Alain Le Blanche - Academia.edu (original) (raw)
Papers by Alain Le Blanche
European radiology, May 23, 2024
Abdominal Imaging, Feb 1, 1997
Do visceral-spermatic vein shunts have any clinical impact on sclerotherapy of varicoceles? The s... more Do visceral-spermatic vein shunts have any clinical impact on sclerotherapy of varicoceles? The spermatic venograms of 500 consecutive patients were retrospectively reviewed to classify visceral-spermatic communications. Men with an average age of 27.8 years (range 11-65 years old) underwent sclerotherapy of a varicocele. Of the 500 men, 445 were referred for oligoasthenospermia (89%), 45 for pain (9%), and 10 for prevention of infertility (2%). After bilateral catheterization, percutaneous sclerosis was performed below the upper third of the sacroiliac joint. Three hundred forty patients (68%) had left-sided, 10 (2%) had right-sided, and 150 (30%) had bilateral varicoceles. Left side: Of 46 (9.4%) anastomoses, one (0.2%) communicated with the splenic vein and 45 (9.2%) with the inferior mesenteric vein of which 25 (5.1%) were a colic trunk with a competent valve, 15 (3.1%) were venules, and five (1%) were a single or double anastomosis. Right side: Of 48 (29.6%) anastomoses to the superior mesenteric vein, 34 (21%) were venules, 12 (7.4%) were a colic trunk with a competent valve, and two (1.2%) were a single or double vein. Our varicocele recurrence rate was only 1.2%. Visceral-spermatic vein communications are classified by number, morphology, and site. Percutaneous sclerotherapy could be optimized when performed caudally to these communications.
Arteriosclerosis, Thrombosis, and Vascular Biology, Oct 1, 2002
Objective-Smooth muscle cell (SMC) proliferation within the intima is regulated by heparan sulfat... more Objective-Smooth muscle cell (SMC) proliferation within the intima is regulated by heparan sulfates. We studied a low molecular weight (LMW) fucoidan (sulfated polysaccharide from brown seaweed) on SMC proliferation in vitro and intimal hyperplasia in vivo. Methods and Results-In vitro study revealed that LMW fucoidan reduces rabbit SMC proliferation and is internalized in SMC perinuclear vesicles. On rabbit iliac arteries perfused in vivo with fluorolabeled LMW fucoidan after angioplasty, the labeling was mainly located on sites of injury. Pharmacokinetic studies showed that LMW fucoidan exhibited in rats an elimination half-life of 56Ϯ25 minutes (nϭ8) after intravenous administration and a constant plasma rate for Ն6 hours after intramuscular administration. After stent implantation in their iliac arteries, rabbits were also treated with LMW fucoidan (5 mg/kg IM twice a day). Histomorphometric analysis at day 14 indicated that LMW fucoidan reduced intimal hyperplasia by 59% (1.79Ϯ0.4 versus 0.73Ϯ0.2 mm 2 , PϽ0.0001) and luminal cross-sectional area narrowing by 58% (0.38Ϯ0.08 versus 0.16Ϯ0.04, PϽ0.0001). Blood samples showed no anticoagulant activity due to LMW fucoidan. Conclusions-This natural polysaccharide with high affinity for SMCs and sustained plasma concentration markedly reduced intimal hyperplasia, suggesting its use for the prevention of human in-stent restenosis.
Journal de Radiologie, 2009
Journal De Gynecologie Obstetrique Et Biologie De La Reproduction, 2006
Embolisation des fibromes utérins (EFU) : technique récente et résultats préliminaires de l'expér... more Embolisation des fibromes utérins (EFU) : technique récente et résultats préliminaires de l'expérience amiénoise. Indications, technique, résultats du site d'enregistrement international
Les hemorragies du post partum (HPP) ont deux origines, l'atonie uterine et/ou le traumatisme... more Les hemorragies du post partum (HPP) ont deux origines, l'atonie uterine et/ou le traumatisme obstetrical. Elles constituent 60 % des causes de mort maternelle, estimees evitables dans 70 % des cas. Une precarite hemodynamique peut s'installer en une heure, en cas d'echec des ressources pharmacologiques ou de l'exploration uterine. La rapidite d'intervention par embolisation doit emaner d'un protocole ecrit du staff multidisciplinaire radio-gyneco-anesthesiologique, incluant un eventuel transport heliporte vers une unite de radiologie vasculaire interventionnelle. La ligature arterielle ne peut arreter l'hemorragie dans 58 % des cas, alors que le succes technique de l'embolisation est de 90 ± 5 %. Il est necessaire de realiser une embolisation arterielle uterine bilaterale et/ou vaginale proximale, avec de l'eponge synthetique resorbable de gros calibre (2 x 15 mm) decoupee extemporanement. Les particules sont a proscrire. Les regles reviennent da...
