[Persistent sciatic artery: findings using spiral-CT]. / Artère sciatique persistante: aspect en TDM hélicoïdale.

Persistent sciatic artery (PSA), a rare anatomical anomaly, results from lack of regression of the embryonic dorsal axial artery combined with a poorly developed superficial femoral artery. The authors report the case of a 68-year old man presenting with subacute ischemia of the right lower limb. Arteriography showed complete bilateral persistent sciatic arteries. CT scan with 3D reconstructions was helpful to demonstrate the PSA descending along the back of the thigh and to exclude an aneurysmal complication.

Carotid arterial stenosis: evaluation at CT angiography with the volume-rendering technique.

PURPOSE: To determine whether computed tomographic (CT) angiography with the volume-rendering technique (VRT) can be used to accurately quantify carotid arterial stenosis and to identify occlusions. MATERIALS AND METHODS: Spiral CT was performed in 23 patients who were referred for carotid stenosis evaluation. VRT images and shaded-surface display (SSD) images of 46 carotid arterial bifurcations were compared with findings from digital subtraction angiography (DSA). RESULTS: Agreement on stenosis category between VRT CT angiography and DSA was found in 39 (85%) of the 46 carotid arteries studied. VRT CT angiography was 92% (49 of 53) sensitive and 96% (82 of 85) specific for the detection of grade 2-3 stenoses (> or = 70% stenosis). Agreement on stenosis category between SSD CT angiography and DSA was found in 38 (83%) of the 46 carotid arteries studied. SSD CT angiography was 91% (48 of 53) sensitive and 93% (79 of 85) specific for the detection of grade 2-3 stenoses. Calcified stenoses were correctly graded at VRT CT angiography in 10 of the 10 cases with heavy mural calcified plaques, while eight of the 10 stenoses were accurately quantified at SSD CT angiography. CONCLUSION: These results indicate that VRT CT angiography is as accurate as SSD CT angiography in the evaluation of carotid arterial bifurcations.

Right nonrecurrent inferior laryngeal nerve and arteria lusoria: the diagnostic and therapeutic implications of an anatomic anomaly. Review of 17 cases.

The authors report 17 cases of a right non-recurrent inferior laryngeal n. (NRILN) observed during 15 years of practice of thyroid and parathyroid surgery. In their last two cases, the existence of an aberrant right subclavian a., constantly associated with NRILN, was confirmed by MRI angiography. On the basis of the literature and their own experience, the authors review the incidence of this double anomaly, its embryologic explanation and its anatomic and surgical importance. They stress the diagnostic factors and the therapeutic implications, very different in children and adults, of a particular vascular anomaly whose outcome is little understood.

[Volume rendering technique in 3D vascular imaging]. / Apport de la technique de rendu de volume en imagerie 3D vasculaire.

We used volume rendering technique (VRT) for generating three-dimensional (3D) images of the vasculature from spiral computed tomography (CT) data sets. This paper describes the methods used for volume rendering and focuses on the specific aspects of volume rendering as applied to vascular imaging.

MR imaging of osteomyelitis and neuropathic osteoarthropathy in the feet of diabetics.

Distinguishing between osteomyelitis and neuropathic osteoarthropathy of the foot frequently presents a clinical and radiologic challenge in patients with diabetes. Magnetic resonance (MR) imaging was performed in 26 diabetic patients to observe changes in signal intensity in the complicated diabetic foot. In every patient with osteomyelitis (n = 13), signal intensity abnormalities were seen within the bone marrow (low signal intensity on T1-weighted images and high signal intensity on T2-weighted images in 12 cases). Most of these patients had cortical lesions (n = 9) or associated soft-tissue infection (n = 12). Normal bone marrow signal intensity was observed in three of the four patients without osteomyelitis. Characteristic MR imaging findings (decreased signal intensity in bone marrow regardless of pulse sequence) were seen in patients with chronic neuropathic osteoarthropathy (n = 7), who were easily distinguished from patients with osteomyelitis. Conversely, in patients with acutely evolving neuropathic osteoarthropathy (n = 2), signal intensity changes within the bone marrow were similar to those observed in osteomyelitis, leading to potential diagnostic pitfalls. Familiarity with MR imaging findings observed in osteomyelitis and neuropathic osteoarthropathy can help identify these two entities, allowing early diagnosis and appropriate therapy.

Lhermitte-Duclos disease associated with syringomyelia.

A 23-year-old man presented with a 2-week history of intracranial hypertension. CT showed a large, nonenhancing cerebellar mass with surrounding calcification and displacement of the fourth ventricle. MRI revealed a septate lesion, with low signal on T1-weighted and high signal on T2-weighted images. The cerebellar tonsils were displaced below the foramen magnum and there was associated syringomyelia. The MRI features were characteristic of Lhermitte-Duclos (LD) disease (dysplastic gangliocytoma) and the diagnosis was confirmed following surgery. In this case, we emphasise the usefulness of MRI in the diagnosis of LD disease and consider the possible pathogenesis of the associated syringomyelia.

[Mycotic aneurysm of the posterior tibial artery and pseudo-phlebitis: contribution of color Doppler ultrasonography]. / Anévrisme mycotique de l'artère tibiale postérieure et pseudophlébite: apport de l'échographie Doppler couleur.

