Abstract:
RATIONALE AND OBJECTIVES:Computed tomography (CT) was used to noninvasively monitor local drug pharmacokinetics from polymer implants in rat livers before and following radiofrequency ablation. MATERIALS AND METHODS:Polymer matrixes containing carboplatin (a platinum-containing chemotherapeutic agent) were implanted into rat livers either immediately after radiofrequency ablation (n = 15) or without prior treatment (n = 15). The animals were divided into five subgroups (n = 3 per group) and subjected to a terminal CT scan at 6, 24, 48, 96, or 144 hours. Carboplatin concentration in tissue and within the implant matrix was correlated with CT intensity, and standard curves were produced for each environment. This correlation was used to evaluate the differences in drug transport properties between normal and ablated rat livers. A quantitative image analysis method was developed and used to evaluate the release rate and tissue distribution of carboplatin in normal and ablated liver tissue. The CT data were validated by previously reported atomic absorption spectroscopy measurement of implant and tissue drug levels. RESULTS:Correlation of carboplatin concentration and Hounsfield units results in a linear relationship with correlation coefficients (slopes) of 15 and 4 Hounsfield units/(mg/mL), for carboplatin in tissue and polymer, respectively. Noninvasive monitoring of local pharmacokinetics in normal and ablated tissues indicates that ablation before local carboplatin delivery increases the retention of carboplatin within the polymer matrix and drastically increases the drug retention in the ablated tissue volume (over 3-fold difference) resulting in a higher average dose to the surrounding tissue. At 1.6 mm from the implant boundary, carboplatin concentration is significantly higher in ablated tissue at 48, 96, and 144 hours (P <.05), and reaches 4.7 mg/mL in ablated tissue at 48 hours. In comparison, the concentration in normal liver at 1.6 mm reaches only 0.7 mg/mL at the same time point. The drug penetrates 3.1 mm in ablated liver compared with 2.3 mm in normal liver also at 48 hours. After 144 hours, the drug is still detected at 3.1 mm in ablated liver but not in normal liver. The differences are significant (P <.05) at both 48 and 144 hours. Correlation with chemical analysis suggests that CT data accurately predicts the drug pharmacokinetics in both ablated and normal livers. CONCLUSION:This work shows that X-ray CT imaging is a useful and promising technique for in vivo monitoring of the release kinetics of locally delivered radiopaque agents.
journal_name
Acad Radioljournal_title
Academic radiologyauthors
Exner AA,Weinberg BD,Stowe NT,Gallacher A,Wilson DL,Haaga JR,Gao Jdoi
10.1016/j.acra.2004.09.007keywords:
subject
Has Abstractpub_date
2004-12-01 00:00:00pages
1326-36issue
12eissn
1076-6332issn
1878-4046pii
S1076-6332(04)00556-2journal_volume
11pub_type
杂志文章abstract:RATIONALE AND OBJECTIVES:Diffraction-enhanced imaging (DEI) is a type of phase contrast x-ray imaging that has improved image contrast at a lower dose than conventional radiography for many imaging applications, but no studies have been done to determine if DEI might be useful for diagnosing lung injury. The goals of t...
journal_title:Academic radiology
pub_type: 杂志文章
doi:10.1016/j.acra.2011.08.005
更新日期:2011-12-01 00:00:00
abstract::Despite the widespread belief that advanced imaging should be very helpful in guiding oncology treatment decision and improving efficiency and success rates in treatment clinical trials, its acceptance has been slow. Part of this is likely attributable to gaps in study design and statistical methodology for these imag...
journal_title:Academic radiology
pub_type: 杂志文章,评审
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journal_title:Academic radiology
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abstract:RATIONALE AND OBJECTIVES:The authors hypothesized that electrocardiographic triggering near end systole could minimize motion artifacts in electron-beam computed tomography (CT) of the coronary artery. MATERIALS AND METHODS:The study included 2,660 patients who underwent coronary artery calcium scanning with electron-...
journal_title:Academic radiology
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abstract:RATIONALE AND OBJECTIVES:The authors performed this study to determine whether intrathoracic inoculation of non-small-cell lung carcinoma with fluoroscopic guidance would provide for more accurate implantation. MATERIALS AND METHODS:A tumor cell inoculum (2 x 10(6) cells per 0.15 mL) was injected percutaneously under ...
