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M Oudkerk

Publications and source records attributed to M Oudkerk.

At least 73 records · Page 4Linked to original sources
PubMed2000

Cerebral white matter lesions and depressive symptoms in elderly adults.

BACKGROUND: There is evidence for a vascular cause of late-life depression. Cerebral white matter lesions are thought to represent vascular abnormalities. White matter lesions have been related to affective disorders and a history of late-onset depression in psychiatric patients. Their relation with mood disturbances in the general population is not known. We investigated the relation between white matter lesions and the presence of depressive symptoms or a history of depression in a population-based study. METHODS: In a sample of 1077 nondemented elderly adults, we assessed the presence and severity of subcortical and periventricular white matter lesions using magnetic resonance imaging, presence of depressive symptoms, and history of depression. Using multiple regression analysis, we examined the relation among white matter lesions, depressive symptoms, and history of depression. RESULTS: Most of the subjects had white matter lesions. Persons with severe white matter lesions (upper quintile) were 3 to 5 times more likely to have depressive symptoms as compared with persons with only mild or no white matter lesions (lowest quintile) (periventricular odds ratio [OR] = 3.3; 95% confidence interval [CI], 1.2-9.5; subcortical OR = 5.4; 95% CI, 1.8-16.5). In addition, persons with severe subcortical but not periventricular white matter lesions were more likely to have had a history of depression with an onset after age 60 years (OR = 3.4; 95% CI, 1.1-10.7) compared with persons with only mild or no white matter lesions. CONCLUSION: The severity of subcortical white matter lesions is related to the presence of depressive symptoms and to a history of late-onset depression.

Age of Onset↗
PubMed2000

Cerebral white matter lesions and cognitive function: the Rotterdam Scan Study.

Cerebral white matter lesions (WMLs) have been associated with cognitive dysfunction. Whether periventricular or subcortical WMLs relate differently to cognitive function is still uncertain. In addition, it is unclear whether WMLs are related to specific cognitive domains such as memory or psychomotor speed. We examined the relationship between periventricular and subcortical WMLs and cognitive functioning in 1,077 elderly subjects randomly sampled from the general population. Quantification of WMLs was assessed by means of an extensive rating scale on 1.5-T magnetic resonance imaging scans. Cognitive function was assessed by using multiple neuropsychological tests from which we constructed compound scores for psychomotor speed, memory performance, and global cognitive function. When analyzed separately, both periventricular and subcortical WMLs were related to all neuropsychological measures. When periventricular WMLs were analyzed conditional on subcortical WMLs and vice versa, the relationship between periventricular WMLs and global cognitive function remained unaltered whereas the relationship with subcortical WMLs disappeared. Subjects with most severe periventricular WMLs performed nearly 1 SD below average on tasks involving psychomotor speed, and more than 0.5 SD below average for global cognitive function. Tasks that involve speed of cognitive processes appear to be more affected by WMLs than memory tasks.

Aged↗
PubMed2000

MR imaging of clear cell sarcoma (malignant melanoma of the soft parts): a multicenter correlative MRI-pathology study of 21 cases and literature review.

OBJECTIVE: To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts). DESIGN AND PATIENTS: MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, signal intensities on T1- and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study. RESULTS: On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody. CONCLUSIONS: Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well-defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images.

Adolescent↗
PubMed2000

Coronary arteries.

Coronary angiography (CA) is presently considered the gold standard for the assessment of the coronary arteries. However, the presence of ionizing radiation, its invasiveness and the small associated risk of morbidity prompted long ago the development of more patient-friendly imaging modalities. A promising technique, magnetic resonance imaging (MRI), has been regarded as the major modality in the coming decade. Although still in its infancy qualitatively, its flexibility and non-invasiveness opens the door for a comprehensive evaluation of the heart and the coronary arteries in one single sitting with high anatomical definition and excellent soft tissue contrast capabilities, double-oblique tomographic sections and the possibility to quantify an innumerable number of cardiovascular physiological parameters. Numerous ideas have been assessed, comprising breath-hold and free-breathing two-dimensional and three-dimensional measurements. New ongoing trials with intravascular contrast agents may provide for all these techniques the long-awaited essential boost for reliable magnetic resonance coronary angiography (MRCA). Introduction of parallel MRI acquisition techniques, such as simultaneous acquisition of spatial harmonics (SMASH) and sensitivity encoding (SENSE) may provide the speed enhancement required to shorten imaging time for all techniques explored to date.

