Publications by authors named "Louis Boyer"

62 Publications

Position paper on stress cardiac magnetic resonance imaging in chronic coronary syndrome: Endorsed by the Société française de radiologie (SFR), the Société française d'imagerie cardiovasculaire (SFICV) and the Société française de cardiologie (SFC).

Arch Cardiovasc Dis 2021 Apr 19. Epub 2021 Apr 19.

Aix-Marseille Université, Department of Radiology and Cardiovascular Imaging, Hôpital Timone, AP-HM, CNRS, Centre de Résonance Magnétique Biologique et Médicale (CRMBM), 13385 Marseille, France.

This paper is intended to update the former consensus between the French Societies of Radiology and Cardiology about the use of stress cardiac magnetic resonance imaging in chronic coronary syndrome, published in 2009. The Delphi method was used to build the present consensus. This expert panel consensus includes recommendations for indications, the procedure (with patient preparation), stress-inducing drugs, the acquisition protocol, interpretation and risk stratification by stress magnetic resonance imaging.
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http://dx.doi.org/10.1016/j.acvd.2021.02.004DOI Listing
April 2021

Biodosimetry in interventional radiology: cutaneous-based immunoassay for anticipating risks of dermatitis.

Eur Radiol 2021 Mar 31. Epub 2021 Mar 31.

Service de Radiologie CHU Gabriel-Montpied, Clermont-Ferrand, France.

Objectives: Interventional radiology procedures expose individuals to ionizing radiation. However, existing dosimetry methods do not provide the dose effectively absorbed to the skin, and do not consider the patient's individual response to irradiation. To resolve this lack of dosimetry data, we developed a new external irradiation biodosimetry device, DosiKit, based on the dose-dependent relationship between irradiation dose and radiation-induced H2AX protein phosphorylation in hair follicles. This new biological method was tested in Clermont-Ferrand University Hospital to evaluate the assay performances in the medical field and to estimate DosiKit sensitivity threshold.

Methods: DosiKit was tested over 95 patients treated with neuroradiological interventions. For each intervention, lithium fluoride thermoluminescent dosimeters (TLD) were used to measure total dose received at each hair collection point (lateral and occipital skull areas), and conventional indirect dosimetry parameters were collected with a Dosimetry Archiving and Communication System (DACS).

Results: Quantitative measurement of radiation-induced H2AX protein phosphorylation was performed on 174 hair samples before and after the radiation exposure and 105 samples showed a notable induction of gammaH2AX protein after the radiological procedure. According to a statistical analysis, the threshold sensitivity of the DosiKit immunoassay was estimated around 700 mGy.

Conclusions: With this study, we showed that DosiKit provides a useful way for mapping the actually absorbed doses, allowing to identify patients overexposed in interventional radiology procedures, and thus for anticipating risk of developing dermatitis.

Key Points: • DosiKit is a new external irradiation biodosimetry device, based on the dose-dependent relationship between irradiation dose and radiation-induced H2AX protein phosphorylation in hair follicles. • DosiKit was tested over 95 patients treated with neuroradiological interventions. • The threshold sensitivity of the DosiKit immunoassay was estimated around 700 mGy and DosiKit provides a useful way for mapping the actually absorbed doses.
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http://dx.doi.org/10.1007/s00330-021-07885-yDOI Listing
March 2021

The role of computed tomography in adrenal gland infarction diagnosis during pregnancy: Two case reports.

J Med Vasc 2021 Feb 9;46(1):28-31. Epub 2020 Dec 9.

Radiology Department, University Hospital Estaing, Clermont-Ferrand, France.

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http://dx.doi.org/10.1016/j.jdmv.2020.11.004DOI Listing
February 2021

Proposals for the use of artificial intelligence in emergency radiology.

Diagn Interv Imaging 2021 Feb 2;102(2):63-68. Epub 2020 Dec 2.

Department of Musculoskeletal Imaging, Lille University Hospital, 59000 Lille, France; Lille University School of Medicine, 59000 Lille, France; Collège des Enseignants en Radiologie de France (CERF), 75013 Paris, France; Société Française de Radiologie, 75013 Paris, France.

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http://dx.doi.org/10.1016/j.diii.2020.11.003DOI Listing
February 2021

Optimized radiological alert thresholds based on device dosimetric information and peak skin dose in vascular fluoroscopically guided intervention.

Eur Radiol 2021 May 6;31(5):3027-3034. Epub 2020 Nov 6.

Pôle Interhospitalier d'Imagerie Diagnostique et de Radiologie Interventionnelle, CHU, 63003, Clermont-Ferrand, France.

Objectives: The National Council on Radiation Protection (NCRP) report no. 168 recommended that during fluoroscopically guided interventions (FGIs), each patient should be monitored when one of the following thresholds is reached: an air kerma > 5 Gy, a kerma area product (KAP) > 500 Gy.cm, a fluoroscopy time > 60 min, or a peak skin dose (PSD) > 3 Gy. Whereas PSD is the most accurate metric regarding the prevention of radiological risks, it remains the most difficult parameter to assess. We aimed to evaluate the relevance of the other, more accessible metrics and propose new optimized threshold (OT) for improved patient follow-up.

Methods: Overall, 108 patients who underwent FGI in which at least one NCRP threshold was reached and PSD was measured were considered. The correlation between all metrics was assessed using principal component analysis (PCA). ROC curves and the sensitivity/specificity of both NCRP and OT to predict PSD > 3 Gy were evaluated.

Results: The PCA shows that FGI can be decomposed with two components based on time and dose variables. Only KAP and kerma were correlated with PSD. The overall sensitivity and specificity of the new OT regarding KAP (67.6/93.0), kerma (97.3/81.7), and time (62.2/62.0) were better compared with NCRP thresholds (97.3/16.9, 40.5/95.4, and 21.6/74.7).

