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Biomedical subjects

E Henze

Publications and source records attributed to E Henze.

At least 55 records · Page 3Linked to original sources
PubMed1997

Ventilation scintigraphy of the middle ear.

UNLABELLED: In this study, an attempt was made to administer radioactive gas into the tympanic cavity to measure initial gas trappings as well as clearance from the middle ear to evaluate eustachian tube function. METHODS: Twenty-eight patients were administered 50 MBq 133Xe gas. Three different methods for gas application were tested: (a) direct injection through a tympanostomy tube in two patients, (b) administration through a nasopharyngeal catheter combined with Valsalva maneuvers in six subjects without middle ear dysfunction and (c) insufflation into the pharyngeal space through a nose olive performed in 12 patients with normal eustachian tube function and in eight patients with one-sided tube dysfunction. RESULTS: All three approaches were successful in visualizing middle ear ventilation, demonstrating tracer trapping within the tympanic cavities in 20 of 28 patients. Semiquantitative evaluation by region of interest techniques revealed a left-to-right uptake ratio of 48.4%-51.6% in 13 patients without tube dysfunction. Five patients with one-sided tube dysfunction showed a significantly lower median uptake of 31.6% (p = 0.01). The clearance half-lives ranged from 9 to 283 min in normal subjects and 37-64 min in patients with one-sided tube malfunction, demonstrating no statistically significant difference between the two groups and a trend towards increased washout in patients with tympanic dysfunction. CONCLUSION: Middle ear ventilation scintigraphy with 133Xe through a nose olive is an easy-to-perform test to evaluate eustachian tube function and has a success rate of about 70%, thus, reflecting the complex physiological mechanisms involved.

Adult↗
PubMed1997

[Quantitative salivary gland scintigraphy--a recommended examination prior to and after radioiodine therapy].

AIM: The aim of this study was to evaluate possible deterioration of salivary gland function due to radioiodine therapy with low activities using standardized quantitative salivary gland scintigraphy (qSZ). In addition, the prevalence of sialopathies was estimated in patients with thyroid dysfunction. METHODS: Prior to routine thyroid scintigraphy qSZ was performed after i.v. injection of 36-126 MBq 99mTc-pertechnetate, and both uptake and excretion fraction were calculated as a measure of parenchymal function and saliva excretion, respectively 312 healthy patients served as reference for a normal data base. 144 patients underwent qSZ prior to and 3 months after radioiodine therapy. Results of qSZ in another 674 thyroid patients were evaluated for determining the prevalence of salivary gland dysfunction. RESULTS: Normal uptake was 0.45 +/- 0.14% and 0.39 +/- 0.12%, and normal excretion fraction amounted to 49.5 +/- 10.6% and 39.1 +/- 9.2% in parotid and submandibular glands, respectively. Despite salivary gland stimulation with ascorbic acid during radioiodine therapy a significant activity-related functional impairment of 14-90% could be measured after application of 0.4-24 GBq of 131I. Prevalence of pretreatment sialopathies was 77/674 = 11.4% in single glands, and there was a global salivary gland functional impairment in 52/674 = 7.7%. CONCLUSION: Together with thyroid scintigraphy qSZ is an easy to perform examination without additional radiation burden. It can be recommended in all patients prior to and after radioiodine therapy both in order to quantify and to document possible parenchymal impairment induced even by low activities of 131I.

Adolescent↗
PubMed1996

Radiotherapy with iodine-131 in recurrent malignant struma ovarii.

Malignant struma ovarii is a very rare disease and, therefore, there is neither common agreement on treatment regimens nor sufficient follow-up experience. We present a case of a 49-year-old woman with malignant struma ovarii of the follicular type, who received ablative radioiodine treatment after thyroidectomy and surgical removal of the primary tumour. During follow-up examinations an increasing thyroglobulin level was found, caused by a tumour relapse with suspected urinary bladder infiltration on CT and proven uptake of radioiodine on whole-body scanning with iodine-131. After administration of 6GBq 131I, complete tumour regression was achieved with no evidence of a new relapse during a 30-month follow-up period. Correspondingly, repeated thyroglobulin measurements were all negative. This case demonstrates the benefit of combined surgical and radioiodine treatment of malignant struma ovarii for both monitoring and therapy of relapse or metastases; thus, the same therapeutic regimen as is employed in primary differentiated thyroid carcinoma may be recommended.

Biomarkers, Tumor↗
PubMed1996

Somatostatin receptor scintigraphy in the staging of small cell lung cancer.

