Intraoperative indocyanine green-visualization in a difficult to localize central cholangiocarcinoma - A case report.

Introduction And Importance: Near infrared fluorescence imaging with indocyanine green (ICG) can facilitate the intraoperative tumour localization and therefore a complete resection. Cholangiocarcinoma is an aggressive tumour and complete resection improves the outcome. Therefore, it is necessary to localize the tumour exactly but the translation of the preoperative imaging into the intraoperative setting can be difficult based only on sonography, computed tomography or magnetic resonance imaging.

Contrast-enhanced ultrasound can guide the therapeutic strategy by improving the detection of colorectal liver metastases.

Background & Aims: CT may miss up to 30% of cases of colorectal liver metastases (CRLMs). We assessed the impact of contrast-enhanced ultrasound (CEUS) on the detection of CRLMs and on changes to the therapeutic strategy; additionally, we assessed the accuracy of CEUS in differentiating unclear focal liver lesions (FLLs) compared to staging-CT.

Methods: We prospectively analyzed all patients with newly diagnosed and histologically confirmed colorectal cancer (CRC) at our tertiary gastroenterological center between December 2015 and May 2019.

Adoption of Splenic Enhancement to Time and Trigger the Late Hepatic Arterial Phase During MDCT of the Liver: Proof of Concept and Clinical Feasibility.

Objective: The purpose of this study was to prospectively investigate the clinical feasibility of adopting splenic enhancement for timing and triggering the acquisition of late hepatic arterial phase images during multiphasic liver MDCT for assessment of hypervascular tumors.

Subjects And Methods: Forty-eight patients (33 men, 15 women; median age, 59 years; chronic liver disease, 23 patients; portal venous hypertension, 17 patients) with a total of 81 hypervascular liver tumors underwent liver MDCT by random assignment to one of two scanning protocols. Scanning delay for the late hepatic arterial phase was determined by assessment of time-to-peak splenic enhancement (splenic-triggering protocol) or aortic enhancement (aortic-triggering protocol).

CT Angiography of the Aorta: Prospective Evaluation of Individualized Low-Volume Contrast Media Protocols.

Purpose To prospectively develop individualized low-volume contrast media (CM) protocols adapted to tube voltage in patients undergoing computed tomographic (CT) angiography of the aorta. Materials and Methods The study was approved by the institutional review board and local ethics committee. All patients provided written informed consent.

Computed Tomography Angiography of Coronary Artery Bypass Grafts: Low Contrast Media Volume Protocols Adapted to Tube Voltage.

Objective: The aim of this study was to evaluate the potential of contrast media (CM) reduction in computed tomography angiography (CTA) of coronary artery bypass grafts (CABGs) when adapting CM volume to automatically selected tube voltages.

Material And Methods: Sixty consecutive patients (mean age, 71 ± 14.5 years) with a total of 176 CABGs (692 bypass segments) underwent contrast-enhanced prospectively electrocardiography-gated high-pitch CTA with automated, attenuation-based tube voltage selection (100 ref.

Optimizing radiation dose by using advanced modelled iterative reconstruction in high-pitch coronary CT angiography.

Purpose: To evaluate the potential of advanced modeled iterative reconstruction (ADMIRE) for optimizing radiation dose of high-pitch coronary CT angiography (CCTA).

Methods: High-pitch 192-slice dual-source CCTA was performed in 25 patients (group 1) according to standard settings (ref. 100 kVp, ref.

Advanced virtual monoenergetic computed tomography of hyperattenuating and hypoattenuating liver lesions: ex-vivo and patient experience in various body sizes.

Objective: To determine the value of advanced virtual monoenergetic images (mono+) from dual-energy computed tomography (CT) of hyperattenuating and hypoattenuating liver lesions in various phantom sizes and patients in comparison with standard monoenergetic images (mono).

Materials And Methods: Anthropomorphic phantoms simulating 4 patient sizes (S, 300 × 200 mm; M, 350 × 250 mm; L, 400 × 300 mm; and XL, 600 × 450 mm) with a liver insert containing both hyperattenuating and hypoattenuating iodine-containing lesions were imaged with dose-equivalent dual-energy (100/150 Sn kilovolt [peak] [kV{p}]) and single-energy (120 kV[p]) protocols on a 192-slice dual-source CT system. In addition, 4 patients with 3 hypoattenuating and 3 hyperattenuating hepatocellular carcinoma were included and underwent dual-energy CT imaging with the same scanner at similar kV(p) settings (100/150 Sn kV[p]).

Automated attenuation-based tube voltage selection for body CTA: Performance evaluation of 192-slice dual-source CT.

Objective: To assess radiation dose and image quality in body CT-angiography (CTA) with automated attenuation-based tube voltage selection (ATVS) on a 192-slice dual-source CT (DSCT).

Methods: Forty patients (69.5 ± 9.

