A supramolecular self-assembly approach is described which allows for the convenient preparation of a wide range of charge transfer (CT) donor-acceptor complexes in aqueous solutions. When one equivalent of the macrocyclic host cucurbit[8]uril (CB[8]) is added to an aqueous donor and acceptor solution, a hetero-ternary complex forms inside the host's ...

BACKGROUND AND PURPOSE: Previous studies have found gray matter alterations in the cerebellum and in the visual system in both adults and adolescents with schizophrenia. The present study was conducted to investigate whether white matter tracts associated with these regions are also affected in the early stages of the disorder. ...

Radiology with oral contrast, or enteroclysis, have traditionally been the techniques of choice in the examination of the small intestine, due to the excellent visualisation of the mucosal pattern. However, the absence of extra-luminal information and the use of ionising radiation have replaced these examinations with sectional techniques which enable ...

PURPOSE: To reduce radiation exposure to paediatric neurosurgical patients from computed tomography (CT), a CT scanning protocol - lower radiation dose and selective scan segment (LDSS) protocol was used for CT brain at the authors' hospital. To evaluate the amount of reduction in radiation exposure by using this LDSS protocol ...

Despite great potential benefits, there are concerns about the possible harm from medical imaging including the risk of radiation-related cancer. There are particular concerns about computed tomography (CT) scans in children because both radiation dose and sensitivity to radiation for children are typically higher than for adults undergoing equivalent procedures. ...

Today CT represents about 10% of all ionizing radiation based imaging modalities, but delivers more than 50% of the total collective dose for diagnostic imaging. Compared to adults the radiation sensitivity of children is considerable higher than in adults. Additionally children differ from adults - factors like body size, mass, ...

Many tools and strategies exist to enable the reduction of radiation exposure from computed tomography (CT). The common CT metrics of x-ray output, CTDI(vol) and DLP, are explained and serve as the basis for monitoring radiation exposure from CT scans. Many strategies to dose optimize CT protocols are explored that, ...

OBJECTIVE: This article reviews the MRI and CT of nasopharyngeal carcinoma. Extension of nasopharyngeal tumors, especially into the skull base and the deep facial spaces, is well illustrated on imaging. Assessment of retropharyngeal and cervical lymphadenopathy is important for treatment planning. MRI is commonly used for monitoring patients after therapy. ...

Computerized tomography (CT) is an extremely powerful imaging modality, which provides extremely valuable information for the diagnosis, staging, and management of pediatric solid tumors. In recent years, the concern of potential risks associated with ionizing radiation from diagnostic imaging - especially from CT - has greatly increased. In children with ...

The advances in computerized technology (CT) technique over the last few decades have greatly modified imaging protocols in children. The range of pathologies that can now be demonstrated has broadened with the advent of newer techniques such as CT perfusion and the ability to perform complex reconstructions. Increasing speed of ...

Radiation induced cavernous hemangioma (RICH) is a late complication of cerebral radiation therapy. Long-term surviving hematopoietic stem cell transplant (HSCT) recipients who have received radiation therapy could be at risk of RICH. We investigated records for 68 patients who underwent HSCT during childhood or adolescence. Magnetic resonance (MR) imaging including ...

A challenge for positron emission tomography/computed tomography (PET/CT) quantitation is patient respiratory motion, which can cause an underestimation of lesion activity uptake and an overestimation of lesion volume. Several respiratory motion correction methods benefit from longer duration CT scans that are phase matched with PET scans. However, even with the ...

Abstract (68)Ga labeled NOTA-RGD was a recently developed positron emission tomography (PET) radiotracer for the visualization of angiogenesis, and is regarded as a promising imaging agent for cancer and several other disorders. In this study, we investigated the whole-body distribution and radiation dosimetry of (68)Ga-NOTA-RGD in humans. Ten cancer patients ...

BACKGROUND: Parathyroid four-dimensional computed tomography (4DCT) provides greater sensitivity than sestamibi with single photon emission CT (SPECT, or SeS) for preoperative localization of parathyroid tumors in patients with primary hyperparathyroidism (PHPT). The radiation dose imparted to the patient during preoperative parathyroid imaging, however, has not been analyzed. METHODS: Patients with ...

This article reviews two important aspects of CT-colonography, namely colonic distension and scan parameters. Adequate distension should be obtained to visualize the complete colonic lumen and optimal scan parameters should be used to prevent unnecessary radiation burden. For optimal distension, automatic carbon dioxide insufflation should be performed, preferably via a ...

Yttrium-90 (Y-90) has internal pair production that can be imaged by PET/CT. Y-90 PET/CT has better spatial resolution than bremsstrahlung SPECT/CT, and it is possible to use Y-90 PET/CT for accurate postradioembolization imaging of hepatic microsphere biodistribution. Y-90 time-of-flight PET/CT represents the current state-of-the-art in postradioembolization imaging. We present a ...

Introduction: Distinction between postoperative recurrent glioma and radiation injury remains a tough diagnostic problem for routine imaging methods. The purpose of this study is to evaluate the differentiated effectiveness of perfusion weighted imaging (PWI) for the two entities. Methods: PWI was performed using Siemens 3.0-T MR system for 35 patients ...

