Solid urethral and peri-urethral lesions are rare and encompass benign and malignant aetiologies. A diagnosis without imaging is often challenging secondary to non-specific clinical symptoms and overlapping findings at the time of physical examination. Magnetic resonance (MR) imaging may be helpful in confirming a diagnosis while providing anatomical detail and ...

PURPOSE: The purposes of this study were to quantify respiration-induced organ motions for pancreatic cancer patients and to explore strategies to account for these motions. METHODS AND MATERIALS: Both 3-dimensional computed tomography (3DCT) and 4-dimensional computed tomography (4DCT) scans were acquired sequentially for 15 pancreatic cancer patients, including 10 randomly ...

Magnetic beads are often used for serum profiling of peptide and protein biomarkers. In these assays, the bead-bound analytes are eluted from the beads prior to mass spectrometric analysis. This study describes a novel matrix-assisted laser desorption/ionization (MALDI) technique for direct application and focusing of magnetic beads to MALDI plates ...

PURPOSE: To compare enhancement of the liver and pancreas quantitatively on late hepatic arterial phase images among various gadolinium-based contrast agents (GBCAs) at 1.5 Tesla (T) MRI. MATERIALS AND METHODS: Patients underwent consecutive MR studies with the following GBCAs: gadopentetate dimeglumine (0.1 mmol/kg) gadobenate dimeglumine (0.05 mmol/kg), gadoxetic acid, and ...

Purpose:To assess tumor conspicuity and radiation dose with a new multidetector computed tomography (CT) protocol for pancreatic imaging that combines spectral CT and split-bolus injection.Materials and Methods:This study was approved by the institutional review board and compliant with HIPAA. The requirement for informed consent was waived. One hundred sixty-three consecutive ...

PURPOSE: Palladium-103 ((103)Pd) may be superior to other isotopes in brachytherapy for localized intermediate-risk prostate cancer because of its relatively short half-life, higher initial dose rate, and greater dose heterogeneity within the target volume; these properties also underscore the need for accurate target delineation and postimplant quality assurance. We assessed ...

There are few cases of giant pediatric intraspinal teratoma. We report a case of a 4-month-old female baby with giant intraspinal teratoma. Magnetic resonance imaging (MRI) of the spine revealed a large intradural tumor from the C7 to S2 level, with solid, cystic, and fatty components. Partial surgical removal of ...

Hypertrophic olivary degeneration (HOD) is secondary degeneration of the inferior olivary nucleus (ION) due to a primary lesion in the dento-rubro-olivary pathway. This pathway is known as the Guillain and Mollert triangle, containing the dentate nucleus and the contralateral red and inferior olivary nuclei (figure e-1 on the Neurology® Web ...

BACKGROUND: A computed tomography (CT) scan is often the only study needed prior to surgery for resectable solid pancreas masses. However, many patients are evaluated with multiple studies and interventions that may be unnecessary. METHODS: We conducted a retrospective review of patients who presented to the Johns Hopkins Multidisciplinary Pancreas ...

PURPOSE: To evaluate feasibility of using deformable image co-registration in three-phase adaptive dose-painting-by-numbers (DPBN) for head-and-neck cancer and to report dosimetrical data and preliminary clinical results. MATERIAL AND METHODS: Between November 2010 and October 2011, 10 patients with non-metastatic head-and-neck cancer enrolled in this phase I clinical trial where treatment ...

PURPOSE: Time-of-flight (TOF) MR imaging is clinically among the most common cerebral noncontrast enhanced MR angiography techniques allowing for high spatial resolution. As shown by several groups TOF contrast significantly improves at ultrahigh field of B0  = 7T, however, spatially varying transmit B1 (B1 (+) ) fields at 7T reduce TOF ...

OBJECTIVES: The aim of this study is to evaluate the use of phase-contrast MR imaging to diagnose normal pressure hydrocephalus (NPH) and differentiate it from other neurological disorders with similar clinical symptoms. METHODS: The study included 108 subjects, of whom 61 were healthy controls and 47, patients; in the patient ...

