Detection of Pulmonary tuberculosis: comparing MR imaging with HRCT.

BACKGROUND: Computer Tomography (CT) is considered the gold standard for assessing the morphological changes of lung parenchyma. Although novel CT techniques have substantially decreased the radiation dose, radiation exposure is still high. Magnetic Resonance Imaging (MRI) has been established as a radiation- free alternative to CT for several lung diseases, but its role in infectious diseases still needs to be explored further. Therefore, the purpose of our study was to compare MRI with high resolution CT (HRCT) for assessing pulmonary tuberculosis. METHODS: 50 patients with culture-proven pulmonary tuberculosis underwent chest HRCT as the standard of reference and were evaluated by MRI within 24 h after HRCT. Altogether we performed 60 CT and MRI examinations, because 10 patients were also examined by CT and MRI at follow- up. Pulmonary abnormalities, their characteristics, location and distribution were analyzed by two readers who were blinded to the HRCT results. RESULTS: Artifacts did not interfere with the diagnostic value of MRI. Both HRCT and MRI correctly diagnosed pulmonary tuberculosis and identified pulmonary abnormalities in all patients. There were no significant differences between the two techniques in terms of identifying the location and distribution of the lung lesions, though the higher resolution of MRI did allow for better identification of parenchymal dishomogeneity, caseosis, and pleural or nodal involvement. CONCLUSION: Technical developments and the refinement of pulse sequences have improved the quality and speed of MRI. Our data indicate that in terms of identifying lung lesions in non-AIDS patients with non- miliary pulmonary tuberculosis, MRI achieves diagnostic performances comparable to those obtained by HRCT but with better and more rapid identification of pulmonary tissue abnormalities due to the excellent contrast resolution.

Sonographic assessment of facial HIV-related lypoatrophy.

OBJECTIVE: To investigate the utility of ultrasonography (US) for assessing and grading facial lypoatrophy (FLA) in patients with HIV. DESIGN: The social effect of FLA is huge and may reduce antiretroviral therapy adherence. Strategies for the early detection of FLA are crucial, because complete correction of FLA in late stages is unlikely. METHODS: Fifty-two HIV-positive patients undergoing highly active antiretroviral therapy underwent US with nasogenian transversal scan using a high-frequency broadband transducer (5-17 MHz) to detect FLA. Intra- and interobserver variability were calculated to assess US reproducibility. Concerning FLA grading, patients were categorized in five clinical classes and four US classes. RESULTS: Our results regarding inter- and intraobserver coefficients of variation permit the validation of US as a reproducible technique (p<.001), and a high correlation between US and clinical classification was obtained, with complete concordance for more advanced FLA classes. CONCLUSIONS: The lack of a reference objective method to quantify subcutaneous fat is a major difficulty in measuring HIV-related FLA. Our results, in accordance with data from the literature, suggest that US is an ideal tool for assessing and grading FLA. Furthermore, US may be suitable for routine evaluation in HIV-infected patients for early detection of FLA and to select its optimal management.

Progressive multifocal leukoencephalopathy in HIV-infected patients in the era of HAART: radiological features at diagnosis and follow-up and correlation with clinical variables.

The magnetic resonance (MR) imaging patterns of HIV-infected patients affected by progressive multifocal leukoencephalopathy (PML) in the HAART era have not been extensively documented. The aim of the present study is to describe the MR features of PML in HIV-infected patients at diagnosis, and the evolution during follow-up, evaluating the impact of HAART on imaging, and to correlate the MR pattern with the virological and immunological levels and with survival. We retrospectively reviewed MR imaging at baseline and at the last available follow-up within 6 months of diagnosis (median 4 months, range 1-6) of 31 HIV-positive patients affected by PML. A closer follow-up [median interval from diagnosis 39 days (range 20-139)] was also reported. At the onset of neurological disorder, 19 patients were naive for antiretroviral therapy, 7 patients were on HAART, and 5 patients were experienced but were not taking antiretroviral therapy. Upon PML diagnosis no significant differences at imaging were observed between naive and experienced patients and HAART-treated or non-HAART-treated patients. MR findings were not related to immunological status, either at baseline or at follow-up. A radiological improvement within 6 months was associated with a higher probability of a more favorable clinical evolution [OR 14.0 (2.2-87.2), p = 0.003]. The overall probability of survival at 6 months was 61.5%. A better survival was observed in patients with stable or improved MR imaging findings within 6 months [HR 4.55 (95%CI 1.36-15.19, p = 0.009]. Although HAART prolonged the survival of HIV-positive patients affected by PML, it did not seem to influence the PML MR pattern of presentation and the imaging evolution. Only the radiological outcome was predictive of clinical outcome.

Reduced computed tomography radiation dose in HIV-related pneumonia: effect on diagnostic image quality.

