Dependence of intravoxel incoherent motion diffusion MR threshold b-value selection for separating perfusion and diffusion compartments and liver fibrosis diagnostic performance.

BACKGROUND: Intravoxel incoherent motion (IVIM) tissue parameters depend on the threshold b-value. PURPOSE: To explore how threshold b-value impacts PF ( f), Dslow ( D), and Dfast ( D*) values and their performance for liver fibrosis detection. MATERIAL AND METHODS: Fifteen healthy volunteers and 33 hepatitis B patients were included. With a 1.5-T magnetic resonance (MR) scanner and respiration gating, IVIM data were acquired with ten b-values of 10, 20, 40, 60, 80, 100, 150, 200, 400, and 800 s/mm2. Signal measurement was performed on the right liver. Segmented-unconstrained analysis was used to compute IVIM parameters and six threshold b-values in the range of 40-200 s/mm2 were compared. PF, Dslow, and Dfast values were placed along the x-axis, y-axis, and z-axis, and a plane was defined to separate volunteers from patients. RESULTS: Higher threshold b-values were associated with higher PF measurement; while lower threshold b-values led to higher Dslow and Dfast measurements. The dependence of PF, Dslow, and Dfast on threshold b-value differed between healthy livers and fibrotic livers; with the healthy livers showing a higher dependence. Threshold b-value = 60 s/mm2 showed the largest mean distance between healthy liver datapoints vs. fibrotic liver datapoints, and a classification and regression tree showed that a combination of PF (PF < 9.5%), Dslow (Dslow < 1.239 × 10-3 mm2/s), and Dfast (Dfast < 20.85 × 10-3 mm2/s) differentiated healthy individuals and all individual fibrotic livers with an area under the curve of logistic regression (AUC) of 1. CONCLUSION: For segmented-unconstrained analysis, the selection of threshold b-value = 60 s/mm2 improves IVIM differentiation between healthy livers and fibrotic livers.

Correlation between 18F-FDG PET CT SUV and symptomatic or asymptomatic pulmonary tuberculosis.

OBJECTIVE: To explore the difference of 18F-FDG PET/CT images between the symptomatic and asymptomatic pulmonary tuberculosis, as well as the correlation between the standard uptake value (SUV) and the symptomatic/asymptomatic pulmonary tuberculosis. METHODS: A study dataset of 57 pulmonary tuberculosis cases was retrospectively assembled and analyzed. Among these cases, 30 were diagnosed having symptomatic pulmonary tuberculosis and 27 were asymptomatic pulmonary tuberculosis. PET/CT was performed in all 57 cases. The clinical data, CT images and PET/CT radioactive uptake data were analyzed using statistical data analysis software. RESULTS: All 57 cases showed radioactively high uptake, with the maximum standard uptake value (SUVmax) of the lesion ranging from 1.60 to 27.30 and a mean value of 6.63±4.82. The symptomatic cases had an SUVmax of 8.76±4.97 and the asymptomatic cases had an SUVmax of 4.27±3.39. The SUVmax as well as singular or multiple lesions showed statistical differences between symptomatic and asymptomatic cases. CONCLUSION: The symptomatic pulmonary tuberculosis cases show significantly higher SUVmax than the asymptomatic cases. Based on the criteria of SUVmax greater than 2.0 to define active lesions, 100% of symptomatic cases might have active lesions while 70.4% of asymptomatic cases might have active lesions. Therefore, focused attention should be clinically paid on the asymptomatic cases of pulmonary tuberculosis to avoid miss diagnosis and delayed treatment.

Differences in pulmonary nodular consolidation and pulmonary cavity among drug-sensitive, rifampicin-resistant and multi-drug resistant tuberculosis patients: the Guangzhou computerized tomography study.

