Publications by authors named "Hadizadeh D"

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 PDF

Purpose: 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 PDF

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 PDF

Introduction: 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.

View Article and Find Full Text PDF

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 PDF

Purpose: 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.

View Article and Find Full Text PDF

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).

View Article and Find Full Text PDF

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 PDF

Purpose: 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 PDF

Current 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 PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Purpose: To evaluate whether a 3 D proton density-weighted fat-suppressed sequence (PDwFS) of the knee is able to replace multiplanar 2D-PDwFS.

Materials And Methods: 52 patients (26 men, mean age: 41.9 ± 14.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Background Posterior instability is a pathologic movement occurring in the spondylolytic cleft. Purpose To present a new classification system for the evaluation of spondylolytic cleft by positional magnetic resonance imaging (MRI) and determine the prevalence of the different types. Material and Methods A total of 176 segments of the lumbar spine with spondylolysis or isthmic spondylolisthesis were examined using positional MRI.

View Article and Find Full Text PDF

Unlabelled: Alcohol addiction is the most common drug addiction. Alcohol passes both the placenta as well as the blood-brain barrier and is in multiple ways neurotoxic. Liver diseases and other systemic alcohol-related diseases cause secondary damage to the CNS.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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 PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

In the first decade of the twenty-first century, whole-body magnetic resonance scanners with high field strengths (and thus potentially better signal-to-noise ratios) were developed. At the same time, parallel imaging and "echo-sharing" techniques were refined to allow for increasingly high spatial and temporal resolution in dynamic magnetic resonance angiography ("time-resolved" = TR-MRA). This technological progress facilitated tracking the passage of intra-venously administered contrast agent boluses as well as the acquisition of volume data sets at high image refresh rates ("4D-MRA").

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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 PDF