scholarly journals Reassessing Alberta Stroke Program Early CT Score on Non-Contrast CT Based on Degree and Extent of Ischemia

2021 ◽  
Vol 23 (3) ◽  
pp. 440-442
Author(s):  
Johanna M. Ospel ◽  
Bijoy K. Menon ◽  
Martha Marko ◽  
Arnuv Mayank ◽  
Aravind Ganesh ◽  
...  
Keyword(s):  
Contrast Ct

1264: Predictors of Shock-Wave Lithotripsy Success for Proximal Ureteral Calculi on Non-Contrast CT?

2007 ◽  
Vol 177 (4S) ◽  
pp. 417-417
Author(s):  
Eric A. Singer ◽  
Jared D. Christensen ◽  
Susan Messing ◽  
Erdal Erturk
Keyword(s):  
Shock Wave ◽  
Shock Wave Lithotripsy ◽  
Ureteral Calculi ◽  
Contrast Ct

Bubble study as a medium of contrast for computerized tomography coronary angiography. (Preprint)

2020 ◽  
Author(s):  
Vijay Shah ◽  
Justyn Huang
Keyword(s):  
Pulmonary Artery ◽  
Diagnostic Yield ◽  
Negative Contrast ◽  
Hounsfield Unit ◽  
Hounsfield Units ◽  
Computed Tomographic ◽  
Invasive Test ◽  
Clinical Difference ◽  
Contrast Ct ◽  
Scan Protocol

BACKGROUND Computed tomographic coronary angiogram (CTCA) is a non-invasive test with a negative predictive value of nearly 100% for the detection of coronary artery study. While diagnostic yield of a dedicated CTCA with bubble contrast is not yet evaluated OBJECTIVE To assess the diagnostic performance of injected bubble contrast and ability to measure difference in hounsfield units and use it as a "negative contrast" in computed tomographic METHODS This is a single center, single patient study. Baseline acquisition of a non-contrast CT scan was acquired to get hounsfield unit count in the aorta and pulmonary artery- (Calcium scan protocol) 1.4 mGy (19.5 mGy/cm). Secondly, Echo contrasts (Definity) - 5mls was injected and an echocardiogram confirmed filling in the aortic region. Finally, bubble contrast (1ml air, 8mls water and 1mls blood was drawn up and agitated through a 3 way tap) - was injected, a timing run was initiated to calculate for the bubbles to opacity the pulmonary artery. The same scan protocol was used– 1.4 mGy (19.5 mGy/cm). RESULTS Hounsfield units’ difference in the aorta and pulmonary artery from baseline compared to echo contrast and bubble contrast were not significant. CONCLUSIONS We believe this is the first ever recorded case to use bubbles as CT contrast. While results were not significant, secondary to small volume of bubbles injected. Further research needs to be implemented to assess clinical difference with amount of bubbles and volume required. CLINICALTRIAL Single centre study

Pre‐contrast CT attenuation of the thyroid gland is lower in brachycephalic dogs versus non‐brachycephalic dogs

2020 ◽  
Author(s):  
Olga Amorós ◽  
Yvonne Espada ◽  
Anna Vila ◽  
Alejandro Jiménez ◽  
Rosa Novellas
Keyword(s):  
Thyroid Gland ◽  
Ct Attenuation ◽  
Contrast Ct

scholarly journals Deep learning–based reconstruction may improve non-contrast cerebral CT imaging compared to other current reconstruction algorithms

2021 ◽  
Author(s):  
Luuk J. Oostveen ◽  
Frederick J. A. Meijer ◽  
Frank de Lange ◽  
Ewoud J. Smit ◽  
Sjoert A. Pegge ◽  
...  
Keyword(s):  
Deep Learning ◽  
White Matter ◽  
Image Quality ◽  
Iterative Reconstruction ◽  
Quality Characteristics ◽  
Model Based ◽  
Hybrid Iterative Reconstruction ◽  
Contrast Ct ◽  
Lower Noise ◽  
Reconstruction Time

