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Biomedical subjects

L Van Hoe

Publications and source records attributed to L Van Hoe.

At least 55 records · Page 3Linked to original sources
PubMed1996

Assessment of accuracy of renal artery stenosis grading in helical CT angiography using maximum intensity projections.

The purpose of the study was to investigate whether visual inspection of maximum intensity projection (MIP) images is a reliable method for assessment of the severity of renal artery stenoses (RAS). Therefore, 20 RAS were investigated with helical CT. Native axial images and MIP images were analysed separately or in combination ("two-step method"). A phantom study was performed to investigate the influence of window setting on apparent stenosis severity. Accuracy for diagnosis of 50-69% and 70-99% RAS and the mean inter-observer agreement were 82.5%, 77.5% and 82.5% respectively, using study of MIP images alone, and 100%, 97.5% and 95% using the "two-step method". The phantom study showed that the apparent severity of vascular stenoses on MIP images depends on the selected window centre values. It is concluded that combined evaluation of both MIP images and native axial images is more reliable than study of MIP images alone for assessing the severity of RAS.

Aged↗
PubMed1996

Spiral CT of intracranial aneurysms: correlation with digital subtraction and magnetic resonance angiography.

Spiral CT and magnetic resonance angiography (MRA) were performed in ten patients with 14 intracranial aneurysms known from conventional angiography. All lesions, the smallest 3 mm in diameter, were visible on spiral CT and MRA. The neck of the aneurysm and its anatomical relations could very accurately be determined in all cases. Advantages of spiral CT over MRA are: a short acquisition time with reduction of motion artefacts, no dependence on flow rate or cardiac output, and excellent visualisation of calcification, thrombus and bony landmarks. Disadvantages are the necessity for iodinated contrast medium, long postprocessing and reconstruction time and the possibility of overlap of bone and venous blood.

Aged↗
PubMed1996

Supra- and juxtarenal aneurysms of the abdominal aorta: preoperative assessment with thin-section spiral CT.

PURPOSE: To assess the contribution of thin-section spiral computed tomography (CT) to the preoperative radiologic evaluation of juxta- and suprarenal abdominal aortic aneurysms. MATERIALS AND METHODS: Thirty-eight patients (26 men, 12 women; age range, 60-81 years) with infrarenal (n = 23), juxtarenal (n = 8), and suprarenal (n = 7) aneurysms underwent digital subtraction angiography (DSA) and 2-mm-collimation spiral CT. Cine-interactive display of overlapping axial, reformatted, and maximum intensity projection images were used for CT image analysis. CT findings were compared with angiographic and surgical findings. RESULTS: The proximal extent of the juxta- and suprarenal aneurysms (n = 15) could be correctly predicted in 12 cases (80%) with DSA and was exactly determined in 14 (93%) with CT. All renal arteries except three accessory renal arteries were correctly depicted with spiral CT (83 of 86 [96%]). With DSA as the standard of reference, renal artery stenoses of at least 70% were accurately assessed in 95% of cases. CONCLUSION: Thin-section spiral CT can provide additional information in the preoperative diagnosis of juxta- and suprarenal aneurysms.

Aged↗
PubMed1996

Focal liver lesions: fast T2-weighted MR imaging with half-Fourier rapid acquisition with relaxation enhancement.

PURPOSE: To compare the clinical usefulness of the half-Fourier rapid acquisition with relaxation enhancement (RARE) technique at T2-weighted magnetic resonance (MR) imaging of focal liver lesions with that of multishot RARE MR imaging and contrast material-enhanced helical computed tomography (CT). MATERIALS AND METHODS: Half-Fourier RARE and multishot RARE imaging and helical CT were performed in 48 patients with 102 focal liver lesions and in three patients with diffuse metastatic liver disease. Images were compared qualitatively and quantitatively for image quality, lesion conspicuity, and ability to help differentiate solid lesions from hemangiomas. RESULTS: All half-Fourier RARE images were free of respiratory artifact. In the 48 patients with 102 focal lesions, CT, half-Fourier RARE, and multishot RARE images depicted 101, 99, and 90 lesions (99%, 97%, and 88%), respectively. CT failed to depict focal lesions in one patient with diffuse metastatic liver disease. All techniques had high accuracy for distinction of hemangiomas from solid masses (areas under the receiver operating characteristic curves were between 0.96 and 0.99). CONCLUSION: Half-Fourier RARE MR imaging is a rapid and accurate technique for detection and characterization of focal liver lesions.

Adult↗
PubMed1996

Endometrioid cystadenocarcinoma of the ovary.

The authors present the US- and CT-findings in a patient with endometroid cystadenocarcinoma of the right ovary. The importance of detecting a small solid component in an otherwise typical "endometrioma" is stressed. The contribution of MR is discussed.

Adult↗
PubMed1995

Extramedullary hematopoiesis encasing the pelvicalyceal system: CT findings.