Background: Pulmonary nodular consolidation (PN) and pulmonary cavity (PC) may represent the two most promising imaging signs in differentiating multidrug-resistant (MDR)-pulmonary tuberculosis (PTB) from drug-sensitive (DS)-PTB. However, there have been concerns that literature described radiological feature differences between DS-PTB and MDR-PTB were confounded by that MDR-PTB cases tend to have a longer history. This study seeks to further clarify this point. Methods: All cases were from the Guangzhou Chest Hospital, Guangzhou, China. We retrieved data of consecutive new MDR cases [n=46, inclusive of rifampicin-resistant (RR) cases] treated during the period of July 2020 and December 2021, and according to the electronic case archiving system records, the main PTB-related symptoms/signs history was ≤3 months till the first computed tomography (CT) scan in Guangzhou Chest Hospital was taken. To pair the MDR-PTB cases with assumed equal disease history length, we additionally retrieved data of 46 cases of DS-PTB patients. Twenty-two of the DS patients and 30 of the MDR patients were from rural communities. The first CT in Guangzhou Chest Hospital was analysed in this study. When the CT was taken, most cases had anti-TB drug treatment for less than 2 weeks, and none had been treated for more than 3 weeks. Results: Apparent CT signs associated with chronicity were noted in 10 cases in the DS group (10/46) and 9 cases in the MDR group (10/46). Thus, the overall disease history would have been longer than the assumed <3 months. Still, the history length difference between DS patients and MDR patients in the current study might not be substantial. The lung volume involvement was 11.3%±8.3% for DS cases and 8.4%±6.6% for MDR cases (P=0.022). There was no statistical difference between DS cases and MDR cases both in PN prevalence and in PC prevalence. For positive cases, MDR cases had more PN number (mean of positive cases: 2.63 vs. 2.28, P=0.38) and PC number (mean of positive cases: 2.14 vs. 1.38, P=0.001) than DS cases. Receiver operating characteristic curve analysis shows, PN ≥4 and PC ≥3 had a specificity of 86% (sensitivity 25%) and 93% (sensitivity 36%), respectively, in suggesting the patient being a MDR cases. Conclusions: A combination of PN and PC features allows statistical separation of DS and MDR cases.

Chinese expert consensus on imaging diagnosis of drug-resistant pulmonary tuberculosis.

Tuberculosis (TB) remains one of the major infectious diseases in the world with a high incidence rate. Drug-resistant tuberculosis (DR-TB) is a key and difficult challenge in the prevention and treatment of TB. Early, rapid, and accurate diagnosis of DR-TB is essential for selecting appropriate and personalized treatment and is an important means of reducing disease transmission and mortality. In recent years, imaging diagnosis of DR-TB has developed rapidly, but there is a lack of consistent understanding. To this end, the Infectious Disease Imaging Group, Infectious Disease Branch, Chinese Research Hospital Association; Infectious Diseases Group of Chinese Medical Association of Radiology; Digital Health Committee of China Association for the Promotion of Science and Technology Industrialization, and other organizations, formed a group of TB experts across China. The conglomerate then considered the Chinese and international diagnosis and treatment status of DR-TB, China's clinical practice, and evidence-based medicine on the methodological requirements of guidelines and standards. After repeated discussion, the expert consensus of imaging diagnosis of DR-PB was proposed. This consensus includes clinical diagnosis and classification of DR-TB, selection of etiology and imaging examination [mainly X-ray and computed tomography (CT)], imaging manifestations, diagnosis, and differential diagnosis. This expert consensus is expected to improve the understanding of the imaging changes of DR-TB, as a starting point for timely detection of suspected DR-TB patients, and can effectively improve the efficiency of clinical diagnosis and achieve the purpose of early diagnosis and treatment of DR-TB.

The sensitivity and specificity of 18F-FDG PET/CT in spinal leptomeningeal metastases: the synergistic effect of the 18F-FDG PET-CT to gadolinium-enhanced MRI.

