Abstract：
RATIONALE AND OBJECTIVES:Urinary calculi are now commonly detected with helical computed tomography (CT), and it has been proposed that stone composition can be determined from CT attenuation values. However, typical scans are made with a beam collimation of 5 mm or more, resulting in volume averaging and reduction in accuracy of attenuation measurement. The authors tested a model for correction of errors in attenuation values, even at section widths larger than the width of the object. MATERIALS AND METHODS:Human urinary stones were scanned with helical CT at different beam collimation widths. A computer model was used to predict the effect of beam width and stone size on accuracy of measured attenuation. RESULTS:At 3-mm collimation, the model corrected the attenuation readings with an underestimation of 12% +/- 1 (compared with values at 1-mm collimation; 127 stones; diameters of 1.7-11.3 mm). With attenuation measured at 10-mm collimation, the model underestimated the true value by 34% +/- 3 (103 stones), with a significant negative correlation with stone diameter on magnitude of error (diameters of 3.0-11.3 mm). Correlation of data from patient scans with subsequent in vitro scanning of the same stones confirmed the validity of the model, but corrected in vivo scans consistently yielded lower values for the stones than in vitro. CONCLUSION:Volume averaging effects on attenuation in helical CT are predictable in vitro for urinary calculi--and presumably for other roughly spherical structures--as long as section width does not excessively exceed the diameter of the structure.
journal_name
Acad Radioljournal_title
Academic radiologyauthors
Williams JC Jr,Saw KC,Monga AG,Chua GT,Lingeman JE,McAteer JAdoi
10.1016/S1076-6332(03)80619-0keywords:
subject
Has Abstractpub_date
2001-06-01 00:00:00pages
478-83issue
6eissn
1076-6332issn
1878-4046pii
S1076-6332(03)80619-0journal_volume
8pub_type
杂志文章abstract：RATIONALE AND OBJECTIVES:The impact of varying image acquisition parameters on the precision of measurements using quantitative computed tomography is currently based on studies performed before the advent of helical image acquisition and multidetector-row scanners. The aim of this study was to evaluate helical multide...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2008.08.007
更新日期：2009-02-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:To determine the impact of COVID-19 workflow changes on patient throughput at the outpatient imaging facilities of a large healthcare system in New York City. MATERIALS AND METHODS:COVID-19 workflow changes to permit social distancing and patient and staff safety included screening at the time...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2020.12.016
更新日期：2021-01-04 00:00:00
abstract：PURPOSE:To determine whether coronary artery anomalies can be detected on noncontrast computed tomography (CT) coronary artery calcium scoring (CCS) studies. MATERIALS AND METHODS:A total of 126 patients (mean age 62 years; 35 women) underwent noncontrast CCS and contrast enhanced coronary CT angiography (cCTA). Thirt...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2012.12.006
更新日期：2013-05-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:Dimeric nonionic iodinated contrast has a lower osmolality than monomeric nonionic iodinated contrast but is available at lower iodine concentrations. Less dilution of intravascular fluid by influx from the extravascular space is proposed to occur with decreasing osmolality. The purpose of this...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2005.01.015
更新日期：2005-05-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:A method is presented to track guide wires during endovascular interventions under X-ray fluoroscopy. Accurate guide wire tracking can be used to improve guide wire visualization in the low quality fluoroscopic images, and to estimate the position of the guide wire in world coordinates for navi...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/s1076-6332(03)00539-7
更新日期：2003-12-01 00:00:00
abstract：RATIONALE AND OBJECTIVE:Emphysema is characterized by airspace dilation, inflammation, and irregular deposition of elastin and collagen in the interstitium. Computed tomographic studies have reported that lung mass (LM) may be increased in smokers, a finding attributed to inflammatory and parenchymal remodeling process...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2016.10.011
更新日期：2017-04-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The purpose of this prospective randomized study was to compare the long-term instructional effectiveness of a computer-based radiology multimedia textbook (MMTB) with that of a traditional lecture. METHODS:Volunteer faculty/fellows and residents were randomly assigned to either a computer-bas...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/s1076-6332(05)80731-7
更新日期：1994-11-01 00:00:00
abstract：BACKGROUND:To evaluate the utilization and efficacy of various treatments for management of adult patients with splenic trauma, highlighting the evolving role of splenic artery embolization. MATERIALS AND METHODS:The National Trauma Data Bank (NTDB) was queried for patients who sustained splenic trauma between 2007 an...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2020.11.010
更新日期：2020-12-04 00:00:00
abstract：RATIONALE AND OBJECTIVES:Peritumoral features have been suggested to be useful in improving the prediction performance of radiomic models. The aim of this study is to systematically investigate the prediction performance improvement for sentinel lymph node (SLN) status in breast cancer from peritumoral features in radi...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2020.10.015
更新日期：2020-11-04 00:00:00
abstract：RATIONALE AND OBJECTIVE:Radiology faces a severe and growing shortage of radiologic technologists. One way of redressing this problem is to improve the quality of education provided to radiologic technology students. Yet growing clinical demands increasingly erode faculty time for teaching. This study examined whether ...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/s1076-6332(03)80029-6
更新日期：2003-04-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The purpose of this study was to determine the percentage of patients with known pelvic fractures who have additional findings of intraabdominal injury, as diagnosed at abdominal computed tomography (CT), and to determine if patients with specific types or patterns of fractures are more likely ...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/S1076-6332(99)80209-8
更新日期：1999-04-01 00:00:00
abstract：:In medicine, an eponym is a word-typically referring to an anatomic structure, disease, or syndrome-that is derived from a person's name. Medical eponyms are ubiquitous and numerous. They are also at times controversial. Eponyms reflect medicine's rich and colorful history and can be useful for concisely conveying com...
