We present a novel interpretation of non-monoexponential diffusion-weighted signal decay with b-value in terms of the theory of anomalous diffusion. Anomalous diffusion is the theory of diffusing particles in environments that are not locally homogeneous, such as brain tissue. In such environments the model of restricted diffusion commonly employed in ...

Pineoblastomas are uncommon pineal tumors, which demonstrate rapid growing and poor prognosis. We report the case of a 43-year-old man with an enhancing pineal region mass, which showed restriction of the diffusion on diffusion-weighted (DW) MR images. The surgical biopsy defined the diagnosis of pineoblastoma and the therapy was initiated ...

A stimulated-echo-based technique was developed to measure the regional apparent diffusion coefficient (ADC) of hyperpolarized 3He during a single breathhold for diffusion times of 25 ms or greater. Compared to previous methods, a substantially shorter minimum diffusion time was achieved by decoupling diffusion sensitization from image acquisition. A hyperpolarized-gas phantom ...

OBJECTIVE: The purposes of this study were to describe the imaging appearance of diffuse neurofibroma in 10 patients and to summarize demographic data on a large group of patients. MATERIALS AND METHODS: Retrospective review of the pathology and radiology teaching databases at two institutions yielded the cases of 339 patients ...

PURPOSE: To retrospectively compare different magnetic resonance (MR) imaging techniques and pulse sequences for the depiction of brain injury in neonatal hypoxic-ischemic encephalopathy. MATERIALS AND METHODS: The institutional review board approved this retrospective study and waived informed consent. Term-born neonates underwent MR imaging within 10 days after birth because of ...

Diffusion-weighted MRI (DW-MRI) is a functional imaging technique that displays information about the extent and direction of random water motion in tissues. Water movement in tissues is modified by interactions with hydrophobic cellular membranes, intracellular organelles and macromolecules. DW-MRI provides information on extracellular-space tortuosity, tissue cellularity and the integrity of ...

Apparent diffusion coefficient (ADC) values at magnetic resonance imaging (MRI) are useful to distinguish vasogenic and cytotoxic edema due to cerebovascular diseases. Dural arteriovenous fistulas (DAVFs) with retrograde leptomeningeal venous drainage may cause cerebral edema by venous congestion. We report herein the course of ADC values of cerebral edema before ...

We present 4 cases of carcinoma ex pleomorphic adenoma of the parotid gland. In 3 of the 4 cases, diffusion-weighted and apparent diffusion coefficient (ADC) mapping images clearly revealed carcinoma as a hypercellular area with low ADC values and pleomorphic adenoma as a hypocellular area with high ADC values. Diffusion-weighted ...

INTRODUCTION: The CT, MR, and diffusion-weighted initial and follow-up imaging findings in neonatal herpes simplex virus type 2 (HSV-2) encephalitis were assessed. METHODS: The clinical, laboratory and imaging findings in 12 patients (eight girls and four boys) with proven neonatal HSV-2 encephalitis with follow-up were retrospectively reviewed. Patterns of brain ...

The purpose of this study was to report patients with pharmacoresistant West syndrome of unknown cause whose magnetic resonance imaging (MRI) with diffusion weighted imaging (DWI) showed a transient decrease of diffusion in subcortical structures. Of 20 patients investigated over a 2-year period, three males and three females constitute the ...

The response of the central nervous system to space radiation is largely unknown. The hippocampus, which is known for its critical role in learning and memory, was evaluated for its response to heavy-ion radiation. At 1 month, animals exposed to brain-only 56Fe-particle irradiation (0-4 Gy) were examined using contrast-enhanced T1 ...

PURPOSE: To retrospectively measure the mean apparent diffusion coefficient (ADC) with diffusion-weighted magnetic resonance (MR) imaging and the mean metabolic ratio (MET) with three-dimensional (3D) hydrogen 1 ((1)H) MR spectroscopic imaging in regions of interest (ROIs) drawn over benign and malignant peripheral zone (PZ) prostatic tissue and to assess ADC, ...

OBJECTIVES: Diffusion-weighted (DW) magnetic resonance imaging (MRI) provides functional information widely used in the diagnosis of acute cerebral stroke. We reported our initial experience of this imaging technique of upper urinary tract (UUT) urothelial carcinoma (UC). METHODS: Diffusion-weighted magnetic resonance imaging was carried out in 10 consecutive patients with suspected ...

