Background: The use of artificial intelligence applications in medicine is becoming increasingly common. At the same time, however, there are few initiatives to teach this important and timely topic to medical students. One reason for this is the predetermined medical curriculum, which leaves very little room for new topics that were not included before.
View Article and Find Full Text PDFPurpose: Spectral shaping employing a tin filter can be used for dose reduction in CT of the abdomen in patients with urolithiasis. As ureteral stents may be in direct contact with the calculus, a good image quality is mandatory. The goal of this study was to obtain data of the effect of tin filtering on image quality and dose in patients with urolithiasis in direct contact with ureteral stents.
View Article and Find Full Text PDFInvest Radiol
October 2022
Objective: High spatial and temporal resolution contrast-enhanced magnetic resonance angiography (MRA) with gadolinium-based contrast agents (GBCAs) at standard dose offers both detailed anatomic information on both arterial and venous vessels and hemodynamic characteristics. Several preclinical and clinical dynamic 3-dimensional (3D) MRA studies that focused on arterial vessels only proposed that high image quality may also be achieved with significantly reduced GBCA doses, calling into question the need to use standard doses. A systematic analysis of GBCA doses and resulting image quality for both arteries and veins has not yet been performed.
View Article and Find Full Text PDFIntroduction: To evaluate treatment response of uterine fibroids after ultrasound guided high-intensity focused ultrasound (USgHIFU) with a special focus on fibroid size and characterization based on Funaki classification scheme, as well as clinical response to treatment of leading fibroid-associated symptoms.
Materials And Methods: Uterine fibroids treated by USgHIFU were assigned to Funaki type 1-3 based on T2-w-MRI. Differences in size, non-perfused volume ratio (NPVR) and volume reduction over time were determined using T1-/T2-w MRI sequences and contrast-enhanced sonography.
Purpose: Compressed sensing (CS) is a method to accelerate MRI acquisition by acquiring less data through undersampling of k-space. In this prospective study we aimed to evaluate whether a three-dimensional (3D) isotropic proton density-weighted fat saturated sequence (PDwFS) with CS can replace conventional multidirectional two-dimensional (2D) sequences at 1.5 Tesla.
View Article and Find Full Text PDFPurpose: Quantitative and qualitative analysis of gadopentetate dimeglumine (GD) versus standard-dose (sGb) and half-dose (hGb) gadobutrol in thoracoabdominal time-resolved contrast-enhanced magnetic resonance angiography (4D-MRA) with dynamic computed tomography (dCT) as the quantitative reference in minipigs.
Materials And Methods: 7 anesthetized Goettingen minipigs received thoracoabdominal dCT (0.37 s rotation time) and transverse 4D-MRA (0.
Background And Purpose: Kinetic parameters of T1-weighted dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are considered to be influenced by microvessel environment. This study was performed to explore the extent of this association for meningiomas.
Materials And Methods: DCE-MRI kinetic parameters (contrast agent transfer constants K and k, volume fractions v and v) were determined in pre-operative 3T MRI of meningioma patients for later biopsy sites (19 patients; 15 WHO I, no previous radiation, and 4 WHO III pre-radiated recurrent tumors).
Purpose: Magnetic resonance (MR) imaging biomarkers can assist in the non-invasive assessment of the genetic status in glioblastomas (GBMs). Telomerase reverse transcriptase (TERT) promoter mutations are associated with a negative prognosis. This study was performed to identify MR imaging biomarkers to forecast the TERT mutation status.
View Article and Find Full Text PDFPurpose: Kinetic parameters derived from dynamic contrast-enhanced MRI (DCE-MRI) were suggested as a possible instrument for multi-parametric lesion characterization, but have not found their way into clinical practice yet due to inconsistent results. The quantification is heavily influenced by the definition of an appropriate arterial input functions (AIF). Regarding brain tumor DCE-MRI, there are currently several co-existing methods to determine the AIF frequently including different brain vessels as sources.
View Article and Find Full Text PDFCurrent biopsy planning based on contrast-enhanced T1W (CET1W) or FLAIR sequences frequently delivers biopsy samples that are not in concordance with the gross tumor diagnosis. This study investigates whether the quantitative information of transfer constant K maps derived from T1W dynamic contrast-enhanced MRI (DCE-MRI) can help enhance the quality of biopsy target selection in glioma. 28 patients with suspected glioma received MRI including DCE-MRI and a standard neuronavigation protocol of 3D FLAIR- and CET1W data sets (0.
View Article and Find Full Text PDFJ Cancer Res Clin Oncol
August 2017
Purpose: To investigate the clinical potential of pretreatment apparent diffusion coefficient (ADC) on diffusion-weighted magnetic resonance imaging (DWI) for therapy response and outcome prediction in patients with liver-predominant metastatic colorectal cancer (CRC) undergoing radioembolization with Yttrium-microspheres (90Y-RE).
Methods: Forty-six consecutive patients with unresectable CRC liver metastases underwent standardized clinical DWI on a 1.5 T MR scanner prior to and 4-6 weeks after 90Y-RE.
Purpose: To investigate the effect of the choice of the curve-fitting model on the perfusion fraction (f ) with regard to tissue type characterization, correlation with microvascular anatomy, and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters. Several curve-fitting models coexist in intravoxel incoherent motion (IVIM) MRI to derive the (f ).
