[Helical CT of abdominal aorta]. / Angioscanner hélicoïdal de l'aorte abdominale.

The purpose was to illustrate that single or multirow spiral CT angiography has become the main modality for the examination of the abdominal aorta. Our multidisciplinary group investigates weekly 15 abdominal aortas, with a single slice spiral CT since 1995, and a 4 row detector spiral CT since 1999. CT scans protocols and parameters optimization for the 2 CT systems are described. Indications and results of CT to investigate the various abdominal aortic diseases are illustrated and discussed: aneurisms (pretherapeutic staging, selection of indications of endovascular stent-grafting); obstructive aorto-arteriopathies (pretherapeutic staging, follow up after endovascular revascularization); dissection (diagnosis, pretherapeutic staging, follow up); inflammatory diseases; normal patterns and principal complications after surgery. Situations where multislice CT is superior to single slice CT and compared advantages of MRI are discussed. CT is at the present time the main technique to image abdominal aorta. Multislice CT is especially interesting to explore the whole aorta, poly traumatisms, and to plan and follow up endovascular treatments.

Effects of tiludronate on bone loss in paraplegic patients.

Immobilization secondary to spinal cord injury is associated with a marked and rapid atrophy of trabecular bone (disuse osteoporosis). This is due to an early increase of osteoclastic bone resorption associated with a pronounced decreased osteoblastic bone formation. Bisphosphonates are antiosteoclastic compounds and they have been effective in preventing disuse osteoporosis. However, some of them also depress osteoblastic activity and may impair the mineralization process. Tiludronate was shown effective in reducing bone resorption in several metabolic bone diseases without inducing mineralization defects. Twenty paraplegic patients (6 females and 14 males) were randomly assigned to three groups: 6 patients entered the placebo group; 7 patients received tiludronate 200 mg/day; and 7 received 400 mg/day. Histomorphometric analysis was performed on transiliac bone biopsies before and after 3 months treatment. An insignificant decrease of bone volume was observed in the placebo group and the 200 mg group. In patients receiving 400 mg/day, a slight increase was noted. Osteoid parameters changed nonsignificantly in three groups although the 400 mg group exhibited a slight tendency to decrease osteoid volume and thickness. Eroded surfaces increased in all groups. The number of osteoclasts (identified histochemically by TRAP staining) increased in the placebo group but decreased in groups receiving tiludronate. Tiludronate appears effective in reducing bone resorption without impairing bone formation in a manner that preserved bone mass and bone cell coupling.

Superoxide release from interleukin-1B-stimulated human vascular cells: in situ electrochemical measurement.

Release of superoxide anion by cultured vascular cells was investigated with the use of selective microelectrodes. Local concentration of superoxide anion (O2*-) was followed by differential pulse amperometry on a carbon microfiber at 0.1 V/SCE. The oxidation current allows O2*- detection in the 10(-8) M concentration range without interference of the other major oxygen species. Interleukin-1beta-stimulated O2*- release that progressively increased to reach local concentrations at the cell membrane level of 76 +/- 11 nm 40-60 min after stimulation in human cord vein endothelial cells, and 131 +/- 18 nm 1-2 h after stimulation in internal mammary artery smooth muscle cells. In the two types of cells, the O2*- oxidation signal was suppressed in the presence of superoxide dismutase. Spontaneous O2*-release from unstimulated cells was undetectable. These results demonstrate that selective microelectrodes allow direct and real-time monitoring of local O2*- released from vascular endothelial as well as from smooth muscle cells submitted to an inflammatory stimulus.

Endovascular Doppler guide wire in renal arteries. Correlation with angiography in 20 patients.

RATIONALE AND OBJECTIVES: To evaluate the feasibility of endovascular Doppler recording in renal arteries and to compare the reliability of Doppler parameters for detection of renal artery stenosis. METHODS: The authors examined 36 renal arteries in 20 patients with a 0.018" endovascular flow wire. Peak systolic velocity and the renal artery-to-aortic peak were measured in the main renal artery. From intrarenal waveforms, acceleration, acceleration time, and the renal resistive index were obtained. Spectral analysis with consensus scoring of early systolic peak was also performed. RESULTS: Twelve significantly stenosed renal arteries and 26 normal renal arteries were examined with the Doppler guide wire, without complications. Peak systolic velocity was the only parameter significantly different in renal artery stenosis (P = 0.037). Peak systolic velocity also differed significantly between hypertensive and normotensive patients. Tardus parvus was specific for severe renal artery stenosis. CONCLUSIONS: Endovascular Doppler is a safe and accurate method for the determination of velocity measurements and may be useful during percutaneous renal artery revascularization.