Because of its widespread accessibly, computed tomographic angiography (CT-A) is a promising technique in the detection of intracranial circulatory arrest in brain death (BD). Several studies assessed this tool, but neither have standardized evaluation parameters been developed nor has information about specificity become available. We conducted a prospective study between ...

In this work, we have studied electric field-induced magnetization effect of multiferroic BiFeO3 (BFO) nanowires in situ using magnetic force microscopy (MFM). Changes in magnetic domain contrast have been observed in the MFM phase images under applied electric potential, which indicate local magnetoelectric (ME) coupling in the nanowires. The values ...

Many tools and strategies exist to enable reduction of radiation exposure from computed tomography (CT). The common CT metrics of x-ray output, the volume CT dose index and the dose-length product, are explained and serve as the basis for monitoring radiation exposure from CT. Many strategies to dose-optimize CT protocols ...

Hypointensity in the hepatocyte phase is believed to be a key feature of hypovascular early hepatocellular carcinoma, which indicates malignancy. The 3 cases we present suggest that the converse is not true. Three small hepatocellular lesions showed isointensity/hyperintensity on gadoxetic acid-enhanced, hepatocyte-phase magnetic resonance images and were pathologically confirmed as ...

The objectives of this study were to explore utilization of multi-detector row computed tomography (MDCT) in screening for hepatocellular carcinoma (HCC) and to modify a liver CT protocol with a goal of dose reduction. An electronic mail survey querying HCC surveillance practices was sent. One hundred forty consecutive patients referred ...

The aim of this study was to evaluate the image quality of low-dose computed tomographic (CT) urography using adaptive iterative dose reduction 3-dimensional (AIDR 3D) compared with routine-dose CT using filtered back projection (FBP). Thirty patients underwent low- and routine-dose CT scans in the nephrographic and excretory phases of CT ...

Magnetic resonance imaging has become more frequently utilized for staging, preoperative planning, and post-neoadjuvant evaluation of rectal cancer. It offers detailed resolution of the layers of the rectal wall, visualization of the mesorectal fascia, and identification of locoregional nodal involvement. Many advances have been made since the original protocols and ...

PURPOSE: To identify an improved method for measuring spinal cord cross-sectional area (CSA) using magnetic resonance imaging (MRI) in multiple sclerosis (MS). MATERIALS AND METHODS: MRI was performed on 15 controls and 15 MS patients and repeated in nine controls and nine patients after 6 months. At this timepoint, an ...

PURPOSE: To determine whether the presence of a hypovascular nodule in the liver showing hypointensity on hepatocyte-phase of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) is a risk factor for hypervascular hepatocellular carcinoma (HCC) in patients with chronic liver disease. MATERIALS AND METHODS: Forty-one patients with pathologically confirmed hypervascular HCC and ...

BACKGROUND AND PURPOSE:In patients with acute stroke, the location and extent of intravascular thrombi correlate with clinical and imaging outcomes and have been used to predict the success of intravenous thrombolysis. We hypothesized that 4D-CTA reconstructed from whole-brain CTP more closely outlines intracranial thrombi than conventional single-phase CTA.MATERIALS AND METHODS:Sixty-seven ...

PURPOSE OF REVIEW: High-risk prostate cancers (PCa), that is, those with prostate-specific antigen greater than 20 ng/dl, Gleason Score of at least 8, or extraprostatic spread, are nowadays commonly treated by surgery and radiotherapy combined with a fixed period of systemic treatment. Implementing these strategies requires an exhaustive assessment of metastatic ...

Diagnostic imaging of the liver by ultrasound, computed tomography (CT) and magnetic resonance tomography (MRT) is generally limited to the visualization of the morphology. In order to exploit the intriguing liver tropism of the human hepatitis B Virus (HBV) for molecular imaging of the liver, peptidic tracers derived from the ...

BACKGROUND AND PURPOSE:The risk of hemorrhage in the context of developmental venous anomaly is considered to be very low, but it has never been evaluated by susceptibility-weighted MR imaging at 3T. The goal of the present study was to evaluate the prevalence of hypointense foci (ie, microhemorrhage or cavernous malformation) ...

