Abstract:
:Methods are presented for the quantification of spatial resolution in x-ray computed tomographic (CT) images. Model-dependent methods are derived and compared with model independent methods for computation of the Modulation Transfer Function (MTF). These techniques are applied to phantom images of point, line, edge, and ring discontinuities. The model-dependent methods utilize multiparameter fits of a two-dimensional model function to the image data. Model predictions are compared with results obtained in a model-independent way by numerical transformation of the data. Results of resolution measurements of an Imatron C-100 CT scanner at UCSF and a second experimental scanner at the UCSF Physics Research Laboratory are presented.
journal_name
Invest Radioljournal_title
Investigative radiologyauthors
Assimakopoulos PA,Boyd DP,Jaschke W,Lipton MJdoi
10.1097/00004424-198603000-00012subject
Has Abstractpub_date
1986-03-01 00:00:00pages
260-71issue
3eissn
0020-9996issn
1536-0210journal_volume
21pub_type
杂志文章abstract::Due to the small size of the bronchial arteries, the bronchial circulation is difficult to study and remains poorly understood. We have utilized single photon emission computed tomography (SPECT) as a noninvasive means of studying the bronchial circulation. Imaging studies were performed in sheep before and after the ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199001000-00014
更新日期:1990-01-01 00:00:00
abstract:OBJECTIVES:We compared the image quality and diagnostic performance of 2 fat-suppression methods for black-blood T2-weighted fast spin-echo (FSE), which are as follows: (a) short T1 inversion recovery (STIR; FSE-STIR) and (b) spectral adiabatic inversion recovery (SPAIR; FSE-SPAIR), for detection of acute myocardial in...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e3182718672
更新日期:2013-01-01 00:00:00
abstract::Left ventricular volume has been measured with ultrafast computed tomography. However, the accuracy with which this can be done is unknown. We therefore imaged with ultrafast computed tomography 11 rectangular phantoms, 20 to 225 ml, and 17 left ventricular casts, 15 to 112 ml. Two observers planimetered serial tomogr...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199101000-00006
更新日期:1991-01-01 00:00:00
abstract::The magnitude and timing of the effects of postural change on pulmonary blood flow distribution were studied in dogs by means of computed tomography (CT) and radioactive microspheres. A change in the mean attenuation values was demonstrated by CT in the anterior and posterior lung zones after change from the supine to...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198211000-00007
更新日期:1982-11-01 00:00:00
abstract::Analysis of 46 sacroiliac joints removed in toto at random during routine autopsies was undertaken to define the pathologic and radiographic alterations of this joint in middle-aged and elderly patients. Each joint was sectioned, photographed and radiographed and large microscopic slides were prepared. Sacroiliac oste...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-197511000-00008
更新日期:1975-11-01 00:00:00
abstract:PURPOSE:The aim of this study was to compare qualitative and quantitative image quality and geometric distortion of 4 magnetic resonance diffusion-weighted imaging (DWI) sequences of the prostate using comparable imaging parameters and similar acquisition times. METHODS AND MATERIALS:Axial T2-weighted turbo spin echo ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000429
更新日期:2018-04-01 00:00:00
abstract::The effect of contrast media (CM) dilution on contrast enhancement was studied using CM representing four structurally different molecular types at osmolalities ranging from 135 to 1340 mosm/kg. Diatrizoate (ionic monomer), iopamidol (nonionic monomer), ioxaglate (ionic dimer), and iodecol (nonionic dimer) were each g...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198809001-00014
更新日期:1988-09-01 00:00:00
