Preliminary experience of CT imaging of the ischaemic brain penumbra through spectral processing of multiphasic CTA datasets.

To assess ischaemic penumbra through the post-processing of the spectral multiphasic CT Angiography (mCTA) data in acute ischaemic stroke (AIS) patients. Thirty one consecutive patients strongly suspected of severe Middle Cerebral Artery AIS presenting less than 6 h after onset of symptoms or with unknown time of onset of symptoms underwent a standardized CT protocol in spectral mode including Non Contrast CT, mCTA, and Perfusion CT (CTP) on a dual-layer MDCT system. Areas disclosing delayed enhancement on iodine density (ID) maps were highlighted by subtraction of the serial mCTA datasets.

Comparison of image quality between spectral photon-counting CT and dual-layer CT for the evaluation of lung nodules: a phantom study.

Objectives: To evaluate the image quality (IQ) of a spectral photon-counting CT (SPCCT) using filtered back projection (FBP) and hybrid iterative reconstruction (IR) algorithms (iDose), in comparison with a dual-layer CT (DLCT) system, and to choose the best image quality according to the IR level for SPCCT.

Methods: Two phantoms were scanned using a standard lung protocol (120 kVp, 40 mAs) with SPCCT and DLCT systems. Raw data were reconstructed using FBP and 9 iDose levels (i1/i2/i3/i4/i5/i6/i7/i9/i11) for SPCCT and 7 for DLCT (i1/i2/i3/i4/i5/i6/i7).

CT dose optimization for the detection of pulmonary arteriovenous malformation (PAVM): A phantom study.

Purpose: To determine the lowest suitable dose level for the detection of pulmonary arteriovenous malformation (PAVM) using a task-based image quality assessment.

Material And Methods: A phantom was scanned using the standard chest protocol (STD) and 4 other ultra-low dose protocols (ULD) using various kVp. Raw data were reconstructed using level 5 of the hybrid iterative reconstruction algorithm (iDose) for the STD protocol, and level 6 of iDose and levels 1 to 3 of model-based iterative reconstruction (IMR) for the ULD protocols.

Pulmonary hypertension detection by computed tomography pulmonary transit time in heart failure with reduced ejection fraction.

Aims: To evaluate the relationships between pulmonary transit time (PTT), cardiac function, and pulmonary haemodynamics in patients with heart failure with reduced ejection fraction (HFrEF) and to explore how PTT performs in detecting pulmonary hypertension (PH).

Methods And Results: In this prospective study, 57 patients with advanced HFrEF [49 men, 51 years ± 8, mean left ventricular (LV) ejection fraction 26% ± 8] underwent echocardiography, right heart catheterization, and cardiac computed tomography (CT). PTT was measured as the time interval between peaks of attenuation in right ventricle (RV) and LV and was compared between patients with or without PH and 15 controls.

Virtual versus true non-contrast dual-energy CT imaging for the diagnosis of aortic intramural hematoma.

Purpose: To assess whether virtual non-contrast (VNC) images derived from contrast dual-layer dual-energy computed tomography (DL-DECT) images could replace true non-contrast (TNC) images for aortic intramural hematoma (IMH) diagnosis in acute aortic syndrome (AAS) imaging protocols by performing quantitative as well as qualitative phantom and clinical studies.

Materials And Methods: Patients with confirmed IMH were included retrospectively in two centers. For in vitro imaging, a custom-made phantom of IMH was placed in a semi-anthropomorphic thorax phantom (QRM GmbH) and imaged on a DL-DECT at 120 kVp under various conditions of patient size, radiation exposure, and reconstruction modes.