Afshin Gangi
Université de Strasbourg, Imagerie Interventionnelle, Faculty Member
Purpose To retrospectively evaluate the safety and efficacy of percutaneous image-guided laser photocoagulation for the treatment of spinal osteoid osteoma (OO) in proximity to neural structures. Materials and Methods This study was... more
Purpose To retrospectively evaluate the safety and efficacy of percutaneous image-guided laser photocoagulation for the treatment of spinal osteoid osteoma (OO) in proximity to neural structures. Materials and Methods This study was institutional review board-approved with waivers of informed consent. From January 1994 until October 2014, 58 patients with spinal OO (mean age, 25 years; 40 men, 17 women) were treated in one institution by using laser photocoagulation with combined computed tomographic (CT) and fluoroscopic guidance. One patient was excluded because of less than 3 months of follow-up. All patients had typical clinical and imaging findings. Clinical features, radiologic data, and procedure-related data were reviewed, and limitations, complications, and failure rate were evaluated. All data were expressed as means ± standard deviation. P values of less than .05 were indicative of statistical significance. Results OO was in the vertebral body for 18 of 57 patients, the n...
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... 187 Patients. Afshin Gangi * , JL Dietemann * , S. Guth * , JP Steib † , C. Roy *. *Department ... the cases. In 14 cases an epidural leak was observed that caused neuralgia in three cases, only without spinal cord compression. In ...
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Osteoid osteoma is a painful benign bone tumor. The curative treatment of this tumor consists of complete surgical or percutaneous excision of the nidus with immediate and dramatic relief of symptoms. Interstitial laser photocoagulation... more
Osteoid osteoma is a painful benign bone tumor. The curative treatment of this tumor consists of complete surgical or percutaneous excision of the nidus with immediate and dramatic relief of symptoms. Interstitial laser photocoagulation (ILP) is a low-invasive percutaneous technique of thermal destruction (coagulation) of deep-seated tumors elsewhere in the body, using low-power laser energy. The aim of ILP is the local destruction of osteoid osteoma without bone weakening. Twenty-two patients with osteoid osteoma were treated with percutaneous ILP of the nidus under computed tomography guidance. The laser energy was provided by a high-power semiconductor diode laser (805 nm) with a 400-&mgr;m optical fiber. Complete pain relief was obtained in 21 patients. Percutaneous ILP of osteoid osteoma seems to be a promising, simple, precise, and minimally invasive technique as an alternative to traditional surgical and percutaneous ablations.
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We propose a simple, compact, and accurate light guidance system for interventional CT. The system using intersecting laser beams is mounted on the CT gantry and ensures precise needle guidance even when the gantry is tilted. The device... more
We propose a simple, compact, and accurate light guidance system for interventional CT. The system using intersecting laser beams is mounted on the CT gantry and ensures precise needle guidance even when the gantry is tilted. The device does not require additional software/hardware. Phantom simulations and clinical experiments have demonstrated an accuracy of +/- 1 degrees and +/- 1 mm. The laser guidance system for CT makes the intervention safer, faster, and more accurate.
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We present two cases of bilateral, symmetrical pedicular clefts associated with dural ectasia in von Recklinghausen's disease (neurofibromatosis). In one case the pedicular cleft was at the T12 level, while in the other it was at L4,... more
We present two cases of bilateral, symmetrical pedicular clefts associated with dural ectasia in von Recklinghausen's disease (neurofibromatosis). In one case the pedicular cleft was at the T12 level, while in the other it was at L4, and was responsible for spondylolisthesis. Two hypotheses are advanced to explain the cleft: (1) a congenital, dysplastic osseous defect and (2) bilateral stress
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Interstitial laser photocoagulation (ILP) was performed in experimental models prior to clinical trials to determine the feasibility of bone photocoagulation using an 805-nm diode laser and to define parameters influencing lesion size and... more
Interstitial laser photocoagulation (ILP) was performed in experimental models prior to clinical trials to determine the feasibility of bone photocoagulation using an 805-nm diode laser and to define parameters influencing lesion size and shape. Laser energy was applied in continuous-wave mode at a power of 2 W to an ex vivo freshly ablated pig femur. Two hundred and eighty ILPs were performed followed by histologic examinations to determine the coagulation size with a freshly cleaved fiber tip compared to a precharred fiber tip. Another study was designed to determine the temperatures achieved in bone using ILP and to correlate them with histologic findings. Histologic examination has underestimated the coagulation size with precharred fibers that varied from 3.4 mm (200 J) to 9.2 mm (1200 J) in diameter. Thermal data were significantly different with presumed lesions of 16 mm in diameter for 1200 J energy.
