Biomedical subjects
Publications and source records attributed to P Champsaur.
Interrogation of patients still painful after lumbar intervertebral disk surgery provides with a series of informations each of them having only an indicative value, while they altogether compound a score helping assess the presence or the absence of a recurring disk herniation.
The discovery of an image of central bone calcification raises the differential diagnosis of bone infarction and chondroma. The matrix of chondroma is characteristic of cartilage. It produces typical cartilaginous calcifications: rings, arcs, coarse, irregular grains, moth-eaten appearance. These calcifications are predominantly observed in the centre of the image. They are situated in a bone defect, often multilocular, sometimes accompanied by multiple scratch marks of the cortical endosteum. In contrast, infarction is characterized by the presence of a serpiginous calcified border at the interface between live bone and dead bone. In the centre, the bony trabeculae are still visible on CT sections, in contrast with chondroma. On MRI, chondromas present a heterogeneous lobular appearance on T2-weighted sequences (checkerboard appearance) due to alternating zones of high signal intensity cartilaginous matrix and low signal intensity calcified or ossified fibrous septa. On MRI, bone infarction is characterized by a continuous peripheral line with a marked low signal intensity.
Painful hip with normal X-rays (including false-lateral view of both hips) is the main indication for hip arthrography, searching for focal chondropathy. In the presence of moderate hip degenerative arthritis contrasting with increasing disability, a labrum lesion must be investigated. Such lesions are of two kinds, mainly degenerative (of the superior labrum) or post-traumatic (of the posterior labrum). Arthrography allows the diagnosis of cystic changes located in the acetabulum. It also allows the diagnosis and evaluation of the extent of synovial osteochondromatosis or villonodular synovitis. In three indications, computed tomographies must be added to plain arthrography: posterior labrum lesions, osteochondromatosis (looking for foreign bodies in the acetabular fossa) and cystic changes in the acetabulum (with density measurements). In all cases, a complete conventional radiological assessment must be available. Strict asepsis must be ensured. When osteochondromatosis is suspected, evaluation of articular capacity must be systematic.
Stress fractures of the tibia may disclose a longitudinal orientation which is obvious at bone scanning; a mild periostosis may appear on plain films; CT demonstrates a radially-oriented fracture in one aspect of the diaphyseal cortex. A cortical dissection-like vertically oriented insufficiency fracture may involve the medial aspect of the femoral shaft underlying the lesser trochanter; the fracture is concentric to the femoral cortex at CT. Insufficiency fractures of the sacrum may be misdiagnosed on plain films; bone scanning displays a typical H-shaped increased uptake which is a specific pattern. Insufficiency fractures of the pubis may appear as tumoral bone destruction; however no soft tissue mass is present at CT which in addition demonstrates normal fat tissue abutting the osseous lesion.
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Myositis ossificans circumscripta (MOC) is a benign proliferation of fibrous tissue with large amounts of bone within soft tissues. Its clinical and radiological course is described and the value of CT and MR imaging is emphasized. Differential diagnosis includes soft tissue hematoma, infection or tumor. Florid reactive periostitis of the phalanges, turret exostosis, bizarre periosteal osteochondromatous proliferation in the hand and fibro-osseous pseudotumor of the digits are also described.
Calcific deposit within soft tissues is frequently a clue for diagnosis. The radiological analysis of a calcific deposit within soft tissues includes the following aspects: the basic structure of the calcification, the grade of differentiation of the calcification, the site of the calcification, the number of calcific deposits, the shape of the calcification, the changes in the adjacent non-calcified soft tissues and in the adjacent bone, the course of the clinical signs, the course of the radiological abnormalities.
