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1.
AJNR Am J Neuroradiol ; 41(8): 1405-1413, 2020 08.
Article in English | MEDLINE | ID: mdl-32675335

ABSTRACT

BACKGROUND AND PURPOSE: Phase imaging helps determine a lesion's susceptibility. However, various inhomogenous phase patterns could be observed in the serial phase images of a lesion and render image interpretation challenging. We evaluated the diagnostic accuracy of differentiating cerebral microbleeds and calcifications from phase patterns in axial locations. MATERIALS AND METHODS: This study retrospectively enrolled 31 consecutive patients undergoing both CT and MR imaging for acute infarction exhibiting dark spots in gradient-echo magnitude images. Six patients had additional quantitative susceptibility mapping images. To determine their susceptibility, 2 radiologists separately investigated the phase patterns in the border and central sections and quantitative susceptibility mapping of dark spots. Sensitivity and specificity were compared using the McNemar test. Interobserver reliability and correlation analysis were determined using the κ coefficient and Pearson correlation coefficient, respectively. RESULTS: Among 190 gradient-echo dark spots, 62 calcifications and 128 cerebral microbleeds were detected from CT. Interobserver reliability was higher for the border phase patterns (κ = 1) than for the central phase patterns (κ = 0.77, P < .05). The sensitivity and specificity of the border phase patterns in identifying calcifications were higher than those of the central phase patterns (98.4% and 100% versus 79% and 83.6%), particularly for lesions >2.5 mm in diameter (100% and 100% versus 66.7% and 61.1%). The same values were obtained using quantitative susceptibility mapping for identification (100% and 100%). A high correlation between the size and susceptibility of cerebral microbleeds and calcifications suggested that greater phase changes may be caused by larger lesions. CONCLUSIONS: The border phase patterns were more accurate than the central phase patterns in differentiating calcifications and cerebral microbleeds and was as accurate as quantitative susceptibility mapping.


Subject(s)
Calcinosis/diagnostic imaging , Cerebral Hemorrhage/diagnostic imaging , Image Interpretation, Computer-Assisted/methods , Neuroimaging/methods , Aged , Aged, 80 and over , Cerebral Hemorrhage/pathology , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Retrospective Studies , Sensitivity and Specificity , Tomography, X-Ray Computed
2.
Clin Radiol ; 71(1): e21-7, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26620708

ABSTRACT

AIM: To elucidate the cause of cerebral hypoperfusion on the stent placement side after carotid artery stent placement (CAS) measured by pseudocontinuous arterial spin labelling (PCASL) perfusion imaging. MATERIALS AND METHODS: Consecutive patients with symptomatic internal carotid artery stenosis receiving CAS were included in the study. Cerebral blood flow (CBF) was measured by PCASL perfusion imaging at 3 T magnetic resonance imaging (MRI) the day before and 3 days after the procedure. Changes in cerebral haemodynamics after CAS were assessed. RESULTS: Twenty-two patients were included; 17 patients had increased or stationary CBF after CAS and five patients had significantly reduced CBF on the stenting side after CAS whereas CBF increased on the contralateral side. High stent position was noticed in the five patients. After labelling plane adjustment to avoid labelling on the stent, no more cerebral hypoperfusion was noticed. CONCLUSION: When using PCASL perfusion imaging to monitor post-stenting CBF, the stent may cause an artefact that leads to a low CBF in the territory of the stented vessel. Routinely adding a fast T2 star gradient-echo echo-planar-imaging covering the upper neck region before PCASL perfusion imaging to identify the stent position and avoid the stent-related artefact is recommended.


Subject(s)
Carotid Artery, Internal , Carotid Stenosis/pathology , Carotid Stenosis/surgery , Cerebrovascular Circulation , Magnetic Resonance Angiography/methods , Spin Labels , Stents , Aged , Artifacts , Echo-Planar Imaging , Hemodynamics , Humans , Middle Aged
3.
Prostate Cancer Prostatic Dis ; 17(3): 280-5, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25027863

ABSTRACT

BACKGROUND: Selecting appropriate candidates for postprostatectomy radiotherapy is challenging, because adverse pathological features cannot accurately predict clinical recurrence. Biomarkers that identify residual disease activity may assist clinicians when counseling patients on the risks, benefits and costs of secondary treatment. NADiA ProsVue PSA slope results ≤2.0 pg ml(-1) month(-1) are predictive of a reduced risk of clinical recurrence; however, its clinical utility has not yet been studied. METHODS: We prospectively enrolled men treated by radical prostatectomy in a multicenter, institutional review board-approved clinical trial. At postsurgical follow-up, investigators (N=17) stratified men into low-, intermediate- or high-risk groups for prostate cancer recurrence based on clinicopathological findings and other factors. Investigators documented their initial treatment plan for each subject and serially collected three serum samples for ProsVue testing. After the ProsVue result was reported, investigators recorded whether or not the initial treatment plan was changed. The proportion of cases referred for secondary treatment before and after ProsVue was reported, and the significance of the difference determined. RESULTS: Complete assessments were reported for 225 men, 128 (56.9%) of whom were stratified into intermediate- and high-risk groups. Investigators reported that they would have referred 41/128 (32.0%) at-risk men for secondary treatment. However, after results were known, they referred only 15/128 (11.7%) men. The difference in proportions (-20.3%, 95% confidence interval (CI) -29.9 to -10.3%) is significant (P<0.0001). Odds of a referral was significantly reduced after results were reported (odds ratio 0.28, 95% CI 0.15-0.54, P<0.0001). CONCLUSIONS: Knowledge of a ProsVue result had significant impact on the final treatment plan. A ProsVue result ⩽2.0 pg ml(-1) month(-1) significantly reduced the proportion of men at risk of recurrence who otherwise would have been referred for secondary treatment.