abstract:OBJECTIVE:The aim of this study was to compare quantitative and semiquantitative parameters (signal-to-noise ratio [SNR], contrast-to-noise ratio [CNR], image quality, diagnostic confidence) from a standard brain magnetic resonance imaging examination encompassing common neurological disorders such as demyelinating dis...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000256
更新日期:2016-08-01 00:00:00
abstract::Erythrocytes at various concentrations were examined with a sensitive A-mode ultrasonic scanner; simultaneous measurements were made under light microscopic control. Individual erythrocytes caused weak (about 1 dB) echoes while erythrocyte aggregates (ten to 100 cells) produced stronger echoes (up to 15 dB), grossly p...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198508000-00014
更新日期:1985-08-01 00:00:00
abstract:OBJECTIVES:The aim of this study was to assess quantitative ultra-high b-value (UHB) diffusion magnetic resonance imaging (MRI)-derived parameters in comparison to standard clinical apparent diffusion coefficient (SD-ADC-2b-1000, SD-ADC-2b-1500) for the prediction of clinically significant prostate cancer, defined as G...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000712
更新日期:2021-02-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:The authors report on the development and preliminary validation of a technique for measuring contrast-to-noise ratio (CNR) at all points along selected vessel segments in the original three-dimensional magnetic resonance angiography (MRA) dataset. METHODS:Contrast-to-noise ratio dependencies ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199311000-00005
更新日期:1993-11-01 00:00:00
abstract::Dense cavitary "photopenia" was observed on 21 of 200 consecutive stress perfusion scintigrams. A prominent finding in many cases, it sometimes occupied only a portion of the region overlying the ventricular cavity, was often seen in some projections and not others, and was frequently adjacent to myocardial perfusion ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198507000-00009
更新日期:1985-07-01 00:00:00
abstract:OBJECTIVES:: To evaluate the performance of a gadolinium-based contrast compound (P846) as well as an ultra-small particle of iron oxide agent (P904) in contrast-enhanced magnetic resonance angiography (MRA) in rabbits and to compare those agents with gadoterate meglumine (Gd-DOTA) for first pass and steady state imagi...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e31821ae21f
更新日期:2011-08-01 00:00:00
abstract:RATIONAL AND OBJECTIVES:The feasibility of tubal occlusion by selective salpingography was tested in an animal model; three novel occluding materials also were tested for this application. METHODS:Unilateral selective salpingography was performed in three groups of six rabbits; fallopian tubes were embolized with etha...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199402000-00007
更新日期:1994-02-01 00:00:00
abstract::Post-angioplasty restenosis (PARS) in atherosclerotic lesions of medium and small arteries occurs in about one-third of cases in the first year following percutaneous transluminal angioplasty (PTA) (early PARS). PARS includes acute spasm, dissection with reclosure, elastic recoil, fibrocellular proliferative response,...
journal_title:Investigative radiology
pub_type: 临床试验,杂志文章,多中心研究
doi:10.1097/00004424-198811000-00002
更新日期:1988-11-01 00:00:00
abstract:OBJECTIVE:The objective of this study was to evaluate the diagnostic performance and safety of magnetic resonance (MR) imaging-guided percutaneous mediastinal biopsy procedures using a 0.23-T open MR system with optical tracking navigation. MATERIALS AND METHODS:A retrospective analysis of 59 participants (38 males an...
journal_title:Investigative radiology
pub_type: 临床试验,杂志文章
doi:10.1097/RLI.0b013e31827a4a17
更新日期:2013-06-01 00:00:00
abstract:OBJECTIVES:The safety of nonionic contrast agents with that of ionic iodinated contrast agents in children is compared. METHODS:A comprehensive literature search was conducted to identify all publications on the safety profile of nonionic contrast agents administered intravenously to children. This information was com...
