PURPOSE: To evaluate if two gadolinium perfusion studies can be performed during the same table occupancy without degradation of the derived data in the second study. MATERIAL AND METHODS: Magnetic resonance (MR) perfusion studies of the whole brain were performed on 12 patients during the administration of two gadolinium boluses ...

Rapid magnetic resonance imaging (MRI) makes it possible to detect the fast kinetics of tissue response after intravenous administration of a paramagnetic contrast medium (CM), reflecting the status of tissue microcirculation. In this paper, the basic physical and tracer kinetic principles of dynamic relaxivity and susceptibility contrast-enhanced MRI are reviewed. ...

BACKGROUND CONTEXT: Symptoms of spinal stenosis are position-dependent. Stand up magnetic resonance imaging (MRI) and myelography can demonstrate further dynamic components of spinal stenosis that may go unrecognized on supine MRI. PURPOSE: To describe a radiographic finding seen on standard supine MRI that is an indicator for dynamic spinal stenosis ...

An abnormal opacity was found incidentally on chest radiography in a 19-year-old Japanese man with lumbago. Chest computed tomography (CT) revealed a 55 x 40 mm well-defined mass with smooth margins in the lower lobe of the right lung (S6). Contrast-enhanced dynamic CT showed that the lesion was not enhanced, ...

PURPOSE: To compare two methods for assessing the single kidney glomerular filtration rate (SK-GFR) in humans using dynamic contrast-enhanced (DCE)-MRI. MATERIALS AND METHODS: Images were acquired from 39 separate MR studies of patients with atherosclerotic renovascular disease (ARVD). Data from the kidneys and descending aorta were analyzed using both a ...

MRI is widely used for noninvasive hemodynamic-based functional brain imaging. In traditional spatial encoding, however, gradient switching limits the temporal resolution, which makes it difficult to unambiguously identify possible fast nonhemodynamic changes. In this paper we propose a novel reconstruction approach, called dynamic inverse imaging (InI), that is capable of ...

OBJECTIVE: The purpose of this study was to correlate the degree of contrast enhancement on dynamic contrast-enhanced T1-weighted MRI and the relative cerebral blood volume (rCBV) values on T2*-weighted MRI in patients with high-grade brain neoplasms. SUBJECTS AND METHODS: Ten patients with biopsy-proven high-grade gliomas underwent dynamic contrast-enhanced MRI using ...

OBJECTIVE: We describe the effects of tumor necrosis factor alpha (TNFalpha) on tumor microvasculature in a murine colon carcinoma model using serial dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). MATERIAL AND METHODS: Mice with subcutaneous murine colon carcinomas (MC-38) were imaged at 4.7 T after administration of 0.2 mmol/kg gadolinium-DTPA. ...

PURPOSE: To characterize tumor vascularization by dynamic-contrast enhanced (DCE) MRI using low and medium molecular weight paramagnetic contrast agents (CA) and inversion recovery (IR) true fast imaging with steady state precession (TrueFISP) in tumor-bearing rats and mice. MATERIALS AND METHODS: T(1) mapping was performed using IR True FISP in phantoms ...

Tracheomalacia (TM) associated with esophageal atresia (OA) generally is located in the thoracic segment of the trachea, and the close anatomical relationships it has with the aortic arch and the other mediastinal structures play a remarkable role in the dynamic obstruction of the airways. Only correct preoperative imaging studies permit ...

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is being used in oncology as a noninvasive method for measuring properties of the tumor microvasculature. There is potential for DCE-MRI to be used as an imaging biomarker to measure antiangiogenic effects of cancer treatments. This article reviews the general methodology for performing DCE-MRI ...

OBJECTIVE: To evaluate the clinical utility of dynamic magnetic resonance (MR) sialographic images as a diagnostic tool for patients with Sjögren's syndrome. METHODS: The morphological findings and various kinds of functional parameters in volunteers on dynamic MR sialographic images were compared with those in five patients with definite Sjögren's syndrome. ...