Interdependencies of acquisition, detection, and reconstruction techniques on the accuracy of iodine quantification in varying patient sizes employing dual-energy CT.

Purpose: To assess the impact of patient habitus, acquisition parameters, detector efficiencies, and reconstruction techniques on the accuracy of iodine quantification using dual-source dual-energy CT (DECT).

Materials And Methods: Two phantoms simulating small and large patients contained 20 iodine solutions mimicking vascular and parenchymal enhancement from saline isodensity to 400 HU and 30 iodine solutions simulating enhancement of the urinary collecting system from 400 to 2,000 HU. DECT acquisition (80/140 kVp and 100/140 kVp) was performed using two DECT systems equipped with standard and integrated electronics detector technologies.

Performance of turbo high-pitch dual-source CT for coronary CT angiography: first ex vivo and patient experience.

Objectives: To evaluate image quality, maximal heart rate allowing for diagnostic imaging, and radiation dose of turbo high-pitch dual-source coronary computed tomographic angiography (CCTA).

Methods: First, a cardiac motion phantom simulating heart rates (HRs) from 60-90 bpm in 5-bpm steps was examined on a third-generation dual-source 192-slice CT (prospective ECG-triggering, pitch 3.2; rotation time, 250 ms).

High-pitch coronary CT angiography with third generation dual-source CT: limits of heart rate.

To determine the average heart rate (HR) and heart rate variability (HRV) required for diagnostic imaging of the coronary arteries in patients undergoing high-pitch CT-angiography (CTA) with third-generation dual-source CT. Fifty consecutive patients underwent CTA of the thoracic (n = 8) and thoracoabdominal (n = 42) aorta with third-generation dual-source 192-slice CT with prospective electrocardiography (ECG)-gating at a pitch of 3.2.

Ultralow-dose chest computed tomography for pulmonary nodule detection: first performance evaluation of single energy scanning with spectral shaping.

Purpose: The purpose of this study was to evaluate the image quality and sensitivity of ultralow radiation dose single-energy computed tomography (CT) with tin filtration for spectral shaping and iterative reconstructions for the detection of pulmonary nodules in a phantom setting.

Methods: Single-energy CT was performed using third-generation dual-source CT (SOMATOM Force; 2 × 192 slices) at 70 kVp, 100 kVp with tin filtration (100Sn kVp), and 150Sn kV with tube current-time product adjustments resulting in standard dose (CT volume dose index, 3.1 mGy/effective dose, 1.

Combining automated attenuation-based tube voltage selection and iterative reconstruction: a liver phantom study.

Objectives: To determine the value of combined automated attenuation-based tube-potential selection and iterative reconstructions (IRs) for optimising computed tomography (CT) imaging of hypodense liver lesions.

Methods: A liver phantom containing hypodense lesions was imaged by CT with and without automated attenuation-based tube-potential selection (80, 100 and 120 kVp). Acquisitions were reconstructed with filtered back projection (FBP) and sinogram-affirmed IR.

Precision of iodine quantification in hepatic CT: effects of iterative reconstruction with various imaging parameters.

Objective: The objective of this study was to evaluate the feasibility of using iterative reconstructions in hepatic CT to improve the precision of Hounsfield unit quantification, which is the degree to which repeated measurements under unchanged conditions provide consistent results.

Materials And Methods: An anthropomorphic liver phantom with iodinated lesions designed to simulate the enhancement of hypervascular tumors during the late hepatic arterial phase was imaged, and images were reconstructed with both filtered back projection (FBP) and iterative reconstructions, such as adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR). This protocol was further expanded into various dose levels, tube voltages, and slice thicknesses to investigate the effect of iterative reconstructions under all these conditions.

Lesion detection and assessment of extrahepatic findings in abdominal MRI using hepatocyte specific contrast agents--comparison of Gd-EOB-DTPA and Gd-BOPTA.

Background: To evaluate the contrast agent performance of Gd-EOB-DTPA and Gd-BOPTA for detection and assessment of extrahepatic findings, semi-quantitatively and qualitatively.

Methods: 13 patients with 19 extrahepatic lesions underwent liver MRI with Gd-EOB-DTPA and Gd-BOPTA. Quantitative and relative SNR measurements were performed in each dataset in the arterial and portalvenous phase within the extrahepatic lesion, aorta, inferior vena cava, portal vein, spleen, pancreas and renal cortex.

Towards task-based assessment of CT performance: system and object MTF across different reconstruction algorithms.

Purpose: To investigate a measurement method for evaluating the resolution properties of CT imaging systems across reconstruction algorithms, dose, and contrast.

Methods: An algorithm was developed to extract the task-based modulation transfer function (MTF) from disk images generated from the rod inserts in the ACR phantom (model 464 Gammex, WI). These inserts are conventionally employed for HU accuracy assessment.

