirical fluoroquinolone treatment was associated with a poor outcome. Mycobacterium tuberculosis isolates could obtain ofloxacin resistance within 1 week.

https://thorax.bmj.com/content/thoraxjnl/61/10/903.full.pdf

Empirical treatment with a fluoroquinolone delays the treatment for tuberculosis and is associated with a poor prognosis in endemic areas.

OBJECTIVE. The purpose of this study was to prospectively evaluate the usefulness of scoring perfusion defects on perfusion images at dual-energy CT for assessment of the severity of pulmonary embolism.SUBJECTS AND METHODS. Thirty patients (13 men, 17 women; mean age, 55 ± 15 [SD] years; range, 26–81 years) with pulmonary thromboembolism underwent dual-source CT at two voltages (140 and 80 kV). The weighted average image of two acquisitions was used for CT angiograms, and a color-coded iodine image was used for perfusion images. Two thoracic radiologists with 15 and 6 years of clinical experience independently assigned perfusion defect scores to perfusion images and both a CT angiographic (CTA) obstruction score and right ventricular–to–left ventricular (RV/LV) diameter ratio to CT angiograms. The CTA obstruction score was based on the Qanadli method. The perfusion defect score was defined as Σ (n · d) / 40 × 100, where n is the number of segments and d is the degree of perfusion from 0 to 2. Correlations...

https://www.ajronline.org/doi/pdf/10.2214/AJR.09.2681

Dual-Energy CT for Assessment of the Severity of Acute Pulmonary Embolism: Pulmonary Perfusion Defect Score Compared With CT Angiographic Obstruction Score and Right Ventricular/Left Ventricular Diameter Ratio

A variety of tumors, including primary malignant tumors, secondary malignant tumors, and benign tumors, can occur in the tracheobronchial tree. Primary malignant tumors commonly originate from the surface epithelium or the salivary glands, whereas most benign tumors arise from the mesenchymal tissue. At computed tomography (CT), primary malignant tumors manifest as a polypoid lesion, a focal sessile lesion, eccentric narrowing of the airway lumen, or circumferential wall thickening. At fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET), most squamous cell carcinomas show high uptake, whereas adenoid cystic carcinoma and mucoepidermoid carcinoma show variable uptake depending on the grade of differentiation. High-grade malignancies tend to show high and homogeneous uptake. Carcinoid tumors commonly show intense enhancement at contrast material-enhanced CT, which can be helpful in making the diagnosis, and usually have lower uptake at FDG PET than would be expected for a malignant tumor. Secondary malignant tumors occur as a result of either hematogenous metastasis or direct invasion by a malignancy from an adjacent structure. Their CT manifestations are similar to those of primary malignant tumors, with uptake at FDG PET depending primarily on the metabolic activity and degree of differentiation of the primary tumor. Among the benign tumors, hamartoma and lipoma can show characteristic CT findings such as "popcorn" calcification or internal fat. However, CT findings in most benign tumors are nonspecific. At FDG PET, benign tumors usually show little or no uptake and can be differentiated from malignant tumors. Knowledge of the characteristic CT and FDG PET findings of tracheobronchial tumors can aid in diagnosis and treatment planning.

https://pubs.rsna.org/doi/pdf/10.1148/rg.291085126

Tumors in the Tracheobronchial Tree: CT and FDG PET Features

Purpose: The purpose of our study was to describe the clinical and radiological mani-festations of tuberculosis in patients with end-stage renal disease.Materials and Methods: The medical records, chest radiographs, and CT scans of 42 patients with tuberculosis among 871 consecutive patients with end-stage renal disease were reviewed. Patterns of initial chest radiographs were categorized as primary, postprimary, miliary, or atypical, according to the predominant radiologic findings.Results: Chest radiographs and CT scans revealed pulmonary tuberculosis in 28 patients and extrapulmonary tuberculosis in 15. The pattern of chest radiographs indicative of pulmonary tuberculosis was primary in 12 cases, postprimary in 11, miliary in one, demonstrated atypical infiltrates in three, and was normal in one. Tuberculosis involved the extrathoracic lymph nodes in six cases, the peritoneum in four, the spine in three, and the bone marrow in two. The primary pattern, seen in 12 patients, manifested as pleural effusion or segmental consolidation, and in ten of the twelve the former was dominant.Conclusion: The radiological pattern of pulmonary tuberculosis in end-stage renal disease is often primary, and extrapulmonary involvement is frequent.

https://jksronline.org/Synapse/Data/PDFData/1016JKRS/jkrs-44-345.pdf

Tuberculosis in Patients with End-Stage Renal Disease

Angiolipoma is a rare benign soft tissue tumor, an unusual variant of lipoma, consisting of fatty and vascular components and located in the subcutis, usually in the trunk and extremities. We report a case of posterior mediastinal angiolipoma extending into the spinal canal and showing both fat and angiomatous features on CT scan.

/pdf/angiolipoma-of-the-posterior-mediastinum-with-extension-into-4yy98lxy7x.pdf

Angiolipoma of the posterior mediastinum with extension into the spinal canal: a case report.

Rationale and Objectives:We assess the value of computed tomography perfusion image (CTPI) obtained by postprocessing the CT data in the diagnosis of pulmonary embolism.Methods:An experimental pulmonary embolism model was made in 6 pigs by injecting 2 types of emboli into the pulmonary arteries. For

CT perfusion image of the lung: value in the detection of pulmonary embolism in a porcine model.

Background: To assess the frequency of visualization of pancreatic arteries in the arterial phase of helical computed tomography (CT).

Helical CT anatomy of pancreatic arteries

OBJECTIVE To compare the clinical utility of the different imaging techniques used for the evaluation of tracheobronchial diseases. MATERIALS AND METHODS Forty-one patients with tracheobronchial diseases [tuberculosis (n = 18), bronchogenic carcinoma (n = 10), congenital abnormality (n = 3), post-operative stenosis (n = 2), and others (n = 8)] underwent chest radiography and spiral CT. Two sets of scan data were obtained: one from routine thick-section axial images and the other from thin-section axial images. Multiplanar reconstruction (MPR) and shaded surface display (SSD) images were obtained from thin-section data. Applying a 5-point scale, two observers compared chest radiography, routine CT, thin-section spiral CT, MPR and SSD imaging with regard to the detection, localization, extent, and characterization of a lesion, information on its relationship with adjacent structures, and overall information. RESULTS SSD images were the most informative with regard to the detection (3.95+/-0.31), localization (3.95+/-0.22) and extent of a lesion (3.85+/-0.42), and overall information (3.83+/-0.44), while thin-section spiral CT scans provided most information regarding its relationship with adjacent structures (3.56+/-0.50) and characterization of the lesion (3.51+/-0.61). CONCLUSION SSD images and thin-section spiral CT scans can provide valuable information for the evaluation of tracheobronchial disease.

/pdf/evaluation-of-tracheobronchial-diseases-comparison-of-86q0yrny9h.pdf

Myung Jin Chung

Papers

Tuberculosis in Patients with End-Stage Renal Disease

Angiolipoma of the posterior mediastinum with extension into the spinal canal: a case report.

CT perfusion image of the lung: value in the detection of pulmonary embolism in a porcine model.

Helical CT anatomy of pancreatic arteries

Evaluation of Tracheobronchial Diseases: Comparison of Different Imaging Techniques