Pharmaceuticals, 2021
Endometriosis is one of the major gynecological diseases of reproductive-age women. This disease ... more Endometriosis is one of the major gynecological diseases of reproductive-age women. This disease is characterized by the presence of glands and stroma outside the uterine cavity. Several studies have shown the major role of inflammation, angiogenesis, adhesion and invasion, and apoptosis in endometriotic lesions. Nevertheless, the mechanisms underlying endometriotic mechanisms still remain unclear and therapies are not currently efficient. The introduction of new agents can be effective by improving the condition of patients. PPARγ ligands can directly modulate these pathways in endometriosis. However, data in humans remain low. Thus, the purpose of this review is to summarize the potential actions of PPARγ agonists in endometriosis by acting on inflammation, angiogenesis, invasion, adhesion, and apoptosis.
Jean-François Deux, Anne Meddahi-Pellé, Alain F. Le Blanche, Laurent J. Feldman, Sylvia In-Stent ... more Jean-François Deux, Anne Meddahi-Pellé, Alain F. Le Blanche, Laurent J. Feldman, Sylvia In-Stent Restenosis Model Low Molecular Weight Fucoidan Prevents Neointimal Hyperplasia in Rabbit Iliac Artery Print ISSN: 1079-5642. Online ISSN: 1524-4636 Copyright © 2002 American Heart Association, Inc. All rights reserved. Greenville Avenue, Dallas, TX 75231 is published by the American Heart Association, 7272 Arteriosclerosis, Thrombosis, and Vascular Biology doi: 10.1161/01.ATV.0000032034.91020.0A 2002;22:1604-1609; originally published online August 1, 2002; Arterioscler Thromb Vasc Biol. http://atvb.ahajournals.org/content/22/10/1604 World Wide Web at: The online version of this article, along with updated information and services, is located on the
Journal of Neurology and Neuroscience, 2016
Journal de Radiologie, 2009
Cognitive, Affective, & Behavioral Neuroscience
In this study, we employed a visuo-motor imagery task of alertness as a mental training to examin... more In this study, we employed a visuo-motor imagery task of alertness as a mental training to examine temporal processing of motor responses within healthy young adults. Participants were divided into two groups (group 1; n = 20 who performed the mental training before the real physical task and a control group who performed the physical task without mental training). We vary the time interval between the imperative stimulus and the preceding one (fore-period) in which temporal preparation and arousal increase briefly. Our behavioural results provide clear evidence that mental training reinforces both temporal preparation and arousal, by shortening reaction time (RT), especially for the shortest fore-periods (FP) within exogenous "FP 250 ms" (p = 0.008) and endogenous alertness "FP 650 ms" (p = 0.001). We investigated how the brain controls such small temporal changes. We focus our neural hypothesis on three brain regions: anterior insula, dorsolateral prefrontal cortex, and anterior cingulate cortex and three putative circuits: one top-down (from dorsolateral prefrontal cortex to anterior cingulate cortex) and two bottom-up (from anterior insula to dorsolateral prefrontal cortex and anterior cingulate cortex). In fMRI, effective connectivity is strengthened during exogenous alertness between anterior insula and dorsolateral prefrontal cortex (p = 0.001), between anterior insula and cingulate cortex (p = 0.01), and during endogenous alertness between dorsolateral prefrontal cortex and anterior cingulate cortex (p = 0.05). We suggest that attentional reinforcement induced by an intensive and short session of mental training induces a temporal deployment of attention and allow optimizing the time pressure by maintaining a high state of arousal and ameliorating temporal preparation. Keywords Attention. Arousal. Mental training. Time pressure. Connectivity Accurate timing of future events is a fundamental ability that we routinely apply in various activities that our environment
Behavioural brain research, Jan 3, 2018
Great progress has been made in understanding how people make financial decisions. However, there... more Great progress has been made in understanding how people make financial decisions. However, there is little research on how people make health and treatment choices. Our study aimed to examine how participants weigh benefits (reduction in disease progression) and probability of risk (medications' side effects) when making hypothetical treatment decisions, and to identify the neural networks implicated in this process. Fourteen healthy participants were recruited to perform a treatment decision probability discounting task using MRI. Behavioral responses and skin conductance responses (SCRs) were measured. A whole brain analysis were performed to compare activity changes between "mild" and "severe" medications' side effects conditions. Then, orbitofrontal cortex (OFC), ventral striatum (VS), amygdala and insula were chosen for effective connectivity analysis. Behavioral data showed that participants are more likely to refuse medication when side effects ar...