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Percutaneous injection of ethanol was evaluated in terminally ill cancer patients with painful osteolytic bone metastases treated previously without success by radiation or chemotherapy and conventional pain therapy. Twenty-five patients... more
Percutaneous injection of ethanol was evaluated in terminally ill cancer patients with painful osteolytic bone metastases treated previously without success by radiation or chemotherapy and conventional pain therapy. Twenty-five patients with 27 bone metastases in various locations underwent one to three instillations of 3-25 ml ethanol (95%) under CT guidance, which allowed precise needle positioning and control of the diffusion of alcohol thus minimizing the complications. Within 24 to 48 h 74% of the cases experienced a reduction of analgesic needs. Percutaneous ethanol injection under CT guidance is useful in reducing pain and in improving the quality of life of patients with advanced stages of cancer and painful bone metastases.
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Few studies evaluated left ventricular (LV) involvement in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The aim of this study is to determine the frequency, clinical presentation, and pattern of LV involvement in... more
Few studies evaluated left ventricular (LV) involvement in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The aim of this study is to determine the frequency, clinical presentation, and pattern of LV involvement in ARVD/C (LV-ARVD/C). We retrospectively evaluated the cardiac magnetic resonance (CMR) in 202 patients referred between 2008 and 2012 to our institution, and we determined the presence or the absence of CMR criteria in the revised task force criteria 2010 for the diagnosis of ARVD/C. A total of 21 patients were diagnosed with ARVD/C according to the revised task force criteria 2010. All included patients had no previous history of myocarditis, acute coronary syndrome, or any other cardiac disease that could interfere with the interpretations of structural abnormalities. The LV involvement in ARVD/C was defined by the presence of one or more of the following criteria: LV end-diastolic volume (LVEDV; >95 mL/m(2)), LV ejection fraction (LVEF; <55%),...
Research Interests: Cardiology, Computed Tomography, Treatment Outcome, Risk assessment, Adipose tissue, and 16 moreHumans, Left Ventricular Assist Device, Female, Follow-up studies, Clinical Sciences, Adult, Public health systems and services research, Circulation, Spatial resolution, Risk Assessment, Implantable defibrillators-cardioverters, Right Ventricle, Coronary Artery Disease, Signal to Noise Ratio, Heart Ventricles, and Left Ventricle
Radiofrequency ablation is increasingly used in the treatment of hepatic tumors. Planning the percutaneous intervention is essential and particularly difficult. In this paper, we focus on an automated computation of optimal needle... more
Radiofrequency ablation is increasingly used in the treatment of hepatic tumors. Planning the percutaneous intervention is essential and particularly difficult. In this paper, we focus on an automated computation of optimal needle insertion in computer-assisted surgery with 3D visualization. First, we review our method which delineates on the skin of a virtual patient the candidate zones for needle insertion, i.e., those which allow safe access to the tumor. In each case, we look for the trajectory that minimizes the volume of burnt tissue. Secondly, we introduce a quasi-exhaustive method that allies sampling and certified minimization to form a strong argument for the accuracy of our results. We also compare results of applying both methods on 7 representative reconstructed patient cases.
Research Interests: Algorithms, Computer Aided Design, Computer assisted orthopaedic surgery, Humans, Computer Simulation, and 10 moreThree Dimensional Imaging, Virtual patients, Radiofrequency Ablation, Computer User Interface Design, Trajectory Optimization, Reproducibility of Results, Computer Aided Surgery, Catheter ablation, Computer assisted surgery, and Needles
Percutaneous radiofrequency ablation has become a frequently used technique for the treatment of liver cancers, but still remains very difficult to plan. In this paper, we propose a robust method to delineate on the skin of a 3D... more
Percutaneous radiofrequency ablation has become a frequently used technique for the treatment of liver cancers, but still remains very difficult to plan. In this paper, we propose a robust method to delineate on the skin of a 3D reconstructed patient the zones that are candidate for an insertion, because they allow a safe access to the tumor without meeting any organ, and to compute automatically within these zones an optimal trajectory minimizing the volume of necrosis covering the tumor.
