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Biomedical subjects

M J van Kroonenburgh

Publications and source records attributed to M J van Kroonenburgh.

At least 19 recordsLinked to original sources

[Progressive lymphoedema in the legs of children and adolescents].

In three children, two girls aged 18 months and 15 years and a boy aged 16 years, lymphoedema of the legs was diagnosed. Investigation by dynamic lymphoscintigraphy showed no or diminished activity of lymph vessels in the lower extremities. The patients were treated by manual compression therapy and compression stockings, which controlled the oedema. Early recognition and diagnosis are important, as otherwise irreversible complications and reduced mobility may occur.

Adolescent↗

MR imaging, single-photon emission CT, and neurocognitive performance after mild traumatic brain injury.

BACKGROUND AND PURPOSE: Mild traumatic brain injury (mTBI) (Glasgow Coma Scale = 14-15) is a common neurologic disorder and a common cause of neurocognitive deficits in the young population. Most patients recover fully from mTBI, but 15% to 29% of patients have persistent neurocognitive problems. Although a partially organic origin is considered likely, little brain imaging evidence exists for this assumption. The aims of the present study were to establish the prevalence of posttraumatic lesions in mTBI patients on MR images and to assess the relation between these imaging findings and posttraumatic symptoms. Secondly, we explored the value of early posttraumatic single-photon emission CT (SPECT) for the evaluation of mTBI. METHODS: Twenty-one consecutive patients were included in the study. Patients underwent MR examination, technetium-99m hexamethylpropylene amine oxime SPECT, and neurocognitive assessment within 5 days after injury. Neurocognitive follow-up was conducted 2 and 6 months after injury, and MR imaging was repeated after 6 months. Lesion size and brain atrophy were measured on the MR studies. RESULTS: Twelve (57%) of 21 patients had abnormal MR findings, and 11 (61%) of 18 had abnormal SPECT findings. Patients with abnormal MR or SPECT findings had brain atrophy at follow-up. The mean neurocognitive performance of all subjects was within normal range. There was no difference in neurocognitive performance between patients with normal and abnormal MR findings. Patients with abnormal MR findings only showed significantly slower reaction times during a reaction-time task. Seven patients had persistent neurocognitive complaints and one patient met the criteria for a postconcussional syndrome. CONCLUSION: Brain lesions are common after mTBI; up to 77% of patients may have abnormal findings either on MR images or SPECT scans, and these lesions may lead to brain atrophy. The association between hypoperfusion seen on acute SPECT and brain atrophy after 6 months suggests the possibility of (secondary) ischemic brain damage. There is only a weak correlation between neuroimaging findings and neurocognitive outcome.

Adolescent↗

Radiosynthesis and biodistribution of 123I-labeled antagonists of the histamine H3 receptor as potential SPECT ligands.

We have synthesized three 123I-labeled histamine H3 receptor ligands, i.e., [123I]GR 190028, [123I]FUB 271, and [123I]iodoproxyfan, in moderate to good radiochemical yields via a Cu+-assisted I-for-123I exchange method. Biodistribution in the rat of these compounds revealed high hepatic and pulmonary uptake. Brain uptake was moderate, but for [123I]iodoproxyfan, brain uptake was high enough for a pilot single photon emission computed tomography (SPECT) study in the rabbit. However, for this compound, the cerebral uptake could not be blocked by a pretreatment with [R]-alpha-methylhistamine, a selective, high-affinity histamine H3 receptor agonist, both in the SPECT study in the rabbit and in the biodistribution study in the rat. Apparently, [123I]iodoproxyfan is binding to a non-H3 receptor binding site. None of the three investigated compounds is suitable for use as a SPECT ligand for the H3 receptor in the brain.

Animals↗

Sustained local drug delivery from a radiopaque implanted reservoir.