Journal de Radiologie, 2009
Journal de Radiologie, 2007
Emergency departments frequently encounter pathology resulting from injury to the foot and ankle,... more Emergency departments frequently encounter pathology resulting from injury to the foot and ankle, with approximately 6000 case per day in France. In an ankle sprain, 85% of the lesions involve the lateral collateral ligament. Many other, much rarer, types of lesion with different therapeutic consequences can present, however. Interpretation of the initial conventional radiographs is vital to establishing the type
Surgical and Radiologic Anatomy
The current clinical imaging technique applied to the sacroiliac joint (SIJ) is coronal Computed ... more The current clinical imaging technique applied to the sacroiliac joint (SIJ) is coronal Computed Tomography (CT). The aims of this study were: 1) to section the cartilage, the ligaments of the SIJ, and their relations to adjacent organs, in a coronal plane; 2) to correlate anatomical and magnetic resonance (MR) sections; 3) to extend these data in vivo. A topographic dissection of a 52 year-old female specimen was performed to identify the various components, and spatial relationships of the SIJ. Another fresh frozen 50 year-old female cadaver was chosen on CT criteria of normality, and examined with a high resolution (HR) T1-weighted spin echo sequence, in a plane parallel to the ventral limit of the first two sacral vertebrae. This cadaver was then sliced with a sliding gauge device (slice thickness: 5 mm, and device thickness: 1 mm). The SIJ of a 28 year-old nulliparous volunteer, were examined in HR MR imaging, and with a faster sequence, for comparison with the post mortem data...
ABSTRACT To determine the precise role of arteriography and contrast-enhanced magnetic resonance ... more ABSTRACT To determine the precise role of arteriography and contrast-enhanced magnetic resonance angiography (MRA) to evaluate the peripheral vascular bed in critical ischemia of the lower limbs in candidates for distal vascularization. Fifteen patients (mean age 66 +/- 18 years) underwent MRA and arteriography. In all, 23 lower limbs were studied by non-selective arteriography with aortic injection (n=12) or selective arteriography with iliofemoral injection (n=11). The strength of agreement between MRA and selective arteriography was good (k=0.75) for analysis of leg arteries. MRA was better than non-selective arteriography (p<0.035) to evaluate artery patency. In our study, only MRA improved the treatment decision. In patients requiring an assessment of the peripheral vascular bed before distal revascularization, contrast-enhanced MRA can be the first exam. In case of an inadequate MRA, only selective arteriography needs to be performed.
Magnetic Resonance Imaging, 1993
The ability of superparamagnetic iron oxides (SPIO) and ultrasmall superparamagnetic iron oxides ... more The ability of superparamagnetic iron oxides (SPIO) and ultrasmall superparamagnetic iron oxides (USPIO) to act as positive contrast enhancers due to a marked TI relaxivity was investigated. At low concentrations, an important signal enhancement was observed in vitro, reaching 120% for SPIO and 140% for USPIO in a spin echo 500/22 sequence. The more heavily the sequence was TI-weighted the greater the enhancement. As the concentration increased, the signal dropped. The in vivo study of USPIO in the rat showed that at low doses (14 prmol Fe/kg), the myocardial signal was enhanced by 30070, whereas at high doses (77 pmol Fe/kg), it fell by -50%. These results indicate that in TI-weighted spin echo sequences, the MR signal can be enhanced by low concentrations of superparamagnetic compounds. This effect could be useful in perfusion imaging, and is also important for a better understanding of any possible paradoxical positive enhancement which could occur in perfused organs.