ABSTRACT: A 44-year-old man with a previously resected right parietal oligodendroglioma received left unilateral electroconvulsive therapy (ECT). We present images of his brain magnetic resonance imaging, ECT electrode placement, and the electroencephalogram tracing from his ECT.

Organ preservation protocols that incorporate chemoradiotherapy have shown good efficacy in bladder cancer. Owing to changes in rectal filling, urinary inflow and subsequent bladder volume with bladder wall deformations, irradiation must take into account interfractional and intrafractional internal target motion. Growing evidence suggests that image guidance during irradiation is essential ...

OBJECTIVE: Radiation exposure represents significant risk to both operating room health care workers and their patients. The commonplace surgical implantation of spinal instrumentation often relies on fluoroscopy for guidance and verification. Advances in computerized tomography (CT)-based intraoperative navigation have improved accuracy of screw placement. The objective of this article is ...

Since its introduction in the 1970s, diagnostic computed tomography (CT) imaging has grown rapidly and developed into a standard diagnostic test for a wide variety of cardiovascular conditions. Although this has undoubtedly led to improved medical care, it has also been associated with a significant increase in population-based radiation exposure ...

Inflammatory activity in atherosclerotic plaque is a risk factor for plaque rupture and atherothrombosis and may direct interventional therapy. Inflammatory activity can be evaluated at the (sub)cellular level using in vivo molecular MRI. This paper reviews recent progress in contrast-enhanced molecular MRI to visualize atherosclerotic plaque inflammation. Various MRI contrast ...

What's known on the subject? and What does the study add? Radiation exposure is a cause of cancer. Increasing use of CT scans has increased patient exposure to ionizing radiation which may increase long-term risk of cancer. Not all scans performed may be medically necessary. Up to 30% of patients ...

Since the discovery of the X-ray radiation by Wilhelm Conrad Roentgen in 1895, the field of medical imaging has developed into a huge scientific discipline. The analysis of patient data acquired by current image modalities, such as computerized tomography (CT), magnetic resonance tomography (MRT), positron emission tomography (PET), or ultrasound ...

Radiation recall is a rare and poorly understood phenomenon, characterized by an acute inflammatory reaction within the previously irradiated area, triggered by a precipitating systemic agent. This reaction typically affects the skin, and radiation recall myositis in the absence of cutaneous involvement has rarely been described in the literature. In ...

INTRODUCTION: High-resolution CT imaging is essential to diagnosis and follow-up of temporal bone pathology. Morphologically, CT is the reference examination. The requirement of long-term follow-up thus exposes patients to cumulative radiation doses. Limiting exposure to ionizing radiation is an increasing concern of public health authorities. The principal advantage of Cone ...

STUDY DESIGN.: Imaging study with an evaluation of incidences and clinical correlation. OBJECTIVE.: To evaluate the incidence of 3 different types of instabilities in patients with spondylolysis or isthmic spondylolisthesis. Clinical findings are correlated with imaging findings, and the imaging findings are analyzed with regard to their clinical implications. SUMMARY ...

CT is widely used for anatomic referencing of PET and SPECT images of small animals but requires sufficiently high radiation doses capable of causing significant DNA damage. Therefore, we described the relationship between radiation dose, biologic damage, and image quality to determine whether CT can be used without significantly compromising ...

The risks and benefits of using computed tomography (CT) as opposed to another imaging modality to accomplish a particular clinical goal should be weighed carefully. To accurately assess radiation risks and keep radiation doses as low as reasonably achievable, radiologists must be knowledgeable about the doses delivered during various types ...

Advances in the field of radiation oncology in the last decade resulted in an increasing number of opportunities to optimize therapy. Increased accuracy to deliver the dose to tumors while sparing normal tissues demands more precise delineation of the tumors. When considering to deliver a boost to more aggressive parts ...

ABSTRACT: Temporal lobe necrosis (TLN) is the most debilitating late-stage complication after radiation therapy in patients with nasopharyngeal cancer (NPC). The bilateral temporal lobes are inevitably encompassed in the radiation field and are thus prone to radiation induced necrosis. The wide use of 3D conformal and intensity-modulated radiation therapy (IMRT) ...

To investigate the research directions of coronary computed tomography (CT) angiography in the diagnosis of coronary artery disease (CAD) based on a systematic review of the literature. A search of articles on coronary CT angiography in the diagnosis of CAD was performed during a 6-year-period between 2005 and 2010 from ...

This study highlights the use of adaptive planning to accommodate testicular shielding in helical tomotherapy for malignancies of the proximal thigh. Two cases of young men with large soft tissue sarcomas of the proximal thigh are presented. After multidisciplinary evaluation, preoperative radiation therapy was recommended. Both patients were referred for ...

Osteoradionecrosis (ORN) of the base of skull is a known complication of external beam radiotherapy in the treatment of nasopharyngeal carcinoma, and is widely believed to be sequelae of radiation-induced endarteritis, leading to cellular death and fibrosis. Differentiating ORN from tumour recurrence is challenging and has direct clinical implications. We ...