Conclusions: This study shows that fluoroscopy time is not a relevant metric when used to predict PSDs > 3 Gy. By adapting KAP and kerma thresholds to predict PSD over 3 Gy, patient follow-ups following vascular FGI can be improved.

Key Points: • In vascular fluoroscopically guided interventions, principal component analysis demonstrates that between fluoroscopy time, KAP, and kerma, only the two last were correlated to the peak skin dose. • Optimized thresholds replacing NRCP ones obtained with ROC curves analysis were 85,451 μGy.cm, 2938 mGy, and 41 min for KAP, kerma, and fluoroscopy time respectively. • Improvements to trigger patient follow-up after vascular fluoroscopically guided interventions may be obtained by using the optimized thresholds.
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http://dx.doi.org/10.1007/s00330-020-07422-3DOI Listing
May 2021

Pneumatosis intestinalis with pneumoperitoneum: Not always a surgical emergency.

Radiol Case Rep 2020 Nov 24;15(11):2459-2463. Epub 2020 Sep 24.

Department of Radiology, Viet Duc University Hospital, 40 Trang Thi Street, Hang Bong Ward, Hoan Kiem District, Hanoi 100000, Vietnam.

Pneumatosis intestinalis (PI) and pneumoperitoneum are commonly recognized as severe signs of gastrointestinal diseases that require emergency surgery. However, these symptoms can also be caused by benign conditions. We describe 4 cases of benign PI and pneumoperitoneum that were detected in different clinical situations (accidental discovery in bilan of aortic dissection (case #1), bilateral pulmonary embolism (case #2), overflow diarrhea due to fecal impaction (case #3), and in follow-up postbiliary digestive anastomosis surgery (case #4), which were addressed with exploratory surgery (case #1) or conservative treatment (the remaining cases), with favorable outcomes. Because PI and pneumoperitoneum can be associated with both life-threatening causes and benign conditions, treatment decisions should be based on the correspondence between clinical and paraclinical features, rather than imaging alone
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http://dx.doi.org/10.1016/j.radcr.2020.09.034DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7522584PMC
November 2020

Chronic Mesenteric Ischemia: An Update.

Authors:
Louis Boyer

Cardiovasc Intervent Radiol 2020 11 6;43(11):1740-1741. Epub 2020 Sep 6.

Radiology Department, Clermont-Ferrand University Hospital, PB 69, 63003, Clermont Ferrand, France.

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http://dx.doi.org/10.1007/s00270-020-02571-wDOI Listing
November 2020

Cerebral venous thrombosis: report of 2 cases of hemorrhagic venous infarction.

Radiol Case Rep 2020 Aug 18;15(8):1295-1300. Epub 2020 Jun 18.

Department of Radiology, University Hospital Gabriel Montpied, Clermont Ferrand, France.

Cerebral venous thrombosis (CVT), a rare but potentially severe cerebrovascular disease, is defined as the thrombosis of a cortical or deep cerebral vein, or a cerebral venous sinus. This article reports 2 cases of CVT. In the first case, the patient is a 40-year-old woman with a history of 2 miscarriages, using oral contraception and presenting intense headache, cervical irradiation, and drowsiness. The second case reports a 43-year-old woman with a history of Crohn disease and daily use of oral contraception, presenting headache, neck pain, and hypersensitivity to noise and light. Noncontrast CT, CT venography, magnetic resonance imaging (MRI) and MR venography (MRV), first-line noninvasive diagnostic modalities in clinical practice, led us to the diagnosis of CVT: hypoplastic lateral sinus CVT in the first case and deep cerebral vein CVT complicated by hemorrhagic infarction in the second case. The early diagnosis of CVT is extremely important, but often a challenge due to highly variable clinical presentation and radiographic findings. MRI and the MRV play a crucial role in case of anatomical variant and in better assessing the extension of thrombus, as well as parenchyma involvement and complications.
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http://dx.doi.org/10.1016/j.radcr.2020.05.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7306535PMC
August 2020

Fluoroscopy guided electrode-array insertion for cochlear implantation with straight electrode-arrays: a valuable tool in most cases.

Eur Arch Otorhinolaryngol 2021 Apr 25;278(4):965-975. Epub 2020 Jun 25.

Department of Otolaryngology-Head Neck Surgery, University Hospital Center, CHU Gabriel Montpied, 58 rue Montalembert, 63000, Clermont-Ferrand, France.

Purpose: To highlight the advantages of real time fluoroscopy guided electrode-array (EA) insertion (FGI) during cochlear implants surgery.

Methods: All surgical procedures were performed in a dedicated operating room equipped with a robotic C-arm cone beam device, allowing for intraoperative real time 2D FGI and postoperative 3D imaging. Only straight EAs were used. Patients were sorted out in three groups: ANAT, with anatomical concerns; HP, with residual hearing; NPR: patients with no particular reason for FGI. In all cases the angle of EA-insertion was measured. In the HP group pre and postoperative hearing were compared. The radiation delivered to the patient was recorded.

Results: Fifty-three cochlear implantation procedures were achieved under fluoroscopy in 50 patients from November 2015 to January 2020 (HP group: n = 10; ANAT group: n = 13; NPR group: n = 27). In the ANAT group, FGI proved to be helpful in 8 cases (61.5%), successfully guiding the surgeon during EA -insertion. On average, the angle of insertion was at 424° ± 55°. In the HP group, a controlled smooth EA-insertion was carried out in all cases but one. The targeted 360° angle of insertion was always reached. Hearing preservation was possible with an eventual average drop of 30 ± 1.5 dB. In the NPR group, FGI helped control the quality of insertion in all cases and appeared very informative in five (17.8%): one EA-misrouting, three stuck EAs, and one case with hidden electrodes out of the cochlea in revision surgery. Final 3D cone beam CT scan double-checked the EA position in all adults. The radiation dose was equivalent to a bit less than four digital subtract radiographs.

