Computed Tomography of the Pancreas: Negative Contrast Medium

Radiology ◽  
1978 ◽  
Vol 128 (3) ◽  
pp. 827-828 ◽  
Author(s):  
G. Nicholas Baldwin
Keyword(s):  
Computed Tomography ◽  
Contrast Medium ◽  
Negative Contrast

scholarly journals A deep-learning method using computed tomography scout images for estimating patient body weight

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shota Ichikawa ◽  
Misaki Hamada ◽  
Hiroyuki Sugimori
Keyword(s):  
Computed Tomography ◽  
Body Weight ◽  
Deep Learning ◽  
Contrast Medium ◽  
Model Performance ◽  
Ct Scanning ◽  
Drug Dosing ◽  
Body Weights ◽  
Dose Management ◽  
Medium Dose

AbstractBody weight is an indispensable parameter for determination of contrast medium dose, appropriate drug dosing, or management of radiation dose. However, we cannot always determine the accurate patient body weight at the time of computed tomography (CT) scanning, especially in emergency care. Time-efficient methods to estimate body weight with high accuracy before diagnostic CT scans currently do not exist. In this study, on the basis of 1831 chest and 519 abdominal CT scout images with the corresponding body weights, we developed and evaluated deep-learning models capable of automatically predicting body weight from CT scout images. In the model performance assessment, there were strong correlations between the actual and predicted body weights in both chest (ρ = 0.947, p < 0.001) and abdominal datasets (ρ = 0.869, p < 0.001). The mean absolute errors were 2.75 kg and 4.77 kg for the chest and abdominal datasets, respectively. Our proposed method with deep learning is useful for estimating body weights from CT scout images with clinically acceptable accuracy and potentially could be useful for determining the contrast medium dose and CT dose management in adult patients with unknown body weight.

scholarly journals A technical note on intra-arterial cone-beam computed tomography for the evaluation of flow-diverter stents: Image quality differences between diluted and non-diluted contrast medium

2019 ◽  
Vol 26 (2) ◽  
pp. 164-169
Author(s):  
Naci Kocer ◽  
Sedat G Kandemirli ◽  
Daniel Ruijters ◽  
Michalis Mantatzis ◽  
Osman Kizilkilic ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Contrast Medium ◽  
Cone Beam Computed Tomography ◽  
Vessel Wall ◽  
Flow Diverter ◽  
Cone Beam ◽  
Gray Scale ◽  
Stent Deployment ◽  
Contrast Technique

Background Design of flow-diverter stents for flexibility, tractability, and low profile limits their radiopacity on conventional digital subtraction angiography. Cone-beam computed tomography (CBCT) offers higher spatial resolution for the evaluation of flow-diverter stents. However, CBCT requires optimal dilution and timing of contrast medium for simultaneous visualization of the stent, arterial lumen, and vessel wall. There are only limited data on the effects of different contrast dilutions on CBCT image quality in neurointerventional applications. Materials and methods In our institution, intra-arterial CBCTs were acquired during stent deployment and at follow-ups with 10% diluted contrast. We had recently started acquiring intra-arterial CBCTs with non-diluted contrast. Retrospective analysis of our flow-diverter data identified eight cases with different aneurysm locations who had intra-arterial CBCT with 10% diluted contrast immediately after flow-diverter stent deployment and with non-diluted contrast technique during follow-ups. For each case, the image quality between diluted and non-diluted contrast techniques was compared qualitatively by assessing stent visualization and quantitatively by plotting gray-scale intensity values along the vessel lumen. Results In two sets of CBCT images per each case, there was no substantial difference between diluted and non-diluted CBTC techniques for the evaluation of stent architecture and lumen opacification. Gray-scale intensity values perpendicular to the lumen revealed similar intensity values along the neighboring parenchyma, vessel wall, and lumen for the two different contrast techniques. Conclusion Intra-arterial CBCT angiography can be performed without contrast dilution and still achieve adequate image quality in certain cerebral aneurysms treated with flow diverter. The non-diluted contrast technique avoids the time loss during preparation of diluted contrast and installation of diluted contrast to the injector in angiography suites with a single power injector.

Positron Emission Tomography with 11C-Methionine and Computed Tomography of Intracranial Tumours Compared with Histopathologic Examination of Multiple Biopsies

1987 ◽  
Vol 28 (6) ◽  
pp. 673-681 ◽  
Author(s):  
M. Mosskin ◽  
H. von Holst ◽  
M. Bergström ◽  
V. P. Collins ◽  
L. Eriksson ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Contrast Medium ◽  
Mass Effect ◽  
Tumour Cells ◽  
Emission Tomography ◽  
Normal Brain ◽  
Positron Emission ◽  
Multiple Biopsies ◽  
Before And After

A selected group of 36 patients with suspected supratentorial gliomas were investigated with positron emission tomography (PET) using 11C-methionine and transmission computed tomography (CT) before and after intravenous injection of contrast medium. Every examination was performed with the head fixed in a plastic helmet and a baseplate to guarantee that the slice orientation was the same at examinations with the two modalities and over time. Guided by the examinations, multiple stereotactic biopsies were performed with the biopsy instrument mounted on the baseplate. Regional accumulation of methionine was compared with histology of the corresponding samples and with attenuation before and after injection of contrast medium as well as mass effect on CT. Typically, there was a low attenuating lesion with a slight mass effect on CT. There was an increased accumulation compared with normal brain tissue in 31 cases of tumours and ordinary or decreased accumulation in 3 cases of tumours. In 22 cases with increased accumulation of methionine the extension of the tumour judged by PET corresponded with that of histology. In 4 cases tumour cells were found outside the area with pathologic methionine uptake. In 5 patients there were areas with increased methionine accumulation where no tumour cells were found. In 22 cases PET using methionine was more accurate than CT in defining the tumour boundaries as determined from the histologic findings. Four groups of biopsy specimens with different amounts of methionine accumulation are described. The uptake in a single biopsy gives good but not exact information about the histology of the specimen.

scholarly journals 526. A comparative study between Air and CO_2 as negative contrast medium for barium enema

1991 ◽  
Vol 47 (8) ◽  
pp. 1556
Author(s):  
Kohji Sasamori ◽  
Shinichi Ohtani ◽  
Kazuo Niwa ◽  
Yasuo Mochizuki ◽  
Isao Gotoh
Keyword(s):  
Comparative Study ◽  
Contrast Medium ◽  
Barium Enema ◽  
Negative Contrast

Contrast-enhanced angiographic cone-beam computed tomography without pre-diluted contrast medium

2015 ◽  
Vol 57 (11) ◽  
pp. 1121-1126 ◽  
Author(s):  
K. I. Jo ◽  
S. R. Kim ◽  
J. H. Choi ◽  
K. H. Kim ◽  
P. Jeon
Keyword(s):  
Computed Tomography ◽  
Contrast Medium ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Contrast Enhanced
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