Biomedical subjects

I J Mertens

Publications and source records attributed to I J Mertens.

4 recordsLinked to original sources

PubMed2000

Aspirin renography and captopril renography in the diagnosis of renal artery stenosis.

UNLABELLED: Preliminary data suggest that aspirin renography is more sensitive than captopril renography for indicating renal artery stenosis (RAS). Considering that aspirin, compared with captopril, reduces renal blood flow and, thus, tubular tracer delivery in poststenotic kidneys, aspirin renography is expected to be more useful, particularly if tubular tracers are used. METHODS: We prospectively compared aspirin renography (20 mg/kg orally) and captopril renography (25 mg orally) with 99mTc-mercaptoacetyltriglycine in 75 consecutive patients suspected of having RAS. RESULTS: RAS, diagnosed as stenosis of more than 50% on angiography, was found unilaterally in 34 patients and bilaterally in 17 patients. RAS was absent in 24 patients. The sensitivities for unilateral RAS or bilateral RAS (i.e., stenosis that was at least unilateral) were, respectively, 88% and 88% for captopril renography and 82% and 94% for aspirin renography (not significant). The overall specificity was 75% for captopril renography and 83% for aspirin renography (not significant). Tracer uptake ratios, time to peak activity, and percentage of 20-min tracer retention were also not significantly different for captopril and aspirin renography. Subgroup analysis of modest (50-75%) and severe (> or =75%) RAS, or of plasma creatinine greater than 120 micromol/L, also showed no difference between captopril and aspirin renography. CONCLUSION: We conclude that for identification of RAS, the usefulness of aspirin renography equals, but does not surpass, that of captopril renography.

Aged↗

PubMed1999

Undetectable serum thyroglobulin in a patient with metastatic follicular thyroid cancer.

The case of a 54-year-old woman with metastatic follicular thyroid cancer and undetectable serum thyroglobulin is presented. Many years after the patient had a subtotal thyroidectomy for a large goiter that had no clear evidence of malignancy, metastatic bone disease developed. When the bone metastases were detected and during the follow-up period, serum thyroglobulin values remained undetectable, but radioiodine uptake in the metastases was abundant. This case indicates that the combination of 1-131 scintigraphy and serum thyroglobulin values is superior to the measurement of serum thyroglobulin alone in detecting well-differentiated, metastatic thyroid cancer.

Adenocarcinoma, Follicular↗

PubMed1999

Integrated visualization of functional and anatomic brain data: a validation study.

UNLABELLED: Two-dimensional SPECT display and three methods for integrated visualization of SPECT and MRI patient data are evaluated in a multiobserver study to determine whether localization of functional data can be improved by adding anatomical information to the display. METHODS: SPECT and MRI data of 30 patients were gathered and presented using four types of display: one of SPECT in isolation, two integrated two-dimensional displays and one integrated three-dimensional display. Cold and hot spots in the peripheral cortex were preselected and indicated on black-and-white hard copies of the image data. Nuclear medicine physicians were asked to assign the corresponding spots in the image data on the computer screen to a lobe and a gyrus and give a confidence rating for both localizations. Interobserver agreement using kappa statistics and average confidence ratings were assessed to interpret the reported observations. RESULTS: Both the interobserver agreement and the confidence of the observers were greater for the integrated two-dimensional displays than for the two-dimensional SPECT display. An additional increase in agreement and confidence was seen with the integrated three-dimensional display. CONCLUSION: Integrated display of SPECT and MR brain images provides better localization of cerebral blood perfusion abnormalities in the peripheral cortex in relation to the anatomy of the brain than single-modality display and increases the confidence of the observer.

Cerebral Cortex↗

PubMed1998

Fluorine-18-FDG detection of laryngeal cancer postradiotherapy using dual-head coincidence imaging.

UNLABELLED: The aim of this study was to investigate whether, in patients treated for laryngeal carcinoma, a differentiation was possible between local recurrence or local control using a dual-head SPECT camera with PET capability. METHODS: Eleven male patients (age range 51-71 yr; mean age 62 yr) who had previously undergone radiotherapy for laryngeal carcinoma were studied using 5 mCi (185 MBq) 18F-fluorodeoxyglucose (FDG). The mean interval between initial treatment and 18F-FDG PET was 21.9 mo (range 6-65 mo). Six patients had histologically proven local recurrence and five patients showed local control clinically. The mean follow-up in the local control group was 5.2 mo. RESULTS: Fluorine-18-FDG PET scans were positive in all six local relapses. Histopathological examination of the laryngectomy specimen revealed a mean tumor size of 2.6 cm (range 1.4-5.0 cm). In one patient, false-positive uptake was seen in an inflammatory lymph node. Fluorine-18-FDG PET scans were negative in all five patients with local control. CONCLUSION: It is possible to differentiate between local recurrence and local control in patients previously treated for laryngeal carcinoma with a dual-head SPECT scanner with PET capability.

Aged↗