A rare case of symmetric renal extramedullary hematopoiesis is hypothesized in a patient with long-standing Vaquez' disease and myelofibrosis. At CT, soft tissue densities were found in the renal hilar area encasing the pelvicalyceal system. Although there is nothing specific about the CT findings, the diagnosis can be suggested in the proper clinical setting. The association with generalized osteosclerosis is another diagnostic clue.

Diagnosis, Differential↗
PubMed1995

Case report: pseudotumoral pelvic retroperitoneal fibrosis associated with orbital fibrosis.

We report the case of a man with bilateral orbital fibrous pseudotumours and a large pelvic mass which was initially thought to be malignant. Sonographically guided transrectal core biopsies showed it to be a fibrotic retroperitoneal pseudotumour. The mass decreased after steroid therapy. The computed tomography and magnetic resonance imaging features of this unusual form of pelvic fibrosis as well as the association with heterotopic fibrosis are discussed.

Fibrosis↗
PubMed1995

Helical CT for the preoperative localization of islet cell tumors of the pancreas: value of arterial and parenchymal phase images.

OBJECTIVE: In two-phase helical CT, organs are scanned in both the arterial and the parenchymal phase after IV injection of contrast material. The purpose of our study was to evaluate the usefulness of two-phase helical CT for the preoperative localization of pancreatic islet cell tumors. MATERIALS AND METHODS: Ten patients with 11 surgically proven islet cell tumors were included in the study. Helical CT scans of the pancreas were obtained with 5-mm collimation and overlapping image reconstruction. Images were obtained in the arterial and parenchymal phases after contrast material injection. A test bolus was used for tailored bolus timing. Images were analyzed by two observers. If a tumor was detected, its density relative to the surrounding parenchyma was scored by consensus, using a five-point scale. RESULTS: Nine of 11 tumors could be located using two-phase helical CT (sensitivity, 82%), including one 4-mm gastrinoma. Two lesions smaller than 5 mm could not be visualized. Two tumors were easier to detect (n = 1) or could only be detected on parenchymal-phase images (n = 1). Tumor conspicuity was better on arterial-phase images in two patients. CONCLUSION: Our results show that obtaining CT scans in both the arterial and the parenchymal phase leads to improved detection of pancreatic islet cell tumors.

Adenoma, Islet Cell↗
PubMed1995

Abdominal pain in the postpartum: role of imaging.

The post-delivery evaluation of the obstetric patient presenting with severe abdominal pain can be a challenge to the obstetrician, the internist, and the radiologist. Besides non-pregnancy-related causes of abdominal pain, several pregnancy-related complications should be included in the list of differential diagnoses. Based on pathogenesis, these conditions can be divided in four categories: thromboembolic disease, infectious complications, mechanical complications, and complications of preeclampsia. Most disease processes can be adequately visualized with sonography. CT can be indicated for the evaluation of the extent of ovarian vein thrombosis and for depiction of deep abdominal collections in obese patients or in cases of abundant overlying abdominal gas. MRI can be useful to provide the specific diagnosis of hemorrhagic liver infarction in the clinical setting of a HELLP syndrome.

Abdominal Pain↗
PubMed1995

[Spiral CT of the renal blood vessels].

Spiral CT angiography has been successfully applied to the detection and grading of renal artery stenoses. In this manuscript the technique, the diagnostic accuracy and the advantages and limitations of this new method are discussed.

Angiography↗
PubMed1995

[Spiral CT angiography].

Spiral CT angiography (CTA) is a promising technique for the evaluation of vascular lesions. We review some important technical aspects in CTA such as longitudinal resolution, determination of injection scan interval and limitations of three-dimensional rendering techniques. Several current and potential applications are discussed.

Angiography↗
PubMed1995

[Spiral CT of cerebral aneurysms].

Spiral CT was performed in 9 patients with 13 cerebral aneurysms known from angiography. All lesions were detected by spiral CT, the smallest lesion measuring 3 mm in diameter. The neck of the aneurysm and the anatomical relations could be determined very accurately in all cases. Advantages of spiral CT over magnetic resonance angiography include: the short examination time, the independence of flow rate and cardiac output, and the excellent visualisation of calcification, thrombus and the bony landmarks. Disadvantages are the necessity of iodinated contrast media, the long postprocessing and reconstruction time and the possibility of overlap from bone and venous blood.

Cerebral Angiography↗
PubMed1995

[Spiral CT of the liver: detection of focal liver lesions].

The advantages of spiral CT mainly reside in the possibility to scan the entire liver volume in a single period of about 20 to 30 seconds, while the patient holds his breath. This high acquisition speed allows to selectively evaluate the entire liver during the arterial and/or portal venous phase. In addition, spiral CT is a true volumetric technique that allows a posteriori calculation of perfectly contiguous or even overlapping slices. These two specifications, high acquisition speed and the absence of data gaps improves the detection of focal liver lesions.

Humans↗