PURPOSE: The objective of this study was to compare the diagnostic quality of low-dose computed tomography (CT) with that of standard-dose chest CT in the diagnosis of infectious lung diseases. MATERIALS AND METHODS: Thirty chest CT scans [high-resolution computed tomography (HRCT), 15; spiral CT, 15] were performed in HIV-positive patients with an infectious lung disease. Two additional slices were obtained at two lower exposures (HRCT, 120 kV/70 mAs and 120 kV/50 mAs; spiral CT, 100 kV/56 mAs and 100 kV/40 mAs) after chest routine CT. Observers compared the quality of the images obtained at different parameters and image noise. Objective evaluation of image noise was also made. RESULTS: Diagnostic image quality was excellent in 93% of the low-dose HRCT scans and in 86% of the low-dose spiral CT scans, rates that are always acceptable in any case. Significant differences were found in noise levels between the low-dose and reference scans; however, artifacts did not compromise detection of abnormalities. In HRCT, a mean reduction of 77% from the standard technique to the low-dose scan is possible in total and in lung effective doses. In spiral CT, this reduction is lower at 71%. These values can reach a further reduction with ultra-low-dose imaging (84% in HRCT and 80% in spiral CT). CONCLUSIONS: Chest CT image quality appears to be adequate to evaluate pulmonary infectious diseases, even with an effective reduction in radiation dose. Standard-dose CT with a higher patient effective dose may be appropriate for selected cases.

Reduced value of thallium-201 single-photon emission computed tomography in the management of HIV-related focal brain lesions in the era of highly active antiretroviral therapy.

To evaluate the diagnostic value of thallium-201 single-photon emission computed tomography (201Tl SPECT) in the management of focal brain disorders in the era of highly active antiretroviral therapy (HAART), a validation study of diagnostic procedure was performed in a tertiary clinical care center in Italy. Thirty-eight consecutive HIV-infected patients with neurological impairment and focal brain lesions (FBL) were enrolled in a prospective evaluation and underwent diagnostic procedures according to a standardized protocol based on modified previously released guidelines. Six out of seven PCNSL presented high uptake at 201Tl SPECT [sensitivity 86% (95% CI 42-99); specificity 77% (95% CI 58-90); positive predictive value (PPV) 46% (95% CI 20-74); negative predictive value (NPV) 96% (95% CI 78-100)]. Among toxoplasmic encephalitis (TE) cases 14 showed no uptake and 5 showed an increased uptake [sensitivity 74% (95% CI 49-90); specificity 42% (95% CI 21-66); PPV 56% (95% CI 35-75); NPV 61% (95% CI 32-85)]. Patients taking HAART were more likely to display an increased uptake of 201Tl in the cerebral lesions than patients without HAART (OR 5.07; 95% CI 1.19-21.5). Considering only the patients with diagnosis of TE, 60% of patients who showed high radionuclide uptake were taking HAART, while 79% of patients without relevant uptake were not taking HAART. As a result of the impact of HAART, the diagnostic value of 201Tl SPECT in the management of HIV-associated FBL could be substantially reduced. This observation suggests that in HAART-treated patients, this diagnostic tool be used only when combined with other more specific diagnostic markers.

Relationship between body mass index and bone mineral density in HIV-infected patients referred for DXA.

INTRODUCTION: Reduced bone mass density (BMD) is a frequent observation in HIV-infected persons. Relationship between body mass index (BMI), weight, height and BMD was reported for many populations. In particular, BMI has been found to be inversely related to the risk of osteoporosis. METHODS: This is a cross-sectional, monocentric study where all HIV-infected patients referred to first DXA scan in clinical routine during 2010-2013 were included. Osteopenia and osteoporosis were defined by T- score <-1 and <-2.5, respectively. Patients were categorized according to WHO BMI classification: underweight <18.5 kg/m(2); normal weight 18.5-24.9 kg/m(2); over weight 25-29.9 kg/m(2); obese >30 kg/m(2). Statistical analysis was carried using logistic regression. RESULTS: A total of 918 patients were included: median age 49 years (IQR, 44-55); 59.4% male; 93% Caucasian. Median anthrometric characteristics were: 68 kg (IQR, 59-78); 1.7 m (IQR, 1.6-1.75); 23.5 kg/m(2) (IQR, 21.4-26.2). Underweight was found in 5%, normal weight in 61%, overweight in 26% and obesity in 8% of patients. According to T-scores, 110 (11.2%) patients were osteoporotic and 502 (54.7%) had osteopenia. In the femoral neck area, the prevalence of osteoporosis was slightly lower (5.7%) than lumbar spine site (9.2%). Agreements between sites of T-scores for the diagnosis of osteoporosis were 26 and 172 and 346 for osteopenia and normal BMD values, respectively. T-scores at femoral neck or lumbar spine positively correlated with BMI (p<0.001) (Figure 1). Among predictors of osteopenia/osteoporosis, univariable analysis showed: older age (p<0.0001); lower weight (p<0.0001); increasing height (p<0.002). Patients underweight had a higher risk of osteopenia (p=0.02) as well as of osteoporosis (p=0.003). Patients with BMI above normal had a reduced risk of low BMD (osteopenia p<0.0001; osteoporosis p<0.03). Controlling for calendar year, gender, ethnicity, and age, BMI was confirmed as risk factor if below normal (AdjOR of osteopenia 2.42 [95% CI 1.16-5.07] p=0.02; AdjOR of osteoporosis 3.22 [95% CI 1.60-6.49] p=0.001). CONCLUSIONS: Our findings indicate that almost 66% of HIV-infected patients have subnormal bone mass. Further, as in other patient populations, in the HIV infection also low BMI is an important risk factor for osteopenia/osteoporosis. This finding highlights the compelling need for standardized screening actions, particularly in patients weighting below normal.