Background/Objectives:Postprandial bloating is a common symptom in patients with functional gastrointestinal (GI) diseases. Whole meal bread (WMB) often aggravates such symptoms though the mechanisms are unclear. We used magnetic resonance imaging (MRI) to monitor the intragastric fate of a WMB meal (11% bran) compared with a rice pudding (RP) meal.Subjects/Methods:Twelve ...

OBJECTIVE: To evaluate the image findings of focal fat deposition (FFD) in the liver on gadobenate dimeglumine (Gd-BOPTA)- and gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI, particularly during the hepatobiliary phase (HBP), and the relationship between relative enhancement (RE) and fat signal fraction (FSF) of FFD. SUBJECTS AND METHODS: Twenty-one patients with 27 ...

BACKGROUND: CartoSound™ (CS) module is useful in integrating 3-dimensional (3D) left atrial (LA) image with CT image. Integration method, however, has not been established. We reported the accuracy of LA electroanatomical (EA) and CT image integration by registering LA roof (LAR) and posterior wall (LAPW). METHODS: The consecutive 56 atrial ...

PURPOSE: This study aimed at demonstrating the feasibility of retrospectively fused (18)F FDG-PET and MRI (PET/MRI fusion image) in diagnosing pancreatic tumor, in particular differentiating malignant tumor from benign lesions. In addition, we evaluated additional findings characterizing pancreatic lesions by FDG-PET/MRI fusion image. METHODS: We analyzed retrospectively 119 patients: 96 ...

PURPOSE: Measurement of venous oxygenation (Yv ) is a critical step toward quantitative assessment of brain oxygen metabolism, a key index in many brain disorders. The present study aims to develop a noninvasive, rapid, and reproducible method to measure Yv in a vessel-specific manner. THEORY: The method, T2 -Relaxation-Under-Phase-Contrast MRI, ...

Purpose:To assess effects of an automated kilovoltage selection tool on radiation dose, tube current, and image quality in pediatric contrast material-enhanced thoracoabdominal computed tomography (CT) and CT angiography.Materials and Methods:The institutional review board approved this retrospective study of 87 children (median age, 10.5 years; age range, 1 day to 19 ...

PURPOSE: To identify parameters associated with ovarian malignancy using multiparametric quantitative magnetic resonance imaging (MRI). MATERIALS AND METHODS: After Institutional Review Board (IRB) approval, women with ovarian masses underwent preoperative imaging with 3 T MRI. Dynamic contrast-enhanced (DCE)-MRI with pharmacokinetic modeling, quantitative T2 mapping, and diffusion-weighted imaging with quantitative mapping ...

Currently, the BEAMnrc/EGSnrc Monte Carlo (MC) system does not provide a spiral CT source model for the simulation of spiral CT scanning. We developed and validated a spiral CT phase-space source model in the BEAMnrc/EGSnrc system. The spiral phase-space source model was implemented in the DOSXYZnrc user code of the ...

OBJECTIVES: To evaluate the performance characteristics of endoscopic ultrasonography (EUS) compared with computed tomography (CT) and magnetic resonance imaging (MRI) and determine the incremental diagnostic yield and accuracy of EUS with or without fine needle aspiration (FNA) over CT and MRI for prediction of neoplastic pancreatic cysts. METHODS: The EUS ...

OBJECTIVE. The purpose of this study was to evaluate whether two-phase dual-energy CT can differentiate between lung perfusion patterns of patients with chronic pulmonary thromboembolism (PTE) and those of patients with acute PTE. SUBJECTS AND METHODS. A total of 114 patients clinically suspected to have PTE were prospectively enrolled. All ...

Purpose: Four-dimensional computed tomography (4D CT) images have been recently adopted in radiation treatment planning for thoracic and abdominal cancers to explicitly define respiratory motion and anatomy deformation. However, significant image distortions (artifacts) exist in 4D CT images that may affect accurate tumor delineation and the shape representation of normal ...

Aim: The aim of this paper was to evaluate the role of net-enhancement (NE) of benign salivary glands with multiphase multidetector row CT (MDCT). Methods: Forty-eight patients (M=27, F=21), aged 35-76 years old (mean =57) with benign parotid neoplasms were examinated with 4 MDCT, at 20'', 40'', 70'' e 9' ...