We report the case of a 74-year-old woman who presented with deterioration in gait, short-term memory loss and urinary incontinence. She had a past history of excision of a cervical dermal sinus tract at the age of 5 years. CT scan in 2004 revealed ventriculomegaly and an extremely hypodense ovoid ...

In fecal-tagging CT colonography (ftCTC), positive-contrast tagging agents are used for opacifying residual bowel materials to facilitate reliable detection of colorectal lesions. However, tagging agents that have high radiodensity tend to artificially elevate the observed CT attenuation of nearby materials toward that of tagged materials on Hounsfield unit (HU) scale. ...

PURPOSE: To retrospectively compare diffusion-weighted (DW) magnetic resonance (MR) imaging with standard breath-hold T2-weighted MR imaging for focal liver lesion (FLL) detection and characterization, by using consensus evaluation and other findings as the reference standard. MATERIALS AND METHODS: Approval for this retrospective HIPAA-compliant study was obtained from the institutional review ...

To compare the diagnostic accuracy of MnDPDP MR imaging and diffusion-weighted imaging (DWI), alone and in combination, for detecting colorectal liver metastases in patients with suspected metastatic disease. Thirty-three consecutive patients with suspected colorectal liver metastases underwent MR imaging. Three image sets (MnDPDP, DWI and combined MnDPDP and DWI) were ...

BACKGROUND AND PURPOSE: Lesions in diffusion-weighted imaging (DWI-L) have been commonly described in transient global amnesia (TGA). We investigated a possible relationship between brain ischemia and TGA. METHODS: Twenty-eight patients underwent transcranial and carotid Doppler ultrasonography (including microembolus detection) and MRI within 24 hours of TGA onset (including DWI, perfusion-weighted ...

OBJECTIVE: In this study, the authors discussed the feasibility and value of diffusion-weighted (DW) MR imaging in the detection of uterine endometrial cancer in addition to conventional nonenhanced MR images. METHODS AND MATERIALS: DW images of endometrial cancer in 23 patients were examined by using a 1.5-T MR scanner. This ...

PURPOSE: To measure the apparent diffusion coefficient (ADC) of hyperpolarized (HP) (3)He gas using diffusion weighted MRI in healthy volunteers and patients with emphysema and examine the reproducibility and volume dependency. MATERIALS AND METHODS: A total of eight healthy volunteers and 16 patients with emphysema were examined after inhalation of ...

The clinical utility of diffusion-weighted magnetic resonance imaging (DWI) was originally established for acute stroke; however, recent studies suggest that DWI may be more sensitive and specific for the detection and staging of malignant tumors than either computed tomography (CT) or ultrasonography (US). We herein present 4 cases of pancreatic ...

We report a case of a 52-year-old woman with Behcet's disease who presented with dysarthria and right-sided hemiparesis. T2-weighted and diffusion-weighted images (DWI) showed a hyperintense lesion in the left pons with a relatively decreased apparent diffusion coefficient (ADC). Imaging showed almost complete resolution of the lesion after treatment with ...

PURPOSE: To investigate the immediate effects of microwave coagulation on rat tumors in various magnetic resonance (MR) images at high magnetic field strength using histopathological examinations as reference. MATERIALS AND METHODS: Tumors implanted in rat femurs were partially thermocoagulated by microwave. Immediately after, T1- and T2-weighted images, diffusion-weighted images (DWIs), ...

This review covers the fundamentals of diffusion tensor imaging. It is written with the clinician in mind and assumes the reader has a passing familiarity with magnetic resonance imaging (MRI). Topics covered include comparison of diffusion MRI with conventional MRI, water apparent diffusion coefficient (ADC), diffusion anisotropy, tract tracing, and ...

Acute cerebellitis is an unusual central nervous system complication of infectious disease often due to viral etiology. Diagnosis is aided by neuroimaging studies, actually by magnetic resonance imaging in the first place, which shows increased signal intensity on T2-weighted images. However, conventional magnetic resonance imaging may be unrevealing in some ...

PURPOSE: To determine whether the apparent diffusion coefficient (ADC) obtained using a high b-value (2,000 s/mm2) is superior to that using a standard b-value (1,000 s/mm2) for discriminating malignant from normal peripheral tissue in the prostate. METHODS: Twenty-six patients with biopsy-proven prostate cancer underwent 1.5T magnetic resonance (MR) imaging including ...