Research Interests: Algorithms, Artificial Intelligence, Computer assisted orthopaedic surgery, Humans, Three Dimensional Imaging, and 9 more3-D Reconstruction, Radiofrequency Ablation, Reproducibility of Results, Catheter ablation, Liver cancer, Sensitivity and Specificity, *Radiographic Image Enhancement, Region of Interest, and Medical Image Computing
Interstitial laser photocoagulation (ILP) was performed in experimental models prior to clinical trials to determine the feasibility of bone photocoagulation using an 805-nm diode laser and to define parameters influencing lesion size and... more
Interstitial laser photocoagulation (ILP) was performed in experimental models prior to clinical trials to determine the feasibility of bone photocoagulation using an 805-nm diode laser and to define parameters influencing lesion size and shape. Laser energy was applied in continuous-wave mode at a power of 2 W to an ex vivo freshly ablated pig femur. Two hundred and eighty ILPs were performed followed by histologic examinations to determine the coagulation size with a freshly cleaved fiber tip compared to a precharred fiber tip. Another study was designed to determine the temperatures achieved in bone using ILP and to correlate them with histologic findings. Histologic examination has underestimated the coagulation size with precharred fibers that varied from 3.4 mm (200 J) to 9.2 mm (1200 J) in diameter. Thermal data were significantly different with presumed lesions of 16 mm in diameter for 1200 J energy.
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Osteoid osteoma is a painful benign bone tumor. The curative treatment of this tumor consists of complete surgical or percutaneous excision of the nidus with immediate and dramatic relief of symptoms. Interstitial laser photocoagulation... more
Osteoid osteoma is a painful benign bone tumor. The curative treatment of this tumor consists of complete surgical or percutaneous excision of the nidus with immediate and dramatic relief of symptoms. Interstitial laser photocoagulation (ILP) is a low-invasive percutaneous technique of thermal destruction (coagulation) of deep-seated tumors elsewhere in the body, using low-power laser energy. The aim of ILP is the local destruction of osteoid osteoma without bone weakening. Twenty-two patients with osteoid osteoma were treated with percutaneous ILP of the nidus under computed tomography guidance. The laser energy was provided by a high-power semiconductor diode laser (805 nm) with a 400-&mgr;m optical fiber. Complete pain relief was obtained in 21 patients. Percutaneous ILP of osteoid osteoma seems to be a promising, simple, precise, and minimally invasive technique as an alternative to traditional surgical and percutaneous ablations.
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Spinal osteoid osteomas are rare; when they occur, they are usually treated by surgical or percutaneous excision. The aim of percutaneous interstitial laser photocoagulation (ILP) of osteoid osteomas under CT guidance is thermal... more
Spinal osteoid osteomas are rare; when they occur, they are usually treated by surgical or percutaneous excision. The aim of percutaneous interstitial laser photocoagulation (ILP) of osteoid osteomas under CT guidance is thermal destruction of the nidus using low-power laser energy, thus precluding bone resection and open surgery. Three cases of spinal osteoid osteomas were treated with percutaneous ILP of the nidus. Under CT guidance, the needle was positioned in the center of the nidus, at least 8 mm from neurologic structures. Using a high-power semiconductor diode laser (805 nm) with a 400-microm optical fiber, we delivered 600 to 800 joules to the nidus, depending on its size. The procedure was performed with the patient under neuroleptanalgesia and required overnight hospitalization. Complete pain relief was obtained in all three patients within 24 hours of the procedure, and no major complications were incurred. Follow-up ranged from 20 months to 60 months. Percutaneous ILP o...
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Laser energy is able to ablate, coagulate, and vaporize tissues. Its transmissibility in thin optical fibers makes it an ideal tool for use in percutaneous procedures. This article describes two applications in interventional... more
Laser energy is able to ablate, coagulate, and vaporize tissues. Its transmissibility in thin optical fibers makes it an ideal tool for use in percutaneous procedures. This article describes two applications in interventional musculoskeletal radiology. In percutaneous laser disc decompression the laser source is used to vaporize a small portion of the nucleus pulposus. In interstitial laser photocoagulation of osteoid osteoma the laser energy is used to coagulate and destroy the tumor by direct heating.
