Biomedical subjects

O Vignaux

Publications and source records attributed to O Vignaux.

27 records · Page 2Linked to original sources

PubMed1999

Cirrhotic liver enhancement on dual-phase helical CT: comparison with noncirrhotic livers in 146 patients.

OBJECTIVE: The purpose of this study was to prospectively determine any differences in vascular and liver enhancement between patients with cirrhosis and patients without cirrhosis during both the arterial and portal venous phases on dual-phase helical CT. SUBJECTS AND METHODS: Fifty-eight patients with histologically proven cirrhosis (group 1) and 88 without cirrhosis (group 2 = normal findings on CT, group 3 = metastases, group 4 = other liver diseases) underwent dual-phase helical CT of the liver. Attenuation values of liver and vessels were measured on unenhanced scans and on scans obtained during the arterial and portal venous phases. The mean enhancement values per time interval (5 sec) were determined. Results were analyzed taking into account various intrinsic patient parameters. RESULTS: We found no statistically significant difference in terms of mean vascular enhancement and mean liver enhancement during the arterial imaging phase for each time interval among all the groups. The mean peak enhancement and mean liver enhancement during the portal venous phase were significantly lower in group 1 than in other groups. Time to peak enhancement was significantly delayed in group 1. CONCLUSION: In spite of the hepatic arterial buffer response, mean liver enhancement during the arterial phase was not significantly different in patients with cirrhosis compared with patients without cirrhosis. Although portal vein enhancement did not differ significantly, enhancement of cirrhotic liver was significantly lower during the portal venous phase and delayed, presumably because of decreased peripheral portal perfusion. The contrast injection protocol may be tailored to optimize conspicuity of hypovascular tumor.

Adult↗

PubMed1998

Pancreatic tumors: comparison of dual-phase helical CT and endoscopic sonography.

OBJECTIVE: The purpose of this study was to compare dual-phase helical CT and endosonography for the diagnosis and staging of pancreatic tumors. SUBJECTS AND METHODS: Thirty patients with suspected pancreatic tumors underwent endosonography and dual-phase helical CT. A pathologic diagnosis was obtained in all cases with surgery (n = 23) or biopsy (n = 7), resulting in 27 neoplasms. Dual-phase helical CT and endosonographic findings were correlated with surgical and pathologic findings to determine diagnosis and resectability of pancreatic tumors. RESULTS: Overall diagnostic sensitivity was 92% for dual-phase helical CT and 100% for endosonography (p = .45). Overall accuracy for staging of pancreatic tumors was 93% for both dual-phase helical CT and endosonography. Overall accuracy for predicting resectability was 90% for both dual-phase helical CT and endosonography. Accuracy of predicting unresectability was 100% for dual-phase helical CT and 86% for endosonography (p > .80). Differences were not considered statistically significant. CONCLUSION: Dual-phase helical CT and endoscopic sonography do not differ significantly for diagnosis and assessment of resectability of pancreatic tumors.

Adenocarcinoma↗

PubMed1992

[Diagnostic orientation and radiological assessment of anosmia].

The olfactory system is made up of the olfactory epithelium, bulbs and tracts, together with olfactory areas in the brain. Anosmia may results from benign and malignant nasal sinus lesions, but also from lesions involving the CNS structures involved in olfaction. The purpose of this article is to review the different diagnose of anosmia and their CT or MR imaging characteristics.

Brain Neoplasms↗

PubMed1992

[Cholesterol granuloma. Review of the literature apropos of a case].

MRI allows the diagnosis of cholesterol granuloma in the presence of a non contrast-enhanced, erosive solid mass of the apex of the petrous bone or middle ear. Cholesterol granuloma has a suggestive low signal intensity on T1 and T2 weighted sequences (cholesterol crystals, haemoglobin degradation products). These specific features eliminate the principal CT differential diagnoses, particularly cholesteatoma. MRI is also useful for follow-up of treatment.

Cholesterol↗

PubMedDate not supplied

Peliosis hepatis: triphasic helical CT and dynamic MRI findings.

We report the triphasic helical computed tomographic (CT) and dynamic magnetic resonance imaging (MRI) findings in a unique case of biopsy-proven peliosis of the liver. Several reports have described the CT and MRI findings of this entity without specific appearance. This report discusses the usefulness of dynamic helical CT and MRI for the early diagnosis of peliosis.

Female↗

PubMedDate not supplied

Hepatofugal portal flow in advanced liver cirrhosis with spontaneous portosystemic shunts: effects on parenchymal hepatic enhancement at dual-phase helical CT.

BACKGROUND: We investigated whether spontaneous hepatofugal portal flow in advanced cirrhosis affects hepatic enhancement on dual-phase helical computed tomography. METHODS: Fifteen patients with hepatofugal portal flow on Doppler sonography and angiography (group 1) and 15 age- and sex-matched patients with hepatopetal portal flow (control; group 2) underwent dual-phase helical computed tomography. Vascular and liver attenuation values were measured on unenhanced scans and scans obtained during hepatic arterial (HAP; 25 s) and portal venous (PVP; 70 s) phases. RESULTS: Portal vein enhancement was lower during PVP in group 1 than in group 2 ( p < 0.0001). Liver enhancement was higher during HAP and lower and delayed during PVP in group 1 versus group 2 ( p < 0.0001). CONCLUSION: In hepatofugal portal flow, liver enhancement is increased during HAP and compensating for decreased and delayed liver enhancement during PVP, resulting in potential decreased hypervascular tumor conspicuity.

Collateral Circulation↗

PubMedDate not supplied

[Cardiac imaging].

Explore the source record for details and available documents.

Diagnostic Imaging↗

PubMedDate not supplied

Cardiac gas embolism after central venous catheter removal.

Clinical images reporting intracardiac gas level are sparce and, to our knowledge, the presence of gas embolism into the coronary arteries has never been reported. We describe the case of a young man who experiences life-threatening gas embolism with the presence of gas bubbles into cardiac cavities and coronary arteries.

Adolescent↗

PubMedDate not supplied

[Hypersignal of the intervertebral disks in T1-weighted spin-echo MRI sequences].

In magnetic resonance imaging, when there is calcification of the intervertebral disk, signals usually become weaker in all the sequences. Exceptionally, a spontaneous hypersignal is obtained in T1 weighted spin-echo sequences. We report 4 cases of spontaneous hypersignals from disks in T1 weighted spin-echo sequences. In 3 cases, calcifications were visualized with conventional radiology or computed tomography. In 1 case, there was no calcification of the disk, but its density, compared with adjacent disks, was 20 HU greater, suggesting inframacroscopic calcification.

Adult↗