Giant hydatid cyst of the liver with a retroperitoneal growth: a case report.

INTRODUCTION: Hydatid disease is a helminthic anthropozoonosis with worldwide distribution due to the close associations among sheep, dogs, and humans. It can occur almost anywhere in the body with a variety of imaging features, which may change according to the growth stage, associated complications, and affected tissues. A definitive diagnosis requires a combination of imaging, serologic and immunologic studies. Ultrasonography, computed tomography and magnetic resonance imaging are highly accurate in detecting a hepatic hydatid cyst. However, hepatic hydatid cysts in an unusual location and/or of an unusual dimension, with atypical imaging findings, may complicate the differential diagnosis. Surgical treatment remains the best treatment. CASE PRESENTATION: We describe an unusual case of a giant hydatid cyst, with exophytic growth from the right lobe of the liver of a 55-year-old Egyptian man. The cyst was strongly adhered to his ipsilateral kidney, which was displaced in a downwards and anterior direction, close to his abdominal wall, simulating a retroperitoneal origin. This atypical growth raised doubts about the most appropriate surgical approach. Magnetic resonance imaging easily clarified the origin of the cyst as our patient's liver, allowing accurate surgical planning. CONCLUSION: Rarely, hydatid cysts can reach an extremely large size without any additional symptoms. Giant cysts need radical therapy because they might lead to perforation and anaphylaxis in some patients. Magnetic resonance imaging is very useful in the study of hydatid disease because of its capacity to allow a large field of view, multiplanar acquisition, and high contrast resolution. In some unusual hepatic presentations, magnetic resonance imaging can be used to determine the correct anatomical relationships.

IP-10 is an additional marker for tuberculosis (TB) detection in HIV-infected persons in a low-TB endemic country.

OBJECTIVE: In Indian HIV-infected patients, IP-10 response to QuantiFERON-TB Gold In tube (QFT-IT) antigens has been associated to tuberculosis (TB). However, specificity for active TB was lower than that reported by QFT-IT, making accuracy for TB detection questionable. To investigate this uncertainty, likely due to India being highly endemic for TB, and to better identify TB correlates, we evaluated the IP-10-based assay in HIV-infected subjects in Italy, a low-TB endemic country. METHODS: 195 individuals were prospectively enrolled; 118 were HIV-infected (21 with active TB, 97 without active TB, and distinguished as high/low-TB-risk). QFT-IT was performed and IP-10 was evaluated by ELISA. RESULTS: Among the HIV-infected individuals, sensitivity for active TB was 66.7% by IP-10-based test and 52.4% (p = 1) by QFT-IT. IP-10-based assay showed a lower dependence on mitogen-response and CD4 counts than QFT-IT. Among subjects without active TB, a higher proportion of IP-10 responders was shown in high-TB-risk subjects than low-TB-risk subjects (40.0% vs 12.9%), similar to QFT-IT (37.1% vs 4.8%). Low-TB risk subjects showed 87.1% specificity for active TB by IP-10-based test vs 95.2% by QFT-IT. CONCLUSIONS: In a low-TB endemic country, besides IFN-γ, IP-10 response to QFT-IT is associated with active TB and TB risk factors in HIV-infected patients with lower dependence on mitogen-response and CD4 counts.

HIV-related pneumococcal lung disease: does highly active antiretroviral therapy or bacteremia modify radiologic appearance?

We reviewed chest radiographs of 57 HIV-infected patients with pulmonary diseases in whom Streptococcus pneumoniae was the sole respiratory pathogen isolated to evaluate whether highly active antiretroviral therapy (HAART) or bacteremia modify radiographic appearance. Pneumococcal lung disease presented as lobar pneumonia in 40% of the cases, 54% of whom were on HAART; as bronchopneumonia in 42%, 58% on HAART; as interstitial infiltrates in 17%, 60% on HAART. Bacteremia was observed 38 times in 23 patients with CD4 less than 200/mm(3), and in 15 with CD4 greater than 200/mm(3) (p > 0.05). HAART does not significantly influences radiographic appearances of lung disease caused by Streptococcus pneumoniae (p > 0.05). Immunosuppression induced by HIV infection was a major risk factor for development of pneumococcal lung disease (p = 0.04) and influences radiographic appearance; bronchopneumonia (p = 0.006), in particular multifocal (p = 0.008), which was more frequent in subjects with CD4 less than 200/mm(3). Bacteremia influences radiographic appearance of pneumococcal lung disease; lobar pneumonia was more frequent (p = 0.003), and considering CD4 cell count, was more frequent if CD4 cell count was above 200/mm(3). An original finding of this study was the frequency of interstitial changes. This pattern of pneumonia, found in 17% of our patients, could represent a difference between HIV-seropositive and -seronegative subject in displaying pneumococcal lung disease.