Biomedical subjects

Jean-Denis Laredo

Publications and source records attributed to Jean-Denis Laredo.

16 recordsLinked to original sources

PubMed2006

Bone metastases from head and neck paragangliomas: uncommon MR findings in an uncommon condition--report of three cases.

Malignancy (defined as metastatic disease) has been reported in nearly 5% of head and neck paragangliomas. Metastases preferentially target the lymph nodes, lung, liver, or bone. We describe three patients with multiple silent bone metastases exhibiting a fatty halo at MRI that coexisted with expansive bone lesions. In all cases, (123)I-metaiodobenzylguanidine ((123)MIBG) scintigraphy showed no abnormal tracer uptake, whereas (111)In-pentetreotide scintigraphy visualized a few silent bone metastases. These findings indicate that MRI should be included in the staging of paraganglioma patients with risk factors for malignancy.

3-Iodobenzylguanidine↗

PubMed2005

Bone involvement in Erdheim-Chester disease: imaging findings including periostitis and partial epiphyseal involvement.

PURPOSE: To retrospectively review the bone findings at radiography, scintigraphy, computed tomography (CT), and magnetic resonance (MR) imaging in 11 patients with immunohistochemical and histologic proof of Erdheim-Chester disease. MATERIALS AND METHODS: This study was designed as a retrospective review; approval of the institutional review board and patient consent were not required for this type of study. Eleven patients (eight men and three women; mean age, 49 years; range, 17-68 years) with Erdheim-Chester disease underwent conventional radiography of the skeleton and bone scintigraphy. Two patients underwent CT of the femora and 10 underwent CT of the skull. Eight patients underwent MR imaging. Conventional radiographs, bone scintigrams, CT scans, and MR images were reviewed in consensus by four musculoskeletal radiologists. RESULTS: All 11 patients had involvement of the long bones and normal axial skeleton, hands, and feet. Bilateral and symmetric osteosclerosis of the diaphysis of the long bones was present in 52 (26 pairs) (98%) of the 53 bone lesions visible on conventional radiographs. Osteosclerosis was heterogeneous in 65% of the patients and homogeneous in 35%. Diaphysis was involved in 100% and metaphysis in 44 (83%) lesions. Partial epiphyseal involvement sparing the subchondral bone was present in 24 (45%) lesions. Periostitis was seen in 35 (66%) and endosteitis in 50 (94%) of the 53 long bones involved. Bone scintigraphy depicted tracer uptake in all bone lesions visible on radiographs. Skull and face bone lesions were present in two patients. MR imaging depicted a replacement of the normal fatty bone marrow by heterogeneous signal intensity on T1- and T2-weighted spin-echo images. Lesion extent, epiphyseal involvement, and periostitis were clearly depicted at MR imaging. CONCLUSION: This series provides a detailed description of bone involvement in Erdheim-Chester disease. Periostitis and partial epiphyseal involvement of the long bones are also features of this disease. (c) RSNA, 2005.

Adolescent↗

PubMed2005

Contribution of helical computed tomography to the evaluation of early hip osteoarthritis: a study in 18 patients.

OBJECTIVES: To show that helical computed tomography arthrograms (HCTA) with multiplanar reformations can document cartilage lesions and their characteristics in patients with suspected hip osteoarthritis and normal or inconclusive hip radiographs. METHODS: We retrospectively reviewed abnormal HCTAs from patients with mechanical hip pain and normal findings on anteroposterior and oblique ("faux profil") radiographs of the pelvis. HCTA in all patients consisted in acquiring 1 mm transverse slices and obtaining coronal and sagittal reformations. Radiographs and HCTAs were read separately by two experienced radiologists, who then worked together to reach a consensus. RESULTS: We identified 18 patients with abnormal HCTA findings and a full set of imaging studies. Mean age was 47.8 years, and there were 14 women and four men. Acetabular cartilage lesions were found consistently; they were often deep and predominated in the anterosuperior region. A labral fissure was noted in 12 patients. The sagittal and coronal reformations proved more informative than the acquired transverse slices. Interobserver reproducibility was excellent for the HCTA diagnosis of cartilage lesions. CONCLUSIONS: In patients with hip pain and normal radiographs, HCTA can provide a diagnosis of hip osteoarthritis by showing cartilage lesions, which are usually located in the anterosuperior part of the acetabulum.