The aim of this study was to adapt the human magnetic resonance imaging (MRI) sequences for use in the routine examination of canine mammary glands. MRI was performed on 10, middle- to old-aged dogs of different breeds. It was found that T1- and T2-weighted spin echo, short T1 inversion recovery ...

According to the type of sequences used, either morphological or dynamic functional study can be performed using magnetic resonance imaging (MRI). The aim of this study is to find out if vascular information found, in dynamic MR sequences, already exists in anatomical MR sequences in the particular case of Legg-Calvé-Perthes ...

OBJECTIVE: Our purpose was to identify the MR features of focal splenic lesions with an emphasis on enhancement patterns. The addition of a contrast-enhanced dynamic sequence to unenhanced MR images improves the study of focal splenic lesions. The analysis of the MR features along with the clinical history permits either ...

OBJECTIVES: We sought to compare pharmacokinetic modeling of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data by assuming a linear and nonlinear relationship between signal intensity (SI) and contrast agent (CA) concentration. MATERIALS AND METHODS: Data sets were generated by computer-based simulation studies and DCE-MRI examination of 5 tumor-bearing mice using ...

OBJECTIVE: The objective was to determine the enhancement kinetics of the normal ovaries in healthy women on dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging. METHOD: Twenty-one women who had normal ovulatory cycles (volunteers; mean age=26.3 years, range=20-35), normal hormone profile, and apparently normal ovaries on ultrasonographic scan underwent DCE-MR imaging on ...

PURPOSE: To compare a superparamagnetic iron oxide (SPIO), VSOP-C184, with a gadopentetate dimeglumine with regard to signal-enhancing effects on T1-weighted dynamic magnetic resonance (MR) images and with another SPIO contrast medium with regard to signal-reducing effects on delayed T2-weighted MR images. MATERIALS AND METHODS: All experiments were approved by the ...

The purpose of this study was to evaluate the effectiveness of dynamic contrast-enhanced MRI (DC-MRI) for assessing the pattern of invasion of tongue carcinomas. We studied 20 cases of squamous cell carcinoma of the tongue that showed peripheral enhancement patterns on DC-MRI. The diameter of each tumor was >2.0 cm ...

Abnormal microcirculation is a feature of many neoplastic and non-neoplastic diseases. Physiological variables that characterize tissue microcirculation (capillary permeability and the volume of the extravascular extracellular fluid) are altered in pathological states. Pharmacokinetic analysis of dynamic contrast enhanced MRI (DCE-MRI) has found a widespread use in the assessment of abnormal ...

Dynamic computed tomography (CT) myelography was conducted in 15 patients with cervical degenerative disease to assess the lesions responsible for their symptoms. CT myelography was performed using a multi-detector row helical CT system in dynamic positions (flexion or extension or both) in addition to the neutral position. Fine sagittal reconstructed ...

PURPOSE: To investigate the role of ferucarbotran-enhanced dynamic MR imaging using multishot spin-echo echo-planar sequence in the evaluation of hemodynamics of focal hepatic lesions. MATERIALS AND METHODS: Sixty-three focal hepatic lesions (24 benign and 39 malignant) from 53 consecutive patients who underwent both ferucarbotran-enhanced MR imaging and dynamic computed tomography ...

OBJECTIVES: To determine whether the failure of chemotherapy in patients with regionally metastatic or unresectable transitional cell carcinoma (TCC) of the bladder can be predicted early in the course of chemotherapy with magnetic resonance (MR) imaging. METHODS: In this prospective study, 36 patients with regionally metastatic or unresectable TCC of ...

Superparamagnetic iron oxide (SPIO) particles are as MR contrast media composed of iron oxide crystals coated with dextran or carboxydextran. These particles are sequestered by phagocytic Kupffer cells in normal reticuloendothelial system (RES), but are not retained in tumor tissue. Consequently, there are significant differences in T2/T2* relaxation between normal ...