journal_title:Investigative radiology
pub_type: 杂志文章,评审
doi:10.1097/00004424-199311001-00027
更新日期:1993-11-01 00:00:00
abstract:OBJECTIVES:The aim of this study was to assess the effectiveness of a model-based iterative reconstruction (MBIR) in improving image quality and diagnostic performance of ultralow-dose computed tomography (ULDCT) of the lung. MATERIALS AND METHODS:The institutional review board approved this study, and all patients pr...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e3182562a89
更新日期:2012-08-01 00:00:00
abstract::Compounds containing mobile protons can act as contrast agents by increasing the value of the term (1/12 - 1/11). The efficiency of this method is markedly pH- and field-dependent. There are many such compounds allowing a choice to be made based on the characteristics of the tissue or organ, magnetic field strength, a...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198809001-00058
更新日期:1988-09-01 00:00:00
abstract:OBJECTIVES:The objective of this study was to evaluate the use of dielectric pads for improving high spatial resolution imaging of the inner ear at 7 T. MATERIALS AND METHODS:Two sets of dielectric pads were designed using electromagnetic simulations and implemented using a deuterated suspension of barium titanate. Th...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000026
更新日期:2014-05-01 00:00:00
abstract:OBJECTIVE:This study aims for targeted biopsy validation of magnetic resonance fingerprinting (MRF) and diffusion mapping for characterizing peripheral zone (PZ) prostate cancer and noncancers. MATERIALS AND METHODS:One hundred four PZ lesions in 85 patients who underwent magnetic resonance imaging were retrospectivel...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000569
更新日期:2019-08-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Paclitaxel added to angiographic contrast medium (CM) has been shown to inhibit restenosis in the porcine coronary overstretch model. This study determined early local tissue concentrations after the administration of different paclitaxel doses and preparations. MATERIALS AND METHODS:Fifteen p...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/01.rli.0000116125.96544.64
更新日期:2004-03-01 00:00:00
abstract::Due to the nature of three-dimensional Fourier transform (3-DFT) data acquisition in magnetic resonance imaging (MRI), the spatial relation between a resolved volume element (a voxel) and the object can be manipulated easily. Those manipulations have practical consequences in terms of registering slice positions with ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199012000-00006
更新日期:1990-12-01 00:00:00
abstract:OBJECTIVES:The aim of this study was to compare F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) (with and without diffusion-weighted imaging [DWI]) to F-FDG PET/computed tomography (CT), with regard to the assessment of nodal and extranodal involvement, in patients with Hodgkin lym...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000218
更新日期:2016-03-01 00:00:00
abstract:OBJECTIVES:To test the feasibility of combining inner-volume imaging (IVI) techniques with conventional multishot periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) techniques for targeted-PROPELLER magnetic resonance imaging. MATERIALS AND METHODS:Perpendicular section-selective ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e3181a8b015
更新日期:2009-08-01 00:00:00
abstract:OBJECTIVE:Hydration is widely accepted as an effective measure to prevent contrast media (CM)-induced acute kidney injury (AKI). Whether bicarbonate (NaHCO₃) infusion has a greater effect than saline is disputed. Effective prevention of CM-induced AKI by NaHCO₃ has been found by several clinical trials. However, others...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e31822311a9
更新日期:2011-11-01 00:00:00
abstract:OBJECTIVE:We aimed to assess whether migraine is associated with changes in the distribution of the venous drainage through primary and secondary pathways by using phase-contrast magnetic resonance imaging (MRI). METHODS:We examined 26 patients (37.3 ± 13.9 years) with recurring migraine headaches and 26 age- and gend...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0b013e318210ecf5
更新日期:2011-07-01 00:00:00
abstract::Over the past 120 years, continuous developments in medical imaging has improved diagnosis and treatment for many diseases and has thereby improved treatment outcome and quality of life of many patients. The number of computed tomography (CT) examinations is today increasing by 4% per year worldwide, for a total of ap...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000696
更新日期:2020-09-01 00:00:00
abstract::Observation of the relaxivity of MRI contrast media over a wide range of magnetic fields is not only necessary for predicting their efficiency at any field but also compulsory for understanding and improving their mechanisms of action. The best experimental approach to this problem is the field cycling method, which a...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198809001-00047
更新日期:1988-09-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Dynamic contrast enhanced (DCE) MR mammography (MRM) uses tumor capillary density differences for prognosis. The heterogeneous response of permeability-surface area products (PS = Kp<-->t) was examined in mammary tumors, as a function of contrast agent size, to determine what effect ROI size mi...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-200204000-00003
更新日期:2002-04-01 00:00:00