Background: Magnetic resonance imaging (MRI) plays an important role in the diagnosis of leptomeningeal metastases (LM); however, some sub-centimeter lesions may be missed. Positron emission tomography/computed tomography (PET/CT) has a high sensitivity and may play a synergistic role with MRI in diagnosing spinal LM (SLM). We aimed to retrospectively evaluate the detection of SLM with 18F-fluorodeoxyglucose PET/CT (18F-FDG PET/CT) compared to that of whole spinal cord MRI in a single center. Methods: Patients with SLM who had undergone 18F-FDG PET/CT and MRI were enrolled. 18F-FDG PET/CT imaging findings were independently reviewed by 2 nuclear medicine physicians. 18F-FDG PET/CT findings of SLMs were described. A consistency test was conducted to assess the patient-based diagnostic results obtained by the 2 physicians. Patient-based sensitivity, accuracy, and specificity in diagnosing SLM between 18F-FDG PET/CT and MRI of the whole spinal cord were compared using the chi-square or Fisher's exact test. A P value of <0.05 was considered statistically significant. The receiver operating characteristic (ROC) curve was obtained to assess the diagnostic performance of maximum standardized uptake value (SUVmax) to diagnose SLM. Results: A total of 16 patients with SLM were included in this study from October 2010 to April 2022. The primary tumor involved the lungs, liver, ovaries, prostate, esophagus, and unknown primary site. The mean age of patients, including 13 males and 3 females, was 57.8±11.2 (range, 34-73) years. Of 16 patients with SLM, 10 had nodular diseases, 2 had linear diseases, and 4 had mixed diseases. The kappa value of the consistency test of the 2 radiologists' diagnostic results was 0.765. The patient-based sensitivity, specificity, and accuracy of 18F-FDG PET/CT in diagnosing SLM were 87.5%, 89.2%, and 88.7%, respectively and those of whole spinal cord MRI were 75.0%, 100.0%, and 92.5%, respectively. There were no significant differences in sensitivity, specificity, and accuracy between the 2 methods, with P values of 0.654, 0.115, and 0.506, respectively. However, more nodular diseases were observed on PET/CT. The area under the ROC curve (AUC) for the prediction of SLM by SUVmax was 0.907 [95% confidence interval (CI): 0.831-0.983]. When SUVmax ≥2.45, the Youden index was the largest, and the sensitivity and specificity were 89.3% and 75.7%, respectively. Conclusions: 18F-FDG PET/CT is a good choice of imaging modality for assessing SLM. In the diagnosis of SLMs, PET/CT and enhanced MRI can play a better synergistic role.

Role of 18F-FDG PET/CT in the diagnosis and management of patients with Langerhans cell histiocytosis.

Background: Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasm that can involve multisystem organs. Positron emission tomography/computed tomography (PET/CT) has been widely used in tumor staging and efficacy evaluation. However, at present, there are few 18F-fluorodeoxyglucose (FDG) PET/CT studies on LCH. This study aimed to explore the possible role of 18F-FDG PET/CT in the diagnosis and management of patients with LCH. Methods: 18F-FDG PET/CT images of 22 Chinese patients diagnosed with LCH on biopsy or surgery histopathology between January 2011 and December 2020 were retrospectively analyzed. The incidence of LCH in each system was assessed by a PET/CT scan. The imaging characteristics were analyzed semiquantitatively and qualitatively. The discrepancies between PET/CT and conventional imaging modalities were recorded. Evaluations of curative effect according to RECIST1.1 and PERCIST1.0 were compared using Fisher's exact chi-squared test, and P values <0.05 were considered significant. Results: Eight (36.4%) of the 22 patients presented with single system involvement (4 isolated site involvement, 4 multiple site involvement), and 14 (63.6%) presented with multiple system involvement. Twenty-one (95.5%) patients had hypermetabolic lesions. Musculoskeletal, lymphatic, respiratory, liver, skin-soft tissue and thyroid involvement were seen in 14 (63.6%), 13 (59.1%), 5 (22.7%), 4 (18.2%), 5 (22.7%) and 1 (4.5%) patient, respectively. Cranial and facial bones were the most common sites of musculoskeletal involvement. Ten patients underwent PET/CT follow-up, and there was no significant difference in curative effect evaluations according to RECIST1.1 and PERCIST1.0. However, among the complete remission cases assessed by RECIST1.1, three were partial metabolic responses assessed by PERCIST1.0, while among the partial response cases assessed by RECIST1.1, one was metabolic progressive disease assessed by PERCIST1.0. Conclusions: 18F-FDG PET/CT is an imaging modality option for the diagnosis and assessment of the curative effect of LCH.

Annotations of Lung Abnormalities in Shenzhen Chest X-ray Dataset for Computer-Aided Screening of Pulmonary Diseases.

