Serial anatomy of the larynx in MRI: MRI-histologic correlations.

The larynx is an organ with a complex anatomic structure. MRI allows the performance of sections in the three planes of space, so that this study of the soft parts of the larynx yields results superior to those of other imaging techniques. Together with laryngoscopy, MRI is most often used in assessing the extension of malignant laryngeal tumors. This assessment is fundamental in choosing the indications for surgery, but the published reports of MRI of the larynx are sometimes discordant. The visualization of certain important anatomic structures such as the conus elasticus is uncertain. Our aim was to study the MRI radio-anatomy of the larynx based on correlations between MRI and histologic sections. Eight anatomic specimens were studied: four in the transverse plane, two in the sagittal plane, and two in the frontal plane. The MRI and histologic sections made at the same levels were compared. These comparisons allowed a description of the sectional radio-anatomy of the larynx and an assessment of the reliability and limitations of MRI. All the major anatomic structures could be identified. It was possible to demonstrate the conus elasticus. We were able to visualize the vocal process of the arytenoid cartilage, which has not to our knowledge been previously described in the literature.

[Differential diagnosis of infective spondylodiscitis and erosive degenerative disk disease]. / Diagnostic différentiel entre spondylodiscite infectieuse et discopathie dégénérative erosive.

PURPOSE: To assess the value of imaging in the differential diagnosis of erosive intervertebral osteochondrosis (EIVO) versus infectious discitis (ID). MATERIALS AND METHODS: Twelve cases of EIVO and 30 cases of ID were reviewed to define the usefull signs for differential diagnosis on plain films, CT, and MR. RESULTS: No single sign is sufficient, but the association of several signs is suggestive of EIVO: discal vacuum phenomenom, well-defined sclerosis and erosions of vertebral endplates, high signal strip surrounding low signal of vertebral endplates on T1-weighted images. CONCLUSION: Imaging is helpful in difficult differential diagnosis of EIVO versus ID.

Anteroposterior atlantoaxial subluxation in cervical spine osteoarthritis: case reports and review of the literature.

Nontraumatic anteroposterior atlantoaxial subluxation (AAS) has been described in several rheumatic or inherited disorders, especially rheumatoid arthritis and to a lesser extent the inflammatory spondyloarthropathies. We describe AAS secondary to osteoarthritis (OA) of the cervical spine in a 76-year-old man and a 73-year-old woman with severe cervical OA, symptomatic C1-C2 facet joints, and signs of generalized OA. Only 6 similar cases exist in the literature. OA should be added to the causes of AAS, and conversely AAS should be assessed in cases with severe OA of the upper cervical spine.

The intravertebral vacuum phenomenon ("vertebral osteonecrosis"). Migration of intradiscal gas in a fractured vertebral body?

STUDY DESIGN: Retrospective cohort. OBJECTIVES: To compare the prevalence of the association between contiguous intervertebral disc and vertebral collapses with or without an intravertebral vacuum phenomenon. SUMMARY OF BACKGROUND DATA: The mechanism of occasional gas accumulation within some vertebral collapses is poorly known. The current hypothesis is that this phenomenon is indicative of bone ischemia. In fact, avascular necrosis as the main pathologic event remains speculative, and should not explain per se the presence of gas within a vertebral body. METHODS: Comparison of the prevalence of intervertebral disc vacuum phenomenon adjacent to the affected vertebral body in 23 cases of intravertebral vacuum phenomenon in 19 patients (intravertebral vacuum phenomenon group) and in 708 osteoporotic collapses without intravertebral vacuum phenomenon in 199 patients (control group). RESULTS: There were no differences in sex and age between the two groups, and all the patients in the intravertebral vacuum phenomenon group had signs of underlying osteoporosis. A vacuum phenomenon in at least one intervertebral disc adjacent to the collapses on radiographs, conventional tomography, computed tomography, or magnetic resonance imaging was found in 19 cases (83%) in the intravertebral vacuum phenomenon group, compared with 13% in the control group (P < 0.0001). Considering plain radiographs only, this association was found in 50% of the intravertebral vacuum phenomenon group and in 9.7% of the control group (P < 0.0001). The intervertebral and intravertebral gaseous collections were connected through a fractured endplate in six cases. CONCLUSIONS: The high prevalence of the association of contiguous intervertebral and intravertebral vacuum phenomenon could have implications in the pathogenesis of the intravertebral vacuum phenomenon. We hypothesize that the intravertebral vacuum phenomenon could simply be the result of migration of an intradiscal-gaseous collection through the fractured endplate of some osteoporotic collapses.