Nitric oxide production by endothelial cells: comparison of three methods of quantification.

Vascular endothelial cells have been found to produce a relaxant mediator, identified as nitric oxide (NO) and implicated in numerous physiological functions. Subsequently, there has been an intensive search for accurate and specific detection methods to measure biological NO production. In the present study, we compared three approaches to evaluate NO production, based respectively on the Griess reaction (that quantifies nitrites and nitrates after their reduction), on the hemoglobin reaction (that quantifies oxyhemoglobin to methemoglobin transformation by NO), and on the electrochemical NO detection with a porphyrinic micro-probe. Comparison was made both under standard conditions and biological conditions, through calibration curves and measurements of histamine-induced NO production by cultured human endothelial cells and its modulation by L-arginine and N(omega)-monomethyl-L-arginine. We demonstrated that these three methods differ in terms of sensitivity and selectivity. The hemoglobin reaction and nitrate measurements suffer from a lack of specificity. Nitrite determination by the Griess reaction was hardly suitable for kinetic studies but it remains useful for the evaluation of basal NO production. The electrochemical technique, although it does not allow measurement of basal NO production, is the only one to exhibit great sensitivity and specificity and to allow instantaneous and non destructive measurements. This study brings up the potential hazards and pitfalls that may be associated with the various methods.

[Value of abdominal-pelvic computed tomography in adult rheumatoid purpura]. / Apport de la tomodensitométrie abdominopelvienne dans le purpura rhumatoïde de l'adulte.

PURPOSE: Henoch-Schonlein purpura is a rare eventuality in adulthood. Abdominal involvement can worsen the short-term prognosis and justify medical treatment to avoid surgery. METHODS: Abdominopelvic computed tomography (CT) was performed in six adult patients (four men and two women; age range, 19-74 years) with Henoch-Schonlein purpura before any treatment. Abdominal symptoms were concomitant with the purpuric rash in two cases and followed it in the other cases. RESULTS: The small bowel was always involved with a parietal thickening, and the target sign was observed in three patients. The lesions were located in the duodenum in two patients, the jejunum in two and the ileum in five. Two segments were involved in one patient and three segments in another patient. A peritoneal effusion was always present. No colonic lesion was discovered on CT. Once the results were known, all patients received steroids with initially intravenous methylprednisolone in five patients at doses ranging from 80 to 1,000 mg/day. On follow-up, none of the patients underwent surgery. CONCLUSION: Abdominopelvic CT scan demonstrated signs suggestive of intestinal vasculitis. An underlying neoplasia or an eventual other cause of abdominal pain were explored and a steroid therapy was then began with a good outcome. Abdominal CT can be helpful in the diagnosis of abdominal involvement in Henoch-Schonlein purpura.

[Idiopathic epiphoras in adults treated with lacrymal-nasal stents]. / Traitement des épiphoras idiopathiques de l'adulte par stent lacrymo-nasal.

Fluoroscopic nonsurgical placement of an expandable polyurethane stent is less invasive than surgery for the treatment of epiphora due to obstruction of the nasolacrimal duct. It needs to be performed with the collaboration of an ophthalmologist, using a high resolution digital subtraction imaging unit.

[Chronic hematic cyst of the orbit (orbital subperiosteal hematoma)]. / Kyste hémorragique chronique de l'orbite (hématome sous-périosté orbitaire).

A case of chronic hematic cyst of the orbit which caused unilateral globe displacement with painful diplopia is described in a 72-year-old man. CT scans showed an extraconal soft tissue mass located between the orbital roof and the superior rectus muscle with a bone lysis. Characteristic appearance on MRI (benign signs, subperiosteal localization of the hematoma) has been confirmed by removal surgery. Chronic hematic cyst of the orbit is uncommon and MRI is helpful to establish this diagnostic.

