Abstract:
OBJECTIVE:A postprocessing method of rank filtering inhomogeneity correction using nonlinear rank filtering of magnetic resonance imaging (MRI) scans is described. The method addresses some of the problems of homomorphic unsharp masking (HUM) using mean or median filtering. METHODS:Maximum rank filtering was used to estimate the bias image, which was then smoothed and used to normalize the original image. The coefficient of variation within and between tissue classes before and after inhomogeneity correction was calculated in simulated brain phantom images and clinical T1-weighted MRI images. Comparison was made with mean filter-based and median filter-based HUM. RESULTS:Maximum rank filtering reduced within and between class coefficients of variation. Performance of median filtering was inferior to that of mean filtering, and both were inferior to performance of maximum rank filtering. CONCLUSION:The method is easy to implement and is effective against different bias types. It is less prone to edge effects than mean and median filtering.
journal_name
J Comput Assist Tomogrjournal_title
Journal of computer assisted tomographyauthors
Chen J,Reutens DCdoi
10.1097/01.rct.0000175498.57083.80keywords:
subject
Has Abstractpub_date
2005-09-01 00:00:00pages
668-76issue
5eissn
0363-8715issn
1532-3145pii
00004728-200509000-00020journal_volume
29pub_type
杂志文章abstract:PURPOSE:Our goal was to determine the predictive value of coronary artery calcification (CAC) on preoperative CT of the thorax for cardiac complications of noncardiac thoracic surgery. METHOD:Of 117 patients undergoing noncardiac thoracic surgical procedures between January 1, 1993, and June 1, 1995, at our institutio...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-199707000-00018
更新日期:1997-07-01 00:00:00
abstract::In a case of cerebral infarction the lesions were isointense to slightly hyperintense in the T2-weighted MR images obtained approximately 2 weeks after the onset. Earlier (1 week after onset), they had been markedly hyperintense. The probably mechanisms behind this phenomenon, referred to as "MR fogging" are discussed...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-199101000-00029
更新日期:1991-01-01 00:00:00
abstract::We present the case of unilateral nonhemorrhagic adrenal infarct in a 29-week pregnant 21-year-old woman. The patient presented with right upper quadrant pain, nausea, and vomiting. Ultrasonography of the right upper quadrant and appendix was negative for pathology. Magnetic resonance imaging of the abdomen demonstrat...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/RCT.0000000000000887
更新日期:2019-11-01 00:00:00
abstract:PURPOSE:The purpose of this work was to determine the accuracy of predicting arterial enhancement from peripheral versus central venous test bolus injections at CT angiography (CTA). METHOD:In 40 patients with abdominal aortic aneurysms, aortoiliac enhancement profiles were predicted by mathematical deconvolution of t...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-200103000-00024
更新日期:2001-03-01 00:00:00
abstract:OBJECTIVE:Optic nerve glioma is a common finding in patients with neurofibromatosis type 1 (NF-1). Although dural ectasia of the optic nerve is encountered rarely, it has to be considered in the differential diagnosis. MATERIALS AND METHODS:Three patients affected by NF-1 were examined sequentially by CT and MRI. RES...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-199409000-00009
更新日期:1994-09-01 00:00:00
abstract::Computed tomography assessment of 634 surgically proven solitary pulmonary nodules included 12 pulmonary carcinoid tumors. Five were central (involving or directly abutting the bronchial tree), and seven were peripheral (surrounded by parenchyma). Three central and one peripheral lesion had CT numbers indicative of fo...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-198903000-00010
更新日期:1989-03-01 00:00:00
abstract::Spiral CT (SCT) differs from conventional CT in that the entire heart can be rapidly imaged in the axial plane following the peripheral infusion of small quantities of contrast material. As contrast material travels through coronary artery bypass graft segments, good image detail is achieved, allowing visualization of...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-199303000-00014
更新日期:1993-03-01 00:00:00