A new polymeric biomaterial that contains covalently bound iodine, and is therefore radiopaque, was used to construct a sustained local drug-delivery device. A polymeric wall was designed to be porous (i.e., passage of low-molecular-weight molecules across the wall is possible), self-healing, and biocompatible. Once implanted, the sphere cavity can be filled and refilled with a concentrated solution of a (cytostatic) drug, which is subsequently released by slow diffusion into the tissue region surrounding the sphere. This principle of sustained local drug delivery is shown by a series of in vitro experiments on the release of 5-fluorouracil, and in vivo animal experiments, using x-ray fluoroscopic and scintigraphic techniques.

Animals↗

Lung and gastric uptake in bone scintigraphy of sarcoidosis.

We report on 99mTc-MDP uptake in lungs and stomach in a patient with hypercalcaemia and renal failure due to elevated 1,25(OH)2vitD3 because of sarcoidosis. Presently, this typical scan pattern has only been described in patients with malignancies, parathyroid adenoma and drug-induced vitamin D intoxication. We offer possible explanations for the findings in our patient.

Aged↗

Baseline and postcaptopril renal blood flow measurements in hypertensives suspected of renal artery stenosis.

UNLABELLED: Renal blood flow (RBF) measurements using first-pass radionuclide angiography with DTPA, a glomerularly filtered agent, failed to show significant differences between normal and stenotic kidneys. Since MAG3 is an ideal agent for the study of RBF, this agent might be an attractive alternative tracer to detect differences in RBF. METHODS: An angiographically controlled prospective study was performed in 48 hypertensive patients, in whom a diagnosis of renovascular hypertension was suspected on clinical grounds. The study was done to determine whether RBF measurements using first-pass radionuclide angiography with 99mTc-MAG3 could be helpful in the diagnostic work-up of the patients. Additionally, the study was done before and after ACE-inhibition. RESULTS: On renal angiography, 29 patients showed to have normal renal arteries (50 patients had normal kidneys and 8 patients had small kidneys). Nineteen patients had renal artery stenosis (13 uni- and 6 bilateral disease). In the patients with normal kidneys, the mean value of RBF measurements ranged from 10.5% to 10.9% of cardiac output. Only small stenotic and small kidneys with normal renal arteries showed a significant reduced baseline RBF as compared with normal kidneys (both p < 0.05); this difference disappeared after ACE-inhibition only for the small kidneys with normal renal arteries. In patients with stenosed kidneys, RBF tended to be reduced both at baseline and after captopril, but the differences with normal kidneys were not statistically significant. After ACE-inhibition RBF increased in the majority of kidneys, but postcaptopril RBF data did not differ significantly from those at baseline. CONCLUSION: RBF measurements using first-pass radionuclide angiography with 99mTc-MAG3, either before or after ACE-inhibition, cannot reliably discriminate between patients with essential hypertension and patients with renal artery stenosis.

Captopril↗

Interpretation of captopril renography by nuclear medicine physicians.

UNLABELLED: This study was designed to assess intra- and interobserver variability and diagnostic accuracy of nuclear medicine physicians in their evaluation of baseline and captopril renograms. METHODS: The diagnostic performance of three experienced nuclear medicine physicians according to their interpretation of baseline, captopril and paired renograms was assessed. To this end, the readers evaluated the renograms of 28 hypertensive patients in whom a diagnosis of renovascular hypertension was suspected on the basis of clinical clues. All patients also underwent angiography. The readers were unaware of the angiographic diagnosis. RESULTS: Thirteen of 28 patients proved to have renal artery stenosis (8 unilateral, 5 bilateral) on renal angiography. The concordance in the renographic diagnoses between the three readers was reasonably good, with an intraobserver agreement and kappa (observed agreement corrected for chance) ranging from 64% to 89% and from 0.52 to 0.75, respectively, and an interobserver agreement and kappa ranging from 68% to 86% and from 0.61 to 0.82. The sensitivity of their interpretation of paired baseline plus captopril renograms in relation to the angiographic diagnosis is poor and below 50%. The post-test probability of RAS in case of a negative renographic study was found to be rather similar to the pre-test probability (prevalence) of 46%. Blinding readers to which renogram was obtained after captopril imaging increased their accuracy. CONCLUSION: The intra- and interobserver agreement between experienced nuclear medicine physicians who evaluate renograms was found to be reasonably good. Blinding readers as to which renogram is the pre- and post-captopril image seems to enhance their diagnostic accuracy in instances of positive scans.