Conclusion: The FGI is a very useful adjunct in cochlear implantation in all cases of expected surgical pitfalls, in patients with residual hearing, and even in case without preoperative particular reason, with low irradiation.
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http://dx.doi.org/10.1007/s00405-020-06151-zDOI Listing
April 2021

Joint Position Paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the French Society of Diagnostic and Interventional Cardiac and Vascular Imaging on magnetic resonance imaging in patients with cardiac electronic implantable devices.

Arch Cardiovasc Dis 2020 Jun - Jul;113(6-7):473-484. Epub 2020 May 27.

Clinique Pasteur, 31076 Toulouse, France.

Magnetic resonance imaging (MRI) has become the reference imaging technique for the management of a large number of diseases. The number of MRI examinations increases every year, simultaneously with the number of patients receiving a cardiac electronic implantable device (CEID). The presence of a CEID was considered an absolute contraindication for MRI for many years. The progressive replacement of conventional pacemakers and defibrillators by "magnetic resonance (MR)-conditional" CEIDs and recent data on the safety of MRI in patients with "MR-non-conditional" CEIDs have gradually increased the demand for MRI in patients with a CEID. However, some risks are associated with MRI in CEID carriers, even with MR-conditional devices, because these devices are not "MR safe". Specific programming of the device in "MR mode" and monitoring patients during MRI remain mandatory for all patients with a CEID. A standardized patient workflow based on an institutional protocol should be established in each institution performing such examinations. This joint position paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the French Society of Diagnostic and Interventional Cardiac and Vascular Imaging describes the effect of and risks associated with MRI in CEID carriers. We propose recommendations for patient workflow and monitoring and CEID programming in MR-conditional, "MR-conditional non-guaranteed" and MR-non-conditional devices.
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http://dx.doi.org/10.1016/j.acvd.2020.03.015DOI Listing
September 2020

European guidelines on chronic mesenteric ischaemia - joint United European Gastroenterology, European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Gastrointestinal and Abdominal Radiology, Netherlands Association of Hepatogastroenterologists, Hellenic Society of Gastroenterology, Cardiovascular and Interventional Radiological Society of Europe, and Dutch Mesenteric Ischemia Study group clinical guidelines on the diagnosis and treatment of patients with chronic mesenteric ischaemia.

United European Gastroenterol J 2020 05 16;8(4):371-395. Epub 2020 Apr 16.

Department of Gastroenterology and Hepatology, Erasmus MC University Medical Center, Rotterdam, the Netherlands.

Chronic mesenteric ischaemia is a severe and incapacitating disease, causing complaints of post-prandial pain, fear of eating and weight loss. Even though chronic mesenteric ischaemia may progress to acute mesenteric ischaemia, chronic mesenteric ischaemia remains an underappreciated and undertreated disease entity. Probable explanations are the lack of knowledge and awareness among physicians and the lack of a gold standard diagnostic test. The underappreciation of this disease results in diagnostic delays, underdiagnosis and undertreating of patients with chronic mesenteric ischaemia, potentially resulting in fatal acute mesenteric ischaemia. This guideline provides a comprehensive overview and repository of the current evidence and multidisciplinary expert agreement on pertinent issues regarding diagnosis and treatment, and provides guidance in the multidisciplinary field of chronic mesenteric ischaemia.
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http://dx.doi.org/10.1177/2050640620916681DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7226699PMC
May 2020

Stroke-Associated Intra-Aortic Chord.

Circ Cardiovasc Imaging 2019 10 1;12(10):e009589. Epub 2019 Oct 1.

Department of Cardiac Surgery, Aix Marseille University, Children's Hospital La Timone, Marseille, France (V.F.).

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http://dx.doi.org/10.1161/CIRCIMAGING.119.009589DOI Listing
October 2019

Combined biembolization induces higher hypertrophy than portal vein embolization before major liver resection.

HPB (Oxford) 2020 02 31;22(2):298-305. Epub 2019 Aug 31.

Department of Vascular Radiology, Hôpital Gabriel Montpied, CHU Clermont-Ferrand, Place Henri Dunant, 63000 Clermont-Ferrand, France; UMR Auvergne CNRS 6284, Clermont-Ferrand Faculty of Medicine, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France.

Background: Combined preoperative portal and hepatic vein embolization (biembolization, BE) has been recently described and may further enhance preoperative FLR growth. The objective of this study was to compare the efficacy of combined preoperative biembolization and portal vein embolization (PVE).

Methods: This study was performed between 2010 and 2017. From 2010 to 2014, patients only underwent preoperative PVE. After 2014, BE was proposed as an alternative to PVE. Liver volumetry was assessed by a CT-scan before BE or PVE and then three weeks later.

Results: During the study period, 72 patients underwent radiological procedures that included 41 PVE (PVE group) and 31 BE (BE group). The time elapsing between the procedure and surgery was similar (p = 0.760). The mean percentage of FLR ratio hypertrophy in the PVE group was 31.9% (±34), but reached 51.2% (±42) in the BE group (p = 0.018) and this difference remained significant under multivariate analysis that included age, gender, body mass index, diabetes mellitus, cirrhosis and NASH. The kinetic growth rates were 19% (±17%) and 8% (±13%) in the BE and PVE groups, respectively (p = 0.026).

Conclusion: This study shows that BE induces higher hypertrophy than portal vein embolization before major liver resection with no more morbidity.
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http://dx.doi.org/10.1016/j.hpb.2019.08.005DOI Listing
February 2020

Quantification of steatosis in alcoholic and nonalcoholic fatty liver disease: Evaluation of four MR techniques versus biopsy.

Eur J Radiol 2019 Sep 19;118:169-174. Epub 2019 Jul 19.

CHU Estaing, Service de radiologie, Clermont-Ferrand, France.