Coronary Angiography↗
PubMed2000

Carotid atherosclerosis and cerebral white matter lesions in a population based magnetic resonance imaging study.

Cerebral white matter lesions are frequently observed on magnetic resonance imaging of elderly, nondemented persons. There is evidence that white matter lesions are involved in the pathophysiology of cognitive decline and dementia. White matter lesions can be divided into those in the periventricular and those in the subcortical region. Pathological and epidemiological studies suggest that atherosclerosis is involved in the pathogenesis of these lesions. Our study reports on the association between atherosclerosis in the carotid arteries and white matter lesions in a population-based study among 1077 elderly subjects. We randomly sampled 1077 subjects aged between 60-90 years from two prospective population-based studies. All subjects underwent ultrasonography of the carotid artery. In addition, 1.5 T magnetic resonance imaging was performed; white matter lesions in the subcortical and periventricular regions were rated separately. With increasing number of plaques in the carotid artery the severity of periventricular white matter lesions increased (Ptrend = 0.03), but not the severity of subcortical white matter lesions (Ptrend = 0.19). In addition, an increase in intima media thickness was borderline significantly associated with an increased severity of periventricular white matter lesions (Ptrend = 0.09), but not of subcortical white matter lesions (Ptrend = 0.68). These findings suggest that partly dissimilar pathogenetic mechanisms are involved in the etiology of periventricular and subcortical white matter lesions.

Aged↗
PubMed2000

Decreased energy and phosphorylation status in the liver of lung cancer patients with weight loss.

BACKGROUND/AIMS: Altered energy status has been reported in the liver of tumour-bearing animals, but data on energy status in humans are scarce. Therefore, bioenergetics in tumour-free liver of lung cancer patients were monitored using 31P magnetic resonance spectroscopy (MRS) with infusion of L-alanine as a gluconeogenic challenge. METHODS: Twenty-one overnight-fasted lung cancer patients without liver metastases, with (CaWL) or without weight loss (CaWS), and 12 healthy control subjects (C) were studied. Hepatic energy status was monitored before and during an i.v. L-alanine infusion of 1.4-2.8 mmol/kg + 2.8 mmol x kg(-1) x h(-1) for 90 min by 31p MR spectroscopy. RESULTS: Baseline levels of ATP in WL lung cancer patients, expressed relative to total MR-detectable phosphate, were reduced (CaWL, 9.5+/-0.9% vs. CaWS, 12.6+/-0.8% and C, 12.4+/-0.8%; p<0.05) and inversely correlated with the degree of weight loss in lung cancer patients (r=-0.46, p=0.03). Pi/ATP ratios were increased (p<0.05), indicating reduced liver phosphorylation status. During L-alanine infusion, ATP levels decreased in all groups (p<0.05); in CaWL, ATP levels were lower at all time-points between 0-90 min as compared to both CaWS and C (p<0.05). Pi/ATP ratios were significantly higher after 70-90 min of L-alanine infusion in CaWL compared to CaWS and C (p<0.05). CONCLUSIONS: Hepatic ATP and phosphorylation status are reduced in WL lung cancer patients, in contrast to WS patients and healthy subjects, and continue to decrease during infusion of a gluconeogenic substrate, suggesting impaired energy regenerating capacity in these patients.

Adenosine Triphosphate↗
PubMed2000

Earlier detection of breast cancer by surveillance of women at familial risk.