Abstract Objectives To evaluate image quality and reconstruction times of a commercial deep learning reconstruction algorithm (DLR) compared to hybrid-iterative reconstruction (Hybrid-IR) and model-based iterative reconstruction (MBIR) algorithms for cerebral non-contrast CT (NCCT). Methods Cerebral NCCT acquisitions of 50 consecutive patients were reconstructed using DLR, Hybrid-IR and MBIR with a clinical CT system. Image quality, in terms of six subjective characteristics (noise, sharpness, grey-white matter differentiation, artefacts, natural appearance and overall image quality), was scored by five observers. As objective metrics of image quality, the noise magnitude and signal-difference-to-noise ratio (SDNR) of the grey and white matter were calculated. Mean values for the image quality characteristics scored by the observers were estimated using a general linear model to account for multiple readers. The estimated means for the reconstruction methods were pairwise compared. Calculated measures were compared using paired t tests. Results For all image quality characteristics, DLR images were scored significantly higher than MBIR images. Compared to Hybrid-IR, perceived noise and grey-white matter differentiation were better with DLR, while no difference was detected for other image quality characteristics. Noise magnitude was lower for DLR compared to Hybrid-IR and MBIR (5.6, 6.4 and 6.2, respectively) and SDNR higher (2.4, 1.9 and 2.0, respectively). Reconstruction times were 27 s, 44 s and 176 s for Hybrid-IR, DLR and MBIR respectively. Conclusions With a slight increase in reconstruction time, DLR results in lower noise and improved tissue differentiation compared to Hybrid-IR. Image quality of MBIR is significantly lower compared to DLR with much longer reconstruction times. Key Points • Deep learning reconstruction of cerebral non-contrast CT results in lower noise and improved tissue differentiation compared to hybrid-iterative reconstruction. • Deep learning reconstruction of cerebral non-contrast CT results in better image quality in all aspects evaluated compared to model-based iterative reconstruction. • Deep learning reconstruction only needs a slight increase in reconstruction time compared to hybrid-iterative reconstruction, while model-based iterative reconstruction requires considerably longer processing time.

scholarly journals COVID-19-associated ischaemic stroke due to underlying carotid artery thrombosis in a healthy young woman

2021 ◽  
Vol 14 (8) ◽  
pp. e244396
Author(s):  
Kelly Lau ◽  
Irwin White-Gittens ◽  
Jonathan Schor ◽  
Mina Guerges
Keyword(s):  
Carotid Artery ◽  
Ischaemic Stroke ◽  
Heart Association ◽  
Recombinant Tissue Plasminogen Activator ◽  
Haemorrhagic Stroke ◽  
Hypercoagulable State ◽  
Left Internal Carotid Artery ◽  
Ct Angiogram ◽  
Contrast Ct ◽  
Vessel Thrombosis

SARS-CoV-2 has proven its versatility in host presentations; one such presentation is a hypercoagulable state causing large-vessel thrombosis. We report a case on a previously asymptomatic COVID-19-positive patient presenting with an acute ischaemic stroke and an incidental left internal carotid artery thrombus. The patient’s medical, social and family history and hypercoagulability screening excluded any other explanation for the left carotid thrombus or stroke, except for testing positive for the COVID-19. This case explores the known hypercoagulable state associated with COVID-19 and the effect of the virus on the host’s immune response. It also questions whether administration of recombinant tissue plasminogen activator (t-PA), according to the American Heart Association guidelines, following a negative head CT for haemorrhagic stroke is safe without prior extended imaging in this patient population. We recommend, in addition to obtaining a non-contrast CT scan of the brain, a CT angiogram or carotid duplex of the neck be obtained routinely in patients with COVID-19 exhibiting stroke symptoms before t-PA administration as the effects may be detrimental. This recommendation will likely prevent fragmentation and embolisation of an undetected carotid thrombus.

