Can Chest CT Features Distinguish Patients With Negative From Those With Positive Initial RT-PCR Results for Coronavirus Disease (COVID-19)?

OBJECTIVE. The purpose of this study was to explore the value of CT in the diagnosis of coronavirus disease (COVID-19) pneumonia, especially for patients who have negative initial results of reverse transcription-polymerase chain reaction (RT-PCR) testing. MATERIALS AND METHODS. Patients with COVID-19 pneumonia from January 19, 2020, to February 20, 2020, were included. All patients underwent chest CT and swab RT-PCR tests within 3 days. Patients were divided into groups with negative (seven patients) and positive (14 patients) initial RT-PCR results. The imaging findings in both groups were recorded and compared. RESULTS. Twenty-one patients with symptoms (nine men, 12 women; age range, 26-90 years) were evaluated. Most of the COVID-19 lesions were located in multiple lobes (67%) in both lungs (72%) in our study. The main CT features were ground-glass opacity (95%) and consolidation (72%) with a subpleural distribution (100%). Otherwise, 33% of patients had other lesions around the bronchovascular bundle. The other CT features included air bronchogram (57%), vascular enlargement (67%), interlobular septal thickening (62%), and pleural effusions (19%). Compared with that in the group with positive initial RT-PCR results, CT of the group with negative initial RT-PCR results was less likely to show pulmonary consolidation (p < 0.05). CONCLUSION. The less pulmonary consolidation found at CT, the greater is the possibility of negative initial RT-PCR results. Chest CT is important in the screening of patients in whom disease is clinically suspected, especially those who have negative initial RT-PCR results.

Two-Steps Coronary Artery Segmentation Algorithm Based on Improved Level Set Model in Combination with Weighted Shape-Prior Constraints.

Due to the complex topological structure of the coronary artery and the uneven distribution of the contrast agent, the angiography images are inevitably blurred and has low contrast, which causes great difficulty in process of segmentation. For this problem, a two-steps segmentation algorithm based on Hessian matrix and level set is proposed in this paper. Firstly, potential blood vessels of coronary images are preliminary extracted via Hessian matrix eigenvalues feature vectors of the geometric features and the response function. Then a novel regularization and area constraint is introduced into the local data energy fitting functional. Finally, the precision of Coronary Artery image is obtained in the evolution of the level set function. Experiments show that our proposed algorithm has better performance to these comparison segmentation algorithms.

[A four-generation pedigree affected with X-linked adrenal hypoplasia congenita due to a novel missense DAX1 mutation].

OBJECTIVE: To report on the clinical pictures of 7 patients from a pedigree affected with X-linked adrenal hypoplasia congenita (XL-AHC) and hypogonadotropic hypogonadism (HH) and the underlying mutations. METHODS: Seven patients were identified from a four-generation pedigree affected with XL-AHC and HH. Their clinical features, endocrinological changes, treatment and drug response were recorded. The patients were subjected to next-generation sequencing, and the result was verified by Sanger sequencing. PolyPhen-2 was used for predicting the influence of the mutation on protein production. RESULTS: Three deceased patients had manifested adrenal insufficiency (AI) within one year after birth. Two died at 6 and one died at 12. The four survivors presented with salient clinical and endocrinological features of AHC and HH, adrenal and testicular atrophy, and renin-angiotensin compensation. Two adult patients had testicular micro-stone detected by ultrasound.One of them also had remarkable seminiferous tubule degeneration by biopsy. The patients were followed up for 0.5 to 10 years. All required hyper-physiological dose of hydrocortisone to stabilize their clinical condition. In three patients, gonadotropic or androgen replacement induced cardinal masculine development but with unsatisfactory testis growth and sperm production.Genetic analysis revealed a novel missense c.827A>C (p.Q276P) mutation in a hotspot region within a highly conserved domain. PolyPhen-2 predicted the mutation to be highly hazardous. CONCLUSION: The novel p.Q276P mutation of the DAX1 gene probably underlies the XL-AHC and HH in this pedigree with variable clinical presentations in the patients.

Elderly population have a decreased aneurysmal subarachnoid hemorrhage incidence rate than Middle aged population: a descriptive analysis of 8,144 cases in mainland China.