Adult↗

PubMed2005

Complications of percutaneous vertebroplasty and their prevention.

Vertebroplasty is an efficient treatment of vertebral collapses of malignant or benign origin but also carries a risk of complications. Cement extravasation is a frequent occurrence in vertebroplasty. It is well tolerated in the large majority of cases but is also the main source of complications especially nerve root compression in case of cement leakage into the intervertebral foramen and pulmonary embolism of cement complicating venous cement leakage. Rate of these complications are much higher in malignant than in osteoporotic collapses. The risk of neurological complication also increases at the cervical level. In addition, incidence of new vertebral fractures in adjacent vertebrae may be increased by vertebroplasty. General reactions possibly due to a reflex reaction to intramedullary bone injection and fat embolism may also occur. This article reviews the safety measures to reduce the risk of cement extravasation including high quality permanent radiological guidance enabling early detection of cement extravasation, use of conscious sedation, bilateral transpedicular approach at the thoracic and lumbar levels, careful selection of the bone penetration site in order to make a single vertebral needle path, careful needle placement to avoid the risk of cortical breakthrough, use of a well-opacified and refrigerated cement with a toothpaste consistency.

Adult↗

PubMed2004

Aneurysmal bone cysts in children: complications of fibrosing agent injection.

PURPOSE: To report complications of direct fibrosing agent injection in the treatment of aneurysmal bone cysts (ABCs) in children. MATERIALS AND METHODS: The authors retrospectively analyzed all cases of ABCs treated with direct fibrosing agent injection (Ethibloc; Ethnor Laboratories, Ethicon, Noderstedt, Germany) at Robert Debré Hospital since 1994. Histologic diagnosis was assigned by means of surgical biopsy findings prior to treatment. Treatment responses were categorized. Injection was administered with general anesthesia, computed tomographic guidance, and use of a 14- to 16-gauge needle. Contrast material was injected to determine presence of intracystic septa and verify absence of venous opacification. Amount of fibrosing agent injected corresponded to amount of contrast material necessary to fully opacify the cyst. Intraosseous needle track was obliterated with histoacryl injection. RESULTS: Fifteen patients were treated. Mean follow-up was 80 months; no patient was lost to follow-up. One patient experienced pulmonary embolus that necessitated a 7-day intensive care unit stay. Four patients experienced early aseptic fistulization after the first injection, which led to surgical débridement and curettage. Five patients had transient inflammatory reaction with mild 38 degrees C fever, which was controlled with analgesic and antiinflammatory drugs. Eleven patients did not require surgery, and results at latest follow-up were considered to indicate complete healing (type 1 results) in nine and incomplete healing (type 2 results) in two. For type 1 results: Six patients received one injection, two received two injections, and one received three injections. For type 2 results: one patient received one injection, and one received three injections. CONCLUSION: A high rate of major local and general complications was encountered with use of direct fibrosing agent injection; the technique has been abandoned for treatment of ABCs.

Adolescent↗

PubMed2004

End plate marrow changes in the asymptomatic lumbosacral spine: frequency, distribution and correlation with age and degenerative changes.