PURPOSE: To elucidate the performance of apparent diffusion coefficient (ADC) map in localizing prostate carcinoma (PC) using stepwise histopathology as a reference. MATERIALS AND METHODS: Preoperative MR images of 37 patients with PC who had undergone radical prostatectomy were retrospectively evaluated. First, T2-weighted images (T2WI) alone were interpreted (T2WI reading), ...

INTRODUCTION: The purpose of this study was to determine the normative apparent diffusion coefficient (ADC) values at 3T using high b-value (3000 s/mm(2)) diffusion-weighted images (DWI) and compare the signal characteristics of the high b value with standard b-value (1000 s/mm(2)) DWI. METHODS: Institutional review board approval was obtained for ...

BACKGROUND AND PURPOSE: MR imaging-based apparent diffusion coefficient (ADC) and regional cerebral blood volume (rCBV) measurements have been related respectively to both cell and microvessel density in brain tumors. However, because of the high degree of heterogeneity in gliomas, a direct correlation between these MR imaging-based measurements and histopathologic features ...

Marchiafava-Bignami disease (MBD) is characterized by demyelination and necrosis of corpus callosum encountered in chronic alcoholic patients. Etiology is the deficiency of vitamin B complex. Magnetic resonance imaging (MRI) in MBD typically reveals focal lesions of high T2 and FLAIR signal intensity in the corpus callosum. We here present a ...

BACKGROUND AND PURPOSE: For MR perfusion-diffusion (PWI-DWI) mismatch to become routine in thrombolysis patient selection, rapid and reliable assessment tools are required. We examined interrater variability in PWI/DWI volume measurements and developed a rapid assessment tool based on the Alberta Stroke Program Early CT Scores (ASPECTS) system. METHODS: DWI and ...

INTRODUCTION: We have often encountered high signal intensity (SI) of the cingulate gyrus and insula during diffusion-weighted magnetic resonance imaging (DW-MRI) on neurologically healthy adults. To date, cortical signal heterogeneity on DW images has not been investigated systematically. The purpose of our study was to determine whether there is regional ...

We herein report the time-related dynamic changes according to the diffusion-weighted image (DWI) findings after a cerebral ischemic attack in a 63-year-old woman. At 2 weeks after undergoing a lower limb amputation due to diabetic atherosclerosis, she experienced a sudden loss of consciousness and right hemiparesis. Magnetic resonance image revealed ...

OBJECTIVE: The objective of our study was to prospectively evaluate the signal-to-noise ratio (SNR) improvement in diffusion-weighted imaging (DWI) of the appendicular skeleton with the use of a newly developed non-Carr-Purcell-Meiboom-Gill (non-CPMG) single-shot fast spin-echo (SSFSE) sequence and to evaluate its effect on apparent diffusion coefficient (ADC) measurements. SUBJECTS AND ...

Neurocutaneous melanosis (NM) coexisting with the Dandy-Walker complex (DWC) is a rare condition, with fewer than 15 cases reported in the literature. The authors present a case of an infant with NM and DWC suffering from progressive brainstem compression following ventriculoperitoneal (VP) shunt placement for hydrocephalus. This 1-year-old boy with ...

OBJECTIVE: To investigate apparent diffusion coefficient (ADC) mapping with the measurement of renal tissue ADC value of normal and pathological fetal kidneys at various gestational ages (GAs). METHODS: Fifty pregnant women underwent magnetic resonance images (MRI) after ultrasound (US) for suspected fetal genitourinary disorders (16) or for suspected disorders in ...

OBJECTIVE: To assess whether water diffusivity in normal appearing brain tissue including white and gray matter of multiple sclerosis (MS) patients shown by diffusion-weighted imaging (DWI) differs from normal individuals. MATERIAL AND METHOD: Conventional MRI and DWI were performed in 37 multiple sclerosis patients and 31 control subjects, matched for ...

Progressive multifocal leukoencephalopathy (PML) is a rare disease that occurs mainly in immunocompromised patients. Despite the progressive nature of the disease, the changes on MRI during the disease course - which may help in monitoring the disease process - have seldom been reported. Here we describe a patient with polymerase-chain-reaction-proven ...