abstract:PURPOSE:The purpose of our study was to assess the value of additional early arterial phase computed tomography (CT) imaging in the detection of hepatocellular carcinoma (HCC) by comparing three-phase and four-phase imaging by using multidetector row helical CT. METHODS:Twenty-five patients with 33 HCCs underwent four...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-200209000-00005
更新日期:2002-09-01 00:00:00
abstract::We present a case of a child with acute bacterial leptomeningeal infection caused by Streptococcus pneumoniae. There was an extension of infection along multiple Virchow-Robin spaces into the brain parenchyma, resulting in multiple microabscesses. These abscesses showed restricted diffusion on the diffusion-weighted i...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/RCT.0b013e318187ff15
更新日期:2009-07-01 00:00:00
abstract::Twenty-five patients with nonseminomatous germ cell carcinoma of the testis underwent CT and nuclear magnetic resonance (NMR) of the retroperitoneum followed by radical retroperitoneal lymph node dissection for surgical proof of metastatic disease. Computed tomography correctly predicted the presence or absence of ade...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-198408000-00023
更新日期:1984-08-01 00:00:00
abstract:OBJECTIVE:The aim of the study was to establish the reference window settings for display of virtual monoenergetic images (VMIs) from spectral detector computed tomography when assessing hypodense liver lesions. METHODS:In patients with cysts (n = 24) or metastases (n = 26), objective (HU, signal-to-noise ratio [SNR])...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/RCT.0000000000000794
更新日期:2018-11-01 00:00:00
abstract::The utility of gadolinium-enhanced ultrafast MR imaging in the diagnosis of focal nodular hyperplasia (FNH) of the liver was assessed in one patient. Contrast-enhanced serial snapshot-FLASH with a frequency of 30 images/min demonstrated the typical hemodynamic appearance of FNH known from CT studies. ...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:
更新日期:1991-09-01 00:00:00
abstract:PURPOSE:The purpose of this work is to describe the CT and MR appearance of primary malignant fibrous histiocytoma (MFH) of the chest wall. METHOD:Eleven men and eight women (45-76 years old) with primary MFH of the chest wall who underwent both CT and MRI were enrolled, and the imaging interpretation was retrospectiv...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-200207000-00015
更新日期:2002-07-01 00:00:00
abstract::A case of hepatic oil embolism following lymphangiography is presented. The computed tomographic appearance is striking and probably distinctive of embolism to the hepatic vascular system. The postulated mechanism for the embolization is discussed. ...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-198106000-00019
更新日期:1981-06-01 00:00:00
abstract::We report a case of agenesis of dorsal pancreas diagnosed by CT. This anomaly can easily be confused with pancreas divisum on endoscopic retrograde cholangiopancreatography alone. ...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-198701000-00038
更新日期:1987-01-01 00:00:00
abstract:OBJECTIVE:The objective of the study was to characterize the enhancement pattern of hyperfunctioning parathyroid adenomas on multiphase multidetector computed tomography (CT) or 4-dimensional CT. METHODS:We retrospectively studied the enhancement patterns of 48 pathologically confirmed parathyroid adenomas with 4-dime...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/RCT.0b013e31822a1e70
更新日期:2011-09-01 00:00:00
abstract:OBJECTIVE:The objective was to elucidate clinical effectiveness of submillimeter multislice 2- and 3-dimensional computed tomography (CT) for diagnosis of congenital middle ear anomaly. MATERIALS AND METHODS:Preoperative CT and operative findings were retrospectively analyzed in 36 ears of 33 patients. The distance be...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/RCT.0000000000000093
更新日期:2014-09-01 00:00:00
abstract::The CT appearance of hemiazygos continuation of a left-sided inferior vena cava is presented along with discussion of associated anomalies. ...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-198803000-00027
更新日期:1988-03-01 00:00:00
abstract:PURPOSE:We evaluated the usefulness of gadofluorine 8 (G8) and gadolinium diethylenetriamine-pentaacetic acid (Gd-DTPA) for interstitial magnetic resonance lymphography (MRL). METHOD:Phantom imaging studies were conducted with G8 and Gd-DTPA corresponding to 0.1-0.005 micromol Gd/mL, and signal intensity was measured....