Type A dissection of the thoracic aorta: use of MR imaging for long-term follow-up.

PURPOSE: To evaluate routine magnetic resonance (MR) imaging for long-term follow-up in patients who undergo surgery for type A aortic dissection. MATERIALS AND METHODS: Ninety-two MR examinations were performed in 36 patients. Standard spin-echo images were obtained with electrocardiographic gating (n = 92) and rapid images with a fast low-angle shot sequence and intravenous administration of gadopentetate dimeglumine (n = 25). All segments of the native thoracic aorta were evaluated. Anastomoses of the prosthesis and periprosthetic hematoma were carefully analyzed. RESULTS: Of 22 complications that occurred in 18 patients, 18 were diagnosed at MR imaging (nine false aneurysms and nine aneurysms distal to the graft). Nine patients underwent reoperation. The findings at MR imaging correlated with those at surgery. CONCLUSION: Routine follow-up with MR imaging should improve long-term survival in patients who survive emergency surgical repair of type A aortic dissection.

Handling information and knowledge in the FORUM hypermedia authoring system: application to uterine magnetic resonance imaging.

Hypertext and hypermedia are used to access loosely structured information. The lack of conceptual model for hypertext application makes it difficult to represent the mental model of the author. Users are often lost in the information and the objective of the author is not achieved. In this paper, we describe an approach to handle information and knowledge in the FORUM hypermedia authoring system. It allows the author to create and maintain the hypertext more easily and facilitates the navigation of the reader. An application for learning uterine magnetic resonance imaging is also presented.

Intervertebral disk vacuum phenomenon secondary to vertebral collapse: prevalence and significance.

PURPOSE: To evaluate the prevalence of the intervertebral vacuum phenomenon in disks adjacent to vertebral collapses of various causes. MATERIALS AND METHODS: The authors retrospectively studied 310 consecutive patients who had at least one vertebral collapse. The vacuum phenomena were divided into collapse-related (ie, adjacent to a collapse) and degenerative (ie, not associated with a vertebral fracture) ones. Plain radiography was performed in all patients, and, in addition, conventional tomography, computed tomography, and/or magnetic resonance imaging was performed in 175 patients. RESULTS: Collapse-related vacuum phenomena were seen in 15% of patients with plain radiography and in 21% when all of the imaging modalities were considered. They occurred in association with all of the causes of collapse (ie, osteoporosis, multiple myeloma, metastasis, acute trauma, and vertebral osteomyelitis), although the prevalence was lower in association with metastasis or trauma (P = .008). The occurrence of collapse-related vacuum phenomenon was correlated with age (P = .001) and with the coexistence of degenerative disk-related vacuum phenomenon in the same patient (P = .0002). CONCLUSION: Occurrence of a vacuum cleft in disks adjacent to a vertebral collapse is common and appears as the second cause of vacuum phenomenon after degenerative disk disease.

Early-stage avascular necrosis of the femoral head: MR imaging for prognosis in 31 cases with at least 2 years of follow-up.

Thirty-one cases of stage 1 or 2 osteonecrosis (ON) of the hip in 27 patients were studied with T1-weighted coronal magnetic resonance (MR) imaging. Three quantitative parameters were measured on the contiguous MR sections, corresponding to the 2-cm-wide median portion of the femoral head: the angle filled by ON (alpha), the percentage of weight-bearing femoral cortex involved with ON (WB), and the percentage of femoral head surface involved with ON. The clinical and radiologic courses were assessed after at least 2 years of follow-up (mean, 46 months). Core decompression was performed in 12 cases of ON. Values were strikingly lower in the group with good clinical or radiologic outcome versus poor outcome, with very little overlapping. WB was the more reliable parameter. Outcome of hips treated with versus without core decompression appeared closely related with these MR parameters and not with the treatment procedure. Thus, a quantitative approach to determination of extent and location of the lesion on the initial MR image appears accurate for use in the prediction of long-term outcome of ON. Effectiveness of core decompression should be reevaluated on this basis.

[Extrapleural hematoma]. / Hématome extra-pleural.

The authors report a case of a voluminous extra-pleural hematoma in relation to a fracture of the body of the eleventh thoracic vertebra on a 74 year-old man after craniothoracic injury. Thoracic CT Scan showed a homogeneous posterior parietal mass of tissue density (40 HU) outlined by a fatty lining associated with a fracture of the eleventh thoracic vertebra. This allowed a modification in the diagnosis of a hemothorax established previously on conventional radiography. The authors insist on the gravity of this affection when the volume of the hematoma is important. But this is very rare (6 cases out of which 5 were autopsic findings). If present it requise an urgent surgical treatment without forgetting the fiability of CT Scan which relies on putting into evidence the pleural lining sign.