PURPOSE: Rupture of an intracranial aneurysm is a life-threatening acute cerebrovascular event. The purpose of this study was to investigate whether aneurysmal subarachnoid haemorrhage (SAH) incidence rate is higher or lower in elderly population than in middle aged population. MATERIALS AND METHODS: Aneurysmal SAH cases were collected retrospectively from the archives of 21 hospitals in Mainland China. All the cases were collected from September 2016 and backward consecutively for a period of time up to 8 years. SAH was initially diagnosed by brain computed tomography (CT). CT angiography (CTA) or digital subtraction angiography (DSA) was followed and SAH was confirmed to be due to cerebral aneurysm rupture. For cases when multiple bleeding occurred, the age of the first SAH was used in this study. The total incidence from all hospitals at each age group were summed together for females and males respectively; then adjusted by the total population number at each age group for females and males which was from the 2010 population census of the People's Republic of China. RESULTS: In total there were 8,144 cases of intracranial aneurysmal SAH, with 4,861 females and 3,283 males. For females the relative aneurysmal SAH incidence rate started to decrease after around 65 years old, while for males the relative aneurysmal SAH incidence rate started to decrease after around 53 years old. CONCLUSION: Our data tentatively suggest elderly patients may be at a reduced risk of rupture compared with patients who are younger while have similar other risk factors.

Segmentation of pulmonary nodules using adaptive local region energy with probability density function-based similarity distance and multi-features clustering.

BACKGROUND: Pulmonary nodules in computerized tomography (CT) images are potential manifestations of lung cancer. Segmentation of potential nodule objects is the first necessary and crucial step in computer-aided detection system of pulmonary nodules. The segmentation of various types of nodules, especially for ground-glass opacity (GGO) nodules and juxta-vascular nodules, present various challenges. The nodule with GGO characteristic possesses typical intensity inhomogeneity and weak edges, which is difficult to define the boundary; the juxta-vascular nodule is connected to a vessel, and they have very similar intensities. Traditional segmentation methods may result in the problems of boundary leakage and a small volume over-segmentation. This paper deals with the above mentioned problems. METHODS: A novel segmentation method for pulmonary nodules is proposed, which uses an adaptive local region energy model with probability density function (PDF)-based similarity distance and multi-features dynamic clustering refinement method. Our approach has several novel aspects: (1) in the proposed adaptive local region energy model, the local domain for local energy model is selected adaptively based on k-nearest-neighbour (KNN) estimate method, and measurable distances between probability density functions of multi-dimension features with high class separability are used to build the cost function. (2) A multi-features dynamic clustering method is used for the segmentation refinement of juxta-vascular nodules, which is based on the nodule segmentation using active contour model (ACM) with adaptive local region energy and vessel segmentation using flow direction feature (FDF)-based region growing method. (3) it handles various types of nodules under a united framework. RESULTS: The proposed method has been validated on a clinical dataset of 113 chest CT scans that contain 157 nodules determined by a ground truth reading process, and evaluating the algorithm on the provided data leads to an average Tanimoto/Jaccard error of 0.17, 0.20 and 0.24 for GGO, juxta-vascular and GGO juxta-vascular nodules, respectively. CONCLUSIONS: Experimental results show desirable performances of the proposed method. The proposed segmentation method outperforms the traditional methods.

Quadrupedal head position enhances recovery from chronic maxillary sinusitis.

OBJECTIVES: The position of human maxillary ostia is high on their superomedial walls, which may be suboptimal for natural drainage. Human maxillary sinuses exhibit better passive drainage through their ostia when tilted anteriorly to mimic a quadrupedal head position. We all know that sufficient drainage is very important for the treatment of chronic rhinosinusitis (CRS). Chronic maxillary sinusitis (CMS) is the high incidence of CRS. The aim of this study was to investigate the efficacy of quadrupedal head position in patients with CMS. METHODS: One hundred six patients diagnosed with CMS were enrolled. Patients were randomized to quadrupedal head position group and non-quadrupedal head position group for 6 weeks of treatment. Treatment outcomes were measured using 1) Lund-Mackay scoring system of pre-and post-treatment computer tomography (CT); and 2) Sinonasal Quality-of-Life (QoL) Survey completed at baseline and 6 weeks of therapy. RESULTS: There were statistically significant differences in QoL scores and CT scores between quadrupedal head position group and non-quadrupedal head position group. The quadrupedal head position group had much more improvements in QoL scores and CT scores than that of non-quadrupedal head position group. One patient in the quadrupedal head position group required functional endoscopic sinus surgery (ESS) due to persistent symptoms, and nine patients in non-quadrupedal head position group needed ESS. There were less patients that required ESS in the quadrupedal head position group than in the non-quadrupedal head position group. CONCLUSIONS: The improvements of QoL scores and CT scores were significantly better in the quadrupedal head position group than that in the non-quadrupedal head position group. Quadrupedal head position can be valuable adjuvant therapy for patients with CMS.

ICU and Sepsis: Role of Myeloid and Lymphocyte Immune Cells.