Journal of Vascular and Interventional Radiology, 2001
To experimentally evaluate gadolinium (Gd)-, carbon dioxide (CO(2))-, and iodixanol-enhanced digi... more To experimentally evaluate gadolinium (Gd)-, carbon dioxide (CO(2))-, and iodixanol-enhanced digital subtraction angiography (DSA) versus histomorphometry in the assessment of renal artery stenosis. Fifteen male New Zealand White rabbits weighing 4.0 kg underwent percutaneous catheterization. Renal artery stenosis was induced by bilateral overdilation-deendothelialization (balloon diameter = 2 mm). The percentage of artery overdilation was 33%. After 4 weeks, the rabbits were randomized into two groups: group A underwent right-sided therapeutic percutaneous transluminal renal angioplasty (PTRA) (balloon diameter = 1.5 mm). After another 4 weeks, the renal arteries were evaluated by gadoterate-, iodixanol-, and CO(2)-enhanced selective quantitative DSA. The rabbits were then killed and renal arteries were perfusion-fixed for 60 minutes. Serial orcein-stained 4-um-thick slices were prepared for histomorphometry. Based on morphometric data of single-stenosis versus post-PTRA restenosis lesions, no significant difference was observed between Gd- and iodixanol-enhanced quantitative DSA (r(2) > 0.95), although the iodine/Gd density ratio was equal to 3.5. Carbon dioxide less reliably allowed quantitative DSA (r(2) < 0.75). Gd-based contrast agents represent a highly reliable alternative in experimental quantitative DSA evaluation of renal artery restenosis.
Journal of Vascular and Interventional Radiology, 2008
European radiology, May 23, 2024
Abdominal Imaging, Feb 1, 1997
Do visceral-spermatic vein shunts have any clinical impact on sclerotherapy of varicoceles? The s... more Do visceral-spermatic vein shunts have any clinical impact on sclerotherapy of varicoceles? The spermatic venograms of 500 consecutive patients were retrospectively reviewed to classify visceral-spermatic communications. Men with an average age of 27.8 years (range 11-65 years old) underwent sclerotherapy of a varicocele. Of the 500 men, 445 were referred for oligoasthenospermia (89%), 45 for pain (9%), and 10 for prevention of infertility (2%). After bilateral catheterization, percutaneous sclerosis was performed below the upper third of the sacroiliac joint. Three hundred forty patients (68%) had left-sided, 10 (2%) had right-sided, and 150 (30%) had bilateral varicoceles. Left side: Of 46 (9.4%) anastomoses, one (0.2%) communicated with the splenic vein and 45 (9.2%) with the inferior mesenteric vein of which 25 (5.1%) were a colic trunk with a competent valve, 15 (3.1%) were venules, and five (1%) were a single or double anastomosis. Right side: Of 48 (29.6%) anastomoses to the superior mesenteric vein, 34 (21%) were venules, 12 (7.4%) were a colic trunk with a competent valve, and two (1.2%) were a single or double vein. Our varicocele recurrence rate was only 1.2%. Visceral-spermatic vein communications are classified by number, morphology, and site. Percutaneous sclerotherapy could be optimized when performed caudally to these communications.