RATIONALE AND OBJECTIVES: The aim of this study was to determine if educating residents about the potential effects of radiation exposure from computed tomographic (CT) imaging alters ordering patterns. This study also explored whether referring physicians are interested in radiation education and was an initial effort to address their CT ...

To compare the ability of normalized versus non-normalized metabolite ratios to differentiate recurrent brain tumor from radiation injury using magnetic resonance spectroscopy (MRS) in previously treated patients. Twenty-five patients with previous diagnosis of primary intracranial neoplasm confirmed with biopsy/resection, previously treated with radiation therapy (range, 54-70 Gy) with or without ...

Objective-To assess the effect of computed tomography (CT) scan protocols (radiation amounts) and fabrication methods on biomodel accuracy and variability. Sample-Cadaveric femur of a Basset Hound. Procedures-Retroreconstructions (n = 158) were performed of 16 original scans and were visually inspected to select 17 scans to be used for biomodel fabrication. ...

OBJECTIVES: To compare image quality and radiation dose of high-pitch dual-source computed tomography (DSCT), dual energy CT (DECT) and conventional single-source spiral CT (SCT) for pulmonary CT angiography (CTA) on a 128-slice CT system. METHODS: Pulmonary CTA was performed with five protocols: high-pitch DSCT (100 kV), high-pitch DSCT (120 kV), DECT (100/140 kV), ...

BACKGROUND AND PURPOSE: Positron emission tomography (PET) imaging with [F-18] fluoromisonidazole (FMISO) has been validated as a hypoxic tracer [1,2]. Head and neck cancer exhibits hypoxia, inducing aggressive biologic traits that impart resistance to treatment. Delivery of modestly higher radiation doses to tumors with stable areas of chronic hypoxia can ...

Purpose: To determine whether magnetic resonance (MR) imaging and MR spectroscopic imaging findings can improve predictions made with the Kattan nomogram for radiation therapy. Materials and Methods: The institutional review board approved this retrospective HIPAA-compliant study. Ninety-nine men who underwent endorectal MR and MR spectroscopy before external-beam radiation therapy for ...

BACKGROUND AND PURPOSE: MDCT has some specific scan parameters that may systematically increase or decrease radiation dose to patients. This study explored the scan protocol parameters that impact radiation dose in temporal bone MDCT and determined the optimal scan parameters that balance radiation dose with diagnostic image quality. MATERIALS AND ...

Greater than 10% of diagnostic imaging studies performed in developed countries are CT examinations. In the United States, as many as 60 million CT studies are performed each year, up to 7 million of which are performed in pediatric patients. In the spirit of the ALARA principle, both adult and ...

Significant progress has been made in radiation protection for children during the last 10 years. This includes increased awareness of the need for radiation protection for pediatric patients with international partnerships through the Alliance for Radiation Safety in Pediatric Imaging. This paper identifies five areas of significant progress in radiation ...

The use of imaging in both hospital and non-hospital settings has expanded to more than 70 million CT procedures in the United States per year, with nearly 10% of procedures performed on children. The availability of multiple-row detector CT (MDCT) systems has played a large part in the wider usage ...

Use of microscopic computed-tomography (micro-CT) scanning continues to grow in biomedical research. Laboratory-based micro-CT scanners, laboratory-based nano-CT scanners, and integrated micro-CT/SPECT and micro-CT/PET scanners are now manufactured for "turn-key" operation by a number of commercial vendors. In recent years a number of technical developments in X-ray sources and X-ray imaging ...

Background Coronary CT angiography (CCTA) is used daily in acute chest pain triage, although exposing patients to significant radiation dosage. CCTA using prospective ECG gating (PG CCTA) enables significant radiation reduction Purpose To determine whether the routine use of 128 vs. 64 multidetector CT (MDCT) can increase the proportion of ...

Considering the massive increase of computer tomography (CT) examinations in Slovakia during the last 10 y, it can be expected that a higher radiation load may be observed in the Slovak population. Since child population is more sensitive to radiation than adult population, a monitoring has started to see how ...

Imaging centers nationwide are seeking innovative means to record and monitor computed tomography (CT)-related radiation dose in light of multiple instances of patient overexposure to medical radiation. As a solution, we have developed RADIANCE, an automated pipeline for extraction, archival, and reporting of CT-related dose parameters. Estimation of whole-body effective ...

To boost the possibilities of image guidance in radiotherapy by providing images with superior soft-tissue contrast during treatment, we pursue diagnostic quality MRI functionality integrated with a linear accelerator. Large respiration-induced semi-periodic target excursions hamper treatment of cancer of the abdominal organs. Methods to compensate in real time for such ...

Radiotherapy forms part of most therapeutic, preventive, and conditioning regimens in pediatric oncology. Numerous late secondary effects of cranial radiation are well known. However, radiation-induced cavernous angiomas (RICA) have been reported only sporadically and even fewer cases of earlier presentation of RICA have been reported. In this brief report, we ...