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.

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.

[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.

[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.

[Procedures in critical ischemia of the legs in non-emergency situations]. / Conduite à tenir dans les ischémies critiques des membres inférieurs en dehors de l'urgence.

Our experience with 91 operated cases in 84 patients (47 men, 37 women) relates essentially to arterial diseases resulting from overloading and diabetic arteriopathy. Diagnosis of critical ischemia is easy in clinical conditions, but it is advisable to rely on universally recognized hemodynamic standards to define this condition. Ankle pressure should be less than 400 mmHg and the Doppler trace flat or barely perceptible. Patients in our series had a mean ankle pressure of 32.4 mmHg. Local examination can determine the extent of gangrene, whereas general examination detects numerous, often associated defects diabetes, coronary artery disease, rhythm disorders, arterial hypertension, etc. As far as possible, these defects are to be corrected before surgery. X-ray examination (M. Kasbarian) is frequently done in conjunction with conventional aorto-arteriography and digital angiography. The later technique allows arteries to be visualized which are not seen with the conventional technique. The x-ray examination will indicate whether revascularization is feasible, although it cannot show whether it will be efficient. In our series, opacification of the plantar arches was predictive neither of success nor failure. But do tests exist which can predict the success of a revascularization attempt? It would be necessary to be able to estimate ankle pressure after the operation, and several methods have tried to do this. TcPO2 would seem to be a good examination. The possibilities of nuclear magnetic resonance are being studied, and the results thus far are promising. Preoperative explorations are carried out in a different situation. Arteriography performed in the operating room is a simple act which can reveal a usable downstream bed not indicated in preoperative X-rays, although it provides no hemodynamic data. Measurement of peripheral resistances would appear to be a very good predictive examination. Flow measurements by infusion or electronic flowmeter also seem to be predictive for bypass results. Unfortunately, these measurements are at present not widely performed and the critical threshold is assessed differently. Given the difficulty of correctly estimating the value of these numerous methods, many surgeons, ourselves included, have chosen to revascularize patients whenever the upstream bed as evaluated by X-ray indicates the presence of at least one viable artery.

[Uterine cervix cancers: staging by magnetic resonance imaging]. / Cancers du col utérin: stadification par imagerie par résonance magnétique.

The accuracy of Magnetic Resonance Imaging in cervical carcinoma staging for clinical stages superior to IB was studied retrospectively in 27 patients. The MRI results were then correlated with operative findings in 12 cases and with examination carried out under general anesthesia in 15 cases for myometrial, bladder, rectal, parametrial, parietal and vaginal extension. The accuracy of MRI was 81.5% for bladder, 92.5% for rectal, 87% for parametrial and 73% for vaginal extension. The accuracy of staging by MRI was 59%. The contribution of MRI in pre-operative studies for cervical carcinomas has not been properly defined until now. Nevertheless it is a particularly valuable technique due to its non invasive nature.

[Preoperative staging of central bronchopulmonary cancer. X-ray CT-MRI-pulmonary digital subtraction angiography and surgery]. / Bilan pré-opératoire des cancers broncho-pulmonaires centraux. Corrélations TDM-IRM--angiographie pulmonaire numérisée et chirurgie.

In order to evaluate the reliability of medical imaging methods in the assessment of mediastinal invasion by lung cancers, a prospective study was conducted in 30 patients undergoing preoperative computed tomography (CT), magnetic resonance imaging (MRI) and pulmonary digital subtraction angiography. MRI improved the sensitivity of detection of surgically confirmed mediastinal lymphadenopathy, but its specificity in relation to histological results was poor and identical to that of CT. In terms of extension to vascular structures, MRI and CT gave comparable results for the pulmonary artery and vein with two false positives for the pulmonary veins and left atrium with the two methods. MRI was found to be superior to CT for the detection of invasion of the aortic arch. Digital subtraction angiography is not as reliable as the other two modalities, particularly for extension to the pulmonary vein for which it was found to be technically inappropriate. By means of sagittal and frontal scans, MRI was therefore found to be more effective than CT for examination of the subcarinal region and aorto-pulmonary window. In contrast, the persistence of false positives with the two methods and the impossibility of distinguishing between inflammatory lymph nodes and neoplastic lymph nodes means that thoracotomy can never be contraindicated on the basis of the results of imaging alone.

[Diagnosis of gynecologic diseases]. / Diagnostic des affections gynécologiques.

Transabdominal ultrasonography has long been a fist-line examination to explore most of the pelvic diseases. Transvaginal sonography is a simple procedure giving an accurate and reliable diagnosis. These two techniques complement each other and can usefully be performed concomitantly. Computed tomography should be reserved to the extension assessment and follow-up uterine and ovarian tumours. Magnetic resonance imaging is a non invasive technique providing for a three-dimensional, very high quality study of the female pelvis. Its main value resides in the exploration of gynaecological tumours, where it gives a reliable assessment of local and regional extension. These various imaging techniques, therefore, have a definite, non competitive role to play in the exploration of gynaecological diseases. They are the necessary complements of physical examination and endoscopic methods.