Tomography Imaging
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2021 ◽  
pp. 2110575
Author(s):  
Anivind Kaur Bindra ◽  
Sivaramapanicker Sreejith ◽  
Rajendra Prasad ◽  
Mahadeo Gorain ◽  
Rijil Thomas ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260374
Author(s):  
Shiyao Guo ◽  
Yuxia Sheng ◽  
Li Chai ◽  
Jingxin Zhang

Low count PET (positron emission tomography) imaging is often desirable in clinical diagnosis and biomedical research, but its images are generally very noisy, due to the very weak signals in the sinograms used in image reconstruction. To address this issue, this paper presents a novel kernel graph filtering method for dynamic PET sinogram denoising. This method is derived from treating the dynamic sinograms as the signals on a graph, and learning the graph adaptively from the kernel principal components of the sinograms to construct a lowpass kernel graph spectrum filter. The kernel graph filter thus obtained is then used to filter the original sinogram time frames to obtain the denoised sinograms for PET image reconstruction. Extensive tests and comparisons on the simulated and real life in-vivo dynamic PET datasets show that the proposed method outperforms the existing methods in sinogram denoising and image enhancement of dynamic PET at all count levels, especially at low count, with a great potential in real life applications of dynamic PET imaging.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Bo Cui ◽  
Yan Liu ◽  
Shuxiang Chen

Objective. To analyse the X-ray and computed tomography (CT) findings of 128 patients with sports-related knee fractures and to improve the diagnosis rate based on the existing methods of diagnosis of sports knee fractures on X-ray and CT images. Method. In this study, we retrospectively analyse the medical records of 128 cases of sports-related fractures in the hospital, analyse the results of X-ray examination and CT imaging of patients with sports knee fractures, and compare the results obtained by the two examination methods, while referring to MRI images performed. Results. CT examination of knee fractures, tibial plateau fractures, and knee joint free body results were compared with X-ray results ( P < 0.05 ), while CT examination of patella fractures and X-ray results were compared. The difference was not statistically significant ( P > 0.05 ). Conclusion. For imaging examination of knee fractures, a single ordinary X-ray or CT scan should be selected according to the specific situation of the patient. For patients with suspected unstable fractures, when the patient’s informed consent and the condition are not allowed, ordinary X-ray film combined with CT examination is used to improve the accuracy of diagnosis and avoid the existence of hidden fractures, resulting in medical accidents.


2021 ◽  
Vol 7 (12) ◽  
pp. 258
Author(s):  
Alice Scarabelli ◽  
Massimo Zilocchi ◽  
Elena Casiraghi ◽  
Pierangelo Fasani ◽  
Guido Giovanni Plensich ◽  
...  

The aim of this retrospective study is to assess any association between abdominal CT findings and the radiological stage of COVID-19 pneumonia, pulmonary embolism and patient outcomes. We included 158 adult hospitalized COVID-19 patients between 1 March 2020 and 1 March 2021 who underwent 206 abdominal CTs. Two radiologists reviewed all CT images. Pathological findings were classified as acute or not. A subset of patients with inflammatory pathology in ACE2 organs (bowel, biliary tract, pancreas, urinary system) was identified. The radiological stage of COVID pneumonia, pulmonary embolism, overall days of hospitalization, ICU admission and outcome were registered. Univariate statistical analysis coupled with explainable artificial intelligence (AI) techniques were used to discover associations between variables. The most frequent acute findings were bowel abnormalities (n = 58), abdominal fluid (n = 42), hematomas (n = 28) and acute urologic conditions (n = 8). According to univariate statistical analysis, pneumonia stage > 2 was significantly associated with increased frequency of hematomas, active bleeding and fluid-filled colon. The presence of at least one hepatobiliary finding was associated with all the COVID-19 stages > 0. Free abdominal fluid, acute pathologies in ACE2 organs and fluid-filled colon were associated with ICU admission; free fluid also presented poor patient outcomes. Hematomas and active bleeding with at least a progressive stage of COVID pneumonia. The explainable AI techniques find no strong relationship between variables.


2021 ◽  
Vol Volume 14 ◽  
pp. 9287-9296
Author(s):  
Mohammad Abd Alkhalik Basha ◽  
Dina Said Shemais ◽  
Essam Saad abdel wahed Abdelwahed ◽  
Rabab Mahmoud Elfwakhry ◽  
Ayman Fathy Zeid ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 8027
Author(s):  
Rafael Berenguer-Vidal ◽  
Rafael Verdú-Monedero ◽  
Juan Morales-Sánchez ◽  
Inmaculada Sellés-Navarro ◽  
Rocío del Amor ◽  
...  

