4D and multi-phase breath-hold CT imaging with synchronized intravenous contrast injection for liver tumor delineation

AbstractA novel motion correction algorithm for X-ray lung CT imaging has been developed recently. It was designed to perform for routine chest or thorax CT scans without gating, namely axial or helical scans with pitch around 1.0. The algorithm makes use of two conjugate partial angle reconstruction images for motion estimation via non-rigid registration which is followed by a motion compensated reconstruction. Differently from other conventional approaches, no segmentation is adopted in motion estimation. This makes motion estimation of various fine lung structures possible. The aim of this study is to explore the performance of the proposed method in correcting the lung motion artifacts which arise even under routine CT scans with breath-hold. The artifacts are known to mimic various lung diseases, so it is of great interest to address the problem. For that purpose, a moving phantom experiment and clinical study (seven cases) were conducted. We selected the entropy and positivity as figure of merits to compare the reconstructed images before and after the motion correction. Results of both phantom and clinical studies showed a statistically significant improvement by the proposed method, namely up to 53.6% (p < 0.05) and up to 35.5% (p < 0.05) improvement by means of the positivity measure, respectively. Images of the proposed method show significantly reduced motion artifacts of various lung structures such as lung parenchyma, pulmonary vessels, and airways which are prominent in FBP images. Results of two exemplary cases also showed great potential of the proposed method in correcting motion artifacts of the aorta which is known to mimic aortic dissection. Compared to other approaches, the proposed method provides an excellent performance and a fully automatic workflow. In addition, it has a great potential to handle motions in wide range of organs such as lung structures and the aorta. We expect that this would pave a way toward innovations in chest and thorax CT imaging.

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The value of intravenous contrast medium in PSMA PET/CT imaging in patients with biochemical recurrence of prostate cancer

Nuclear Medicine Communications ◽

10.1097/mnm.0000000000001453 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Alain Winiger ◽

Maria del Sol Pérez Lago ◽

Dirk Lehnick ◽

Justus E. Roos ◽

Klaus Strobel

Keyword(s):

Prostate Cancer ◽

Contrast Medium ◽

Biochemical Recurrence ◽

Ct Imaging ◽

Intravenous Contrast ◽

Intravenous Contrast Medium ◽

Psma Pet ◽

Pet Ct

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Abstract 20183: Intraprocedural C-Arm CT Imaging Identifies Incomplete Stent Frame Expansion in Self-Expanding Aortic Valve Prostheses Associated With Perivalvular Aortic Regurgitation

Circulation ◽

10.1161/circ.130.suppl_2.20183 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

C. Huie Lin ◽

Shaun Smithson ◽

Ponraj Chinnadurai ◽

Yi-Ting Shen ◽

Colin Barker ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Regurgitation ◽

Severe Aortic Stenosis ◽

Color Doppler ◽

Longitudinal Axis ◽

Ct Imaging ◽

Breath Hold ◽

Inferior Margin ◽

Valve Prostheses ◽

Post Implantation

Introduction: Transcatheter aortic valve replacement has revolutionized the treatment of severe aortic stenosis, but post implantation perivalvular aortic regurgitation may result in increased mortality. Hypothesis: The purpose of this study was to identify structural abnormalities in the frame of self-expanding aortic valve prostheses (CoreValve®, Medtronic, Minneapolis, MN) immediately following implantation and evaluate their relationship to subsequent perivalvular aortic regurgitation severity. Methods/Results: After implantation of CoreValve, 14 patients with evidence of frame deformation by fluoroscopy underwent intraprocedural C-arm CT imaging (syngo DynaCT®, Siemens Medical Solutions, USA) acquired using 5-s, 200° rotation under breath-hold and rapid right ventricular pacing (120-140bpm). CT-like multi-planar reconstructions (Figure) were performed; perimeter (P), maximum (Dmax) and minimum (Dmin) diameters of the CoreValve frame were measured at multiple levels (0mm, 8mm, 16mm) orthogonal to the longitudinal axis. Ellipticity index (EI) was measured as Dmax divided by Dmin. Color Doppler transthoracic echo was performed the day following valve implantation to assess perivalvular regurgitation. One-way ANOVA demonstrated that degree of perivalvular aortic regurgitation was significantly related to valve frame perimeter underexpansion at the inferior margin of the frame (20.8% [17.2-25.7%], p=0.011) and increased ellipticity index both at the 8mm above the edge of the frame (1.4, [1.3-1.5], p=0.012) and 16mm above the edge of the frame (1.4, [1.3-1.5], p=0.038). Conclusions: Intraprocedural DynaCT effective at determining aortic valve frame deformations in 3D, which was associated with increased perivalvular aortic regurgitation, and may provide a method for risk stratifying post-implantation aortic regurgitation and need for additional procedural maneuvers such as post-stent dilation or additional revalving.