scholarly journals Failure patterns and outcomes of dose escalation of stereotactic body radiotherapy for locally advanced pancreatic cancer: a multicenter cohort study

2020 ◽  
Vol 12 ◽  
pp. 175883592097715
Author(s):  
Xiaofei Zhu ◽  
Yangsen Cao ◽  
Tingshi Su ◽  
Xixu Zhu ◽  
Xiaoping Ju ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Locally Advanced ◽  
Advanced Pancreatic Cancer ◽  
Progression Free Survival ◽  
Locally Advanced Pancreatic Cancer ◽  
Multicenter Cohort Study ◽  
Failure Patterns ◽  
Kaplan Meier ◽  
Prescription Dose ◽  
Contrast Ct

Objective: This study aims to compare recurrence patterns and outcomes of biologically effective dose (BED10, α/β = 10) of 60–70 Gy with those of a BED10 >70 Gy for locally advanced pancreatic cancer (LAPC). Methods: Patients from three centers with a biopsy and a radiographically proven LAPC were retrospectively included and data were prospectively collected from June 2012 to June 2019. Radiotherapy was delivered by stereotactic body radiation therapy. Recurrences were categorized as in-field, marginal, and outside-the-field recurrence. Patients in two groups were required to receive abdominal enhanced contrast CT or MRI every 2–3 months and CA19-9 examinations every month during follow-up. Treatment-related toxicities were evaluated every month. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan–Meier method. Results: After propensity score matching, there were 486 patients in each group. The median prescription dose of the two groups was 37 Gy/5–8 f (range: 36–40.8 Gy/5–8 f) and 42 Gy/5–8 f (range: 40–49.6 Gy/5–8 f), respectively. The median OS of patients with a BED10 >70 Gy and a BED10 60–70 Gy was 20.3 months (95% CI: 19.1–21.5 months) and 18.2 months (95% CI: 17.8–18.6 months) respectively ( p < 0.001). The median PFS of the two cohorts was 15.4 months (95% CI: 14.2–16.6 months) and 13.3 months (95% CI: 12.9–13.7 months) respectively ( p < 0.001). A higher incidence of in-field and marginal recurrence was found in patients with BED10 of 60–70 Gy (in-field: 97/486 versus 72/486, p = 0.034; marginal: 109/486 versus 84/486, p = 0.044). However, more patients with BED10 >70 Gy had grade 2 or 3 acute (87/486 versus 64/486, p = 0.042) and late gastrointestinal toxicities (77/486 versus 55/486, p = 0.039) than those with BED10 of 60–70 Gy. Conclusion: BED10 >70 Gy was found to have the best survival benefits along with a higher incidence of acute and late gastrointestinal toxicities. Therefore, a higher dose may be required in the case of patients’ good tolerance.

scholarly journals Novel selection paradigms for endovascular stroke treatment in the extended time window

2021 ◽  
pp. jnnp-2020-325284
Author(s):  
Mehdi Bouslama ◽  
Diogo C Haussen ◽  
Gabriel Rodrigues ◽  
Clara Barreira ◽  
Michael Frankel ◽  
...  
Keyword(s):  
Time Window ◽  
Ct Perfusion ◽  
Clinical Aspects ◽  
Anterior Circulation ◽  
Stroke Treatment ◽  
Good Outcome ◽  
Potential Alternative ◽  
The Right ◽  
Contrast Ct ◽  
Selection Methodology