Glaucoma is a neurodegenerative disease process that leads to progressive damage of the optic nerve to produce visual impairment and blindness. Spectral-domain OCT technology enables peripapillary circular scans of the retina and the measurement of the thickness of the retinal nerve fiber layer (RNFL) for the assessment of the disease status or progression in glaucoma patients. This paper describes a new approach to segment and measure the retinal nerve fiber layer in peripapillary OCT images. The proposed method consists of two stages. In the first one, morphological operators robustly detect the coarse location of the layer boundaries, despite the speckle noise and diverse artifacts in the OCT image. In the second stage, deformable models are initialized with the results of the previous stage to perform a fine segmentation of the boundaries, providing an accurate measurement of the entire RNFL. The results of the RNFL segmentation were qualitatively assessed by ophthalmologists, and the measurements of the thickness of the RNFL were quantitatively compared with those provided by the OCT inbuilt software as well as the state-of-the-art methods.


Author(s):  
Naeem-Ul-Haq Khan ◽  
Alicia Corlett ◽  
Craig A. Hutton ◽  
Mohammad B. Haskali

AbstractMany cancers of neuroendocrine origin overexpress cholecystokinin-2 receptors (CCK-2R) including medullary thyroid cancer, small cell lung cancer and other lung carcinoids. Fluorine-18 labelled peptides targeting CCK-2R enable direct visualization and quantification of this receptor in vivo using positron emission tomography imaging. CP04 1 and MG11 2 are two previously described truncated peptides derived from the native CCK-2R hormone ligand, gastrin. The N-terminus of the MG11 2 octopeptide was chemically modified with various fluorine containing aromatic (4-fluorobenzoate), heterocyclic (6-fluoronicotinate) and aliphatic (2-fluoropropionate) moieties. To assess the impact these modifications had on CCK-2R binding, ligand-binding assays were conducted using A431 cells overexpressing human CCK-2R. MG11 2 modified by 4-fluorobenzoate (FB-MG11 3) demonstrated the highest binding affinity (0.20 nM) followed by MG11 2 modified by 6-fluoronicotinate (FNic-MG11 4; 0.74 nM) and 2-fluoropropionate (FP-MG11 5; 1.80 nM), respectively. Whilst indirect labelling of MG11 2 using fluorine-18 labelled activated esters of fluorobenzoate and 6-fluoronicotinate was unsuccessful, direct fluorine-18 labelling at the N-terminus modified with 6-nitronicotinate afforded a 47.6% radiochemical yield of [18F]FNic-MG11. Unfortunately, [18F]FNic-MG11 4 was chemically unstable, decomposing slowly through defluorination, thereby impeding any further work with this radiotracer.


2021 ◽  
pp. 019459982110621
Author(s):  
Nathaniel Miller ◽  
Michael Noller ◽  
Matthew Leon ◽  
Yonatan Moreh ◽  
Nora L. Watson ◽  
...  

Objective Inadvertently ingested grill brush bristles can lodge in various locations and lead to a variety of injuries. They can also be difficult to identify and remove. Our primary objective was to perform a systematic review of cases reported in the literature, with analysis of trends in clinical presentation and success of diagnostic modalities and treatment approaches. Data Sources Cases of reported grill brush bristle ingestion reported in PubMed, PubMed Central, and Google Scholar databases through April 30, 2021. Review Methods Databases were searched for the following terms: (“ingestion” OR “injury” OR “barbeque” OR “BBQ” OR “grill” OR “foreign body” OR “brush” AND “wire” OR “bristle”). Data were collected on patient demographics, clinical presentation, and treatment course. Statistical analysis was performed on characteristics with low risk of confounding. Results An overall 57 studies involving 91 patients were included. Grill brush bristles presented most commonly in the upper aerodigestive tract (48/91), followed by the abdomen (26/91) and deep neck (17/91). Computed tomography was the most accurate imaging modality for initial diagnosis, identifying 92.8% of bristles. Less invasive or adjunctive techniques such as endoscopy, intraoperative imaging, or minimally invasive surgery may be useful particularly for bristles located in the head and neck given the low rate of success of transoral surgery (66.7%). Conclusion Although this review of retained bristle may be biased toward complex cases, retained grill brush bristles represent an underrecognized and difficult-to-manage hazard. When cases are suspected, clinicians should obtain computed tomography imaging based on presentation and tailor management appropriately.


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