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Décrire les différentes techniques d’infiltrations rachidiennes sous contrôle TDM. Les différentes approches (position du patient, voies d’abord, préformation des aiguilles d’infiltration) sont détaillées. Les divers produits localement... more
Décrire les différentes techniques d’infiltrations rachidiennes sous contrôle TDM. Les différentes approches (position du patient, voies d’abord, préformation des aiguilles d’infiltration) sont détaillées. Les divers produits localement injectés sont évalués (corticoïdes, sérum salé, anesthésiques locaux de longue durée, analgésiques).RésuméLes sciatiques, cruralgies, névralgies intercostales, névralgies cervico-brachiales, névralgies d’Arnold peuvent bénéficier d’infiltrations péri-radiculaires en divers endroits du trajet de la racine incriminée. Les lombalgies, dorsalgies, cervicalgies peuvent également constituer des indications d’infiltrations ciblées sous contrôle TDM.Conclusion Les infiltrations rachidiennes sont des techniques pouvant donner des résultats satisfaisants dans diverses situations cliniques. L’utilisation de certaines approches atypiques ou de diverses substances permet encore d’améliorer ces résultats. Leurs réalisations sous contrôle TDM apportent une sécurité...
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Femoral neck fracture jeopardizes the vital prognosis of the elderly subject and the functional prognosis of the young subject. The vascular consequence is important, with the risk of osteonecrosis of the femoral head. In young patients,... more
Femoral neck fracture jeopardizes the vital prognosis of the elderly subject and the functional prognosis of the young subject. The vascular consequence is important, with the risk of osteonecrosis of the femoral head. In young patients, predicting the risk of necrosis at the acute stage seems warranted so as to optimize the choice of therapy. CT with injection could be useful to study the residual bone vascularity after an acute fracture of the femoral neck. The CT scan with injection can diagnose ischemia of the femoral head after neck fracture by demonstrating hypoperfusion and thus estimating the risk for osteonecrosis. A CT scan with injection was performed prospectively in 20 adult patients who had given informed consent after verification of the inclusion and exclusion criteria. Ten presented femoral neck fracture and 10 a pertrochanteric fracture, the latter making up the control group. The second control group was the healthy side of patients presenting a femoral neck fract...
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Décrire les différentes techniques de ponctions médiastinales en développant les artifices techniques permettant d’améliorer la faisabilité et la sécurité de ces procédures.Les lésions médiastinales sont souvent jugées difficilement... more
Décrire les différentes techniques de ponctions médiastinales en développant les artifices techniques permettant d’améliorer la faisabilité et la sécurité de ces procédures.Les lésions médiastinales sont souvent jugées difficilement accessibles. Les abords sont délicats, souvent génés par l’interposition d’obstacles anatomiques ou par la proximité immédiate des structures sensibles. Différents abords peuvent être utilisés (sus-sternal, trans-sternal, sous-xyphoïdien, para-sternal, para-vertébral). Certains artifices techniques permettent d’éviter les obstacles potentiels (position atypique du patient, utilisation de sa respiration, injection d’air ou de sérum physiologique, utilisation de sangles).La quasi totalité des masses médiastinales est accessible par voie percutanée en évitant les structures nobles et les obstacles anatomiques.Les ponctions du médiastin peuvent se réaliser dans des conditions de sécurité optimale sous guidage tomodensitométrique en utilisant différents artifices. Ces techniques apportent une alternative efficace, sûre et mini-invasive à la médiastinoscopie.
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... Afshin Gangi, Xavier Buy, Farah Irani, Stéphane Guth, Ali Guermazi, Jean-Pierre Imbert, and Jean-Louis Dietemann ... A. Guermazi, MD, Associate Professor of Radiology Department of Radiology, Chief Section of Musculoskel-etal, Boston... more
... Afshin Gangi, Xavier Buy, Farah Irani, Stéphane Guth, Ali Guermazi, Jean-Pierre Imbert, and Jean-Louis Dietemann ... A. Guermazi, MD, Associate Professor of Radiology Department of Radiology, Chief Section of Musculoskel-etal, Boston University School of Medicine, 88 East ...