Developments in deep learning techniques have led to significant advances in automated abnormality detection in radiological images and paved the way for their potential use in computer-aided diagnosis (CAD) systems. However, the development of CAD systems for pulmonary tuberculosis (TB) diagnosis is hampered by the lack of training data that is of good visual and diagnostic quality, of sufficient size, variety, and, where relevant, containing fine region annotations. This study presents a collection of annotations/segmentations of pulmonary radiological manifestations that are consistent with TB in the publicly available and widely used Shenzhen chest X-ray (CXR) dataset made available by the U.S. National Library of Medicine and obtained via a research collaboration with No. 3. People's Hospital Shenzhen, China. The goal of releasing these annotations is to advance the state-of-the-art for image segmentation methods toward improving the performance of fine-grained segmentation of TB-consistent findings in digital Chest X-ray images. The annotation collection comprises the following: 1) annotation files in JSON (JavaScript Object Notation) format that indicate locations and shapes of 19 lung pattern abnormalities for 336 TB patients; 2) mask files saved in PNG format for each abnormality per TB patient; 3) a CSV (comma-separated values) file that summarizes lung abnormality types and numbers per TB patient. To the best of our knowledge, this is the first collection of pixel-level annotations of TB-consistent findings in CXRs. Dataset: https://data.lhncbc.nlm.nih.gov/public/Tuberculosis-Chest-X-ray-Datasets/Shenzhen-Hospital-CXR-Set/Annotations/index.html.

[The relationship between chest CT findings and viral load in patients with novel influenza A (H1N1)].

OBJECTIVE: To evaluate the value of chest CT findings and dynamic changes of viral load in patients with novel influenza A (H1N1) infection in clinical diagnosis, differential diagnosis and treatment. METHODS: Fifty-one patients with confirmed novel influenza A (H1N1) according to the diagnostic criteria of the Ministry of Health, received chest X-ray, CT scans (HRCT) and viral load tests in our hospital from May to December of 2009. Based on whether there were signs of pneumonia in CT imaging, the patients were divided into a pneumonia group (n = 31) and a non-pneumonia group (n = 20). The relationship between chest CT changes and viral load was observed and analyzed statistically using SPSS 10.5 software. RESULTS: Patchy consolidations of lungs were the main findings in pneumonia group with influenza A (H1N1) infection, and ground-glass opacities were the main CT findings at acute and convalescent phases. Lobular and segmental shadows of the lungs were diffusely distributed, mostly found in lower lungs, especially the left lung. In some cases, the lung diseases were accompanied with mediastinal lymphadenopathy. Co-existence of pulmonary parenchymal, interstitial and pleural diseases was observed. Peak viral load occurred at the early phase of illness, with the mean initial viral load being 7.7 copies/ml and 4.2 copies/ml in the pneumonia and the non-pneumonia groups respectively. The viral nucleic acid became negative 4 days after antiviral treatment (course of 6 days). Dynamic observation of 3 patients with novel influenza A (H1N1) pneumonia showed that, the viral clearance period preceded the absorption of lung lesions in 2 cases, but viral clearance period of a young patient was significantly prolonged. CONCLUSION: In patients with the novel influenza A (H1N1) infection, the viral load in the pneumonia group was significantly higher than that in the group with normal chest imaging. Dynamic observation on chest imaging and viral load may be beneficial for clinicians to start prompt and effective treatment.

[Diagnosis and treatment of 11 patients with acquired immune deficiency syndrome complicated with tuberculosis of mesenteric lymph nodes.].

OBJECTIVE: To study the clinical features of acquired immune deficiency syndrome (AIDS) complicated with tuberculosis of mesenteric lymph nodes. METHODS: Cases (n = 153) with AIDS complicated with tuberculosis hospitalized in this hospital from September 1999 to December 2008 were retrospectively analyzed. Mesenteric lymph node tuberculosis was found in 11 cases, including 7 males and 4 females. One patient was 8 years old, and the other 10 were over 22 years (ranging from 8 to 55 years). RESULTS: In patients with AIDS complicated with tuberculosis, 7% (11/158) had tuberculosis of the mesenteric lymph nodes. The CD(4)(+) cell count was less than 50 x 10(6) cells/L in 8 cases, and (50 - 100) x 10(6) cells/L in 3 cases. The symptoms included fever (11/11), abdominal pain (11/11), abdominal distension (11/11), night sweat (7/11), weight loss (10/11), diarrhea (7/11), anemia (5/11), abdominal mass (3/11), and ascites (1/11). Abdominal ultrasound showed multiple enlarged mesenteric lymph nodes in all of the 11 cases, and abdominal CT scanning presented typical enhanced ring shadows. Biopsy of mesenteric lymph nodes was obtained from 2 cases, and both revealed tuberculoma, caseous necrosis. Longerhan cell infiltration, and positive stain for fast anti-acid bacilli. Enlarged mesenteric lymph nodes became smaller and disappeared after treatment with antituberculous drugs for 6 months and highly active antiretroviral therapy (HAART) for 5 months in all the 11 patients. CONCLUSIONS: There were no specific clinical manifestations in AIDS patients with tuberculosis of mesenteric lymph nodes. However, AIDS patients with CD(4)(+) cell count less than 50 x 10(6) cells/L might be more prone to developing tuberculosis of the mesenteric lymph nodes. Abdominal CT scanning with typical strengthened ring shadow is suggestive of the diagnosis. Anti-tuberculous therapy combined with HAART is recommended for the treatment of patients with suspected tuberculosis.

