Liver lesion localisation and classification with convolutional neural networks: a comparison between conventional and spectral computed tomography.

Purpose: To evaluate the benefit of the additional available information present in spectral CT datasets, as compared to conventional CT datasets, when utilizing convolutional neural networks for fully automatic localisation and classification of liver lesions in CT images.

Materials And Methods: Conventional and spectral CT images (iodine maps, virtual monochromatic images (VMI)) were obtained from a spectral dual-layer CT system. Patient diagnosis were known from the clinical reports and classified into healthy, cyst and hypodense metastasis.

Sparse sampling computed tomography (SpSCT) for detection of pulmonary embolism: a feasibility study.

Objectives: Evaluation of sparse sampling computed tomography (SpSCT) regarding subjective and objective image criteria for the detection of pulmonary embolism (PE) at different simulated dose levels.

Methods: Computed tomography pulmonary angiography (CTPA) scans of 20 clinical patients were used to obtain simulated low-dose scans with 100%-50%-25%-12.5%-6.

Differentiating intrapulmonary metastases from different primary tumors via quantitative dual-energy CT based iodine concentration and conventional CT attenuation.

Introduction: To investigate the utility of quantitative dual-energy spectral CT derived iodine concentration (IC), in comparison with conventional CT attenuation, for the differentiation of pulmonary metastases from different primary malignancies.

Materials And Methods: CT scans were performed on a dual-layer spectral CT. We retrospectively evaluated pulmonary metastases of 130 patients (77 men and 53 women, mean age 63, range 22-87) with primary bone (OS) (osteosarcoma; n = 6), breast (invasive-ductal adenocarcinoma; n = 17), colorectal (CRC) (adenocarcinoma; n = 27), head and neck (HNC) (squamous cell carcinoma; n = 17), kidney (RCC) (clear-cell renal cell carcinoma; n = 10), lung (adenocarcinoma; n = 12), pancreato-biliary (PBC) (adenocarcinoma; n = 18), prostate (adenocarcinoma; n = 5), soft tissue (undifferentiated pleomorphic sarcoma; n = 6), skin (malignant melanoma; n = 6), and urinary tract (transitional-cell carcinoma; n = 6) malignancies.

Evaluation of a computed-tomography-based assessment scheme in treatment decision-making for isolated orbital floor fractures.

Introduction: Treatment decisions for fractures of the orbital floor are based on clinical appearance, ophthalmological examination, and computed tomography (CT) scans. In extensive fractures, decisions are easily made between conservative and surgical treatment. However, objective parameters are rare in inconclusive cases.

Dual layer computed tomography: Reduction of metal artefacts from posterior spinal fusion using virtual monoenergetic imaging.

Introduction: To evaluate the clinical potential of dual layer computed tomography (DLCT) for posterior fusions of the thoracic and lumbar spine and determine the optimal keV-settings for an improved overall image quality and effective reduction of metal artefacts affecting the implant inheriting vertebral body, the spinal canal, the paravertebral muscle and aorta.

Methods And Materials: Twenty patients with posterior thoracic and lumbar spinal fusion, who underwent a 120kVp- DLCT scan were included in this study. Two independent readers evaluated axial 0.

Dual-layer spectral computed tomography: Virtual non-contrast in comparison to true non-contrast images.

Purpose: To evaluate virtual-non-contrast (VNC) images obtained from clinical triphasic scans with a dual-layer spectral computed tomography system regarding accuracy of iodine subtraction.

Material And Methods: From September to December 2016, 62 consecutive patients who underwent a clinical routine triphasic CT examination were included into this retrospective study. VNC images based on the arterial and portal venous phase were generated.

Accuracy of iodine quantification in dual-layer spectral CT: Influence of iterative reconstruction, patient habitus and tube parameters.

Purpose: Evaluation of the influence of iterative reconstruction, tube settings and patient habitus on the accuracy of iodine quantification with dual-layer spectral CT (DL-CT).

Material And Methods: A CT abdomen phantom with different extension rings and four iodine inserts (1, 2, 5 and 10 mg/ml) was scanned on a DL-CT. The phantom was scanned with tube-voltages of 120 and 140 kVp and CTDI of 2.

Experimental feasibility of spectral photon-counting computed tomography with two contrast agents for the detection of endoleaks following endovascular aortic repair.

Objectives: After endovascular aortic repair (EVAR), discrimination of endoleaks and intra-aneurysmatic calcifications within the aneurysm often requires multiphase computed tomography (CT). Spectral photon-counting CT (SPCCT) in combination with a two-contrast agent injection protocol may provide reliable detection of endoleaks with a single CT acquisition.

Methods: To evaluate the feasibility of SPCCT, the stent-lined compartment of an abdominal aortic aneurysm phantom was filled with a mixture of iodine and gadolinium mimicking enhanced blood.

Assessment of quantification accuracy and image quality of a full-body dual-layer spectral CT system.

The performance of a recently introduced spectral computed tomography system based on a dual-layer detector has been investigated. A semi-anthropomorphic abdomen phantom for CT performance evaluation was imaged on the dual-layer spectral CT at different radiation exposure levels (CTDI of 10 mGy, 20 mGy and 30 mGy). The phantom was equipped with specific low-contrast and tissue-equivalent inserts including water-, adipose-, muscle-, liver-, bone-like materials and a variation in iodine concentrations.