Purpose: Given the growing prevalence of obesity and metabolic syndrome, the management of hepatic steatosis, especially its quantification, is a major issue. We assessed the quantification of liver steatosis using four different MR methods, in order to determine the one that is best correlated with the reference method which consists of histological measurement by liver biopsy.

Method: Seventy-one successive patients requiring liver biopsy for acute or chronic liver disease were enrolled prospectively between March 2017 and March 2018, 11 were excluded and 60 were reported. Liver MR (1.5 T) was organised in order to be performed the same day, using four different steatosis quantification techniques (3-echo MRI, 6-echo MRI, 11-echo MRI and MR Spectroscopy). Quantitative histological and imaging data were compared. In a secondary analysis, we studied the possible influence of alcohol drinking, hepatic iron overload, and the presence of liver fibrosis.

Results: All four MR techniques were found to have excellent correlations with the histological measurements: 3-echo MRI (r = 0.852, p < 0.001), 6-echo MRI (r = 0.819, p < 0.001), 11-echo MRI (r = 0.818, p < 0.001) and MR Spectroscopy (r = 0,812, p < 0,001). Interestingly, we also found that the presence of alcohol consumption, iron overload and fibrosis did not interfere with measurements, whichever technique was used.

Conclusion: In the evaluation of hepatic steatosis, our study showed very good correlations of all four MR techniques with the histological standard. There was no confounding factor in a representative group of patients with associated liver conditions such as alcohol consumption, fibrosis and iron overload, for each technique. All four MR techniques may be used in daily practice.
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http://dx.doi.org/10.1016/j.ejrad.2019.07.025DOI Listing
September 2019

Three-dimensional magnetic resonance imaging of fetal head molding and brain shape changes during the second stage of labor.

PLoS One 2019 15;14(5):e0215721. Epub 2019 May 15.

Image Guided Therapies, Pascal Institute, UCA CNRS SIGMA, University of Clermont Auvergne, Clermont-Ferrand, France.

To demonstrate and describe fetal head molding and brain shape changes during delivery, we used three-dimensional (3D) magnetic resonance imaging (MRI) and 3D finite element mesh reconstructions to compare the fetal head between prelabor and the second stage of labor. A total of 27 pregnant women were examined with 3D MRI sequences before going into labor using a 1 Tesla open field MRI. Seven of these patients subsequently had another set of 3D MRI sequences during the second stage of labor. Volumes of 2D images were transformed into finite element 3D reconstructions. Polygonal meshes for each part of the fetal body were used to study fetal head molding and brain shape changes. Varying degrees of fetal head molding were present in the infants of all seven patients studied during the second phase of labor compared with the images acquired before birth. The cranial deformation, however, was no longer observed after birth in five out of the seven newborns, whose post-natal cranial parameters were identical to those measured before delivery. The changing shape of the fetal brain following the molding process and constraints on the brain tissue were observed in all the fetuses. Of the three fetuses presenting the greatest molding of the skull bones and brain shape deformation, two were delivered by cesarean-section (one after a forceps failure and one for engagement default), while the fetus presenting with the greatest skull molding and brain shape deformation was born physiologically. This study demonstrates the value of 3D MRI study with 3D finite element mesh reconstruction during the second stage of labor to reveal how the fetal brain is impacted by the molding of the cranial bones. Fetal head molding was systematically observed when the fetal head was engaged between the superior pelvic strait and the middle brim.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0215721PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6519794PMC
January 2020

Incidence of Chronic Radiodermatitis after Fluoroscopically Guided Interventions: A Retrospective Study.

J Vasc Interv Radiol 2019 May;30(5):692-698.e13

Department of Dermatology, Estaing Hospital, CHU Clermont-Ferrand, Clermont-Auvergne University, 1 Place Lucie Aubrac, F-63003 Clermont-Ferrand Cedex 1, France; Department of Medicine, Clermont-Auvergne University, France.

Purpose: To assess the incidence and risk factors for chronic radiodermatitis after fluoroscopically guided interventions (FGIs) in high-risk patients.

Materials And Methods: Between 2010 and 2016, of 55,782 patients who underwent FGIs, 359 had a risk procedure for skin injury (maximal skin dose > 3 Gy, air kerma > 5 Gy, dose area product [DAP] > 500 Gy.cm, or fluoroscopy time > 60 minutes). Ninety-one of these patients were examined by a dermatologist for radiodermatitis (median time after procedure, 31.2 months [95% confidence interval, 14.2-50.7]). In each case, the clinical features and topography of the skin lesions were recorded and their incidence calculated. The characteristics of the patients and of the FGIs were tested as risk factors.

Results: Eight patients (8.8%) had chronic radiodermatitis; 19 (20.9%) had acute radiodermatitis. Body mass index, DAP value, and air kerma were the only risk factors identified.

Conclusions: This study shows that chronic radiodermatitis may be considered a frequent side effect in an at-risk population. The lesions are commonly benign, but extensive sclerosis can occur. Patients should be better informed about the side effects and offered a skin exam periodically.
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http://dx.doi.org/10.1016/j.jvir.2019.01.010DOI Listing
May 2019

CT-scan contouring technique allows for direct and reliable measurements of the cochlear duct length: implication in cochlear implantation with straight electrode-arrays.

Eur Arch Otorhinolaryngol 2019 Aug 22;276(8):2135-2140. Epub 2019 Apr 22.

Department of Radiology, CHU Gabriel Montpied, Université Clermont Auvergne, 58 Rue Montalembert, 63000, Clermont-Ferrand, France.

Objectives: The advent of hybrid electro-acoustic implants requires precise positioning of the electrode-array (EA) within the cochlea. The cochlea size, that is, the length of the cochlear scala tympani, is often indirectly estimated from distance A by Escudé's method. This technique has been confirmed by anatomical studies, in a bunch of cadaveric specimens, but it is not yet widely established in the field of computed tomography (CT). We compared cochlear duct length obtained by Escudé's method to those directly acquired on CT images.