Sarcoma of the common pulmonary artery are rare malignant tumors which can mimic pulmonary embolism. In the case presented here, the inaugural signs were particularly misleading: multiple pulmonary lacunae on computed tomography. The unusual aspect and asymmetric localizations at pulmonary angiography then suggested the doubtful nature of the embolism etiology. Magnetic resonance imaging findings suggested the diagnosis of sarcoma of the pulmonary artery. Certain diagnosis was obtained at pathology examination of the surgical specimen after thoracotomy. A malignant fibrous histiocytoma was identified. Curative resection was not possible and chemotherapy was performed. Unusual parenchymal lesions were then evidenced on the radiography. Better and better magnetic resonance imaging criteria are described in the literature and help distinguish between thromboembolism and sarcoma of the pulmonary artery. Follow-up of the clinical course is thus improved. It is nevertheless necessary to evaluate intravascular extension to determine whether curative surgery is possible.
Unilateral spondylolytic spondylolisthesis may cause lateral tilt of the overlying spinous processes towards the normal isthmus on PA views. Bilateral spondylolytic spondylolisthesis is generally located at the L5-S1 level. The vertebral shift is usually moderate. Instability at the level of spondylolisthesis may be demonstrated by stress lateral views but is uneasy to quantify. In case of sciatica associated to spondylolisthesis, foraminal stenosis is probably the most frequent cause but foraminal compression of the spinal ganglion is difficult to assess on imaging.
26-Gauge fine needle for lumbar puncture allows lower rate and intensity of post lumbar puncture syndrome. This technique drammatically decreases discomfort in patients who undergo myelography and helps in keeping this imaging modality indicated when necessary.
Lumbar foraminal injection under fluoroscopic guidance is indicated either for a diagnostic purpose to determine which nerve root is painful or for a selective steroid injection. Lumbar foraminal approach is based on that of the posterolateral extradural diskography. Selective puncture of the first sacral foramen under fluoroscopic guidance may be indicated for the treatment of sacral symptomatic meningeal cysts, a very unfrequent lesion.
This is a review article on fibrous dysplasia of bone. All aspects of this condition including, macroscopic and histologic findings, lesion distribution, clinical, radiological and biological findings as well as evolution and treatment are discussed. A classification of skeletal lesions based on then appearance on plains films and computed tomography is proposed; 3 radiological types are differentiated: non-expanding bone lesions, expanding lesions with a thick periosteal reaction and expanding lesions with a thin periosteal shell. Main features of osteofibrous dysplasia are also discussed.
There are two types of labrum acetabulare lesions. The first, posterior in the labrum, must be evocated when hip pain occurs secondary after slight traumatisms. The second, much more frequent, superior in the labrum, is responsible for important hip pain contrasting with slight X-ray abnormalities of the pelvis, except for frequent acetabular dysplasia. Not only arthrography, but also coronal arthro-tomography and CT-arthrography are necessary for the diagnosis of labrum acetabulare lesions.
Knee puncture for arthrography via a lateral parapatellar approach is described. Direct puncture of the femorotibial space, via a ventral approach, is more painful and should only be used when the lateral parapatellar route is not possible, namely in case of complete suprapatellar plica.
During a transjugular intrahepatic portosystemic shunt (TIPS) procedure, a Strecker stent was accidently pushed into the superior mesenteric vein. After successful shunt placement, the stent was withdrawn into the hepatic vein. A multipurpose basket catheter was attached to the distal end of the stent and a loop snare to the proximal end. In this way it was possible to stretch the stent and retrieve it percutaneously through the jugular sheath.
We describe a case in which a transjugular intrahepatic portosystemic shunt (TIPS) was inserted to enable palliative treatment of an adenocarcinoma of the esophagus. The cirrhotic patient presented with esophageal varices in contact with a tumor of the esophagus. By relieving portal pressure, TIPS reduced the risk of hemorrhage during laser resection and prevented recurrence of esophageal varices.
UNLABELLED: The imaging anatomy of the paranasal sinuses presents some complexity. The paranasal sinuses develop within facial and cranial bones. They communicate with one another and with the nasal cavity. Knowledge of normal anatomy is mandatory for accurate diagnosis of sinonasal pathology. The most frequent anatomical variants should be identified to decrease surgical risks. CT is the main imaging modality for the evaluation of sinonasal pathology. LEARNING OBJECTIVES: to review the normal sinonasal anatomy and its frequent anatomical variants at CT imaging.