Assessment of vascular contrast and depiction of stenoses in abdominopelvic and lower extremity vasculature: comparison of dual-energy MDCT with digital subtraction angiography.

Rationale And Objectives: To assess whether dual-energy computed tomography (DECT) multidetector computed tomography (MDCT) angiography improves vascular contrast beyond MDCT angiography and digital subtraction angiography (DSA) while preserving the ability to precisely characterize stenoses, using DSA as reference standard.

Materials And Methods: This prospective, Health Insurance Portability and Accountability Act-compliant, institutional review board-approved study was performed on 25 patients referred for lower extremity DECT angiography and subsequent DSA. Spectral data were postprocessed to create single-energy 120 kVp (MDCT series) and iodine-only (DECT series) datasets.

Radiation dose reduction in abdominal computed tomography during the late hepatic arterial phase using a model-based iterative reconstruction algorithm: how low can we go?

Objective: The aim of this study was to compare the image quality of abdominal computed tomography scans in an anthropomorphic phantom acquired at different radiation dose levels where each raw data set is reconstructed with both a standard convolution filtered back projection (FBP) and a full model-based iterative reconstruction (MBIR) algorithm.

Materials And Methods: An anthropomorphic phantom in 3 sizes was used with a custom-built liver insert simulating late hepatic arterial enhancement and containing hypervascular liver lesions of various sizes. Imaging was performed on a 64-section multidetector-row computed tomography scanner (Discovery CT750 HD; GE Healthcare, Waukesha, WI) at 3 different tube voltages for each patient size and 5 incrementally decreasing tube current-time products for each tube voltage.

Clinical impact of 18F-choline PET/CT in patients with recurrent prostate cancer.

Purpose: To investigate the clinical value of (18)F-fluorocholine PET/CT (CH-PET/CT) in treatment decisions in patients with recurrent prostate cancer (rPCA).

Methods: The study was a retrospective evaluation of 156 patients with rPCA and CH-PET/CT for restaging. Questionnaires for each examination were sent to the referring physicians 14-64 months after examination.

Hepatic hemangiomas: difference in enhancement pattern on 3T MR imaging with gadobenate dimeglumine versus gadoxetate disodium.

Purpose: To compare intraindividual differences in enhancement pattern of hepatic hemangiomas between gadobenate dimeglumine (Gd-BOPTA) and gadoxetate disodium (Gd-EOB-DTPA)-enhanced 3T MR imaging.

Materials And Methods: This is a HIPAA-compliant, IRB-approved retrospective study with waiver for informed consent granted. From 10/07 to 5/09, 10 patients (2 males, 8 females; mean age, 57.

Liver MRI in the hepatocyte phase with gadolinium-EOB-DTPA: does increasing the flip angle improve conspicuity and detection rate of hypointense lesions?

Purpose: To compare conspicuity and detection rate of hypointense lesions on T1-weighted (T1w) gradient echo (GRE) sequences with low and high flip angles (FA) in hepatocyte phase magnetic resonance imaging (MRI) using gadoxetate disodium.

Materials And Methods: This Health Insurance Portability and Accountability Act (HIPAA)-compliant study was Institutional Review Board (IRB)-approved. The study population consisted of patients with hypointense liver lesions undergoing MRI with gadoxetate disodium, with hepatocyte-phase fat suppressed 3D T1w GRE sequences at both low (10-12°) and high (30-35°) FA.

Contrast enhanced liver MRI in patients with primary sclerosing cholangitis: inverse appearance of focal confluent fibrosis on delayed phase MR images with hepatocyte specific versus extracellular gadolinium based contrast agents.

Rationale And Objectives: To assess the enhancement pattern of focal confluent fibrosis (FCF) on contrast-enhanced hepatic magnetic resonance imaging (MRI) using hepatocyte-specific (Gd-EOB-DTPA) and extracellular (ECA) gadolinium-based contrast agents in patients with primary sclerosing cholangitis (PSC).

Materials And Methods: After institutional review board approval, 10 patients with PSC (6 male, 4 female; 33-61 years) with 13 FCF were included in this retrospective study. All patients had a Gd-EOB-DTPA-enhanced liver MRI exam, and a comparison ECA-enhanced MRI.

Contrast-enhanced magnetic resonance angiography: first-pass arterial enhancement as a function of gadolinium-chelate concentration, and the saline chaser volume and injection rate.

Objective: To evaluate the effect of the contrast medium (CM) concentration and the saline chaser volume and injection rate on first-pass aortic enhancement characteristics in contrast-enhanced magnetic resonance angiography using a physiologic flow phantom.

Materials And Methods: Imaging was performed on a 3.0-T magnetic resonance system (MAGNETOM Trio, Siemens Healthcare Solutions, Inc, Erlangen, Germany) using a 2-dimensional fast low angle shot T1-weighted sequence (repetition time, 500 milliseconds; echo time, 1.