[CT dacryography without selective lacrimal duct catheterization: review of 39 patients]. / Dacryoscanner par instillation sans cathétérisme des voies lacrymales: 39 patients.

OBJECTIVES: Dacryographies and CT dacryographies are usually performed after catheterization of a lacrimal canaliculus. We evaluated the quality of opacification on CT scan after simple instillation of contrast medium, without any catheterization. PATIENTS AND METHODS: 39 patients (78 nasolacrimal ducts) were examined for lacrimal pathways obstruction by CT scan after instillation of diluted contrast medium. Additional CT scan imaging was performed after catheterization when the first study did not provide adequate opacification. RESULTS: CT dacryography after instillation is a well tolerated technique. In our study, it allowed detection of all pathologic lacrimal ducts; 7 normal lacrimal pathways (after catheterization) were not opacified after instillation (false positives). The sensitivity of the method was 100%, its specificity 84%. CONCLUSION: CT dacryography after instillation is a physiologic, simple and sensitive method to evaluate lacrimal obstruction. We propose it as a first step, catheterization being used only in the absence of opacification after instillation.

[Cost efficiency study of lacrimal canal obstruction treatment]. / Etude coût-efficacité du traitement de l'obstruction du canal lacrymal.

OBJECTIVE: To compare three methods used to clear the lacrimal canal. PATIENTS AND METHODS: A total of 32 files (20 for the dacryocysto-rhinostomy by endoscopic way, 5 for the dacryocysto-rhinostomy by external way and 7 cases of percutaneous stenting) were reviewed. For each, costs of performed interventions were reviewed. An average of the total cost per patient was calculated for all three methods and was then correlated to the initial efficiency of the method. RESULTS: Results show that the average cost for stenting is up to 1,366.80 EUR, for the endoscopic way is up to 2 001.53 EUR and for the external way is up to 2,220.46 EUR. ANOVA (Analysis of Variance) gives significant results when comparing stent to endoscopic way (p=0.000007) and to the external way (p =0.02). The analysis of sensitivity concerning the success rate of various treatments shows that the stent was potentially the most cost-effective and that a failure rate of 35.1% is rather acceptable by comparison to the endoscopic method. If the stent is considered as an outpatient intervention, then, a failure rate of 50% is acceptable. CONCLUSION: If the failure rate stays under 35.1%, the stent may be considered as a short-term cost-effective method.

[Radio-anatomic study of the angle of origin of dysplastic renal arteries]. / Etude radio-anatomique de l'angle d'origine des artères rénales dysplasiques.

PURPOSE: To compare the angulation at the origin of dysplastic renal arteries compared to atherosclerotic renal arteries, in order to improve the technique for percutaneous transluminal angioplasty of FMD. MATERIALS AND METHODS: Retrospective analysis of 40 aortograms in patients who underwent renal angioplasty for dysplastic stenosis, with comparison with 45 control aortograms (with or without atherosclerotic lesions of the renal arteries). The angle of implantation of the renal arteries was measured relative to the aortic axis in the frontal plane, taking into account only the angulation of its proximal segment. We identified three types of kidneys with regard to their position relative to the renal artery ostium. RESULTS: The angle of implantation of dysplastic renal arteries is significantly sharper compared with the control group (63.8 degrees vs 80.9 degrees, p = 0.0001), irrespective of the side. The angulation did not correlate with the position of the kidney or the direction of the renal artery, suggesting a congenital origin. CONCLUSION: The angle of implantation of the dysplastic renal arteries relative to the aortic axis in the frontal plane is sharper than the angle measured in non dysplastic renal arteries.

[Comparative assessment of helical CT-angiography, 2D TOF MR-angiography and 3D gadolinium enhanced MRA in aorto-iliac occlusive disease]. / Evaluation comparative de l'angio-TDM spiralée, de l'angio-IRM 2D temps de vol et 3d gadolinium en pathologie athéromateuse aorto-iliaque.