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journal_title:Academic radiology
pub_type: 杂志文章
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abstract:RATIONALE AND OBJECTIVES:We evaluated the inter- and intraobserver reproducibility of measuring five morphologic parameters of the anorectum in defecography (evacuation proctography). METHODS:Measurements from 42 defecographic studies were statistically analyzed. The parameters measured during resting, squeezing, and ...
journal_title:Academic radiology
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journal_title:Academic radiology
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pub_type: 杂志文章,多中心研究
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更新日期:2001-03-01 00:00:00
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journal_title:Academic radiology
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更新日期:2003-08-01 00:00:00
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journal_title:Academic radiology
pub_type: 杂志文章
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更新日期:2000-12-01 00:00:00
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journal_title:Academic radiology
pub_type: 杂志文章
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更新日期:2014-07-01 00:00:00
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journal_title:Academic radiology
pub_type: 杂志文章
doi:10.1016/j.acra.2017.11.024
更新日期:2018-06-01 00:00:00
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更新日期:2010-12-01 00:00:00
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journal_title:Academic radiology
pub_type: 杂志文章,评审
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pub_type: 杂志文章
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journal_title:Academic radiology
pub_type: 杂志文章,meta分析,评审
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journal_title:Academic radiology
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doi:10.1016/s1076-6332(96)80448-x
更新日期:1996-03-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:To quantify the relationship between dose of contrast administered and contrast kinetics of malignant breast lesions. MATERIALS AND METHODS:A total of 108 patients with 120 malignant lesions were selected for an institutional review board-approved review. Dynamic magnetic resonance protocol: o...
journal_title:Academic radiology
pub_type: 杂志文章
doi:10.1016/j.acra.2009.06.015
更新日期:2010-01-01 00:00:00
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journal_title:Academic radiology
pub_type: 杂志文章
doi:10.1016/j.acra.2006.11.004
更新日期:2007-02-01 00:00:00
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journal_title:Academic radiology
pub_type: 杂志文章
doi:10.1016/j.acra.2011.04.007
更新日期:2011-09-01 00:00:00
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journal_title:Academic radiology
pub_type: 杂志文章
doi:10.1016/j.acra.2015.08.021
更新日期:2015-12-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Hyperpolarized (3)He magnetic resonance imaging (MRI) previously revealed the temporal and spatial heterogeneity of ventilation defects in asthmatics, but these findings have not been used in treatment studies or to guide personalized therapy. Our objective was to exploit the temporal and spati...
journal_title:Academic radiology
pub_type: 杂志文章
doi:10.1016/j.acra.2014.08.002
更新日期:2014-11-01 00:00:00
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journal_title:Academic radiology
pub_type: 杂志文章
doi:10.1016/j.acra.2007.06.002
更新日期:2007-09-01 00:00:00
abstract::This case study chronicles the impact of Hurricane Katrina on the Department of Radiology at the Louisiana State University School of Medicine in New Orleans and the department's subsequent efforts to recover and re-dedicate itself to providing quality patient care and resident education. Hurricane Katrina damaged the...
journal_title:Academic radiology
pub_type: 杂志文章
doi:10.1016/j.acra.2009.01.016
更新日期:2009-05-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:The development of curriculum guidelines for radiology residency has been found to be favored by 80% of program directors (PDs) nationwide. I surveyed PDs to develop a consensus of opinion concerning minimum training requirements in the subspecialty rotations. METHODS:A survey developed by mem...
journal_title:Academic radiology
pub_type: 杂志文章
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更新日期:1996-06-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Nephrosclerosis occurs with aging and is characterized by increased kidney subcapsular surface irregularities at autopsy. Assessments of cortical roughness in vivo could provide an important measure of nephrosclerosis. The purpose of this study was to develop and validate an image-processing al...
journal_title:Academic radiology
pub_type: 杂志文章
doi:10.1016/j.acra.2014.05.014
更新日期:2014-11-01 00:00:00