Background and purposeThe optimal selection methodology for stroke thrombectomy beyond 6 hours remains to be established.MethodsReview of a prospectively collected database of thrombectomy patients with anterior circulation strokes, adequate CT perfusion (CTP) maps, National Institute of Health Stroke Scale (NIHSS)≥10 and presenting beyond 6 hours from January 2014 to October 2018. Patients were categorised according to five selection paradigms: DAWN clinical-core mismatch (DAWN-CCM): between age-adjusted NIHSS and CTP core, DEFUSE 3 perfusion imaging mismatch (DEFUSE-3-PIM): between CTP-derived perfusion defect (Tmax >6 s lesion) and ischaemic core volumes and three non-contrast CT Alberta Stroke Program Early CT Score (ASPECTS)-based criteria: age-adjusted clinical-ASPECTS mismatch (aCAM): between age-adjusted NIHSS and ASPECTS, eloquence-adjusted clinical ASPECTS mismatch (eCAM): ASPECTS 6–10 and non-involvement of the right M6 and left M4 areas and standard clinical ASPECTS mismatch (sCAM): ASPECTS 6–10.Results310 patients underwent analysis. DEFUSE-3-PIM had the highest proportion of qualifying patients followed by sCAM, eCAM, aCAM and DAWN-CCM (93.5%, 92.6%, 90.6%, 90% and 84.5%, respectively). Patients meeting aCAM, eCAM, sCAM and DAWN-CCM criteria had higher rates of 90-day good outcome compared with their non-qualifying counterparts(43.2% vs 12%,p=0.002; 42.4% vs 17.4%, p=0.02; 42.4% vs 11.2%, p=0.009; and 43.7% vs 20.5%, p=0.007, respectively). There was no difference between patients meeting DEFUSE-3-PIM criteria versus not(40.8% vs 31.3%,p=0.45). In multivariate analysis, all selection modalities except for DEFUSE-3-PIM were independently associated with 90-day good outcome.ConclusionsASPECTS-based selection paradigms for late presenting and wake-up strokes ET have comparable proportions of qualifying patients and similar 90-day functional outcomes as DAWN-CCM and DEFUSE-3-PIM. They also might lead to better outcome discrimination. These could represent a potential alternative for centres where access to advanced imaging is limited.

scholarly journals Can stone composition be predicted by plain X-ray and/or non-contrast CT? A study validated by X-ray diffraction analysis

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Mohamed Gadelmoula ◽  
Ahmed M. Moeen ◽  
Ahmed Elderwy ◽  
Mohamed S. Abdel-Kader ◽  
Ayman Elqady ◽  
...  
Keyword(s):  
Calcium Oxalate ◽  
Diffraction Analysis ◽  
Great Influence ◽  
Calcium Oxalate Monohydrate ◽  
Categorical Variables ◽  
Stone Analysis ◽  
Stone Composition ◽  
Cutoff Value ◽  
X Ray ◽  
Contrast Ct

Abstract Background The stone composition has a great influence on the outcome of its treatment. There are several tests to predict the composition of stones preoperatively and stone analysis postoperatively. Herein, we want to evaluate if the stone composition could be predicted from plain X-ray KUB (PKUB) and/or non-contrast CT (NCCT) validated by in vitro X-ray powder diffraction analysis (XRD). Methods Between April 2014 and March 2016, 100 cases with urinary tract stones were included in the study. The radio-opacity of the stones in PKUB, stone density by NCCT, and after stone extraction, XRD were performed. Statistical analysis for the results was performed using Chi-square and Fisher exact tests for categorical variables and Mann–Whitney U and Kruskal–Wallis H for the nonparametric variables. The receiver operating characteristic curve was constructed to determine the best cutoff value. Results This study included 74 males and 26 females with a median age of 32 years (range 2–70). Regarding the radio-opacity by PKUB, there were 30 stones dense opaque, 44 opaque, 21 faint opaque, and 5 radiolucent. XRD revealed 97 mixed and 3 pure stones. The calcium oxalate monohydrate (COM) stone composition could be predicted in dense opaque stone by PKUB in 75.9% and urate composition in the radiolucent stone by 40%. The cutoff value of HU density by NCCT to the dense opaque stones in the PKUB was > 1020 and for radiolucent stones was < 590. Conclusion Stone radio-opacity by PKUB and its attenuation value by NCCT could successfully predict its calcium oxalate monohydrate, struvite, and urate composition. However, the chemical stone analysis is still required as most stones are mixed.

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