Updates on 18F-FDG-PET/CT as a clinical tool for tuberculosis evaluation and therapeutic monitoring.

Tuberculosis (TB) is currently the world's leading cause of infectious mortality. The complex immune response of the human body to Mycobacterium tuberculosis (M.tb) results in a wide array of clinical manifestations, thus the clinical and radiological diagnosis can be challenging. 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) scan with/without computed tomography (CT) component images the whole body and provides a metabolic map of the infection, enabling clinicians to assess the disease burden. 18F-FDG-PET/CT scan is particularly useful in detecting the disease in previously unknown sites, and allows the most appropriate site of biopsy to be selected. 18F-FDG-PET/CT is also very valuable in assessing early disease response to therapy, and plays an important role in cases where conventional microbiological methods are unavailable and for monitoring response to therapy in cases of multidrug-resistant TB or extrapulmonary TB. 18F-FDG-PET/CT cannot reliably differentiate active TB lesion from malignant lesions and false positives can also be due to other infective or inflammatory conditions. 18F-FDG PET is also unable to distinguish tuberculous lymphadenitis from metastatic lymph node involvement. The lack of specificity is a limitation for 18F-FDG-PET/CT in TB management.

A Combined Use of Intravoxel Incoherent Motion MRI Parameters Can Differentiate Early-Stage Hepatitis-b Fibrotic Livers from Healthy Livers.

This study investigated a combined use of intravoxel incoherent motion (IVIM) parameters, Dslow ( D), PF ( f), and Dfast ( D*), for liver fibrosis evaluation. Sixteen healthy volunteers (F0) and 33 hepatitis-b patients (stage F1 = 15, stage F2-4 = 18) were included. With a 1.5 T MR scanner and respiration gating, IVIM diffusion-weighted imaging was acquired using a single-shot echo-planar imaging sequence with 10 b values of 10, 20, 40, 60, 80, 100, 150, 200, 400, and 800 s/mm2. Signal measurement was performed on right liver parenchyma. With a three-dimensional tool, Dslow, PF, and Dfast values were placed along the x axis, y axis, and z axis, and a plane was defined to separate healthy volunteers from patients. The three-dimensional tool demonstrated that healthy volunteers and all patients with liver fibrosis could be separated. Classification and regression tree showed that a combination of PF (PF < 12.55%), Dslow (Dslow < 1.152 × 10-3 mm2/s), and Dfast (Dfast < 13.36 × 10-3 mm2/s) could differentiate healthy subjects and all fibrotic livers (F1-4) with an area under the curve of logistic regression (AUC) of 0.986. The AUC for differentiation of healthy livers versus F2-4 livers was 1. PF offered the best diagnostic value, followed by Dslow; however, all three parameters of PF, Dslow, and Dfast contributed to liver fibrosis detection.

Bi-phase age-related brain gray matter magnetic resonance T1ρ relaxation time change in adults.