Subject(s)
Prostate-Specific Antigen/blood , Prostatic Neoplasms/diagnosis , Prostatic Neoplasms/therapy , Aged , Biomarkers, Tumor/blood , Decision Making , Disease Management , Humans , Immunoassay/methods , Male , Middle Aged , Neoplasm Grading , Neoplasm Staging , Prostatectomy , Prostatic Neoplasms/surgery , Retreatment
4.
AJNR Am J Neuroradiol ; 35(6): 1132-6, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24436346

ABSTRACT

BACKGROUND AND PURPOSE: Hyperperfusion syndrome is a devastating complication of carotid stent placement. The shortening of cerebral circulation time after stent placement is seen as a good indicator of the development of hyperperfusion syndrome. The purpose of our study was to evaluate whether patients with ipsilateral transverse sinus stenosis are prone to having shortened cerebral circulation time after stent placement, subsequently leading to the possible development of hyperperfusion syndrome. MATERIALS AND METHODS: Forty-nine patients with >70% unilateral carotid stenosis undergoing stent placement were recruited for analysis. Group A consisted of patients with a stenotic ipsilateral transverse sinus >50% greater than the diameter of the contralateral transverse sinus; the remaining patients were in group B. Quantitative DSA was used to calculate cerebral circulation time. Cerebral circulation time was defined as the time difference between the relative time to maximal intensity of ROIs in the proximal internal carotid artery and the internal jugular vein. ΔCCT was defined as cerebral circulation time before stent placement minus cerebral circulation time after stent placement. ΔCCT, white matter hyperintensity signals, and sulcal effacement in MR imaging were compared between the 2 groups. RESULTS: ΔCCT was significantly shorter in group A (0.65 ± 1.3) than in group B (-0.12 ± 1.4). Three patients had white matter hyperintensity signals in group A, and 1 developed hyperperfusion syndrome. Group B showed no MR imaging signs of hyperperfusion syndrome. CONCLUSIONS: Ipsilateral hypoplastic transverse sinus was associated with prolonged cerebral circulation time before stent placement and greatly shortened cerebral circulation time after stent placement. Inadequate venous drainage might play a role in impaired cerebral autoregulation and might influence the development of poststenting hyperperfusion syndrome.


Subject(s)
Blood Vessel Prosthesis/adverse effects , Carotid Stenosis/therapy , Cerebral Arterial Diseases/etiology , Cerebral Arterial Diseases/physiopathology , Lateral Sinus Thrombosis/etiology , Lateral Sinus Thrombosis/physiopathology , Stents/adverse effects , Aged , Blood Flow Velocity , Carotid Stenosis/complications , Cerebral Arterial Diseases/pathology , Cerebrovascular Circulation , Female , Humans , Lateral Sinus Thrombosis/pathology , Magnetic Resonance Angiography/methods , Male , Perioperative Care , Pulse Wave Analysis/methods , Reproducibility of Results , Retrospective Studies , Sensitivity and Specificity , Syndrome
5.
Prostate Cancer Prostatic Dis ; 11(1): 79-87, 2008.
Article in English | MEDLINE | ID: mdl-17563767

ABSTRACT

Neutral endopeptidase (NEP) is a cell surface peptidase that catalytically inactivates a variety of physiologically active peptides including basic fibroblast growth factor (FGF-2). We investigated the effect of using lentivirus to overexpress NEP in NEP-deficient DU145 prostate cancer cells. Third-generation lentiviral vectors encoding wild-type NEP (L-NEP), catalytically inactive mutant NEP (L-NEPmu), and green fluorescent protein (L-GFP) were stably introduced into DU145 cells. FGF-2 levels in cell culture supernatants decreased by 80% in L-NEP-infected DU145 cells compared to cells infected with L-NEPmu or L-GFP (P<0.05) while levels of other angiogenic factors were not altered. In vitro tubulogenesis of human vascular endothelial cells induced by conditioned media from DU145 cells infected with L-NEP was significantly reduced compared with that from DU145 cells infected with L-GFP (P<0.05). Tumor xenografts from L-NEP-infected DU145 cells were significantly smaller compared to control cell xenografts and vascularity within these tumors was decreased (P<0.05). Our data suggest that stable expression of NEP in DU145 cells inhibits prostate cancer tumorigenicity by inhibiting angiogenesis, with a probable mechanism being proteolytic inactivation of FGF-2.


Subject(s)
Fibroblast Growth Factor 2/metabolism , Neovascularization, Pathologic/prevention & control , Neprilysin/metabolism , Prostatic Neoplasms/blood supply , Prostatic Neoplasms/therapy , Animals , Cell Proliferation , Cells, Cultured , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Genetic Vectors , Humans , Immunoblotting , Immunoprecipitation , Lentivirus/genetics , Male , Mice , Mice, Nude , Neoplasm Invasiveness , Neprilysin/genetics , Prostatic Neoplasms/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Xenograft Model Antitumor Assays
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