Materials And Methods: The lengths of cochlear scala tympani were directly measured on CT scans by contouring the external cochlear wall (contouring technique-CoT). In fifteen patients implanted with a straight EA, the length of the EA and the measured length of the cochlea by the CoT were compared, to check the reliability of the CoT. Then, in 200 CT-scans, the length of the cochlear duct was measured by the CoT then compared to Escudé's method.

Results: In the 200 CT-scans which served for cochlear length measurements, a significant variability between the cochleae were observed, as expected. At 360°, the correlation between the measurements of the length of the cochlear scala tympani between the two techniques differed, with a difference of 0.2 ± 0.7 mm at 360° (extreme: 2 mm; p < 0.001) and 2.2 ± 1.2 mm at 540° (extreme: 5.6 mm; p < 0.001).

Conclusion: The CoT can predict with accuracy the length of EA-insertion depth, more precisely than estimation methods such as Escudé's.
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http://dx.doi.org/10.1007/s00405-019-05432-6DOI Listing
August 2019

Comparison of Patient Skin Dose Evaluated Using Radiochromic Film and Dose Calculation Software.

Cardiovasc Intervent Radiol 2018 May 7;41(5):762-771. Epub 2018 Feb 7.

Pôle d'Imagerie Diagnostique et de Radiologie Interventionnelle, CHU, 63003, Clermont-Ferrand, France.

Purpose: To compare, in an interventional radiology setting, peak skin doses (PSDs) delivered as calculated using a dedicated software tool and as measured using radiochromic film. To assess the utility of this dose calculation software tool in routine clinical practice.

Materials And Methods: First, radiochromic films were positioned on the examination table in the back of an adult anthropomorphic phantom to measure PSD, and X-ray examinations were simulated. Then, films were again positioned in the patient's back for 59 thoracic or abdominopelvic endovascular interventions. The results obtained with the radiochromic films were taken as a reference and were statistically compared with those of the software.

Results: With measured PSDs ranging from 100 to 7000 mGy, the median software-film difference was 8.5%. Lin's concordance coefficient was 0.98 [0.97; 0.99] (p < 0.001), meaning that concordance was excellent between the two methods. For the films where PSD exceeded 1000 mGy, the median difference in the measured value was 8.7% [- 1.3; 21.1], with a maximum discrepancy of 34%. Lin's concordance coefficient was 0.98 [0.96; 1] (p < 0.001), meaning that concordance was excellent between the two methods.

Conclusion: Comparison between radiochromic films and the software tool showed that the software is a suitable tool for a simple and reliable estimation of PSD. The software seems to be a good alternative to films, whose use remains complex.
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http://dx.doi.org/10.1007/s00270-018-1888-1DOI Listing
May 2018

Interventional endoscopic ultrasound: A new promising way for intrahepatic portosystemic shunt with portal pressure gradient.

Endosc Ultrasound 2017 Nov-Dec;6(6):394-401

Department of Digestive and Hepatobiliary Diseases, CHU Estaing; Auvergne University Department/CNRS 6284 Image Sciences for Innovations Techniques, France.

Background And Objectives: Interventional endoscopic ultrasound (EUS) is a promising novel approach for intravascular interventions. The aim of this study was to assess the feasibility and safety of a EUS-guided intrahepatic portosystemic shunt (EGIPS) with portal pressure gradient measurement in a live porcine model.

Methods: The left hepatic vein (LHV) or the inferior vena cava (IVC) was punctured with a needle that advanced into the portal vein (PV). A guidewire was then inserted into the PV, and a needle knife was used to create an intrahepatic fistula between LHV and PV. Portal pressure was recorded. The fistula was dilated with a balloon and a biliary metal stent was deployed between LHV and PV under sonographic and fluoroscopic observation. A portocavography validated the patency of the stent. Necropsies were realized after euthanasia.

Results: Portosystemic stenting was achieved in 19/21 pigs. Final portocavography confirmed stent patency between PV and LHV or IVC in 17 pigs (efficacy of 81%): Four stents were dysfunctional as two were thrombosed and two were poor positioned. Portal pressure was documented before and after shunting in 20/21 pigs. Necropsies revealed that 19/21 procedures were transesophageal and two were transgastric. Hemoperitoneum and pneumothorax were found in one pig and hemothorax was found in two pigs. Morbidity was 14.2% (3/21 animals).

Conclusion: EGIPS was feasible in 91% of cases, functional in 81%, with 14.2% per procedure morbidity. EGIPS still needs to be assessed in portal hypertension pig models with longer follow-up before being considered as an alternative when the transjugular intrahepatic portosystemic shunt fails.
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http://dx.doi.org/10.4103/eus.eus_42_17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5752762PMC
December 2017

Evaluation of Doppler-ultrasonography in the diagnosis of transjugular intrahepatic portosystemic shunt dysfunction: A prospective study.

World J Hepatol 2017 Sep;9(27):1125-1132

Service d'Hépato-Gastroentérologie, Hôpital Trousseau, CHRU Tours, 37044 Tours, France.

Aim: To prospectively evaluate the performance of Doppler-ultrasonography (US) for the detection of transjugular intrahepatic portosystemic shunt (TIPS) dysfunction within a multicenter cohort of cirrhotic patients.

Methods: This study was conducted in 10 french teaching hospitals. After TIPS insertion, angiography and liver Doppler-US were carried out every six months to detect dysfunction (defined by a portosystemic gradient ≥ 12 mmHg and/or a stent stenosis ≥ 50%). The association between ultrasonographic signs and dysfunction was studied by logistic random-effects models, and the diagnostic performance of each Doppler criterion was estimated by the bootstrap method. This study was approved by the ethics committee of Tours.