A positive family history increases the risk for breast cancer which oft en occurs at a much younger age than in the general population. We stud ied whether surveillance of these women resulted in the detection of bre ast cancer in an earlier stage than in symptomatic patients with a famil y history. Between January 1994 and April 1998, 294 women with 15-25% r isk (moderate), mean age:43.3 (22-75) years, were screened with a yearly physical examination and mammography from 5 years before the youngest ag e of onset in the family and 384 women with >25% risk (high) for breast cancer, mean age: 42.9 (20-74) years were screened with a physical examination every 6 months and yearly mammography. From September 1995 breast magnetic resonance imaging (MRI) was also carried out for 109 high risk women where mammography showed over 50% density. 26 breast cancers detected under surveillance were significantly more often found in an early T1N0 stage than the 24 breast cancers in patients with a family history referred in that period because of symptoms: 81 versus 46% (P=0.018). Patients under surveillance were also less frequently node-positive than the symptomatic group: 19 versus 42% (P=0.12). 20 patients with a family history referred by our national screening programme in that period had 21 breast cancers detected, 81% in stage T1N0 and 5% node-positive, which was comparable to the results in our national screening programme T1N0 66%, N+ 24% resulting in a 30% reduction in mortality. The incidence in women under surveillance was 10.1 per 1000 in the 'high' risk group and 13.3 per 1000 in the 'moderate' risk group. Expected incidence in an average risk population aged 40-50 years is 1.5, expected if the group consisted of only gene carriers 15 per 1000. 23% of the breast cancers in the surveillance group were detected at physical examination, but occult at mammography. 38% were detected at mammography and clinically occult. Breast MRI (in the subgroup) detected 3 occult breast cancers. The results of this study show that women with a family history benefit from surveillance as breast cancer was detected significantly more often in a favourable T1N0 stage and a mortality reduction comparable to that obtained in our national screening programme may be expected also in women <50 years of age. Both physical examination and mammography contribute to this result, but the former in this study only contributed in women before menopause. Starting surveillance some years before the youngest age of onset in the family may result in higher detection rates. Screening with MRI can detect breast cancers, still occult at physical examination and mammography.

Adult↗
PubMed2000

First experiences in screening women at high risk for breast cancer with MR imaging.

Women with a genetic predisposition for breast cancer are often advised surveillance with physical examination twice a year and mammography once a year from 25 years onwards. However, the sensitivity of the mammography decreases when breast tissue is dense and this is seen in 40-50% of women under 50 years. We therefore investigated whether magnetic resonance imaging (MRI) in addition to the normal surveillance could detect cancers otherwise missed. In 109 women with over 25% risk of breast cancer, MRI was performed because over 50% dense breast tissue was seen at mammography and no suspect lesion was seen at the previous screening. MRI detected breast cancers in three patients (2.8%) occult at mammography and with no new palpable tumor, twice at stage T1bN0 and T1cN0 once. Two cancers were expected. MRI was false positive in six women, resulting in two benign local excisions because ultrasound or fine needle examination confirmed suspicion. We had no false negative MRI results. MRI proved true benign in four BRCA 1/2 gene mutation carriers at histologic examination. Preoperative wire localization of the malignancies detected at MRI proved necessary as the tumor was not palpable in the lumpectomy specimen nor visible at specimen radiology. The extra cost of breast MRI in addition to mammography and physical examination was [symbol: see text]uro13.930 per detected cancer. The cost of the detection of one breast cancer patient in our national screening program is [symbol: see text]uro9000. During follow-up of patients with a familial risk in whom the first breast cancer was detected at MRI, MRI detected two recurrent cancers in stage T1bN0 and T1cN0 and one contralateral cancer T1aNo. Breast MRI is promising in screening young women at high risk for breast cancer, as it can advance the detection of cancers still occult at mammography and physical examination; but the cost may be considerable.

Adult↗
PubMed2000

Active implementation of a consensus strategy improves diagnosis and management in suspected pulmonary embolism.