The aim of this study was to evaluate somatostatin receptor scintigraphy (SRS) in the staging of patients with small cell lung cancer. Prior to chemotherapy, 20 patients were investigated up to 24 h following an injection of 200 MBq 111In-octreotide. Following chemotherapy and restaging, four patients were re-evaluated. Primary tumour was detected in 18 of 23 studies, which exhibited increasing target-to-back-ground ratios over time. Lymph node metastases and distant metastases were detected in 7 of 27 and 8 of 31 sites, respectively. Thus, the overall sensitivity for detecting metastases was less than 26%. SRS did not result in any upstaging of patients. We conclude that in patients with small cell lung cancer, functional imaging by SRS has no impact on clinical decision making.

Aged↗
PubMed1996

Somatostatin receptor scintigraphy in the differential diagnosis of meningioma.

The aim of this study was to evaluate somatostatin receptor scintigraphy (SRS) in patients with meningioma proven or suspected on magnetic resonance imaging (MRI). Prior to surgery, 47 patients were investigated up to 24 h following the injection of 200 MBq 111In-octreotide. Tracer uptake was compared with the histological presence of meningioma. Histology revealed 43 meningiomas, 3 neurinomas and 1 ependymoma. A true-positive SRS result was obtained in 36 patients, in 13 of whom a tumour volume of < 10 ml was noted. A false-negative SRS result was obtained in seven patients, all of whom had a tumour volume of < 10 ml. Whereas MRI alone was decisive in 38 of 47 patients, it could only provide a differential diagnosis in the remaining 9 patients. A positive SRS result confirmed meningioma in five of these patients, and a negative SRS result excluded meningioma in the other four. Therefore, cases of SRS-negative meningioma do exist. Nevertheless, significant clinical benefit can be obtained from functional imaging with 111In-octreotide in patients with an inconclusive MRI result, as large meningiomas can be excluded by scintigraphy alone, whereas meningiomas of any size may be confirmed in combination with specific MRI results.

Adult↗
PubMed1996

The value of bone scanning in pre-operative decision-making in patients with progressive facial asymmetry.

Hemimandibular elongation is characterized by persistent unilateral growth, resulting in unilateral overgrowth of the mandible. The surgical treatment strategy depends on condylar growth activity, which cannot be assessed by conventional radiological procedures. Therefore, this study was undertaken to evaluate the usefulness of bone scanning in hemimandibular elongation. Twenty-seven patients underwent bone scanning prior to surgery. Growth activity was quantified by calculating the L/R ratio. In the case of more pronounced right-sided growth producing a L/R ratio of less than 1, inverse values were used. Corrective osteotomy was performed in the patients with a L/R < 1.10, whereas patients with a L/R > 1.10 underwent condylectomy. Twenty-three patients had a L/R ratio < 1.10 and were followed up for 3 years. In 16 patients, a corrective osteotomy was performed without any relapse post-operatively. Four patients showed marked unilateral increased uptake. In one patient, a pre-operative bone scan was not considered, and corrective osteotomy was performed with subsequent recurrence of unilateral overgrowth of the mandible. The final patient underwent condylectomy without relapse. In two patients, it was decided to repeat the bone scan after a follow-up period of 12 months. In conclusion, bone scanning has significant clinical value in pre-operative decision-making in hemimandibular elongation by guiding surgical strategy with respect to condylar growth activity.

Adolescent↗
PubMed1996

Reproducibility of left ventricular volume measurements at rest and during bicycle exercise in patients with congestive heart failure: a combined radionuclide and haemodynamic study.

A series of 14 patients with heart failure due to coronary artery disease and impaired left ventricular function underwent radionuclide ventriculography with simultaneous thermodilution measurement of cardiac output by pulmonary artery catheter on two occasions (m1, m2) separated by 6 weeks in order to determine the reproducibility of haemodynamic and left ventricular volume measurements at rest and during supine bicycle exercise. The patients were in NYHA grade II or III and had baseline left ventricular ejection fractions below 40%. Derived haemodynamic variables were calculated from the thermodilution cardiac output and from the radionuclide ejection fraction as follows: stroke volume = thermodilution cardiac output/heart rate; left ventricular end-diastolic volume = stroke volume/ejection fraction; left ventricular end-systolic volume = end-diastolic volume - stroke volume. The percentage difference (PD) between each pair of data (m1, m2) was calculated using the following formula: PD = 100% x (m2-m1)/m1. The data showed that reproducible measurements of left ventricular volume can be obtained at rest and during exercise. The mean (+/- S.D.) PD values for end-systolic volume and end-diastolic volume at rest were - 0.1 +/- 17% and - 0.2 +/- 13%, respectively. The mean PD values for end-systolic volume and end-diastolic volume during exercise were - 0.3 +/- 19% and - 0.7 +/- 15%, respectively. By contrast, the reproducibility of the pulmonary capillary wedge pressure measurements was poor, as reflected by a PD value of 14 +/- 51% for exercise pulmonary capillary pressure. Combining radionuclide ventriculography and the thermodilution measurement of cardiac output is useful for measuring left ventricular volume at rest and during exercise in patients with heart failure. This minimally invasive technique allows for a comprehensive assessment of left ventricular performance and appears to be particularly suited for assessing the effects of therapeutic interventions aimed at minimizing the progressive left ventricular enlargement in heart failure.