Results: Two hundred and eighteen pairs of examinations performed on 87 cirrhotic patients were analyzed. Variables significantly associated with dysfunction were: The speed of flow in the portal vein ( = 0.008), the reversal of flow in the right ( = 0.038) and left ( = 0.049) portal branch, the loss of modulation of portal flow by the right atrium ( = 0.0005), ascites ( = 0.001) and the overall impression of the operator ( = 0.0001). The diagnostic performances of these variables were low; sensitivity was < 58% and negative predictive value was < 73%. Therefore, dysfunction cannot be ruled out from Doppler-US.

Conclusion: The performance of Doppler-US for the detection of TIPS dysfunction is poor compared to angiography. New tools are needed to improve diagnosis of TIPS dysfunction.
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http://dx.doi.org/10.4254/wjh.v9.i27.1125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5620422PMC
September 2017

Comparative anatomy on 3-D MRI of the urogenital sinus and the periurethral area before and during the second stage of labor during childbirth.

Surg Radiol Anat 2018 Apr 26;40(4):371-380. Epub 2017 Sep 26.

Plateforme de recherche IMAGINAITRE, Paris, France.

Purpose Of The Study: To describe the observable MRI changes in the urogenital sinus during the second stage of labor and delivery by comparing the changes in the positions of the anatomical structures of the maternal perineum using MRI-based vector 3-D models.

Materials And Methods: Seven pregnant women underwent 3-D MRI sequences using a Philips 1 T Panorama open MRI during the pre-labor period and during the second stage of labor. A 3-D vector reconstruction platform (BABYPROGRESS, France) enabled the transformation of volumes of 2-D images into finite element meshes. The polygonal meshes labeled with the principal components of the urogenital sinus were used as part of a biomechanical study of the pressure exerted on the perineum during fetal descent.

Results: The expansion of the urogenital sinus was observed in all patients. Qualitative stretching was observed toward the rear and bottom of the iliococcygeus, pubococcygeus, puborectalis and obturator internus muscles. Significant length differences were measured along the iliococcygeus and pubococcygeus muscles but not along the tendinous arch of the levator ani or the puborectalis muscle. The inversion of the levator ani muscle curvature was accompanied by the transmission of pressure generated during fetal descent to the pubic muscle insertions and the descent of the tendinous arch of the levator ani.

Conclusion: Mechanical pressures responsible for the tensioning of the constituent muscles of the urogenital sinus were qualitatively identified during the second stage of labor. MRI-based vector 3-D models allow the quantitative assessment of levator ani muscle stretching during labor, but 2-D MRI is not sufficient for describing perineal expansion. Vector 3-D models from larger scale studies have the potential to aid in the calibration of a realistic simulation based on the consideration of the reaction of each muscular element. These models offer perspectives to enhance our knowledge regarding perineal expansion during childbirth as a risk factor for postpartum perineal defects.
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http://dx.doi.org/10.1007/s00276-017-1925-9DOI Listing
April 2018

A Normal Preoperative Lipase Serum Level Is an Easy and Objective Risk Factor of Pancreatic Fistula After Pancreaticoduodenectomy.

Pancreas 2017 10;46(9):1133-1140

From the *Department of Digestive and Hepatobiliary Surgery, Estaing University Hospital; †UMR 1071 INSERM/Université Clermont-Auvergne; ‡Department of Radiology, Gabriel Montpied University Hospital; §Biostatistics, Délégation à la Recherche Clinique et à l'Innovation, University Hospital of Clermont-Ferrand, Clermont-Ferrand, France; and ∥Department of Surgical Oncology, Léon Bérard Cancer Center, Lyon, France.

Objectives: The evaluation of the risk of postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy is crucial to optimize perioperative strategies. Many risk factors of POPF have been identified and were included in scores. Performances of these scores have to be improved because of the use of subjective and/or intraoperative factors. We tried to identify new risk factors of POPF that could improve the performance of validated scores.

Methods: We analyzed data from a prospective database of 191 consecutive patients who underwent a pancreaticoduodenectomy. Recorded data included a comprehensive inventory of pre-, intra- and postoperative clinical, biological and radiological data.

Results: The rate of POPF was significantly increased in patients with a normal preoperative lipase serum level (LSL) (29.8% vs 6.8%; P = 0.001). After multivariate analysis, a normal preoperative LSL was a strong independent risk factor of both POPF (odds ratio, 7.06; P = 0.001) and clinically relevant POPF (odds ratio, 3.11; P = 0.036). The addition of the normality of the preoperative LSL to the Fistula Risk Score significantly improved its performance (P < 0.001).

Conclusions: A normal preoperative LSL was a strong, easy, and objective preoperative risk factor of POPF. Its addition to the Fistula Risk Score improved its performance and allows a more accurate evaluation of the risk of POPF.
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http://dx.doi.org/10.1097/MPA.0000000000000905DOI Listing
October 2017

CT patterns of acute type A aortic arch dissection: longer, higher, more anterior.

Br J Radiol 2017 Oct 22;90(1078):20170417. Epub 2017 Aug 22.

2 Service de Chirurgie cardio-vasculaire, Hôpital Gabriel Montpied, CHU Clermont-Ferrand, Clermont-Ferrand, France.

Objectives: This study analysed CT patterns of the acute dissected aortic arch using original biometric features along with comparison with normal aortas.

Methods: The diagnostic CT scans of 57 patients (42 males, age (mean ± SD: 64.5 ± 13.8 years) admitted with acute Stanford type A dissection involving the aortic arch were analysed by semi-automatic detection protocol of the true lumen of the dissection. We measured the distances from the apex to the ascending and descending aorta, the curvilinear length of the entire arch and of its segments (especially between the brachiocephalic artery trunk and the left subclavian artery), as well as the surface area, angle, height and shift of the arch. These measurements were compared with results previously obtained in a healthy cohort in an analysis adjusted for age, sex and weight. The surface area and rotation of the false lumen were also analysed.