Our consensus-based strategy in the diagnostic management of patients with pulmonary embolism involves a perfusion lung scan, a ventilation lung scan, compression ultrasonography and pulmonary angiography, in sequence. We compared the diagnostic approach in patients with clinically suspected pulmonary embolism before the active implementation of this strategy (retrospective analysis of 618 patients, April 1992-March 1995) and after (prospective study of 250 patients, April 1995-March 1996), with another assessment 1 year later. The measured outcomes were: (i) final diagnosis of pulmonary embolism either directly by pulmonary angiography, indirectly by compression ultrasonography of the leg veins, or with a high probability from a ventilation/perfusion lung scan; (ii) prescription of anticoagulant therapy. Before strategy implementation, pulmonary embolism was adequately confirmed or excluded in 11% of patients with an abnormal perfusion lung scan; in 55% the diagnosis remained uncertain, but the patient received anticoagulants. After implementation, these figures were 58.5% and 13%, respectively. A modest further improvement was observed 1 year later. Active implementation of a consensus-based strategy in the diagnosis of pulmonary embolism increases definite diagnoses, and reduces the numbers treated with anticoagulants. It induces a rapid change in the diagnostic behaviour of physicians.

Algorithms↗
PubMed2000

MR coronary angiography with breath-hold targeted volumes: preliminary clinical results.

PURPOSE: To assess the clinical value of a magnetic resonance (MR) coronary angiography strategy involving a small targeted volume to image one coronary segment in a single breath hold for the detection of greater than 50% stenosis. MATERIALS AND METHODS: Thirty-eight patients referred for elective coronary angiography were included. The coronary arteries were localized during single-breath-hold, three-dimensional imaging of the entire heart. MR coronary angiography was then performed along the major coronary branches with a double-oblique, three-dimensional, gradient-echo sequence. Conventional coronary angiography was the reference-standard method. RESULTS: Adequate visualization was achieved with MR coronary angiography in 85%-91% of the proximal coronary arterial branches and in 38%-76% of the middle and distal branches. Overall, 187 (69%) of 272 segments were suitable for comparison between conventional and MR coronary angiography. The diagnostic accuracy of MR coronary angiography for the detection of hemodynamically significant stenoses was 92%; sensitivity, 68%; and specificity, 97%. The sensitivity in individual segments was 50%-77%, whereas the specificity was 94%-100%. CONCLUSION: Adequate visualization of the major coronary arterial branches was possible in the majority of patients. The observed accuracy of MR coronary angiography for detection of hemodynamically significant coronary arterial stenosis is promising, but it needs to be higher before this modality can be used reliably in a clinical setting.

Adult↗
PubMed2000

Aortic atherosclerosis at middle age predicts cerebral white matter lesions in the elderly.

BACKGROUND AND PURPOSE: MRI scans of the brains of elderly people frequently show white matter lesions. Clinically, these lesions are associated with cognitive impairment and dementia. A relation between atherosclerosis and white matter lesions was found in some small cross-sectional studies. However, atherosclerosis is a gradual process that starts early in life. We investigated the longitudinal association between aortic atherosclerosis assessed during midlife and late life and cerebral white matter lesions. METHODS: We randomly sampled subjects between 60 and 90 years old from 2 population-based follow-up studies in which subjects had their baseline examinations in 1975 to 1978 (midlife) and in 1990 to 1993 (late life). In 1995 to 1996, subjects underwent 1.5-T MRI scanning; white matter lesions were rated in the deep subcortical and periventricular regions separately. Aortic atherosclerosis was assessed on abdominal radiographs that were obtained from 276 subjects in midlife and 531 subjects in late life. RESULTS: The presence of aortic atherosclerosis during midlife was significantly associated with the presence of periventricular white matter lesions approximately 20 years later (adjusted relative risk, 2.4; 95% CI, 1.2 to 5.0); the relative risks increased linearly with the severity of aortic atherosclerosis. No association was found between midlife aortic atherosclerosis and subcortical white matter lesions (adjusted relative risk, 1.1; 95% CI, 0.5 to 2.3) or between late-life aortic atherosclerosis and white matter lesions. CONCLUSIONS: The pathogenetic process that leads to cerebral periventricular white matter lesions starts already in or before midlife. The critical period for intervention directed at prevention of white matter lesions and its cognitive consequences may be long before these lesions become clinically detectable.