[Aspects and role of spinal MRI in the assessment of solitary plasmacytoma and multiple myeloma. Apropos of 11 cases]. / Aspects et rôle de l'irm du rachis au cours de l'exploration du plasmocytome solitaire et du myélome multiple. A propos de 11 observations.

Spinal MRI was performed in 9 multiple myeloma and 2 solitary plasmacytoma, using sagittal, T 1-weighted (TR: 350-550 ms/TE: 15-26 ms) and T 2-weighted (TR: 2,000-2,500 ms/TE: 60-120 ms) sequences, with additional gadolinium injection in 3 cases. MRI features were the following: 1) round, patchy lesions with low T 1 signal highlighted by gadolinium and bright T 2 signal were present in 10 of the 11 patients: all osteolytic lesions seen on plain X-rays corresponded to such lesions and biopsy performed in 4 cases showed massive marrow replacement by plasma cells. 2) overall marrow signal was dramatically decreased in 3 patients (2 of whom had a high tumoral mass). 3) extra-dural compression was present in 4 cases. 4) 25 vertebral compression fractures (10 of whom with a "benign" appearance) and focal fat deposition were seen. 5) postradiation treatment examination seemed predictive of the outcome in the 2 solitary plasmacytomas. MRI proved to be more sensitive than plain X-rays or bone scintigraphy. Number and size of focal tumor-like lesions did not correlate with the low marrow signal appearance. Both correlated poorly with overall tumoral mass but diffuse abnormalities were associated with rapidly fatal outcome in three cases. These features might reflect qualitative rather than quantitative patterns of the disease (nodular or diffuse macroscopic marrow replacement). These findings are in agreement with those of the few previous studies. MRI is valuable for spinal cord damage assessment. It appears less accurate in benign versus malignant vertebral compression fracture determination than it does in bone metastasis. Its prognostic value is still questionable.

[Ioversol 300 and iopamidol 300 in "whole body" computed tomography. A double-blind clinical trial]. / Ioversol 300 et iopamidol 300 en tomodensitométrie "corps-entier". Essai clinique en double insu.

The authors compared ioversol 300 to iopamidol 300 by double blind study in patients undergoing enhanced computed body tomography. There was no significant difference in clinical tolerance and efficacy between the two products. Only minor reactions were recorded in both groups. Contrast media were not considered to be responsible for the poor diagnostic quality of a few explorations. Ioversol 300 appears as a well tolerated and effective contrast medium for computed body tomography.

Embolization of an intraparotid false aneurysm of the external carotid artery: case report.

A case of posttraumatic false aneurysm of the terminal part of the main external carotid artery involving the entire parotid gland is presented. Embolization with two microcoils allowed immediate thrombosis of the false aneurysm. The lumen of the external carotid artery remained open. Facial paralysis resolved. The atypical clinical presentation and the therapeutic steps in such a case are described.

[Pelvic venous thrombosis and abnormality of the post-renal inferior vena cava]. / Thrombose veineuse pelvienne et anomalie de la veine cave inférieure sous-rénale.

After angiography, a 17 year-old male patient presented a pseudo appendicular syndrome. After two poorly contributive surgical explorations, CT and MR Imaging showed atresia of the infra-renal vena cava, with pelvic thrombophlebitis extending to the gonadal and lumbar collateral circulation.

[MRI in osteoporotic and metastatic vertebral compressions: apropos of 60 cases]. / L'IRM au cours des tassements vertébraux ostéoporotiques et métastatiques: a propos de soixante cas.

Magnetic resonance imaging (MRI) was performed in 60 patients with vertebral compression fractures caused by either bone metastasis (BM) or osteoporosis (OP). In the BM group (20 patients, 62 BM with 22 compression fractures), the signal was decreased on T1-weighted images in all cases and was usually increased on T2 sequences, in the whole vertebral body or in patchy areas. The vertebral body showed a diffuse posterior bulging in 85% of patients; malignant infiltration often involved pedicles, posterior arch or soft tissues. In the OP group (40 patients, 160 vertebral fractures): a significant recession of one of the corners of the vertebral body, different from metastatic bulging, was observed in 37% of patients; the spinal cord signal depended on the stage: during the first 4 months, the signal was low on T1 and high on T2 sequences, with a characteristic band disposition, which may involve most of the vertebral body even in mild fractures; the modifications extended to the pedicles in 5 cases; after 6 months, the signal was normal. MRI specificity was 92% between malignant versus benign compression fractures. MRI had a better sensitivity than bone scan for depicting vertebral BM. In OP, MRI signal modifications disappeared several months before increased uptake of technetium. This study emphasizes the value of MRI for the diagnosis of osteoporotic versus metastatic vertebral compression fractures when morphological and chronological parameters are added to the signal intensity analysis.