We performed neural network clustering on dynamic contrast-enhanced perfusion magnetic resonance imaging time-series in patients with and without stroke. Minimal-free-energy vector quantization, self-organizing maps, and fuzzy c-means clustering enabled self-organized data-driven segmentation with respect to fine-grained differences of signal amplitude and dynamics, thus identifying asymmetries and local abnormalities of brain ...

OBJECTIVES: Image sequences with time-varying information content need appropriate analysis strategies. The exploration of directed information transfer (interactions) between neuronal assemblies is one of the most important aims of current functional MRI (fMRI) analysis. Additionally, we examined perfusion maps in dynamic contrast agent MRI sequences of stroke patients. In this ...

OBJECTIVE: The objective of our study was to compare the diagnostic performance of gadobenate dimeglumine-enhanced MRI with that of 16-MDCT for the detection of hepatocellular carcinoma using receiver operating characteristic (ROC) curve analysis. MATERIALS AND METHODS: Thirty-one patients with 53 hepatocellular carcinomas underwent gadobenate dimeglumine-enhanced dynamic MRI and multiphasic CT ...

PURPOSE: To prospectively determine the prevalence and predictive value of three-dimensional (3D) and dynamic breast magnetic resonance (MR) imaging and contrast material kinetic features alone and as part of predictive diagnostic models. MATERIALS AND METHODS: The study protocol was approved by the institutional review board or ethics committees of all ...

This study used perturbation methods (eg, jitter and shimmer) and nonlinear dynamic methods (eg, phase space reconstruction and correlation dimension) to analyze sustained voices generated by normal subjects and patients with unilateral laryngeal paralysis. We found that normal and pathological voices had low-dimensional dynamic characteristics. For nearly periodic voices, jitter ...

OBJECTIVE: This is Part II of a study on atlantoaxial rotatory fixation (AARF) that aims to introduce a new diagnostic paradigm and a new classification of this condition based on motion analysis of C1C2 rotation using computed tomographic (CT) imaging. This phase of the study is possible because Part I ...

AIM: To evaluate the value of dynamic contrast enhanced magnetic resonance angiography (CE-MRA) for classification of endoleaks after endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: Twenty-eight patients, between 2 days and 54 months after EVAR, were evaluated with CTA, MRI and dynamic CE-MRA. The additional diagnostic value of the dynamic ...

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has become an important source of information to aid cancer diagnosis. Nevertheless, due to the multi-temporal nature of the three-dimensional volume data obtained from DCE-MRI, evaluation of the image data is a challenging task and tools are required to support the human expert. We ...

The mechanisms of endosome biogenesis and maintenance are largely unknown. The small GTPases Rab 5 and Rab 7 are key determinants of early and late endosomes, organizing effector proteins into specific membrane subdomains. Whether such Rab machineries are indefinitely maintained on membranes or can disassemble in the course of cargo ...

PURPOSE: To investigate prospectively the trade-off between temporal and spatial resolution in dynamic contrast material-enhanced bilateral magnetic resonance (MR) imaging of the breast. MATERIALS AND METHODS: Informed consent and institutional review board approval were obtained. An intraindividual comparative study was performed in 30 patients (mean age, 53 years; age range, ...

The outlet obstruction syndrome encompasses all pelvic floor abnormalities which are responsible for an incomplete evacuation of fecal contents from the rectum. It has been estimated that outlet obstruction may be observed in half of constipated patients. A detailed clinical examination still represents the cornerstone of the diagnosis of these ...

In the different studies on the etiology of mental retardation (MR), a diagnosis has been reached in a remarkably variable proportion of cases. This is due to differences in methodology (population examined, age of the patients, degree of MR, time and protocol of investigation, expertise), method of classification (according to ...

Although dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and magnetic resonance spectroscopy (MRS) have great potential to provide routine assessment of cancer treatment response, their widespread application has been hampered by a lack of standards for use. Thus, the National Cancer Institute convened a workshop to assess developments and applications of ...

PURPOSE: Interstitial fluid pressure (IFP) and oxygen (pO(2)) measurements are prognostic factors in cervical cancer. The purpose of this study was to determine the relationship between IFP and oxygenation and parameters derived from dynamic contrast-enhanced computed tomography (DCE-CT). METHODS AND MATERIALS: Dynamic contrast-enhanced computed tomography was performed in 32 patients ...