Age Factors↗
PubMed2000

MR imaging-guided sonography followed by fine-needle aspiration cytology in occult carcinoma of the breast.

OBJECTIVE: In patients with axillary metastases as clinical evidence of possible occult breast cancer, a combined approach of MR imaging, sonography, and aspiration biopsy cytology was evaluated. SUBJECTS AND METHODS: Thirty-one women with metastatic adenocarcinoma in their axillary lymph nodes originating from an unknown primary site underwent MR imaging of the breast because physical examination and mammography findings were normal. Twenty of the 31 women had no history of malignancy, 10 had been previously treated for contralateral breast cancer, and one patient had nodal metastases in the contralateral axilla at the time breast cancer was detected. When a contrast-enhancing lesion was revealed on MR imaging of the breast, sonography and fine-needle aspiration cytology were also performed. RESULTS: MR imaging revealed the primary breast cancer in eight (40%) of the 20 patients without a history of malignancy. MR imaging of the breast revealed a second primary cancer in three (27%) of the 11 patients with previous or simultaneous breast cancer. All lesions were identified with sonography and verified by cytology and histology. CONCLUSION: In women with axillary lymph node metastases from adenocarcinoma, MR imaging of the breast should be added to clinical examination and mammography before defining the breast cancer as occult. The combined approach of MR imaging, sonography, and aspiration fine-needle cytology is a good alternative to the MR imaging-guided biopsy.

Adenocarcinoma↗
PubMed2000

Rapid ELISA assay for plasma D-dimer in the diagnosis of segmental and subsegmental pulmonary embolism. A comparison with pulmonary angiography.

STUDY OBJECTIVE: To assess the accuracy of a rapid ELISA D-dimer assay for the exclusion of pulmonary embolism (PE) in patients suspected of PE, using pulmonary angiography alone as reference method rather than a diagnostic strategy including lung scintigraphy and leg vein ultrasonography. METHODS: In 342 patients who were examined by pulmonary angiography to diagnose or exclude PE, the accuracy of the quantitative rapid VIDAS D-dimer test for the exclusion of PE was evaluated retrospectively. D-dimer levels were assayed in frozen samples collected during the diagnostic work-up at the time of pulmonary angiography while on treatment with unfractionated heparin for 1-2 days. RESULTS: Mean plasma D-dimer concentrations were increased in patients with angiographic evidence of PE (P <0.0001). The sensitivity of D-dimer for segmental PE was 98%, its accuracy in excluding segmental PE was 99%, higher than the respective figures for subsegmental PE (76% and 94%; P <0.01, both). For both forms of PE combined the sensitivity was 90% and the negative predictive value 94%. DISCUSSION: The sensitivity and negative predictive values reported here, are low compared with previous studies using the same rapid ELISA D-dimer assay. This probably reflects an overlooking of mild cases of subsegmental PE in previous studies, although a reduction of D-dimer levels by the heparin pretreatment may have contributed to part of the discrepancy. Prospective studies are needed to clarify this issue.

Adult↗
PubMed1999

1H chemical shift imaging of the human brain at age 60-90 years reveals metabolic differences between women and men.