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Low back pain is a common problem with an important socio-economical impact. It is defined as chronic after 7–12 weeks of non-response to conservative therapies. Its estimated prevalence is 15% in adults, rising to 44% in the elderly... more
Low back pain is a common problem with an important socio-economical impact. It is defined as chronic after 7–12 weeks of non-response to conservative therapies. Its estimated prevalence is 15% in adults, rising to 44% in the elderly (Jacobs et al. 2006). Unlike radicular pain where a cause of nerve root compression is often found, the precise etiology of back
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Image-guided tumor management is a minimally invasive treatment for localized bone tumors. Compared to other modalities, minimally invasive procedures require fewer resources, less time, recovery, and cost, and often reduced morbidity and... more
Image-guided tumor management is a minimally invasive treatment for localized bone tumors. Compared to other modalities, minimally invasive procedures require fewer resources, less time, recovery, and cost, and often reduced morbidity and mortality. Many percutaneous techniques are available. Some aim to treat pain and consolidate bone, i.e. cementoplasty. Others ablate or reduce the tumor, i.e. chemical and thermal ablation techniques.
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Patients treated for hematological malignancies almost always suffer from pain and disability late in the course of their disease. Over the past few years, imaging-guided percutaneous procedures have become useful for providing short, and... more
Patients treated for hematological malignancies almost always suffer from pain and disability late in the course of their disease. Over the past few years, imaging-guided percutaneous procedures have become useful for providing short, and sometimes long-term, pain relief, as well as bone strengthening. Patient selection is essential to the success of these techniques. Thus, the interventional radiologist should play an active central role in minimally invasive management of pain in patients treated for hematological malignancies, and should be part of an interdisciplinary team that determines the appropriate therapy (Gangi et al. 1998). Indeed, the choice between a therapeutic percutaneous procedure and alternative methods of treatment depends on several factors: the location of the lesion, the local and general extent of the disease, the pain and functional disability experienced by the patient, and the patient’s state of health and life expectancy (Cotten et al. 1999). In this chapter, we will primarily, and most importantly, focus on the cementoplasty technique and give secondarily some details about ethanol injection in bone osteolytic lesions.
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T1 mapping is now a clinically feasible method, providing pixel-wise quantification of the cardiac structure's T1 values. Beyond focal lesions, well depicted by late gadolinium enhancement sequences, it has become possible to... more
T1 mapping is now a clinically feasible method, providing pixel-wise quantification of the cardiac structure's T1 values. Beyond focal lesions, well depicted by late gadolinium enhancement sequences, it has become possible to discriminate diffuse myocardial alterations, previously not assessable by noninvasive means. The strength of this method includes the high reproducibility and immediate clinical applicability, even without the use of contrast media injection (native or pre-contrast T1). The two most important determinants of native T1 augmentation are (1) edema related to tissue water increase (recent infarction or inflammation) and (2) interstitial space increase related to fibrosis (infarction scar, cardiomyopathy) or to amyloidosis. Conversely, lipid (Anderson-Fabry) or iron overload diseases are responsible for T1 reduction. In this pictorial review, the main features provided by native T1 mapping are discussed and illustrated, with a special focus on the awaited clinic...
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Bone biopsy is a safe and cost-effective technique, which can be preformed on an outpatient basis under local anesthesia and conscious sedation with minimal complications.
Évaluer la cyphoplastie avec injection de CPC pour traiter les fractures vertébrales traumatiques stables du sujet jeune.Nous avons traité 16 vertèbres chez 15 patients âgés de 15 à 51 ans (moyenne 33 ans) présentant une fracture... more
Évaluer la cyphoplastie avec injection de CPC pour traiter les fractures vertébrales traumatiques stables du sujet jeune.Nous avons traité 16 vertèbres chez 15 patients âgés de 15 à 51 ans (moyenne 33 ans) présentant une fracture traumatique de type Al de la classification de Magerl, portant sur les niveaux Th8 (3), Th11 (1), TH12 (5), Ll (7). La procédure a été réalisée après réduction orthopédique et immobilisation par corset plâtré dans un délai inférieur à 10 jours suivant le traumatisme. Nous avons utilisé le système KyphX® (6 cas) ou le système SkyExpander® (10 cas), puis injecté du CPC. Le soulagement des douleurs et la hauteur vertébrale ont été évalués au cours du suivi.La création d’une cavité intravertébrale a toujours permis l’injection de CPC. Tous les patients ont présenté une réduction significative des douleurs et ont pu enlever leur corset 48 heures après la procédure. La hauteur vertébrale mesurée lors du suivi est restée identique à celle mesurée après réduction orthopédique.La cyphoplastie avec injection de CPC constitue un traitement antalgique et stabilisateur efficace des fractures traumatiques stables du sujet jeune. La restauration de la hauteur vertébrale est inconstante.