Imaging findings in basal cell adenoma (BCA) of the parotid gland have been rarely reported. We report dynamic CT and MRI findings of BCA in the parotid gland in a 78-year-old woman. Dynamic CT study demonstrated strong multinodular contrast enhancement in the early phase which decreased gradually in the later ...

PURPOSE: To examine whether parameters of dynamic, contrast-enhanced MRI (DCE MRI) reflect the degree of infiltration and vessel density in corresponding bone marrow biopsy specimens. MATERIALS AND METHODS: The pelvis of 24 patients with multiple myeloma (MM) was examined using contrast-enhanced DCE MRI. Biopsy was obtained from the spina iliaca ...

The aim of this study is to investigate the efficacy of dynamic computed tomography (CT) during selective angiography (CT-arteriography) of orbital tumors in the evaluation of intratumoral vascular anatomy, feeding artery territory, and histological diagnosis. Among 35 consecutive cases with various orbital lesions, those cases showing tumor staining or pooling ...

New anticancer therapeutics that target tumor blood vessels promise improved efficacy and tolerability in humans. Early phase 1 drug trials have shown that the maximum tolerated dose may be inappropriate for more advanced clinical studies with efficacy endpoints. More advanced clinical trials have demonstrated that morphologic assessments of tumor response ...

OBJECTIVE: The purpose of our study was to evaluate the usefulness of dual-phase dynamic CT in the differentiation of focal eosinophilic necrosis of the liver and metastasis. CONCLUSION: Undetected isoattenuating lesions on arterial phase images that have an indistinct margin, a nonspherical shape, and a homogenous enhancement pattern on portal ...

PURPOSE: To compare dynamic expiratory and end-expiratory computed tomography (CT) for depicting central airway collapse in patients with acquired tracheobronchomalacia (TBM). MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was not needed. Retrospective review was performed of all patients with a CT diagnosis of TBM in ...

AIM: To investigate the correlation between microvessel density and spiral CT perfusion imaging in colorectal carcinoma. METHODS: Thirty-seven patients, with histologically proven colorectal carcinoma, underwent water enema spiral CT scan. The largest axial surface of the primary tumor was searched on unenhanced spiral CT images. At this level, the enhanced ...

A case of transient neurologic deficit associated with the acetazolamide challenge conducted in conjunction with dynamic enhanced computed tomography (CT) perfusion imaging for the evaluation of cerebral hemodynamic impairment is reported in a patient with known cerebrovascular steno-occlusive disease. Combining the acetazolamide challenge with dynamic CT perfusion provides a rapid ...

PURPOSE: An ever recurring challenge in diagnostic radiology is the differentiation between non-malignant and malignant tissue. Based on evidence that microcirculation of normal, non-malignant tissue differs from that of malignant tissue, the goal of this study was to assess the reliability of dynamic contrast-enhanced Magnetic Resonance Imaging (dcMRI) for differentiating ...

OBJECTIVE: To evaluate the relation between morphological features and enhancement parameters in dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging with histopathological prognostic factors. MATERIALS AND METHODS: Fifty-five patients with surgicopathological diagnosis of breast carcinoma were evaluated with 1.0 T MR scanner as a part of their preoperative diagnostic work-up. Dynamic studies ...

OBJECTIVE: Hemangiomas of the airways in infants are commonly diagnosed at bronchoscopy performed for the investigation of stridor or other respiratory symptoms. Occasionally on bronchoscopy the appearances are atypical or the entire extent of the suspected hemangioma cannot be appreciated. We report on the clinical usefulness of dynamic contrast-enhanced CT ...

Magnetic resonance imaging (MRI) is well suited for small animal model investigations to study various human pathologies. However, the assessment of microscopic information requires a high-spatial resolution (HSR) leading to a critical problem of signal-to-noise ratio limitations in standard whole-body imager. As contrast mechanisms are field dependent, working at high ...