OBJECTIVES: To investigate normative value and age-related change of brain magnetic resonance T1ρ relaxation at 1.5T. METHODS: This study was approved by the local ethical committee with participants' written consent obtained. There were 42 adults healthy volunteers, including 20 males (age: 41±16 (mean±standard deviation) years, range: 22-68years,) and 22 females (age: 39±15years, range: 21-62years). MRI was performed at 1.5T using 3D fluid suppressed turbo spin echo sequence. Regions-of-interests (ROIs) were obtained by atlas-based tissue segmentation and T1ρ was calculated by fitting the mean value to mono-exponential model. Correlation between T1ρ relaxation of brain gray matter regions and age was investigated. RESULTS: A regional difference among individual gray matter areas was noted; the highest values were observed in the hippocampus (98.37±5.37ms, median: 97.88ms) and amygdala (94.95±4.34ms, median: 94.73ms), while the lowest values were observed in the pallidum (83.81±5.49ms, median: 83.77ms) and putamen (83.93±4.76ms, median: 83.99ms). Gray matter T1ρ values decreased slowly (mean slope: -0.256) and significantly (p<0.05) with age in gray matter for subjects younger than 40years old, while for subjects older than 40years old there was no apparent correlation between T1ρ relaxation and age. Global white matter measured T1ρ value of 88.65±3.47ms (median: 87.86ms), and the correlation with age was not significant (p=0.18). CONCLUSION: Gray matter T1ρ relaxation demonstrates a bi-phase change with age in adults of 22-68years.

[An epidemic outbreak of respiratory infection caused by Chlamydia pneumoniae in medical workers].

OBJECTIVE: To investigate the clinical manifestations and the chest imaging characteristics of an epidemic outbreak of respiratory infection caused by Chlamydia pneumoniae (CP). METHODS: A prospective study for CP infection in 15 patients from September 2003 was carried out. Sputum and throat swab specimen were obtained and CP DNA was detected by polymerase chain reaction (PCR). Serum samples were obtained and immunoglobulin G and M (IgG and IgM) of antibodies to CP. pneumoniae were studied by microimmunofluorescence test. Chest X-ray and computed tomography were retrospectively analyzed. RESULTS: All patients presented fever, headache, sore throat, hoarseness, muscular ache, and dry cough. Acute cough was often associated with chest pain. The sputum blood was present in 3 patients (20%). Moist rales were heard in 4 patients. Chest imaging abnormalities were present in 67% (10 patients). The organism was demonstrated in 87% (13 patients) by PCR. The most common imaging abnormalities were unilateral and (or) bilateral multi-focal or solitary alveolar nodular opacities (9 patients). The patchy shadows were found in 2 patients, and pulmonary consolidation associated with the local pulmonary edema in 1 patient. Hilar or mediastinal lymphadenopathy and pleural effusion was not found. CONCLUSIONS: The colony occurrences and similar clinical and chest imaging manifestations are characteristics of an outbreak of respiratory infection caused by CP in medical workers. An outbreak of respiratory infection caused by CP should be differentiated from severe acute respiratory syndrome (SARS).

[Radiological features of AIDS complicated by pulmonary tuberculosis and the association with CD4+ T lymphocytes].

OBJECTIVE: To explore the imaging features in cases with AIDS complicated by pulmonary tuberculosis and the association with CD(4)(+) T lymphocytes. METHODS: A retrospective analysis was carried out of the manifestations of chest X-rays in patients with late stage AIDS complicate by pulmonary tuberculosis (n = 26 cases) and patients with pulmonary tuberculosis only (n = 60 cases). The results of measurements of CD(4)(+) T lymphocytes were compared. RESULTS: (1) The chest X-ray features in patients with AIDS complicated by pulmonary tuberculosis showed more patchy and blurring shadows (53.8% vs 8.3%; P < 0.01), more military changes (23.1% vs 5.0%; P < 0.05), more enlarged intrathoracic lymph nodes (34.6% vs 8.3%; P < 0.01) as well as more extra-pulmonary tuberculous processes (23.1% vs 3.3%; P < 0.05) as compared to patients with pulmonary tuberculosis alone. Fewer upper lung or apical lesions (23.1% vs 76.7%; P < 0.01), as well as less consolidation (11.5% vs 71.7%; P < 0.01) and cavity formation (7.7% vs 30.0%; P < 0.05) were found in AIDS patients. No significant difference was found in the occurrence of hydrothorax (11.5% vs 20.0%; P > 0.05). (2) The relative numbers of CD(4)(+) T lymphocytes in patients with AIDS complicated by pulmonary tuberculosis and in patients with pulmonary tuberculosis alone were (5.0 +/- 6.4)% and (65.3 +/- 1.5)% respectively. Atypical manifestations of tuberculosis were found in 15 out of the 26 cases of AIDS patients showing a CD(4)(+) T lymphocytic count < 50/microl, in 3 of the 4 cases with the count between 50/microl - 100/microl, while in cases with CD(4)(+)T lymphocytic count between 100/microl -200/microl (n = 4) and > 200/microl (n = 2), numbers of atypical tuberculosis were 2 and 0 respectively. CONCLUSIONS: The chest X-ray changes of tuberculosis in cases with late stage AIDS were mostly of the atypical pattern, and were related to a significant decrease in CD(4)(+)T lymphocyte count.