Results: Compared to normal aortic arches (N), dissected aortic arches (D) were longer (D: 155 ± 26  mm, N: 135 ± 25  mm, p = 0.002), higher (D: 51 ± 10  mm, N: 45 ± 9  mm, p = 0.04), and with a more anterior apex (shift: D: 1.19 ± 0.56, N: 1.40 ± 0.62, p = 0.007). False lumen occupied between 47-65% of the aorta, turned preferentially clockwise and its rotation decreased progressively along the arch.

Conclusions: The morphology of the dissected aortic arch differs from that of the normal arch. Thus, our compilation of aortic arch measurements may help improve existing endovascular devices and/or design of new endoprostheses. Advances in knowledge: In this article, we provide a comprehensive set of measurements of the dissected aortic arch, and show that dissected aortic arches are longer, higher, and with a more anterior apex than normal arches.
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http://dx.doi.org/10.1259/bjr.20170417DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5853365PMC
October 2017

High Prevalence of Multiple Arterial Bed Lesions in Patients With Fibromuscular Dysplasia: The ARCADIA Registry (Assessment of Renal and Cervical Artery Dysplasia).

Hypertension 2017 09 17;70(3):652-658. Epub 2017 Jul 17.

Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Hypertension Unit (P.-F.P., M.A., L.A.); Department of Radiology (A.A., E.M.), Department of Genetics (X.J.), and Department of Clinical Epidemiology (G.C.); INSERM CIC1418, Paris (M.A., G.C.); Department of Neurology (C.O.) and INSERM U894, Hôpital Sainte-Anne (C.O.), Paris; Faculté de Médecine, Université Paris-Descartes (P.-F.P., M.A., L.A., A.A., E.M., X.J., G.C., C.O.); Department of Cardiology, CHU de Grenoble (J.-P.B., O.O.), Department of Radiology (F.T.), and INSERM U1039 (J.-P.B.), France; Hypertension Unit, CHU Timone, Marseille, France (F.S.); Department of Radiology, CHU Gabriel-Montpied, Clermont-Ferrand, France (L.B.); Hypertension Unit, CHU Rangueil, Toulouse, France (B.B.); Hypertension Unit, Hôpital Cardiologique, Lille, France (C.M.-V.); Normandie Université, University of Caen Normandy, INSERM U919, CHU de Caen, Unité Neurovasculaire, France (E.T.); Department of Vascular Medicine (C.L.H.), Caen, France; Hôpital Saint André, Bordeaux, France (P.G.); Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique (A.P.); Division of Cardiology (A.P.) and Division of Radiology (F.H.), Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium.

Fibromuscular dysplasia (FMD) commonly affects the renal and cervical arteries but has been described to affect other vascular beds as well. The prevalence of and clinical characteristics associated with multisite FMD (string-of-beds or focal stenoses affecting at least 2 vascular beds) are not known. In the prospective ARCADIA registry (Assessment of Renal and Cervical Artery Dysplasia), symptomatic patients with renal artery (RA) FMD underwent tomographic- or magnetic resonance-angiography from the aortic arch to the intracranial arteries and those with cervical FMD from the diaphragm to the pelvis. Of 469 patients (84.0% women), 225 (48.0%) had multisite FMD. In addition, 86 of 244 patients with single-site disease had dissections or aneurisms affecting other vascular beds, totaling 311 patients (66.3%) with lesions in >1 vascular bed. Among patients with a cerebrovascular presentation, the prevalence of RA lesions was higher in patients with than in those without hypertension (odds ratio, 3.4; 95% confidence interval, 1.99-6.15). Among patients with a renal presentation, the prevalence of cervical lesions was higher in patients with bilateral than in those with unilateral RA lesions (odds ratio, 1.9; 95% confidence interval, 0.99-3.57). In conclusion, FMD is a systemic arterial disease. At least 2 vascular beds were affected by dysplastic stenoses in 48.0% of cases and by dysplastic stenoses, aneurysms, and dissections in 66.1% of cases. RA imaging should be proposed to hypertensive patients with a cerebrovascular presentation. Cervical artery imaging should be considered in patients with a renal presentation and bilateral RA lesions.

Clinical Trial Registration: URL: www.Clinicaltrials.gov. Unique identifier: NCT02884141.
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http://dx.doi.org/10.1161/HYPERTENSIONAHA.117.09539DOI Listing
September 2017

Combined Preoperative Portal and Hepatic Vein Embolization (Biembolization) to Improve Liver Regeneration Before Major Liver Resection: A Preliminary Report.

World J Surg 2017 07;41(7):1848-1856

Department of Digestive and Hepatobiliary Surgery, Estaing Hospital, CHU Clermont-Ferrand, 1 Place Lucie et Raymond Aubrac, 63003, Clermont-Ferrand, France.

Background: Insufficient volume of the future liver remnant (FLR) is a major cause of non-resectable disease in patients presenting with primary or metastatic liver tumours. The objective of this study was to evaluate the safety and efficacy of the combined preoperative portal and hepatic vein embolization (biembolization) before extended right liver resections.

Methods: This retrospective study was performed in a tertiary centre between 2014 and 2015. Combined right portal and hepatic vein embolization (biembolization) was proposed, as an alternative to ALPPS procedure, for all patients with primary or metastatic liver tumour, before right extended hepatectomy. CT scan liver volumetry was assessed before biembolization, three weeks after biembolization and one week after surgery.

Results: Seven patients underwent biembolization. All patients had right portal vein embolization (PVE) combined with right hepatic vein embolization (HVE, n = 4), median HVE (n = 2) and right + median HVE (n = 1). Three patients had preoperative liver disease and two received preoperative chemotherapy. No biembolization procedure-related complications occurred. The mean FLR regeneration rate was 52.6% (range: 18.2-187.9) after the biembolization. One patient with gallbladder carcinoma was not operated because of peritoneal carcinomatosis diagnosed after the biembolization. The remnant six patients did not develop postoperative liver failure.