Mycotic aneurysm of the posterior tibial artery and pseudophlebitis: role of color Doppler sonography A case of a 78-year-old male patient presenting with endocarditis caused by Streptococcus bovis and pseudophlebitis of the left lower limb is described. Color Doppler sonography ruled out thrombophlebitis and showed a large pulsatile mass of the posterior compartment of the leg due to a mycotic aneurysm of the posterior tibial artery. This aneurysm was confirmed by angiography and treated by surgery. The important role of color Doppler sonography for the diagnosis of this particular case is emphasized.

Anatomo-radiological study of the popliteal artery during knee flexion.

We studied the morphological modifications of the popliteal artery during knee flexion. An anatomical, radiological study consisted of analysis of lateral arteriographs in different degrees in joint flexion followed by dissection to reveal the anatomical structures involved in the morphological adaptation of the popliteal artery to joint movement. In five non-atheromatous volunteers, 15 MRI angiographic sequences were done at the level of the knee in extension and flexion. The arteriographs and angio MRI showed that as joint flexion increased tortuosities appeared in the supra-articular upper popliteal artery while the middle and lower parts of the popliteal artery kept an even curve retracted from the posterior surface of the joint. Dissection seemed to show that this arterial adaptation occurred between two fixed points, one proximal (the adductor canal) and the other distal (the origin of the anterior tibial artery). Angio MRI seems to be a future route for the assessment of the limb vessels. The contrasting behaviour of the different segments of the popliteal artery allows us to understand better the pathophysiology of trauma and malpositions of the popliteal arterial trunk.

[Effects of contrast media products on erythrocyte aggregation. An ex vivo study]. / Influence des produits de contraste sur l'agrégation érythrocytaire. Une étude ex vivo.

It has been suggested (Fisher and al., Rainiko and al.) that contrast media could interfere with a red blood cell aggregation, low-osmolarity and non ionic contrast media leading to red blood cell aggregates in vitro. Clinical significance of this phenomenon is not known. We have studied 21 consecutive patients admitted in X ray department for pyelography. Sodium and meglumine ioxitalamate (Telebrix 38 R; Guerbet) osmolarity 2 100 mOsm kg--viscosity 8.5 cp at 37 degrees C is used for contrast. Red blood cell aggregation is studied by erythraggregometer Sefam. Samples are collected before (T0), 10 and 30 minutes (T10, T30) after contrast infusion. Hemogram and coagulation parameters are measured in parallel. Results show a significant increase of aggregation times at T10, with a trend towards baseline at T30. Dissociation shear rates follow the same fluctuations. We note a concomitant diminution of both fibrinogen and hematocrit levels, well-correlated with red blood cell aggregation. These results suggest a process of hemodilution which could explain the diminution of red blood cell aggregation with this type of contrast medium.

Gastro-esophageal reflux: comparative study between sonography and pH monitoring.

Sonography appears highly sensitive in characterizing the severity of gastroesophageal reflux, screening the infants at risk of esophagitis. Sonography is also useful in evaluating efficacy of treatment. In our experience reflux is only damaging if constantly repeated and related to severe hiatal dysfunction. Ultrasound (US) is a good alternative for the assessment of hiatal function and gives furthermore indispensable morphological data.

Malignant sacrococcygeal teratoma in an adult.

The authors report the case of a 49-year-old man who had a sacrococcygeal teratoma. Computed tomography showed a mass containing calcification. Digital angiography showed hypervascularization of the lesion. Histologic examination of a transrectal biopsy performed during sigmoidoscopy revealed the lesion to be a malignant teratoma which was not resectable or amenable to treatment.

[Effect of contrast media products on the erythrocyte aggregation and deformability in vitro]. / Influence des produits de contraste sur l'agrégation et la déformabilité erythrocytaire in vitro.

It has been suggested that contrast media could interfere with red blood cell aggregation, hyperosmolar media leading to an inhibition of red blood cell aggregation whereas non ionic products might induce a sludge phenomenon. We present an in vitro study accompanying two contrast media: 1) Ioxitalamate of sodium and meglumin (ionic, hyperosmolar). 2) Iopaminol (non ionic). In their effect on hemorheological parameters of red blood cell aggregation. Blood samples have been obtained from 7 healthy donors. Contrast media have been tested at increased contrast media (O.1, 1, 2, 10, 100 mg/ml of Iodine in final concentration). The following parameters have been studied: hematocrit, fibrinogen level, erythrocyte aggregation using the Erythro-aggregometer*, whole blood viscosity at 3 different shear rates (0.87, 18.74, 118 sec.-1) using Low Shear 30*. Deformability of red blood cell was assessed by ektacytometry. Osmolarity was controlled in each sample. Results show an inhibition effect of both contrasts media on red blood cell aggregation. There is a concomitant decrease of blood viscosity at low shear rates. On the contrary, apparent viscosity increases at high shear rates in parallel with the contrast media concentration. This effect is more pronounced with ioxitalamate above a concentration of 10 mg/ml. Ektacytometric parameters are not modified by contrast media and this could indicate a complete reversibility of the media-induced alteration on red blood cell. In order to precise the prothrombotic effect on contrast media, hemorheological studies have to be completed by the assessment of their effect on hemostatic parameters.

Imaging of the digital arteries: digital subtraction angiography versus conventional arteriography.

A retrospective study of 95 patients was undertaken to compare digital subtraction angiography (DSA) and conventional arteriography of the hand. Eighty patients had conventional angiography and 15 had DSA. In comparison with conventional angiography, DSA is more cost-efficient and facilitates outpatient angiography. It provides images as acceptable as those of conventional angiography. We conclude that intra-arterial DSA is now the procedure of choice for angiographic mapping of the digital arteries.