Opportunities and Challenges of Fluorescent Carbon Dots in Translational Optical Imaging.

The fluorescent carbon dot (C-dot) is a new class of carbon nanomaterials. It has a discrete or quasispherical structure, typically measures less than 10 nm and contains sp(2)/sp(3) carbon, oxygen/nitrogen-based groups and surface-modified functional groups. Compared with semiconductor quantum dots (QDs), C-dots offer much lower toxicity and a better biocompatibility profile. Their other favorable features include easy and inexpensive synthesis and surface modification potential. C-dots can be morphologically classified into graphene-based quantum dots (GQDs) and amorphous carbon nanodots (ACNDs). Numerous methods have been developed to synthesize C-dots, and are mainly divided into 'top-down' and 'bottom-up' routes. In the top-down route, C-dots (mostly GQDs) is derived from the separation of large carbon precursors. The 'bottom-up' method primarily involves the dehydration, polymerization and carbonization of small molecules to form the GQDs and ACNDs through thermal/hydrothermal synthesis, microwave irradiation, and solution chemistry. Potential applications of C-dots have been explored in a number of cellular and in-vivo imaging approaches. However, some difficulties remain, including limited penetration depth and poorly controlled in-vivo pharmacokinetics, which depends on multiple factors such as the morphology, physiochemical properties, surface chemistry and formulation of C-dots. The exact mechanism of in-vivo biodistribution, cellular uptake and long-term toxicological effect of C-dots still need to be elucidated. An integrated multi-disciplinary approach involving chemists, pharmacologists, toxicologists, clinicians, and regulatory bodies at the early stage is essential to enable the clinical application of C-dots.

Imaging manifestations and pathological analysis of severe pneumonia caused by human infected avian influenza (H7N9).

OBJECTIVE: To investigate the imaging and pathological findings of severe pneumonia caused by human infected avian influenza (H7N9), and therefore to further understand and improve diagnostic accuracy of severe pneumonia caused by human infected avian influenza (H7N9). METHODS: The relevant clinical and imaging data of 19 cases, including 10 males and 9 females, with pneumonia caused by human infected avian influenza (H7N9) was retrospectively analyzed. One of the cases had received percutaneous lung biopsy, with the clinical, imaging and pathological changes possible to be analyzed. RESULTS: The lesions were mainly located at lower lobes and dorsal of lungs, involving multiple lobes and segments. Ground-glass opacities and/or pulmonary opacities were the more often imaging manifestations of severe pneumonia caused by human infected avian influenza (H7N9) in early and evolving phases (19/19,100%). By biopsy following percutaneous lung puncture, exudation of slurry, cellulose, RBC and neutrophils, formation of hyaline membrane, squamous metaplasia and organizing exudates were observable at the alveolar space. Some of alveoli collapsed, and some responded to show compensatory emphysema. CONCLUSION: The imaging features of severe pneumonia caused by human infected avian influenza (H7N9) include obvious ground-glass opacity and pulmonary consolidation, mainly at lower lobes and dorsal of lungs, with rapid changes. The cross-analysis of imaging and pathology preliminary can elucidate the pathological mechanisms of ground-glass opacities and pulmonary consolidation of severe pneumonia. Such an intensive study is beneficial to prompt clinicians to observe and evaluate the progress of the disease. In addition, it is also in favor of managing the symptoms and reducing the mortality rate.

Hepatic angiosarcoma with multiple metastases in a young man.

