scholarly journals The utility of a dual-phase, dual-energy CT protocol in patients presenting with overt gastrointestinal bleeding

2021 ◽  
Vol 10 (7) ◽  
pp. 205846012110306
Author(s):  
Payam Mohammadinejad ◽  
Lukasz Kwapisz ◽  
Jeff L Fidler ◽  
Shannon P Sheedy ◽  
Jay P Heiken ◽  
...  

Background Due to their easy accessibility, CT scans have been increasingly used for investigation of gastrointestinal (GI) bleeding. Purpose To estimate the performance of a dual-phase, dual-energy (DE) GI bleed CT protocol in patients with overt GI bleeding in clinical practice and examine the added value of portal phase and DE images. Materials and Methods Consecutive patients with GI bleeding underwent a two-phase DE GI bleed CT protocol. Two gastroenterologists established the reference standard. Performance was estimated using clinical CT reports. Three GI radiologists rated confidence in GI bleeding in a subset of 62 examinations, evaluating first mixed kV arterial images, then after examining additional portal venous phase images, and finally after additional DE images (virtual non-contrast and virtual monoenergetic 50 keV images). Results 52 of 176 patients (29.5%) had GI bleeding by the reference standard. The overall sensitivity, specificity, and positive and negative predictive values of the CT GI bleed protocol for detecting GI bleeding were 65.4%, 89.5%, 72.3%, and 86.0%, respectively. In patients with GI bleeding, diagnostic confidence of readers increased after adding portal phase images to arterial phase images ( p = 0.002), without additional benefit from dual energy images. In patients without GI bleeding, confidence in luminal extravasation appropriately decreased after adding portal phase, and subsequently DE images ( p = 0.006, p = 0.018). Conclusion A two-phase DE GI bleed CT protocol had high specificity and negative predictive value in clinical practice. Portal venous phase images improved diagnostic confidence in comparison to arterial phase images alone. Dual-energy images further improved radiologist confidence in the absence of bleeding.

2020 ◽  
Vol 9 (8) ◽  
pp. 2514
Author(s):  
Arkadiusz Zegadło ◽  
Magdalena Żabicka ◽  
Marta Kania-Pudło ◽  
Artur Maliborski ◽  
Aleksandra Różyk ◽  
...  

With lung cancer being the most common malignancy diagnosed worldwide, lung nodule assessment has proved to be one of big challenges of modern medicine. The aim of this study was to examine the usefulness of Dual Energy Computed Tomography (DECT) in solitary pulmonary nodule (SPN) assessment. Between January 2017 and June 2018; 65 patients (42 males and 23 females) underwent DECT scans in the late arterial phase (AP) and venous phase (VP). We concluded that imaging at an energy level of 65 keV was the most accurate in detecting malignancy in solitary pulmonary nodules (SPNs) measuring ≤30 mm in diameter on virtual monochromatic maps. Both virtual monochromatic images and iodine concentration maps prove to be highly useful in differentiating benign and malignant pulmonary nodules. As for iodine concentration maps, the analysis of venous phase images resulted in the highest clinical usefulness. To summarize, DECT may be a useful tool in the differentiation of benign and malignant SPNs. A single-phase DECT examination with scans acquired 90 s after contrast media injection is recommended.


Author(s):  
Christine U. Lee ◽  
James F. Glockner

58-year-old woman with cirrhosis Axial precontrast (Figure 17.17.1) and arterial phase (Figure 17.17.2) and portal venous phase (Figure 17.17.3) postgadolinium water and fat images from a 3D SPGR Dixon acquisition. Notice that the phase and frequency directions have been swapped on the arterial phase acquisition and that there is a large geographic signal void in the middle of the liver on the water image, with the missing anatomy appearing on the corresponding fat image. All artifacts have been corrected on the portal venous phase images....


2017 ◽  
Vol 68 (4) ◽  
pp. 371-378 ◽  
Author(s):  
Kathleen Eddy ◽  
Andreu F. Costa