journal_title：Academic radiology
pub_type： 杂志文章,评审
doi：10.1016/j.acra.2016.04.011
更新日期：2016-10-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The pathogenesis of brain injury following radiosurgery is poorly understood. To better elucidate the relationship between blood-brain barrier disruption and metabolic derangements, we used magnetic resonance (MR) imaging and 1H MR spectroscopy to detect early changes from focused single-fracti...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/s1076-6332(05)80511-2
更新日期：1995-12-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:To determine the impact of additional coronary calcium scoring on total effective radiation dose and diagnostic accuracy of low-dose computed tomography coronary angiography (CTCA) with prospective electrocardiogram (ECG) triggering. MATERIALS AND METHODS:Sixty-one consecutive patients underwe...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2009.09.007
更新日期：2010-02-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:Introduction of combination of the segmentation tool SegoMeTex and the virtual endoscopy system VIVENDI to perform virtual endoscopic inspections of the human lung. This virtual bronchoscopy system enables visualization of the tracheobronchial tree down to seventh generation. Furthermore, the m...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2004.01.012
更新日期：2004-05-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The objective of this study was to develop and quantitatively evaluate a radiology-pathology fusion method for spatially mapping tissue regions corresponding to different chemoradiation therapy-related effects from surgically excised whole-mount rectal cancer histopathology onto preoperative ma...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2017.12.006
更新日期：2018-07-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:We propose a novel segmentation-based interpolation method to reduce the metal artifacts caused by surgical aneurysm clips. MATERIALS AND METHODS:Our method consists of five steps: coarse image reconstruction, metallic object segmentation, forward-projection, projection interpolation, and fina...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2006.12.015
更新日期：2007-04-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The purpose of ordering an imaging test for headache, which is one of the most common reasons for patient consultation with a primary care physician (PCP), include medical indications as well as patient anxiety and medico-legal concerns. The impact of nonclinical factors on PCPs' ordering patte...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2004.03.050
更新日期：2004-07-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The aim of the study was to investigate the optimal protocols of dual-source computed tomography (CT) angiography in aortic stent grafting in terms of image noise and radiation dose, based on an in vitro phantom study. MATERIALS AND METHODS:A series of helical CT cans were performed on a human...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2010.03.004
更新日期：2010-07-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:Previous cross-sectional studies have demonstrated that airway wall thickness and air trapping are greater in subjects with severe asthma than in those with mild-to-moderate asthma. However, a better understanding of how airway remodeling and lung density change over time is needed. This study ...
journal_title：Academic radiology
pub_type： 临床试验,杂志文章
doi：10.1016/j.acra.2014.05.001
更新日期：2014-08-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:In clinical guideline or criteria development processes, such as those used in developing American College of Radiology Appropriateness Criteria (ACR AC), experts subjectively evaluate benefits and risks associated with imaging tests and make complex decisions about imaging recommendations. The...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2017.01.001
更新日期：2017-05-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The purpose of this study was to compare the efficacy of dual-energy computed tomography (DECT), time-resolved magnetic resonance (MR) imaging (MRI) perfusion measurements, and high-resolution MR angiography (MRA) for the detection of pulmonary embolism (PE) in a rabbit model. MATERIALS AND ME...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2010.09.004
更新日期：2010-12-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The authors performed this study to determine the feasibility of using quantitative 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) to monitor the response of breast cancer bone metastases to therapy. MATERIALS AND METHODS:Twenty-four women with stage IV bone-d...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/s1076-6332(03)80461-0
更新日期：2002-08-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The study aim is to evaluate the quality of radiology requisitions for plain film radiographs on intensive care unit (ICU) patients. MATERIALS AND METHODS:Radiology requisitions for 58 patients in ICU units at our children's hospital and the corresponding original orders for the study, written...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2005.10.017
更新日期：2006-02-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:Current approaches to receiver operating characteristic (ROC) analysis use the MRMC (multiple-reader, multiple-case) paradigm in which several readers read each case and their ratings (or scores) are used to construct an estimate of the area under the ROC curve or some other ROC-related paramet...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2006.07.016
更新日期：2006-11-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:An automated method for identification and segmentation of acute/subacute ischemic stroke, using the inherent bi-fold symmetry in brain images, is presented. An accurate and automated method for localization of acute ischemic stroke could provide physicians with a mechanism for early detection ...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2008.03.013
更新日期：2008-09-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:In vivo tracking cells using gadolinium-based contrast agents have the important advantage of providing a positive contrast on T1-weighted images, which is less likely to be confused with artifacts because of postoperative local signal voids such as metal, hemorrhage, or air. The aim of this st...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2009.03.016
更新日期：2009-09-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The aim of the study is to gauge radiology fellowship directors' experiences with the fellowship application process and perceptions of the National Resident Matching Program Radiology Fellowship Match, as well as compare these perceptions with those of senior residents. METHODS AND MATERIALS:...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2005.09.085
更新日期：2006-01-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:The purpose of this study was to determine if continuous arterial spin-labeling perfusion magnetic resonance imaging could be used to detect testicular perfusion in human subjects. MATERIALS AND METHODS:Continuous arterial spin-labeling magnetic resonance perfusion imaging was performed in sev...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/s1076-6332(03)00576-2
更新日期：2004-01-01 00:00:00
abstract：RATIONALE AND OBJECTIVES:To assess the feasibility of 70-kVp high-pitch non-ECG-gated thoracic aortic computed tomography angiography (CTA) with 40-mL contrast agent compared to 100-kVp standard-pitch CTA with 60-mL contrast agent. MATERIALS AND METHODS:Sixty-seven patients (51 men and 16 women; mean age, 55 ± 14 year...
journal_title：Academic radiology
pub_type： 杂志文章
doi：10.1016/j.acra.2015.03.007
更新日期：2015-07-01 00:00:00