Arteriosclerosis, Thrombosis, and Vascular Biology, Oct 1, 2002
Objective-Smooth muscle cell (SMC) proliferation within the intima is regulated by heparan sulfat... more Objective-Smooth muscle cell (SMC) proliferation within the intima is regulated by heparan sulfates. We studied a low molecular weight (LMW) fucoidan (sulfated polysaccharide from brown seaweed) on SMC proliferation in vitro and intimal hyperplasia in vivo. Methods and Results-In vitro study revealed that LMW fucoidan reduces rabbit SMC proliferation and is internalized in SMC perinuclear vesicles. On rabbit iliac arteries perfused in vivo with fluorolabeled LMW fucoidan after angioplasty, the labeling was mainly located on sites of injury. Pharmacokinetic studies showed that LMW fucoidan exhibited in rats an elimination half-life of 56Ϯ25 minutes (nϭ8) after intravenous administration and a constant plasma rate for Ն6 hours after intramuscular administration. After stent implantation in their iliac arteries, rabbits were also treated with LMW fucoidan (5 mg/kg IM twice a day). Histomorphometric analysis at day 14 indicated that LMW fucoidan reduced intimal hyperplasia by 59% (1.79Ϯ0.4 versus 0.73Ϯ0.2 mm 2 , PϽ0.0001) and luminal cross-sectional area narrowing by 58% (0.38Ϯ0.08 versus 0.16Ϯ0.04, PϽ0.0001). Blood samples showed no anticoagulant activity due to LMW fucoidan. Conclusions-This natural polysaccharide with high affinity for SMCs and sustained plasma concentration markedly reduced intimal hyperplasia, suggesting its use for the prevention of human in-stent restenosis.
Journal de Radiologie, 2009
Journal De Gynecologie Obstetrique Et Biologie De La Reproduction, 2006
Embolisation des fibromes utérins (EFU) : technique récente et résultats préliminaires de l'expér... more Embolisation des fibromes utérins (EFU) : technique récente et résultats préliminaires de l'expérience amiénoise. Indications, technique, résultats du site d'enregistrement international
Les hemorragies du post partum (HPP) ont deux origines, l'atonie uterine et/ou le traumatisme... more Les hemorragies du post partum (HPP) ont deux origines, l'atonie uterine et/ou le traumatisme obstetrical. Elles constituent 60 % des causes de mort maternelle, estimees evitables dans 70 % des cas. Une precarite hemodynamique peut s'installer en une heure, en cas d'echec des ressources pharmacologiques ou de l'exploration uterine. La rapidite d'intervention par embolisation doit emaner d'un protocole ecrit du staff multidisciplinaire radio-gyneco-anesthesiologique, incluant un eventuel transport heliporte vers une unite de radiologie vasculaire interventionnelle. La ligature arterielle ne peut arreter l'hemorragie dans 58 % des cas, alors que le succes technique de l'embolisation est de 90 ± 5 %. Il est necessaire de realiser une embolisation arterielle uterine bilaterale et/ou vaginale proximale, avec de l'eponge synthetique resorbable de gros calibre (2 x 15 mm) decoupee extemporanement. Les particules sont a proscrire. Les regles reviennent da...
Pharmaceuticals, 2021
Endometriosis is one of the major gynecological diseases of reproductive-age women. This disease ... more Endometriosis is one of the major gynecological diseases of reproductive-age women. This disease is characterized by the presence of glands and stroma outside the uterine cavity. Several studies have shown the major role of inflammation, angiogenesis, adhesion and invasion, and apoptosis in endometriotic lesions. Nevertheless, the mechanisms underlying endometriotic mechanisms still remain unclear and therapies are not currently efficient. The introduction of new agents can be effective by improving the condition of patients. PPARγ ligands can directly modulate these pathways in endometriosis. However, data in humans remain low. Thus, the purpose of this review is to summarize the potential actions of PPARγ agonists in endometriosis by acting on inflammation, angiogenesis, invasion, adhesion, and apoptosis.