1H magnetic resonance spectroscopy was used to compare brain metabolism in 540 elderly persons, stratified by sex and age (60-90 years old). An 8 x 8 x 2 cm3 supraventricular brain volume, a transverse plane parallel to the canthomeatal line, was examined by automated 1H chemical shift imaging [point-resolved spectroscopy (PRESS), TE of 35 msec]. Regional choline (Cho), creatine (Cr), and N-acetyl aspartate (NAA) peak areas in the 518 successful examinations (96%) were studied by division through the total area of the particular metabolite in each spectral map. This procedure eliminated intersubject variance, maximized intervoxel variance (26 < or = F < or = 149, P < 0.0001) and reduced the standard deviations in the voxel metabolite signals threefold. Normalized signals in women (n = 257) and men (n = 261) differed in 9 (Cho/sigma Cho), 8 (Cr/sigma Cr), and 10 (NAA/sigma NAA) of 36 voxels examined (P < or = 0.001). In the cingulate gyrus Cho/sigma Cho, Cr/sigma Cr, and NAA/sigma NAA were reduced in men compared with women. These findings are consistent with a sex-related reduction of glucose metabolism in the same brain lobe revealed by positron emission tomography.

Aged↗
PubMed1999

A follow-up study of blood pressure and cerebral white matter lesions.

White matter lesions are often observed on cerebral magnetic resonance imaging scans of elderly people and may play a role in the pathogenesis of dementia. Cross-sectional studies have shown an association between elevated blood pressure and white matter lesions. We prospectively studied the relation between blood pressure and white matter lesions in 1,077 subjects aged 60 to 90 years who were randomly sampled from two prospective population-based studies. One study had blood pressure measurements 20 years before, the other 5 years before. Overall response for the magnetic resonance imaging study was 63%, and declined from 73% among 60- to 70-year-olds to 48% for 80- to 90-year-olds. Diastolic and systolic blood pressure levels assessed 20 years before were significantly associated with subcortical and periventricular white matter lesions. The association between 20-year change in diastolic blood pressure and subcortical white matter lesions was J-shaped (relative risk, 2.2; 95% confidence interval, 1.0-5.2; and relative risk, 3.2; 95% confidence interval, 1.4-7.4, for decrease or increase of more than 10 mm Hg, respectively). The association between concurrent diastolic blood pressure level and white matter lesions was linear in subjects without, and J-shaped in subjects with, a history of myocardial infarction. Our results indicate that the J-shape relationship of diastolic blood pressure is not restricted to cardiovascular disease, but is also manifest in cerebrovascular disease.

Age Factors↗
PubMed1999

[Comparison of conventional and high resolution 2D RARE MRCP in diagnosis of pancreaticobiliary diseases].

PURPOSE: Evaluation of high-resolution 2D-RARE MRCP in the diagnosis of pancreaticobiliary diseases. MATERIALS AND METHODS: 23 patients with various pancreaticobiliary diseases were evaluated using conventional and high-resolution 2D-RARE sequences. RESULTS: High-resolution RARE MRCP allowed for improved delineation of biliary and pancreatic ducts at the expense of reduced signal-to-noise ratio. Pathological findings were significantly (p < 0.001) better demonstrated with high resolution RARE MRCP (score 1.65 +/- 0.54) as compared to the conventional RARE sequence (score 2.58 +/- 0.62). CONCLUSIONS: High-resolution 2D-RARE-MRCP improves the delineation of biliary and pancreatic ducts. This sequence should replace the conventional 2D-RARE sequence.

Adult↗
PubMed1999

Magnetic resonance imaging of the coronary arteries: imaging planes and resulting anatomy in two-dimensional imaging.

Magnetic-resonance imaging techniques use different imaging planes than does conventional coronary angiography to acquire longer segments of a coronary artery in a single tomographic slice. At first sight, these planes appear rather puzzling, because the coronary arteries are displayed in unfamiliar orientations. In this article we will review the existing methodology for obtaining the orientations for the proximal coronary arteries and describe the associated anatomical landmarks that can be seen. Additional orientations for the middle segment of the circumflex and distal right coronary artery are introduced. These orientations are used both in various acquisition techniques and for evaluation of three-dimensional data when using multiplanar reformatting.

Coronary Vessels↗