Hepatic angiosarcoma, also called Kupffer's sarcoma, is a malignant mesenchymal neoplasm of endothelial cells, represents less than two percent of all primary liver neoplasm. Hepatic angiosarcoma is an infrequent and difficult-to-diagnose disease, mostly discovered by chance. Because of its rapid progression and usually fatal outcome, early diagnosis is necessary and complete surgical resection is the key to improve prognosis, but the neoplasm is often disseminated at the time of diagnosis, making resection impossible. Rare cases of hepatic angiosarcoma have been reported in the literature. Here, we report a case of hepatic angiosarcoma with spleen, lungs, right atrium and spine infiltration. Contrast enhanced abdomen CT and MRI scans revealed multiple nodules in the liver and spleen with rich blood supply, at the same time many metastases were noticed at bilateral lungs, right atrium and spine. The lesions rapidly deteriorated during the 2 months following the exams. The diagnosis of hepatic angiosarcoma was made after an open biopsy.

Two public chest X-ray datasets for computer-aided screening of pulmonary diseases.

The U.S. National Library of Medicine has made two datasets of postero-anterior (PA) chest radiographs available to foster research in computer-aided diagnosis of pulmonary diseases with a special focus on pulmonary tuberculosis (TB). The radiographs were acquired from the Department of Health and Human Services, Montgomery County, Maryland, USA and Shenzhen No. 3 People's Hospital in China. Both datasets contain normal and abnormal chest X-rays with manifestations of TB and include associated radiologist readings.

Decreases in molecular diffusion, perfusion fraction and perfusion-related diffusion in fibrotic livers: a prospective clinical intravoxel incoherent motion MR imaging study.

PURPOSE: This study was aimed to determine whether pure molecular-based diffusion coefficient (D) and perfusion-related diffusion parameters (perfusion fraction f, perfusion-related diffusion coefficient D*) differ in healthy livers and fibrotic livers through intra-voxel incoherent motion (IVIM) MR imaging. MATERIAL AND METHODS: 17 healthy volunteers and 34 patients with histopathologically confirmed liver fibrosis patients (stage 1 = 14, stage 2 = 8, stage 3 & 4 = 12, METAVIR grading) were included. Liver MR imaging was performed at 1.5-T. IVIM diffusion weighted imaging sequence was based on standard single-shot DW spin echo-planar imaging, with ten b values of 10, 20, 40, 60, 80, 100, 150, 200, 400, 800 sec/mm2 respectively. Pixel-wise realization and regions-of-interest based quantification of IVIM parameters were performed. RESULTS: D, f, and D* in healthy volunteer livers and patient livers were 1.096±0.155 vs 0.917±0.152 (10(-3) mm2/s, p = 0.0015), 0.164±0.021 vs 0.123±0.029 (p<0.0001), and 13.085±2.943 vs 9.423±1.737 (10(-3) mm2/s, p<0.0001) respectively, all significantly lower in fibrotic livers. As the fibrosis severity progressed, D, f, and D* values decreased, with a trend significant for f and D*. CONCLUSION: Fibrotic liver is associated with lower pure molecular diffusion, lower perfusion volume fraction, and lower perfusion-related diffusion. The decrease of f and D* in the liver is significantly associated liver fibrosis severity.

CT features of focal organizing pneumonia: an analysis of consecutive histopathologically confirmed 45 cases.

OBJECTIVE: To study the CT characteristics of solitary focal organizing pneumonia (FOP). MATERIALS AND METHODS: Chest CT of consecutive 45 patients (34 males and 11 females, median age: 56 years) with confirmed FOP were analyzed. The CT features between large FOP (>3 cm, n=27) and small FOP (≤ 3 cm, n=18) were compared. RESULTS: FOP lesions predominately located in peripheral lungs (86.7%), with the right lower lobe being most common lobe (44.4%). No lesion mainly located in the inner 1/3 of lungs. All large lesions were polygon in shape and had an irregular margin, while small lesions were more likely to be round or oval with an irregular or smooth border. Air bronchogram or small bubble-like lucency was present in majority of the lesions. 42.2% of lesions had incompact internal structure with inhomogeneous density besides air component. Most lesions were associated with a contraction or convergence of surrounding vessels; while no pulmonary vessel was interrupted abruptly by a small FOP lesion. Majority of large lesions had broad contact with the pleura, while only one patient had mild pleural effusion. Mild mediastinal lymph nodes enlargement was present in about 1/5 of the patients. CONCLUSION: Compared with the known CT features of lung cancer, our results suggest differential diagnosis can often be made for large FOP, while small FOP may resemble lung cancer.