OBJECTIVE: To describe a case of adrenal cavernous hemangioma in a 67 year old man who presented left lumbar pain. METHODS: Abdominal ultrasound, contrast enhanced ultrasound of the lesion, abdominal-pelvic CT scan, and then left adrenalectomy and pathology were performed RESULTS: Imaging studies showed a large solid-cystic mass with 12 ...

OBJECTIVES: To review the imaging findings of renal epithelioid angiomyolipomas. METHODS: Eight patients treated at two institutions were pathologically diagnosed as having epithelioid angiomyolipoma. All of them underwent computed tomography, and four underwent magnetic resonance imaging. The tumor size, existence of fat, heterogeneity, computed tomography attenuation, degree of enhancement, enhancement ...

A commonly used figure of merit of magnetoresistive sensors employed to detect magnetic beads labeling biomolecules in lab-on-chip applications is the sensor sensitivity (S0) to external magnetic fields in the linear region of the sensor. In this paper we show that, in case of lock-in detection and bead excitation by ...

The underlying source of T2*-weighted magnetic resonance imaging (T2*MRI) for brain imaging is magnetic susceptibility (denoted by χ). The output of T2*MRI is a complex-valued MR image consisting of magnitude and phase. Recent research has shown that both the magnitude and the phase images are morphologically different from the source ...

BACKGROUND AND PURPOSE: Multi-phase postmortem CT angiography (MPMCTA) is increasingly being recognized as a valuable adjunct medicolegal tool to explore the vascular system. Adequate interpretation, however, requires knowledge about the most common technique-related artefacts. The purpose of this study was to identify and index the possible artefacts related to MPMCTA. ...

BACKGROUND: Tube current modulation in retrospective ECG gated cardiac computed tomography (CT) results in increased image noise and may reduce the accuracy of left ventricular (LV) ejection fraction (EF) and mass assessment. OBJECTIVE: To examine the effects of a novel CT phase-based noise reduction (NR) algorithm on LV EF and ...

OBJECTIVE: 2-[18F]Fluoro-2-deoxyglucose positron emission tomography (FDG-PET) is routinely used for the diagnosis of primary lung cancer. However, the role of FDG-PET in the diagnosis and staging of small-sized lung cancer has not been sufficiently evaluated. The purpose of this study was to determine the utility of FDG-PET for preoperative staging ...

The objective of this study was to determine if area measurements of pleural fluid on computed tomography (CT) reflect the actual pleural fluid volume (PEvol) as measured at autopsy, to establish a formula to estimate the volume of pleural effusion (PEest), and to test the accuracy and observer reliability of ...

Renal dual-phase computed tomograpic angiography (CTA) is used to assess suitability of feline donors prior to transplantation. A prerequisite for successful CTA is optimal synchronization between the arterial passage of contrast material and CT data acquisition. This retrospective study was conducted to compare quality of renal vascular enhancement at dual-phase ...

Almost all cases of cervical spinal dysraphism published to date have involved cystic lesions and were treated in very early childhood. The authors describe a unique case of a 21-year-old woman who harbored a solid cervical rudimentary meningocele. On preoperative CT and MR images, a cutaneous solid mass was shown ...

The magnetic phase shift of an electron wave traveling through a magnetized object is computed by considering the object to be made up of a collection of uniformly magnetized spheres arranged on the nodes of a cubic grid. In the limit of vanishing grid size, this approach becomes equivalent to ...

PURPOSE: Interpretation of F-FDG PET/CT studies in the pancreas is challenging owing to nonspecific FDG uptake in various benign and malignant pancreatic lesions. The purpose of this atlas article was to demonstrate features of various pancreatic lesions encountered at our institution, both benign and malignant, which can result in hypermetabolism ...

Purpose: We assessed the influence of the menstrual cycle on background parenchymal enhancement (BPE) of the breast in the early and delayed phases of dynamic magnetic resonance (MR) imaging and the optimal timing of MR imaging of the breast in Japanese women. Material and Methods: We reviewed dynamic MR images ...