Jean-François Deux, Anne Meddahi-Pellé, Alain F. Le Blanche, Laurent J. Feldman, Sylvia In-Stent ... more Jean-François Deux, Anne Meddahi-Pellé, Alain F. Le Blanche, Laurent J. Feldman, Sylvia In-Stent Restenosis Model Low Molecular Weight Fucoidan Prevents Neointimal Hyperplasia in Rabbit Iliac Artery Print ISSN: 1079-5642. Online ISSN: 1524-4636 Copyright © 2002 American Heart Association, Inc. All rights reserved. Greenville Avenue, Dallas, TX 75231 is published by the American Heart Association, 7272 Arteriosclerosis, Thrombosis, and Vascular Biology doi: 10.1161/01.ATV.0000032034.91020.0A 2002;22:1604-1609; originally published online August 1, 2002; Arterioscler Thromb Vasc Biol. http://atvb.ahajournals.org/content/22/10/1604 World Wide Web at: The online version of this article, along with updated information and services, is located on the
Journal of Neurology and Neuroscience, 2016
Journal de Radiologie, 2009
Cognitive, Affective, & Behavioral Neuroscience
In this study, we employed a visuo-motor imagery task of alertness as a mental training to examin... more In this study, we employed a visuo-motor imagery task of alertness as a mental training to examine temporal processing of motor responses within healthy young adults. Participants were divided into two groups (group 1; n = 20 who performed the mental training before the real physical task and a control group who performed the physical task without mental training). We vary the time interval between the imperative stimulus and the preceding one (fore-period) in which temporal preparation and arousal increase briefly. Our behavioural results provide clear evidence that mental training reinforces both temporal preparation and arousal, by shortening reaction time (RT), especially for the shortest fore-periods (FP) within exogenous "FP 250 ms" (p = 0.008) and endogenous alertness "FP 650 ms" (p = 0.001). We investigated how the brain controls such small temporal changes. We focus our neural hypothesis on three brain regions: anterior insula, dorsolateral prefrontal cortex, and anterior cingulate cortex and three putative circuits: one top-down (from dorsolateral prefrontal cortex to anterior cingulate cortex) and two bottom-up (from anterior insula to dorsolateral prefrontal cortex and anterior cingulate cortex). In fMRI, effective connectivity is strengthened during exogenous alertness between anterior insula and dorsolateral prefrontal cortex (p = 0.001), between anterior insula and cingulate cortex (p = 0.01), and during endogenous alertness between dorsolateral prefrontal cortex and anterior cingulate cortex (p = 0.05). We suggest that attentional reinforcement induced by an intensive and short session of mental training induces a temporal deployment of attention and allow optimizing the time pressure by maintaining a high state of arousal and ameliorating temporal preparation. Keywords Attention. Arousal. Mental training. Time pressure. Connectivity Accurate timing of future events is a fundamental ability that we routinely apply in various activities that our environment
Behavioural brain research, Jan 3, 2018
Great progress has been made in understanding how people make financial decisions. However, there... more Great progress has been made in understanding how people make financial decisions. However, there is little research on how people make health and treatment choices. Our study aimed to examine how participants weigh benefits (reduction in disease progression) and probability of risk (medications' side effects) when making hypothetical treatment decisions, and to identify the neural networks implicated in this process. Fourteen healthy participants were recruited to perform a treatment decision probability discounting task using MRI. Behavioral responses and skin conductance responses (SCRs) were measured. A whole brain analysis were performed to compare activity changes between "mild" and "severe" medications' side effects conditions. Then, orbitofrontal cortex (OFC), ventral striatum (VS), amygdala and insula were chosen for effective connectivity analysis. Behavioral data showed that participants are more likely to refuse medication when side effects ar...
Journal de Radiologie, 2009
Journal de Radiologie, 2007
Emergency departments frequently encounter pathology resulting from injury to the foot and ankle,... more Emergency departments frequently encounter pathology resulting from injury to the foot and ankle, with approximately 6000 case per day in France. In an ankle sprain, 85% of the lesions involve the lateral collateral ligament. Many other, much rarer, types of lesion with different therapeutic consequences can present, however. Interpretation of the initial conventional radiographs is vital to establishing the type
Surgical and Radiologic Anatomy
The current clinical imaging technique applied to the sacroiliac joint (SIJ) is coronal Computed ... more The current clinical imaging technique applied to the sacroiliac joint (SIJ) is coronal Computed Tomography (CT). The aims of this study were: 1) to section the cartilage, the ligaments of the SIJ, and their relations to adjacent organs, in a coronal plane; 2) to correlate anatomical and magnetic resonance (MR) sections; 3) to extend these data in vivo. A topographic dissection of a 52 year-old female specimen was performed to identify the various components, and spatial relationships of the SIJ. Another fresh frozen 50 year-old female cadaver was chosen on CT criteria of normality, and examined with a high resolution (HR) T1-weighted spin echo sequence, in a plane parallel to the ventral limit of the first two sacral vertebrae. This cadaver was then sliced with a sliding gauge device (slice thickness: 5 mm, and device thickness: 1 mm). The SIJ of a 28 year-old nulliparous volunteer, were examined in HR MR imaging, and with a faster sequence, for comparison with the post mortem data...