[Periprosthetic false aneurysm after Bentall's operation: diagnosis with magnetic resonance imaging]. / Faux anévrysme péri-prothétique après intervention de Bentall: diagnostic par imagerie par résonance magnétique.

Periprosthetic false aneurysm due to dehiscence of a suture line represents a serious postoperative complications after Bentall's procedure, because of its asymptomatic presentation and spontaneous course towards progressive increase in size with high risk of sudden rupture. This type of complication justifies systematic radiologic follow-up. Magnetic Resonance Imaging, as proved by our two cases, is a reliable technique in the diagnosis of this complication requiring reoperation.

The normal uterus on magnetic resonance imaging and variations associated with the hormonal state.

Magnetic Resonance Imaging of the pelvis has lead to a new radioanatomical description of the uterus. Variations in the anatomical zones of the uterus were noted with different sequences used in MRI. There was also structural and signal variation depending on hormonal impregnation. Twenty seven MRIs of pelvices were carried out on 16 female volunteers. Eight of them were on oestroprogesterone as the method of contraception (Group I) and had a single MRI. Six were not taking contraceptives (Group II) and had different MRI's during the same cycle. Two women already had already gone through the menopause (Group III). Results showed differences in the size of the uterus (uterine height, length of the uterine body and cervix, diameter of the cervix) between groups I and II but no cyclic changes were observed within group II. The myometrium was found to be thicker in group I and in the luteal phase of group II females in comparison to the follicular phase in the same group. The endometrial cavity was seen in 40% of cases on T1 weighted sequences; on T2 weighted sequences it was seen in all the cases. It was thicker during the second phase in group II than in group I and III. The myometrial signal compared to that of the bladder content (urine) showed a significant increase between early and late echoes on T2 weighted sequences in group I and during the second phase of the menstrual cycle in group II. No variations, or at times a decrease in signal, were observed during the first phase of the cycle in group II.(ABSTRACT TRUNCATED AT 250 WORDS)

PIP: 16 healthy 20-71 year old women underwent magnetic resonance imaging (MRI) in Marseille, France so the radiologists could better understand the anatomy of the uterus under various hormonal states. Group I included 8 women who were taking oral contraceptives (OCs) and underwent only 1 MRI. Group II were 6 women who did not take OCs and underwent 2-4 MRIs during 2 phases of the same menstrual cycle. Group III included 2 postmenopausal women. Uterine height, cervix diameter, and uterine body length were greater in group II than group I (76.9 mm vs. 80 mm; 25.6 mm vs. 28.3 mm; and 49.1 mm vs. 46.25 mm respectively). Cervix length was greater in group I than group II (30.6 mm vs. 29.7 mm). The radiologists did not notice any cyclic changes within group II. The myometrium was thicker in group I (16.9 mm) and in the luteal phase of group II (15.8 mm) compared to the follicular phase of group II (13.75 mm). T2 weighted sequences revealed the endometrial cavity of all cases, but T1 weighted sequences revealed the cavity in 40% of cases. The endometrial cavity was thicker in group II women (6.5 mm [1st phase] and 9.9 mm [2nd phase]) than either group I (2.4 mm) or group II (1 mm) women. T2 weighted sequences in group I and during the 2nd phase of the menstrual cycle in group II showed a great increase in the myometrial signal compared to bladder content between early and late echoes. Further only T2 weighted sequences uncovered the junctional zone. The junctional zone was thickest during the 1st phase of the cycle of group II women than during the 2nd phase. T2 weighted sequence could only reveal the junctional zone in only 1 woman in group III. Knowing the zonal anatomy of the uterus and its changes is helpful in diagnosing adenomyosis, myometrial extension of endometrial carcinomas, extension of cervical carcinomas.

[Hepatic tuberculosis after Hodgkin's disease. Echographic and x-ray computed tomographic aspects. A case report]. / Tuberculose hépatique après maladie de Hodgkin. Aspects échographiques et tomodensitométriques. A propos d'un cas.

The authors report a case of hepatic tuberculosis on a pre-existing Hodgkin disease with hepatic localisations. They point out how echographic and CT imaging are non specific in this disease and so insist on the diagnostic interest of puncture-biopsy under guidance of the hepatic nodules.