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D van Westen

Publications and source records attributed to D van Westen.

5 recordsLinked to original sources
PubMed2006

Tumor extension in high-grade gliomas assessed with diffusion magnetic resonance imaging: values and lesion-to-brain ratios of apparent diffusion coefficient and fractional anisotropy.

PURPOSE: To determine whether the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) can distinguish tumor-infiltrated edema in gliomas from pure edema in meningiomas and metastases. MATERIAL AND METHODS: Thirty patients were studied: 18 WHO grade III or IV gliomas, 7 meningiomas, and 5 metastatic lesions. ADC and FA were determined from ROIs placed in peritumoral areas with T2-signal changes, adjacent normal appearing white matter (NAWM), and corresponding areas in the contralateral healthy brain. Values and lesion-to-brain ratios from gliomas were compared to those from meningiomas and metastases. RESULTS: Values and lesion-to-brain ratios of ADC and FA in peritumoral areas with T2-signal changes did not differ between gliomas, meningiomas, and metastases (P = 0.40, P = 0.40, P = 0.61, P = 0.34). Values of ADC and FA and the lesion-to-brain ratio of FA in the adjacent NAWM did not differ between tumor types (P = 0.74, P = 0.25, and P = 0.31). The lesion-to-brain ratio of ADC in the adjacent NAWM was higher in gliomas than in meningiomas and metastases (P = 0.004), but overlapped between tumor types. CONCLUSION: Values and lesion-to-brain ratios of ADC and FA in areas with T2-signal changes surrounding intracranial tumors and adjacent NAWM were not helpful for distinguishing pure edema from tumor-infiltrated edema when data from gliomas, meningiomas, and metastases were compared.

Adult↗
PubMed2002

Biliary and total extrarenal clearance of inulin and iohexol in pigs. A source of error when determining gfr as body clearance.

Biliary clearance, total extrarenal clearance, body and renal clearance of inulin and iohexol were determined in 11 normal and 11 nephrectomized pigs. The biliary clearance of inulin, calculated as biliary excretion divided by the plasma concentration, was 0.04 and 0.01 ml min(-1) 10 kg(-1) and of iohexol 0.21 and 0.1 ml min(-1) 10 kg(-1), in normal, respectively, nephrectomized pigs (p < 0.05). The extrarenal clearance of inulin, calculated as body minus renal clearance, was 2.7 and 0.7 ml min(-1) 10 kg(-1) and of iohexol 3.7 and 0.7 ml min(-1) 10 kg(-1) in normal, respectively, nephrectomized pigs (p < 0.05). Some hours after injection of the markers their plasma concentrations were much higher in the nephrectomized pigs. This higher plasma concentration was not matched by an equally higher biliary excretion and therefore biliary clearance decreased. The smaller total extrarenal clearance in nephrectomized pigs, i.e. the overestimation of GFR when calculated as body clearance, indicates that this source of error decreases with decreasing renal function.

Animals↗
PubMed1994

Ipsilateral multiple groin hernias.

BACKGROUND: Recurrence rates after surgical repair of groin hernia vary between 3% and 20%. One possible reason for recurrent hernias are ipsilateral multiple hernias, which might have been overlooked at the primary operation. METHODS: In the present series 1010 patients with unclear groin pain underwent herniography. RESULTS: A total of 314 patients had hernias, and seventy-one (23%) of these had multiple hernias. Ipsilateral multiple hernias were found in 18 (6%) patients. Ipsilateral multiple hernias were present in 9 (6%) of 144 patients with an indirect hernia, in 17 (12%) of 144 patients with a direct hernia, in 5 (21%) of 24 patients with a femoral hernia, and in 3 (23%) of 13 patients with an obturator hernia. The hernias were of indirect, direct, femoral, and obturator types. CONCLUSIONS: The frequency of ipsilateral multiple hernias is much higher than the frequency reported during herniorrhaphy. Such overlooked ipsilateral multiple groin hernias may account for some of the so-called recurrences after herniorrhaphy. Therefore a careful exploration of the groin is mandatory. Preoperative herniography may also prove to be useful in patients with recurrent groin symptoms after herniorrhaphy.

Adult↗
PubMed1993

Solid bolus swallowing in the radiologic evaluation of dysphagia.

Patients with dysphagia, heartburn and chest pain are regularly referred for radiologic evaluation of swallowing. The liquid barium swallow has been of great value for the biphasic evaluation of the pharynx and esophagus. Though many patients complain of dysphagia specifically for solids, solid bolus swallow is usually not part of the evaluation. For the present study we therefore included the use of a solid bolus with a diameter of 13 mm and interviewed the patients carefully for any symptoms during this tablet swallow. Of 200 patients examined, the tablet passed through the esophagus without delay in 102. In the 98 patients with delayed passage, the solid bolus arrest occurred in the pharynx in 5 and in the esophagus in 93. Arrest in the esophagus was due to esophageal dysmotility in 48 patients. Twenty of these were symptomatic during the tablet swallow. A narrowing was the cause in 45, of whom 9 had symptoms. In 18 patients (9%) the solid bolus added key information to the radiologic evaluation. We therefore recommend that the solid bolus is included in the routine radiologic work-up of patients with dysphagia. Careful attention to symptoms during the tablet swallow is important.

Adult↗