PURPOSE: To compare helical CT-angiography (CTA) and two techniques of MR angiography (MRA) to conventional angiography in aorto-iliac occlusive disease. MATERIALS AND METHODS: The abdominal aorta and iliac arteries in 22 patients (4 for preoperative assessment of abdominal aortic aneurysm and 18 for peripheral vascular disease) were imaged using four techniques: digital subtraction angiography ("gold standard"), 2D TOF MR angiography, 3D Gd-enhanced MR angiography and helical CT angiography. Source (CTA and 2D TOF MRA) and MIPed images (after subtraction measures before and after gadolinium injection for 3D Gd-MRA) were reviewed. RESULTS: Sensitivity, specificity and accuracy for the detection of significant (>50%) stenosis and occlusion of aorto-iliac arteries were respectively: 38%, 89%, 77% for 2D TOF MRA; 75%, 71%, 72% for 3D Gd-MRA and 95%, 90%, 92% for CTA. Excluding the internal iliac arteries, results were 54%, 96%, 88% for 2D TOF MRA; 96%, 80%, 83% for 3D Gd-MRA and 92%, 93%, 95% for CTA. CONCLUSION: 3D Gd-MRA, a technique with potential for further improvement, is superior to 2D TOF MRA for detecting significant stenosis and occlusion of aorto-iliac arteries. Results at Gd-MRA are nearly similar to those at CTA (after excluding internal iliac arteries). Results at Gd-MRA are not affected by calcified plaque.

[Pituitary gland MRI and Cushing disease: report of 14 operated patients]. / IRM hypophysaire et maladie de Cushing: à propos de 14 patients opérés.

PURPOSE: Evaluate the MR sensibility for detection and localisation of ACTH-secreting microadenomas of the pituitary gland. PATIENTS: and method. The MRI studies of the pituitary gland, performed before transsphenoidal surgical exploration, about 14 patients who present clinical and biological signs of Cushing disease, were reviewed retrospectively. We have always used unenhanced sagittal and coronal spin-echo T1 sequences, and coronal T1 after injection of gadolinium (1 Tesla). RESULTS: The global sensibility for detection of an adenoma was 100% (84 to 92% when the lesional localisation was considered). The injection of gadolinium increased the sensibility of 38 to 42% according the readers. 7 to 14% of the lesions were isointense after injection. The estimation of lesional size after injection was the nearer to the surgical results. The indirect sign most frequently seen (35.7 to 64.3%) was focal bulging of the sellar diaphragm. The only differences between the different radiologists, statistically significant, concerned the lesional size before injection and location of the lesion in the sagittal plane. CONCLUSION: This study confirmed the good sensibility of contrast-enhanced MRI in detection of ACTH-secreting microadenomas. The anatomo-radiological correlations are nevertheless incomplete.

[Aneurysm of the duodeno-pancreatic arcades. Diagnostic imagery and therapeutic indications]. / Anévrysmes des arcades duodéno-pancréatiques. Imagerie diagnostique et indications thérapeutiques actuelles.

BACKGROUND: Aneurysms of the duodenopancreatic arcades account for 2 to 3% of all aneurysms of the digestive arteries. Mortality is high due to the risk of rupture and the difficult diagnostic situation. CASE REPORTS: The first case involved a short wide collar aneurysm implanted on the first centimeter of the superior mesenteric artery, associated with tight stenosis of the celiac trunk. The patient complained of diffuse abdominal pain and was treated surgically. In the second case, there was a false aneurysm of the gastroduodenal artery which developed a few months after acute biliary pancreatitis. The aneurysm was treated by exclusion using a transcutaneously delivered endovascular coil prosthesis. CONCLUSION: These cases illustrate the importance of imaging (magnetic resonance angiography) both for diagnosis and treatment monitoring, allowing early care with very limited morbidity and mortality.

[CT and MRI features of a pseudo adrenal lesion: subcardial diverticulum]. / Aspects TDM et IRM d'une pseudo lésion surrénalienne: le diverticule sous-cardial.

Gastric diverticula are rare. The retroperitoneal site of subcardial diverticula may be suggestive of a left adrenal mass on CT and MR. The authors report two cases. Radiological demonstration of a communication with the stomach confirms the diagnosis.