Purpose This study aimed to update our liver computed tomography (CT) protocol according to published guidelines, and to quantitatively evaluate the effect of these modifications. Methods The modified liver CT protocol employed a faster injection rate (5 vs 3 mL/s), later arterial phase (20-second vs 10-second postbolus trigger), and weight-based dosing of iodinated contrast (1.7 mL/kg vs 100 mL fixed dose). Liver and vascular attenuation values were measured on CTs of patients with cirrhosis from January to September 2015 (old protocol, n = 49) and from October to December 2015 (modified protocol, n = 31). CTs were considered adequate if liver enhancement exceeded 50 Hounsfield units (HU) in portal venous phase, or when the unenhanced phase was unavailable, if a minimum iodine concentration of 500 mg I/kg was achieved. Attenuations and iodine concentrations were compared using the t test and the number of suboptimal studies was compared with Fisher's exact test. Results CTs acquired with the modified protocol demonstrated higher aortic ( P = .001) and portal vein ( P < .0001) attenuations in the arterial phase as well as greater hepatic attenuation on all postcontrast phases ( P = .0006, .002, and .003 for arterial, venous, and equilibrium phases, respectively). Hepatic enhancement in the portal venous phase (61 ± 15 HU vs 51 ± 16 HU; P = .0282) and iodine concentrations (595 ± 88 mg I/kg vs 456 ± 112 mg I/kg; P < .0001) were improved, and the number of suboptimal studies was reduced from 57% to 23% ( P = .01). Conclusions A liver CT protocol with later arterial phase, faster injection rate, and weight-based dosing of intravenous contrast significantly improves liver enhancement and iodine concentrations in patients with cirrhosis, resulting in significantly fewer suboptimal studies.


2015 ◽  
Vol 205 (5) ◽  
pp. W492-W501 ◽  
Author(s):  
Chiao-Yun Chen ◽  
Jui-Sheng Hsu ◽  
Twei-Shiun Jaw ◽  
Ming-Chen Paul Shih ◽  
Lo-Jeh Lee ◽  
...  

Heart ◽  
2018 ◽  
Vol 105 (4) ◽  
pp. 275-322 ◽  
Author(s):  
Rory O’Donohoe ◽  
Samantha Fitzsimmons ◽  
Timothy J C Bryant

Clinical introductionA woman in her 30s presented to the emergency department with sudden-onset abdominal pain with hypotension and tachycardia. She gave a history of congenital heart disease for which she had previously undergone multiple operations. On examination she demonstrated right upper quadrant tenderness. She underwent an urgent multiphase CT (figure 1A–C).Figure 1(A) Arterial phase coronal CT. (B) Arterial phase axial CT. (C) Portal venous phase axial CT.QuestionWhat is the underlying liver pathology?Hepatocellular adenomaCholangiocarcinomaHepatocellular carcinomaFocal nodular hyperplasiaHepatoblastoma


Author(s):  
Christine U. Lee ◽  
James F. Glockner

37-year-old woman with a history of recurrent pancreatitis and abdominal pain Arterial phase (Figure 5.6.1A), portal venous phase (Figure 5.6.1B), equilibrium phase (Figure 5.6.1C), and 8-minute delayed phase (Figure 5.6.1D) postgadolinium 3D SPGR images show multiple splenic lesions that are initially hypoenhancing relative to adjacent spleen and become hyperintense on delayed images....


2020 ◽  
Author(s):  
Jian Wang ◽  
Chang LIU ◽  
Fang Yang ◽  
Wenming Zhang ◽  
Weiqun Ao ◽  
...  

Abstract BackgroundGastric ectopic pancreas (GEPs) is a rare developmental anomaly which is difficult to differentiate it from submucosal tumor such as gastrointestinal stromal tumor (GIST) by imaging methods. So we retrospectively investigated the CT features of them to help us make the correct diagnosis.Materials and MethodsThis study enrolled 17 GEPs and 119 GSTs, which were proven pathologically. We assessed clinical and CT features to identify significant differential features of GEPs from GSTs using univariate and multivariate analyses.ResultsIn univariate analysis, among all clinicoradiologic features, features of age, symptom, tumor marker, location, contour, blurred serosa or fat-line of peritumor, necrosis, calcification, CT attenuation value of unenhancement phase/arterial phase/portal venous phase (CTu/CTa/CTp), the CT attenuation value of arterial phase/portal venous phase minus that of unenhanced phase (DEAP/DEPP), long diameter (LD), short diameter (SD) were considered statistically significant for the differentiation of them. And the multivariate analysis revealed that location, blurred serosa or fat-line of peritumor, necrosis and DEPP were independent factors affecting the identification of them.What's more, ROC analysis showed that the test efficiency of CTp was perfect(AUC= 0.900).ConclusionLocation, blurred serosa or fat-line of peritumor, necrosis and DEPP are useful CT differentiators of GEPs from GSTs. In addition, the test efficiency of CTp in differentiating them was perfect (AUC=0.900).


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