PURPOSE: To investigate the frequency and distribution of end plate marrow signal intensity changes in an asymptomatic population and to correlate these findings with patient age and degenerative findings in the spine. MATERIALS AND METHODS: MR imaging studies of the lumbosacral (LS) spine in 59 asymptomatic subjects were retrospectively reviewed by 2 musculoskeletal radiologists to determine the presence and location of fat-like and edema-like marrow signal changes about the end plates of the L1-2 through L5-S1 levels. The presence of degenerative changes in the spine was recorded as was patient age. Descriptive statistics were utilized to determine the frequency and associations of end plate findings and degenerative changes in the spine. Interobserver variability was determined by a kappa score. Binomial probability was used to predict the prevalence of the end plate changes in a similar subject population. The Fisher exact test was performed to determine statistical significance of the relationship of end plate changes with degenerative changes in the spine, superior versus inferior location about the disc and age of the patient population. RESULTS: Focal fat-like signal intensity adjacent to the vertebral end-plate was noted in 15 out of 59 subjects by both readers, and involved 38 and 36 out of 590 end plates by readers 1 and 2, respectively. Focal edema-like signal intensity adjacent to the vertebral end plate was noted in 8 out of 59 subjects by both readers and involved 11 and 10 out of 590 end plates by readers 1 and 2, respectively. Either fat or edema signal intensity occurred most often at the anterior ( p<.05) aspects of the mid-lumbar spine and was seen in an older sub-population of the study ( p<.05). CONCLUSION: End plate marrow signal intensity changes are present in the lumbar spine of some asymptomatic subjects with a characteristic location along the spine and in vertebral end plates.

Adult↗

PubMed2004

Cortical bone in the human femoral neck: three-dimensional appearance and porosity using synchrotron radiation.

UNLABELLED: A high-resolution CT system using synchrotron radiation allowed visualization of the 3D cortical bone microarchitecture and measurement of intracortical porosity of femoral neck cortical bone specimens from 19 female cadavers imaged at 10.13-microm resolution. 3D reconstruction of specimens showed osteonal system arrangement. Mean porosity was 15.88%. This technique will provide insights into the mechanisms involved in osteoporotic hip fractures. INTRODUCTION: The purpose of this study was to show that a high-resolution CT system using synchrotron radiation (SR) allows visualization of the 3D cortical bone microarchitecture of the human femoral neck and quantification of intracortical porosity. MATERIALS AND METHODS: Bone specimens from the inferior femoral neck were obtained from 19 female cadavers with no hip fracture (mean, 86.9 +/- 8.3 years). The specimens, consisting of embedded approximately 7 x 7 x 12-mm cortical bone parallelepipeds, were imaged using SR at 10.13-microm resolution. Commercial software was used to visualize both the 660 x 660 x 660-voxel volumes and the 2D axial slices through each volume. Qualitative examination of 2D axial slices focused on the appearance of the vessel canal system, presence of small bright zones (fully mineralized tissue) in the osseous matrix, and presence of cracks. A method was developed to automatically measure 3D intracortical porosity after separating pure bone from pores and cortical bone from trabecular bone. RESULTS AND CONCLUSIONS: 3D reconstruction of the specimens showed the entire structure and arrangement of the osteonal systems, parallel to the axis of the femoral neck. Bright zones were seen in the outer cortex. No cracks were observed. Porosity values varied widely from 4.96% to 38.87% (mean, 15.88 +/- 9.87%). This study establishes that SR microtomography can be used to display the 3D bone microstructure of the human femoral neck cortex and to quantify intracortical porosity. This technique will provide insights into the mechanisms involved in cortical bone loss and osteoporotic hip fractures.

Aged↗

PubMed2002

[Hip anatomy and imagery].

Since the advent of new imaging methods (CT, MRI), plain radiographs still play a central role in the evaluation of the non-traumatic painful hip. In rheumatologic practice, standing antero-posterior views of the pelvis, bilateral antero-posterior views of the hips and bilateral lateral view of Lequesne should be performed. This first radiographic evaluation can be completed by a CT arthrogram in the first stage of osteoarthritis or by MRI in synovitis and epiphyseal disorders involving the femoral head (osteonecrosis, transient osteoporosis, subchondral fracture). The physician must be aware of the performance of each imaging in order to use the appropriate radiological exam in each situation.

Decision Making↗

PubMed1999

Percutaneous Biopsy of Primary Soft Tissue Tumors.

This article reviews the technique, results, and complications of percutaneous biopsies of soft tissue tumors. Biopsy of soft tissue tumors may be achieved either with fine needles or core-biopsy needles. The choice between the two biopsy techniques ultimately depends on the experience of the radiologist and pathologist. Since an inadequate technique may severely affect final treatment, the biopsy track should be discussed with the surgeon responsible for future management each time a primary tumor is suspected.