Sepsis is a severe immune system reaction to infection and a major cause of ICU-related fatalities. Because of the high mortality, high cost of treatment, and complex aetiology of sepsis, sepsis has a huge impact on healthcare. Some of the health complications in sepsis are abnormal cardiac functions, hypoperfusion, hypotension, tissue damage, multiple organ failure, and ultimately death. Individuals with weak immune systems and chronic medical conditions are highly vulnerable to sepsis. In sepsis, a patient shows the extreme immune response in the initial stage while prolonged immunosuppression in the later stages. Sepsis-driven immunosuppression ushers in death because sepsis cases develop secondary infections postrecovery. The later immunocompromised state in sepsis is attributed myeloid-derived suppressor cell upregulation and reduced immune activity displayed by lymphocytes (lymphocyte anergy). As a result, it is currently suggested that regulating the immune response is a better therapeutic approach than focusing on inflammation to improve the immune system's capacity to fight infections. Moreover, finding novel and accurate prognostic biomarkers that can help in rapid sepsis diagnoses and deciding better therapeutic strategies will significantly lower clinical case mortality rates.

Diagnosis of male posterior urethral stricture: comparison of 64-MDCT urethrography vs. standard urethrography.

BACKGROUND: There are no reports regarding voiding/retrograde urethrography with 64-row multidetector CT (64-MDCT).To compare the clinical relevance of conventional voiding/retrograde urethrography and 64-MDCT urethrography for the evaluation of male posterior urethral stricture. METHODS: From January to October 2009, 21 men were referred to our institution for the management of posterior urethral stricture. The patients were evaluated with conventional voiding and retrograde urethrography and 64-MDCT urethrography. The patients were examined by open operative intervention which was required in all patients. The radiologic data were compared using the operative findings. RESULTS: 64 MDCT urethrography provided extra clinical data in ten patients. It was superior to conventional urethrography for judging the urethral stricture length in three patients, characterizing the site of urethra-rectal fistula in four patients, and accurately delineating the proximal urethra in six patients. CONCLUSIONS: 64-MDCT urethrography is a promising tool as an alternative to traditional radiographic methods for defining male urethral strictures. It has the advantage of examining patients only in one position, without distortion, and by generating three-dimensional images; it can accurately measure the stricture length, aid in the diagnosis of some associated pathological conditions, such as urethrorectal fistula, and does not expose the physician to radiation.

[Imaging of congenital coronary artery anomalies by dual-source computed tomography angiography].

OBJECTIVE: To investigate the value of dual-source computed tomography (DSCT) angiography in the examination of congenital coronary artery anomalies. METHODS: We retrospectively examined 2530 patients by DSCT angiography between January 2008 and September 2010. Congenital coronary artery anomalies were shown by maximum intensity projection, curved planar reconstruction, and volume rendering. RESULTS: A total of 284 segments with congenital coronary artery anomalies in 225 patients were displayed. The anomalies included those originated from the main branch of coronary artery (n=121, including 35 segments of right coronary artery with high take-off origin and 24 segments of left coronary artery, 17 segments of right coronary artery dated from left aortic sinus, 4 segments of left coronary artery dated from right aortic sinus, 2 segments of left coronary artery dated from posterior aortic sinus, 2 segments of single coronary artery, and 37 segments of para-coronary artery) , coronary artery dysplasia (n=18) , coronary artery fistula (n=9, including 4 segments of right coronary artery-right ventricle fistula, 2 segments of right coronary artery-pulmonary artery fistula, 2 segments of left coronary artery-left ventricle fistula, and 1 segments of left coronary artery-pulmonary artery fistula) , and myocardial bridge (n=136) . In addition, 818 segments of left sinuatrial nodal artery original anomalies in 1720 patients whose sinuatrial nodal artery were well shown. CONCLUSION: DSCT can be helpful in detecting the anomalies of coronary artery.

Multi-contrast imaging information of coronary artery wall based on magnetic resonance angiography.

In order to explore the most suitable image acquisition method for coronary artery wall, the display ability and image quality of segmentation breath-holding target volume acquisition method (the breath-holding method) and real-time navigation whole-hearted acquisition method (the navigation method) of coronary artery magnetic resonance angiography (CMRA) were compared. 26 healthy volunteers were selected to accept the CMRA in 1.5 tunnels magneto-resistance (TMR) equipment by the 2 acquisition methods respectively. The arteries were divided into 9 segments according to the standards of the American Heart Association (AHA). The images were evaluated by 2 magnetic resonance physicians. Satisfaction rate and success rate of each segment of the coronary artery were counted. The results showed that the signal to noise ratio (SNR) and the carrier to noise ratio (CNR) of the images obtained by the breath-holding method were higher than those obtained by the navigation method (P<0.05). Therefore, the segmentation breath-holding target volume acquisition method is proved to have a higher image quality and the simpler and more convenient operations, which is more suitable for the acquisition of positioning images of CMRA.