Conclusions: Biembolization seems to induce safe, reproducible and effective FLR growth before extended right hepatectomy, in patients with primary or metastatic liver tumour.
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http://dx.doi.org/10.1007/s00268-017-4016-5DOI Listing
July 2017

Validation of cadmium-zinc-telluride camera for measurement of left ventricular systolic performance.

J Nucl Cardiol 2018 06 13;25(3):1029-1036. Epub 2017 Feb 13.

Department of Radiology, CHU Gabriel Montpied, Clermont-Ferrand, France.

Background: There are paucity of data comparing measurements of left ventricular systolic performance using cadmium-zinc-telluride (CZT) semiconductor cameras with other imaging modalities. This study compared the new system with echocardiography (echo) and cardiac magnetic resonance (CMR) imaging.

Methods: 60 Patients presenting with ST-elevated myocardial infarction (MI) were included. Each patient underwent echo, myocardial perfusion imaging using Spectrum Dynamics D-SPECT(r) (CZT-SPECT), and CMR 6 weeks after MI. The primary endpoint was the agreement between CZT-SPECT and CMR for left ventricular ejection fraction (LVEF) measurement.

Results: 48 of the 60 patients underwent all 3 studies (echo, CMR, and CZT-SPECT) 40 days after admission. CZT-SPECT and CMR LVEF were well correlated (r = .79, P < .0001), as well as CZT-SPECT vs echo and CMR vs echo (r = .79 and .84, respectively, P < .0001). The segmental LV wall thickening and wall motion also showed good concordance between three techniques.

Conclusions: CZT-SPECT is reliable for LVEF measurement.
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http://dx.doi.org/10.1007/s12350-017-0816-0DOI Listing
June 2018

A new look at left ventricular remodeling definition by cardiac imaging.

Int J Cardiol 2016 Apr 3;209:17-9. Epub 2016 Feb 3.

L'UNAM Université, Angers, France; Université d'Angers, Institut MITOVASC, Laboratoire Cardioprotection, Remodelage et Thrombose, CHU d'Angers, Service de Cardiologie, Angers, France.

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http://dx.doi.org/10.1016/j.ijcard.2016.02.009DOI Listing
April 2016

Diffusion-weighted magnetic resonance enterocolonography in predicting remission after anti-TNF induction therapy in Crohn's disease.

Dig Liver Dis 2016 Mar 22;48(3):260-6. Epub 2015 Nov 22.

University Hospital Estaing, Gastroenterology Department, Clermont-Ferrand, France; UMR 1071 Inserm/Université d'Auvergne, USC-INRA 2018, Microbes, Intestine, Inflammation et Susceptibility of the Host, Clermont-Ferrand, France.

Background: Diffusion-weighted magnetic resonance entero-colonography (DW-MREC) with no rectal distension and with no bowel cleansing is accurate to assess inflammatory activity in ileocolonic Crohn's disease (CD).

Aim: To study DW-MREC parameters as predictors of remission (CDAI < 150 and CRP < 5mg/L) after anti-TNF induction therapy.

Methods: Forty consecutive CD patients were prospectively and consecutively included. All the patients underwent DW-MREC with apparent diffusion coefficient (ADC) and MaRIA calculation before starting anti-TNF. Mean ADC was defined as the mean of the segmental ADC.

Results: Twenty patients (50.0%) experienced remission at W12. Low mean ADC (2.05 ± 0.22 vs 1.89 ± 0.25, p = 0.03) and high total MaRIA (39.2 ± 16.6 vs 51.7 ± 18.2, p = 0.03) were predictive of remission at W12. Using a ROC curve, we determined a mean ADC of 1.96 as predictive cut-off of remission at W12 (AUC = 0.703 [0.535-0.872]) with sensitivity, specificity, positive predictive value and negative predictive value of 70.0%, 65.0%, 66.7% and 68.4%, respectively. In multivariate analysis, mean ADC < 1.96 (OR = 4.87, 95% CI [1.04-22.64]) and total MaRIA > 42.5 (OR = 5.11, 95% CI [1.03-25.37]), reflecting high inflammatory activity, were predictive of remission at week 12.

Conclusions: DW-MREC using quantitative parameters i.e. ADC, is useful in detecting and assessing inflammatory activity but also to predict efficacy of anti-TNF induction therapy in CD.
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http://dx.doi.org/10.1016/j.dld.2015.10.019DOI Listing
March 2016

The brain signature of paracetamol in healthy volunteers: a double-blind randomized trial.

Drug Des Devel Ther 2015 23;9:3853-62. Epub 2015 Jul 23.

CHU Gabriel Montpied, Clermont-Ferrand, Service d'Imagerie Ostéo-articulaire thoracique et neurologique, Clermont-Ferrand, France.

Background: Paracetamol's (APAP) mechanism of action suggests the implication of supraspinal structures but no neuroimaging study has been performed in humans.

Methods And Results: This randomized, double-blind, crossover, placebo-controlled trial in 17 healthy volunteers (NCT01562704) aimed to evaluate how APAP modulates pain-evoked functional magnetic resonance imaging signals. We used behavioral measures and functional magnetic resonance imaging to investigate the response to experimental thermal stimuli with APAP or placebo administration. Region-of-interest analysis revealed that activity in response to noxious stimulation diminished with APAP compared to placebo in prefrontal cortices, insula, thalami, anterior cingulate cortex, and periaqueductal gray matter.

Conclusion: These findings suggest an inhibitory effect of APAP on spinothalamic tracts leading to a decreased activation of higher structures, and a top-down influence on descending inhibition. Further binding and connectivity studies are needed to evaluate how APAP modulates pain, especially in the context of repeated administration to patients with pain.
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http://dx.doi.org/10.2147/DDDT.S81004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4517518PMC
April 2016