Journal Article↗

PubMed1997

Percutaneous Biopsy of Musculoskeletal Lesions.

Percutaneous biopsy is a minimally invasive technique that yields a high diagnostic accuracy at a relatively low cost in musculoskeletal lesions, especially tumors and infection. In this article, technical refinements improving the results of percutaneous biopsy of musculoskeletal lesions are reviewed, especially the type of radiological guidance, the different biopsy needles available, and the technique of approach depending on the lesion site. Reported complications, results, and indications of musculoskeletal percutaneous biopsy are also discussed.

Journal Article↗

PubMed1997

Percutaneous Biopsy of the Synovial Membrane.

Techniques of percutaneous synovial biopsy under fluoroscopic control of large joints of the limbs (other than the knee) may be useful in arthritis of undetermined etiology especially when infection is considered. Main technical refinements include adequate selection of an optimal approach and biopsy site using new imaging methods, use of a Tru-Cut(R) needle, and placement of the cutting window tangential to the joint surface, and selection of an optimal approach and biopsy site. Detailed technique of the synovial biopsy of hip, ankle, shoulder, and elbow joints is discussed.

Journal Article↗

PubMed1997

Lumbar Chymopapain Chemonucleolysis.

Lumbar chemonucleolysis is an alternative treatment of the sciatic pain due to a disc herniation. It gives good results in 70 to 80% of selected patients. When a correct technique is used, the complication rate is lesser than that of the open surgery. The indications of lumbar chemonucleolysis are larger than in the past and include lateral disc herniations, large or migrated disc herniations, and patients under 18 years or over 60 years. Further studies are necessary to determine if magnetic resonance imaging helps in patients selection and improve the success rate of chemonucleolysis.

Journal Article↗

PubMed1997

Steroid Injection of the Appendicular Skeleton and Sacroiliac Joints.

Steroid joint injections may be effective in painful joints due to degenerative disease and posttraumatic changes, as well as rheumatoid arthritis and seronegative spondylarthropathy. Fluoroscopic guidance may be necessary for deep (sacroiliac, hip, and shoulder) or small (wrist, hand, and foot) joints. Detailed technique of the steroid injection is given, especially for the sacroiliac joint.

Journal Article↗

PubMed1997

Distension Arthrography in Frozen Shoulder Syndrome.

Distension arthrography under fluoroscopic control may be useful in frozen shoulder syndrome. The technique consists of an intra-articular injection of 2 to 3 mL of contrast material, 3 mL of 2% lidocaine, 1.5 mL of cortivazol, and distension of the joint capsule with 30 to 40 mL of refrigerated sterile saline solution. This injection is immediately followed by a physiotherapy program. The authors report their experience of distension arthography in 30 shoulders. Results were good to very good in 90% of cases at 40-day follow-up. No recurrence of a frozen shoulder syndrome was observed and no complications were encountered in this series.

Journal Article↗

PubMed1997

Percutaneous Resection of Osteoid Osteomas.

Osteoid osteomas in almost all locations may be treated by percutaneous resection under CT scan guidance. The authors give their own experience with a series of 30 cases. The different techniques of percutaneous resection reported in the literature are reviewed. Advantages of the percutaneous resection are compared to those of classical surgery and other percutaneous techniques such as lesion destruction with thermocoagulation, photocoagulation, and intralesional injection of alcohol.

Journal Article↗

PubMed1997

Aspiration of Tendinous Calcific Deposits.

Needle aspiration of tendinous calcific deposits under fluoroscopic control may be a valuable tool in selected cases of painful shoulders with chronic and debilitating pain resistant to medical treatment. This article reviews the technique and results of this treatment. The aims of this procedure are (1) to evacuate a maximum amount of calcium; (2) to fragment the residual calcific deposits to facilitate its resorption during the following weeks; (3) to reduce the inflammation secondary to the presence and migration of residual calcific deposits by in situ injection of corticosteroids. Good results are obtained in 61Ð74% of cases. Surgical treatment should be restricted to failures of needle aspiration.

Journal Article↗