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Technology of cardiac computed tomography

ESC CardioMed ◽

10.1093/med/9780198784906.003.0112 ◽

2018 ◽

pp. 537-541

Author(s):

Stephan Achenbach

Keyword(s):

Computed Tomography ◽

Heart Rate ◽

Coronary Arteries ◽

Cardiac Computed Tomography ◽

Ct Imaging ◽

Breath Hold ◽

Coronary Angiogram ◽

Data Set ◽

Careful Patient ◽

Patient Preparation

Cardiac imaging by computed tomography (CT) has the unique advantage of providing a fully isotropic data set with high spatial resolution. However, the rapid motion of the heart poses substantial challenges to CT imaging. For this reason, specific techniques have been developed to increase the temporal resolution of CT imaging and to permit either image acquisition or data reconstruction in synchronization with the patient’s electrocardiogram. Next to the use of advanced scanner technology, careful patient preparation is important to avoid artefacts. This includes careful coaching and practising of the breath-hold sequence to lower the heart rate, especially when CT is used to visualize the coronary arteries. With modern scanners, radiation exposure is reasonably low and falls approximately in the range of an invasive coronary angiogram.

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Infected aneurysm of the thoracic aorta probably caused by Bacillus cereus: a case report

BMC Infectious Diseases ◽

10.1186/s12879-019-4602-2 ◽

2019 ◽

Vol 19 (1) ◽

Author(s):

Tzu-Chi Wu ◽

Ching-Chou Pai ◽

Pin-Wen Huang ◽

Chun-Bin Tung

Keyword(s):

Aortic Aneurysm ◽

Bacillus Cereus ◽

Thoracic Aorta ◽

Lung Nodule ◽

Ct Imaging ◽

Aortic Aneurysms ◽

Infected Aneurysm ◽

High Grade Fever ◽

Gram Positive ◽

Intravenous Contrast

Abstract Background An infected aneurysm of the thoracic aorta is a rare clinical condition with significant morbidity and mortality. Patients with fast-growing aortic aneurysms show a high incidence of rupture. Gram-positive organisms, such as the Staphylococcus and Enterococcus species, are the most common cause of infection. Case presentation A 91-year-old man presented at our facility with high grade fever and tachypnea, which he had experienced for the previous two days. He had a history of end-stage renal disease and had been undergoing regular chest computed tomography (CT) follow-up for a left lower lung nodule. CT imaging with intravenous contrast media showed a thoracic aortic aneurysm with hemothorax. Rupture of the aneurysm was suspected. CT imaging performed a year ago showed a normal aorta. Blood samples showed a Bacillus cereus infection. The patient was successfully treated for a mycotic aortic aneurysm secondary to Bacillus cereus bacteremia. Conclusions Here, we report a rare of an infected aneurysm of the thoracic aorta probably caused by Bacillus cereus. Although infected aneurysms have been described well before, an aneurysm infected with Bacillus cereus is rare. Bacillus cereus, a gram-positive spore-building bacterium, can produce biofilms, which attach to catheters. It has recently emerged as a new organism that can cause serious infection.

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