Materials And Methods: In all, 29 patients with brain lesions (12 gliomas, 11 meningiomas, three metastases, two gliotic scars, one multiple sclerosis) underwent IVIM-MRI (32 b-values, 0 to 2000 s/mm ) at 3T.
Eur Radiol
March 2017
Objectives: To investigate whether quantifications of apparent diffusion coefficient (ADC) on diffusion-weighted imaging (DWI) can predict overall survival (OS) in patients with liver-predominant metastatic colorectal cancer (CRC) following selective internal radiation therapy with Yttrium-microspheres (SIRT).
Methods: Forty-four patients underwent DWI 19 ± 16 days before and 36 ± 10 days after SIRT. Tumour-size and intratumoral minimal ADC (minADC) values were measured for 132 liver metastases on baseline and follow-up DWI.
Objectives: To intraindividually compare gadoxetate disodium and gadofosveset trisodium regarding vessel contrast, image quality and vessel delineation in dynamic contrast-enhanced liver MRI at 3.0T.
Methods: Twelve patients underwent 3.
Introduction: Compared to standard arterial-only first-pass MR-angiography (FPMRA), imaging during the equilibrium phase of a blood pool contrast agent (steady state) has been shown to provide higher image quality and better stenosis grading. Homogenous Dixon fat-suppression promises to increase contrast by suppression of fat adjacent to vessels. This study was performed to compare diagnostic image quality and vessel-to-background contrasts in equilibrium phase Dixon-based fat-free MRA (DFSMRA) of run-off vessels to FPMRA imaging and equilibrium phase T1-weighted non-fat-suppressed ultra-high resolution MRA (SSMRA).
View Article and Find Full Text PDFPLoS One
July 2015
Background: Mapping of the great saphenous vein is very important for planning of peripheral and coronary bypass surgery. This study investigated mapping of the great saphenous vein as an adjunct to peripheral MR angiography using a blood pool contrast agent in patients who were referred for evaluation of peripheral arterial occlusive disease and bypass surgery.
Methods: 38 patients with peripheral arterial occlusive disease (21 men; mean age: 71 years, range, 44-88 years) underwent peripheral MR angiography using the blood pool contrast agent Gadofosveset trisodium.
Objectives: To evaluate hepatobiliary magnetic resonance imaging (MRI) using Gd-EOB-DTPA in relation to various liver function tests in patients with liver disorders.
Methods: Fifty-one patients with liver disease underwent Gd-EOB-DTPA-enhanced liver MRI. Based on region-of-interest (ROI) analysis, liver signal intensity was calculated using the spleen as reference tissue.
Purpose: To implement and evaluate high spatial resolution three-dimensional MR contrast-enhanced angiography (3D-CEMRA) of the thighs using a blood pool contrast agent (BPCA) using the quadrature body coil only in patients with peripheral arterial occlusive disease (PAOD) in cases receiver coils cannot be used at 1.5 Tesla (T).
Materials And Methods: Nineteen patients (mean age: 68.
Objectives: The concentration and relaxivities of contrast agents affect quantitative and qualitative image quality in contrast-enhanced time-resolved 4-dimensional magnetic resonance angiography (4D-MRA). Gadobutrol has a high relaxivity and is the only gadolinium (Gd)-based contrast agent approved for clinical use at a 1 M concentration. This promises to confer superior bolus characteristics by generating a steeper and shorter bolus with a higher peak Gd concentration.
View Article and Find Full Text PDFBackground: The incidence of radionecrosis after radiosurgery is 5-20%. That radionecrosis after radiosurgery may be confused with a malignant tumor is a known phenomenon and problem.
Methods: Three similarly treated patients with cAVM, 1 patient with symptomatic radionecrosis and 2 patients with normal post-radiation MRI changes, were selected and studied in detail with magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and magnetic resonance spectroscopy (MRS).
Introduction: Developments in telemedicine have not produced any relevant benefits for orthopedics and trauma surgery to date. For the present project study, several parameters were examined during assessment of x-ray images, which had been photographed and transmitted via cell phone.
Materials And Methods: A total of 100 x-ray images of various body regions were photographed with a Nokia cell phone and transmitted via email or MMS.
Objective: The purpose of this study was to investigate the prevalence of incidental deep venous thrombosis (DVT) in patients with clinically suspected peripheral arterial occlusive disease (PAOD) using contrast-enhanced MR angiography (MRA) with a blood pool contrast agent.
Subjects And Methods: Two hundred fifty-nine MRA examinations with blood pool contrast agent in 245 consecutive patients (161 men; age range, 36-92 years), yielding a total of 4102 assessable arterial and venous vessel segments, were assessed with regard to the rate of incidentally observed acute and organized DVT and arterial stenosis grades. Incidental DVT was confirmed using duplex ultrasound.
Background And Purpose: Follow-up imaging after stent-assisted coiling of intracranial aneurysms is limited by signal loss in the stented vessel segment using magnetic resonance imaging or by streak artifacts caused by aneurysm coils using multidetector computed tomography. In the search for a noninvasive surveillance in this condition, we propose a technique to minimize streak artifacts in multidetector computed tomography by gated data reconstruction and shifting the reconstruction window.
Methods: The effect of the gated data acquisition in 64-row computed tomographic angiography (gCTA) on artifact reduction was evaluated in a preliminary phantom study and compared with nongated CTA, time-of-flight magnetic resonance angiography (TOF-MRA), and digital subtraction angiography (DSA).