OBJECTIVE: The effects of different therapies on enthesitis/osteitis in active ankylosing spondylitis (AS) were evaluated by magnetic resonance imaging (MRI). The aim was to assess the role of quantitative MRI in the evaluation of AS treatment efficacy. MATERIALS AND METHODS: Thirty patients with active spondylitis or bilateral sacroiliitis were selected ...

We demonstrate that a position correlation magnetic resonance imaging (MRI) experiment based on two phase encoding steps separated by a delay can be used for quantifying diffusion across a membrane. This method is noninvasive, and no tracer substance or concentration gradient across the membrane is required. Because, in typical membranes, ...

The apparent water diffusion anisotropy in white matter (WM) of excised spinal cords of myelin-deficient (md) rats and their age-matched controls was studied by high-b-value q-space diffusion MRS and MRI at different diffusion times. Non-monoexponential signal decay was observed at long diffusion times. The mean displacements in the md spinal ...

OBJECTIVE: The relationship between cerebral integrity, recovery of brain function, and neurologic status after mild traumatic brain injury is incompletely characterized. DESIGN: Prospective and randomized study in rodents. SETTING: University laboratory. SUBJECTS: Male Wistar rats (290-310 g). INTERVENTIONS: In rats, quantitative diffusion weighted imaging (DWI), perfusion weighted imaging (PWI), T2-weighted ...

OBJECTIVE: Selective focal MR-Signal (diffusion-) changes in the CA-1 sector of the hippocampus have been described in transient global amnesia (TGA), but the pathophysiological substrate of these lesions is largely unknown. As several imaging and epidemiological findings point to a vascular origin an analysis of the temporal evolution of the ...

The relationship between migraine with aura and patent foramen ovale (PFO) is still debatable. We report 2 cases of migraine with aura attacks after diagnostic microbubble injection for contrast transcranial Doppler (cTCD), in subjects with large PFO. In one case MR images, including diffusion weighted imaging and apparent diffusion coefficient, ...

BACKGROUND AND PURPOSE: In the concept of ischemic penumbra, the volume of salvaged penumbra is considered as the volume of FLAIR normalization on follow-up MRI compared with early diffusion and perfusion abnormalities. Using magnetization transfer imaging, very sensitive to macromolecular disruption, we investigated whether FLAIR normalization was a good marker ...

AIM: To describe the magnetic resonance imaging (MRI) characteristics of heroin-induced leukoencephalopathy or "chasing the dragon syndrome" and, in particular, the diffusion-weighted imaging (DWI) and MR spectroscopy (MRS) features. MATERIAL AND METHODS: Six patients with a clinical or histopathological diagnosis of heroin-induced leukoencephalopathy were identified and MRI examinations, including DWI ...

INTRODUCTION: Epidural spinal cord compression is one of the most critical emergency conditions requiring medical attention and requires prompt and adequate treatment. The aim of our study was to assess the role of diffusion-weighted magnetic resonance (MR) imaging (DWI) in the diagnosis and differentiation of epidural spinal lesions. METHODS: Three ...

BACKGROUND AND PURPOSE: The sensitivity of fetal MR imaging is poor with regard to the evaluation of diffuse ischemic white matter (WM) abnormalities. Our purpose was to evaluate the contribution of diffusion-weighted imaging (DWI) in the analysis of microstructural changes in WM and to correlate neuroimaging with neurofetopathologic findings. MATERIALS ...

BACKGROUND: Little information is available about the diagnosis and management of acute methotrexate (MTX)-induced encephalopathy. METHODS: We reviewed clinical and magnetic resonance imaging (MRI) [including diffusion-weighted imaging (DWI)] characteristics of this complication in pediatric cancer patients treated from 2000 to 2006. RESULTS: Six of 754 (0.8%) patients with leukemia or ...

BACKGROUND AND PURPOSE: To examine whether in vivo proton magnetic resonance spectroscopy ((1)H MRS) and diffusion-weighted magnetic resonance imaging (DW-MRI) can monitor radiation-induced changes in HT29 xenografts in mice. MATERIALS AND METHODS: HT29 xenografts in mice received a dose of 15Gy. In vivo(1)H MRS and DW-MRI were acquired pretreatment and ...