Captopril↗

Eosinophilic enterocolitis diagnosed by means of technetium-99m albumin scintigraphy and treated with budesonide (CIR).

A patient with a 15 year history of diarrhoea of unknown origin is described. Scintigraphy with technetium-99m labelled albumin suggested albumin loss at the terminal ileum and caecum; subsequent colonoscopic biopsies of these macroscopically normal looking areas showed abundant infiltration with eosinophils. A diagnosis of eosinophilic enterocolitis was made. Treatment with prednisolone had good results, but had to be stopped because of severe side effects. Oral cromoglycate and mesalazine were not effective. Budesonide (CIR), a new topically active corticosteroid with very little systemic effects, was at least as effective as prednisolone without producing side effects.

Adult↗

The role of the spleen in pancreas transplantation.

Early graft thrombosis and rejection of the graft are the two major causes of graft failure in pancreas transplantation. Inclusion of the spleen in the pancreatic graft has been purported as a possible solution to both complications, but severe graft-versus-host disease led to abolishment of this procedure. By irradiating the donor spleen ex vivo during cold storage, we successfully prevented graft-versus-host disease, allowing us to evaluate the advantages of clinical pancreaticosplenic transplantation. This study reports our experience with 12 pancreaticosplenic transplantations. Using Doppler flow measurements, we have been able to examine the hemodynamic advantages. Our results confirm the purported benefit. Vascular resistance indices in the pancreatic graft are significantly lower when the donor spleen is included. This, however, did not lower the incidence of thrombosis (2 out of 12 cases) in our study. Serial radionuclide studies with 99mTc-hexamethyl propylene amine oxime were performed for further evaluation of graft perfusion. With time the spleen uptake diminishes, compatible with atrophy of the organ. This was confirmed histologically. No indication of an immunologic advantage of transplanting the pancreas together with the spleen was found. All patients went through severe rejection crises. A transient reduction in platelet count (55-88%, mean 71%) of preoperative values was observed. This platelet drop is not seen in patients with a pancreas without spleen transplantation. We conclude that in pancreas transplantation, inclusion of the irradiated spleen has no obvious advantages for early graft thrombosis and rejection of the graft.

Adult↗

Perfusion imaging of pancreas allografts using technetium-99m hexamethyl propylene amine oxime.

The vascular integrity and major changes in perfusion can be determined by visual interpretation of radionuclide flow studies. We studied the potential of a new radiopharmaceutical technetium-99m hexamethyl propylene amine oxime (99mTc-HMPAO) in the particular setting of pancreas transplantation. Perfusion was measured by perfusion indices (PI). Changes in graft perfusion were estimated by three independent observers. A predefined scale from 0 to 4 was used, with 0 representing no visualisation of the graft and 4 denoting sharp countour delineation and distinct demarcation from the background. In order to investigate the relation between perfusion of the pancreas graft and its exocrine function, we measured the amylase excretion rate (AER) in the urine, expressed in units per hour. It is concluded that 99mTc-HMPAO is a suitable radiopharmaceutical for pancreas allograft imaging. For the assessment of the vascular integrity in the direct postoperative period, the scintigram is very reliable. Although a correlation between exocrine function of the graft and the perfusion score was not established, it is possible to make a clear sorting of AER measurements into different groups.

Amylases↗

Scintigraphic diagnosis of bile leakage after laparoscopic cholecystectomy. A prospective study.

To assess the role of Tc-99m IDA cholescintigraphy in diagnosing bile leakage and bile obstruction after laparoscopic cholecystectomy, 51 studies were performed in 51 patients on the first postoperative day. Two different radioactive bile acid analogs were used, Tc-99m HIDA and Tc-99m trimethylbromo IDA. Scintigraphic findings were correlated with the clinical conditions. Results of seven out of 51 cholescintigrams were abnormal, showing accumulations of activity in the right paracolic gutter. Of these seven patients, only three had clinical symptoms consisting of more than normal postoperative abdominal pain and peritoneal irritation. The other four patients had minimal abnormal accumulation in the right paracolic gutter and showed no clinical signs postoperatively. Complete common bile duct obstruction or other bile duct-related complications, except for bile leakage, were not observed. Cholescintigraphy is feasible for the early detection of bile leakage and bile flow obstruction after laparoscopic cholecystectomy in patients with increased postoperative abdominal discomfort.