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-200307000-00036
更新日期:2003-07-01 00:00:00
abstract::Quantitation of regional myocardial blood flow (MBF) in absolute terms with positron emission tomography (PET) has been difficult to achieve in part because of errors induced by the relatively low spatial resolution of current tomographic instruments. We previously demonstrated that MBF could be accurately measured ov...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-198909000-00021
更新日期:1989-09-01 00:00:00
abstract::Five cases of histologically confirmed olfactory neuroblastoma (esthesioneuroblastomas) have been studied by computed tomography (CT). Both the clinical symptoms (in particular, unilateral nasal obstruction and recurring epistaxis) and radiological findings (opacity of the paranasal sinuses) are nonspecific. Computed ...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:
更新日期:1978-09-01 00:00:00
abstract:PURPOSE:The purpose of this study was to compare the preoperative detectability of hepatocellular carcinomas (HCCs) using combined T2-weighted and dynamic gadolinium-enhanced MRI and combined CT during arterial portography (CTAP) and CT hepatic arteriography (CTHA). METHOD:Thirty-three patients with 43 HCCs underwent ...
journal_title:Journal of computer assisted tomography
pub_type: 临床试验,杂志文章
doi:10.1097/00004728-200109000-00018
更新日期:2001-09-01 00:00:00
abstract:OBJECTIVES:The objective of this study was to assess the objective and subjective qualities of the contrast-enhanced 4-dimensional dual-energy computed tomography using adaptive statistical iterative reconstruction (ASiR) and ASiR-V. METHODS:The virtual monochromatic images at 60 keV were reconstructed using filtered ...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/RCT.0000000000000942
更新日期:2021-01-01 00:00:00
abstract:OBJECTIVES:To investigate the coronary venous system (CVS) and its spatial relationship with coronary arteries by using 256-slice computed tomography (CT). METHODS:One hundred one patients underwent coronary CT angiography by using a 256-slice CT. In each patient, the CVS and its spatial relationship with coronary art...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/RCT.0000000000000949
更新日期:2020-01-01 00:00:00
abstract::This report describes the imaging findings of the first reported case of a bronchobiliary fistula that developed as a complication of liver transplantation. The diagnosis was confirmed by the aspiration of bile from the bronchus. ...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/01.rct.0000131583.52386.cf
更新日期:2004-09-01 00:00:00
abstract::The clinical and MR features of an alcoholic woman with Wernicke encephalopathy are reported. During the acute stage Gd-diethylenetriamine pentaacetic acid enhanced MR revealed damage of the blood-brain barrier bilaterally and symmetrically adjacent to the third ventricle, cerebral aqueduct, and fourth ventricle. The ...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-199111000-00034
更新日期:1991-11-01 00:00:00
abstract::In 95% of cases, computed tomography (CT) enables the articular capsule of the hip joint to be directly visualized. Articular effusion in the hip joint can also be recognized in the CT image. In inflammatory arthritis and active osteoarthrosis of the hip joint, thickening of the articular capsule or articular effusion...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/00004728-198304000-00014
更新日期:1983-04-01 00:00:00
abstract:OBJECTIVE:This study aimed to assess the prevalence and etiologies of focal liver opacification (FLO) in the setting of superior vena cava (SVC) obstruction. METHODS:An archival search using key words to identify patients with SVC obstruction or severe narrowing and who had computed tomographic scans with intravenous ...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/RCT.0b013e31829950a1
更新日期:2013-09-01 00:00:00
abstract::The purpose of this 4-part series is to illustrate the nuances of temporal bone anatomy using a high-resolution (200-mu isotropic) prototype volume computed tomography (CT) scanner. The normal anatomy in axial and coronal sections is depicted in the first and second parts. In this and the subsequent part, the structur...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章,评审
doi:10.1097/00004728-200603000-00034
更新日期:2006-03-01 00:00:00
abstract:OBJECTIVE:To test 2 hypotheses: first, that coronary distensibility can be measured noninvasively using 64-slice computed tomographic angiography (CTA); and second, that the extent of coronary artery disease (CAD) in any individual patient is related to the degree of distensibility detected by CTA. MATERIALS AND METHO...
journal_title:Journal of computer assisted tomography
pub_type: 杂志文章
doi:10.1097/RCT.0000000000000068
更新日期:2014-05-01 00:00:00