ABSTRACT To determine the precise role of arteriography and contrast-enhanced magnetic resonance ... more ABSTRACT To determine the precise role of arteriography and contrast-enhanced magnetic resonance angiography (MRA) to evaluate the peripheral vascular bed in critical ischemia of the lower limbs in candidates for distal vascularization. Fifteen patients (mean age 66 +/- 18 years) underwent MRA and arteriography. In all, 23 lower limbs were studied by non-selective arteriography with aortic injection (n=12) or selective arteriography with iliofemoral injection (n=11). The strength of agreement between MRA and selective arteriography was good (k=0.75) for analysis of leg arteries. MRA was better than non-selective arteriography (p<0.035) to evaluate artery patency. In our study, only MRA improved the treatment decision. In patients requiring an assessment of the peripheral vascular bed before distal revascularization, contrast-enhanced MRA can be the first exam. In case of an inadequate MRA, only selective arteriography needs to be performed.
Magnetic Resonance Imaging, 1993
The ability of superparamagnetic iron oxides (SPIO) and ultrasmall superparamagnetic iron oxides ... more The ability of superparamagnetic iron oxides (SPIO) and ultrasmall superparamagnetic iron oxides (USPIO) to act as positive contrast enhancers due to a marked TI relaxivity was investigated. At low concentrations, an important signal enhancement was observed in vitro, reaching 120% for SPIO and 140% for USPIO in a spin echo 500/22 sequence. The more heavily the sequence was TI-weighted the greater the enhancement. As the concentration increased, the signal dropped. The in vivo study of USPIO in the rat showed that at low doses (14 prmol Fe/kg), the myocardial signal was enhanced by 30070, whereas at high doses (77 pmol Fe/kg), it fell by -50%. These results indicate that in TI-weighted spin echo sequences, the MR signal can be enhanced by low concentrations of superparamagnetic compounds. This effect could be useful in perfusion imaging, and is also important for a better understanding of any possible paradoxical positive enhancement which could occur in perfused organs.
Journal of Vascular and Interventional Radiology, 2001
To experimentally evaluate gadolinium (Gd)-, carbon dioxide (CO(2))-, and iodixanol-enhanced digi... more To experimentally evaluate gadolinium (Gd)-, carbon dioxide (CO(2))-, and iodixanol-enhanced digital subtraction angiography (DSA) versus histomorphometry in the assessment of renal artery stenosis. Fifteen male New Zealand White rabbits weighing 4.0 kg underwent percutaneous catheterization. Renal artery stenosis was induced by bilateral overdilation-deendothelialization (balloon diameter = 2 mm). The percentage of artery overdilation was 33%. After 4 weeks, the rabbits were randomized into two groups: group A underwent right-sided therapeutic percutaneous transluminal renal angioplasty (PTRA) (balloon diameter = 1.5 mm). After another 4 weeks, the renal arteries were evaluated by gadoterate-, iodixanol-, and CO(2)-enhanced selective quantitative DSA. The rabbits were then killed and renal arteries were perfusion-fixed for 60 minutes. Serial orcein-stained 4-um-thick slices were prepared for histomorphometry. Based on morphometric data of single-stenosis versus post-PTRA restenosis lesions, no significant difference was observed between Gd- and iodixanol-enhanced quantitative DSA (r(2) > 0.95), although the iodine/Gd density ratio was equal to 3.5. Carbon dioxide less reliably allowed quantitative DSA (r(2) < 0.75). Gd-based contrast agents represent a highly reliable alternative in experimental quantitative DSA evaluation of renal artery restenosis.
Journal of Vascular and Interventional Radiology, 2008