Bile Duct Diseases↗

SPECT in the diagnosis of Alzheimer's disease and multi-infarct-dementia.

SPECT with Tc-99m HM-PAO as a radiopharmaceutical was performed in 17 patients meeting research criteria for Alzheimer's disease (AD), in 10 patients with a clinical diagnosis of multi-infarct-dementia (MID) and in 12 healthy volunteers. Regional tracer uptake was measured in frontal, parietal, and temporoparietal regions. A statistically significant decrease of tracer uptake in the temporoparietal region was found in AD-patients compared with controls. AD-patients showed less activity in this region than MID-patients, but this difference did not reach statistical significance. In both AD- and MID-patients decrease of tracer uptake was not correlated with dementia severity. We conclude that SPECT brain imaging is not yet ready for routine use in the distinction between AD and MID.

Aged↗

Hereditary cerebral hemorrhage with amyloidosis--Dutch type. Tc-99m HM-PAO single photon emission computed tomography.

We performed single photon emission computed tomography (SPECT) and cerebral CT-scans in nine patients with hereditary cerebral amyloid angiopathy. CT-scans showed 23 focal hypodense lesions, 13 of which were visible on SPECT as a CBF-defect. One patient showed a CBF-defect on SPECT without CT-scan lesion and had a cerebral hemorrhage three months later in that particular region. In two additional patients, who were 50% at risk for this autosomal dominant disease, CBF-defects on SPECT, but no cortical lesions on CT-scan were found. CT-scans may be more sensitive than SPECT to detect chronic lesions caused by cerebral hemorrhages, but another possibility is that hemorrhages do not always lead to persistent CBF-defects. SPECT can show the effect of amyloid deposits on CBF before the angiopathy causes clinical symptoms.

Amyloidosis↗

Imaging of ovarian cancer with radiolabelled monoclonal antibodies.

This article presents the state of the art of immunoscintigraphy (IS) of ovarian cancer. We will review the monoclonal antibodies (MoAbs) used in clinical trials: (HMFG1/2, OC125, H317, H17E2, NDOG2 and 791T/36). We conclude that none of the afore mentioned MoAbs are clearly superior and that IS cannot yet replace laparotomy for the diagnosis of ovarian cancer but may have a role in the follow-up of ovarian cancer, in timing second-look surgery and assessing the response/TD treatment.

Antibodies, Monoclonal↗

Intracerebral uptake of Tc-99m labeled antimelanoma antibodies.

A patient with an intraocular tumor showed accumulation of Tc-99m labeled antimelanoma antibodies in the head. This was not due to a metastatic lesion but proved to be a benign intracranial osteoma. The reasons for this false-positive result are discussed.

Aged↗

Imaging of acute myocardial infarction in pigs with Indium-111 monoclonal antimyosin scintigraphy and MRI.

Indium-111 antimyosin F(ab')2 was used in a series of scintigraphic studies on experimentally induced myocardial infarctions in pigs. Antimyosin distribution recorded by planar images of in vivo pigs and by single photon emission computed tomography (SPECT) of excised hearts delineated areas of myocardial necrosis if infarct volume exceeded 3.3 cm3. Scintigraphic images were compared with magnetic resonance images (MRI) obtained from excised hearts and with photographs of slices of the hearts. Infarct size and localization determined with antimyosin were compared. The MR images, with or without gadolinium-DTPA (Gd-DTPA), of the in vivo pigs were all false-negative; some myocardial wall thinning and high bloodpool signals were visible. Results show that both the antimyosin and the MR technique are specific methods for the visualization of induced myocardial necrosis in this animal model. However, the use of antimyosin is limited to a period ranging from 24 to 72 hours after infarction.

Animals↗