Adult↗
PubMed1996

Quantitative salivary gland scintigraphy in the diagnosis of parenchymal damage after treatment with radioiodine.

This study was undertaken to quantify salivary gland parenchymal damage after radioiodine treatment with a standard protective regimen of ascorbic acid. Altogether, 106 patients underwent quantitative salivary gland scintigraphy with 99Tcm-pertechnetate prior to and 3 months after radioiodine therapy. Parenchymal function was quantified by calculating 99Tcm-pertechnetate uptake 13 min post-injection. Patients received 131I doses ranging from 400 MBq to 24 GBq (cumulative). Among the patients who received large doses of 131I, severe parenchymal destruction could be visually analysed as well as quantitatively evaluated. In contrast, after low-dose radioiodine treatment, mild parenchymal impairment was demonstrated by quantitative evaluation only. In conclusion, standardized quantitative salivary gland scintigraphy is essential for the reliable detection of mild parenchymal malfunction. Despite the standard protection regimen using ascorbic acid as a sialogogue, radioiodine therapy induces loss of salivary gland parenchymal function even with low doses of 131I.

Adult↗
PubMed1995

111In-octreotide imaging in patients with long-standing Graves' ophthalmopathy.

The aim of this study was to examine patients with long-standing Graves' ophthalmopathy using 111In-octreotide scintigraphy. Sixteen patients with inactive ophthalmopathy of up to 114 months duration and 14 normals were investigated for 48 h following an injection of 200 MBq 111In-octreotide. No significant tracer accumulation in the orbital region could be identified in any of the patients with long-standing Graves' ophthalmopathy. The orbit to brain (O/B) ratios after 24 and 48 h were 2.39 +/- 0.36 and 2.15 +/- 0.44 versus 2.17 +/- 0.33 and 2.20 +/- 0.37 for the patients and normals, respectively (N.S.). 111In-octreotide accumulation in ophthalmopathy described in the literature may thus be a passing event limited to its active stage, which is consistent with the concept of imaging a lymphocytic infiltration. In this study, the lack of accumulation of 111In-octreotide in the orbital region during the inactive stage demonstrates an absence of somatostatin receptors in orbital tissue itself. Thus, in patients with inactive Graves' ophthalmopathy, there is no basis for a diagnostic approach with somatostatin.

Case-Control Studies↗
PubMed1995

Value of quantitative salivary gland scintigraphy in the early stage of Sjögren's syndrome.

The aim of this study was to test the impact of quantitative salivary gland scintigraphy in patients with suspected Sjögren's syndrome. Thirteen patients with suspected Sjögren's syndrome were investigated. During clinical work-up, three had severe and four had mild Sjögren's syndrome, while six were normal. Quantitative salivary gland scintigraphy was performed using a standardized method. The normal data-base consisted of 172 patients without any evidence of salivary gland malfunction. Visual and quantitative comparisons of the patients' scintigrams were made. In the patients with severe Sjögren's syndrome, uptake was 0.10 +/- 0.04% and 0.09 +/- 0.03% in the parotid and submandibular glands respectively, confirming the visual diagnosis. In the patients without Sjögren's syndrome, concordance between the visual and quantitative evaluations could also be shown. In contrast, among the patients with mild Sjögren's syndrome, uptake was diminished (P < 0.05), amounting to 0.21 +/- 0.05% and 0.16 +/- 0.02% in the parotid and submandibular glands respectively, while visual analysis indicated normal parenchymatous function. In conclusion, quantitative salivary gland scintigraphy is essential for the reliable detection of parenchymatous malfunction at an early stage of Sjögren's syndrome, which may be missed by visual analysis alone.

Adult↗
PubMed1995

[DACS--a cost-advantageous nuclear medical document archiving and communication system].

A simple and inexpensive solution for the complete digital management of a nuclear medical institution is presented. The starting point was provided by five different gamma cameras, one of which was equipped with a PC-based ICON computer. The remaining cameras were first adapted to ICONs and subsequently integrated into a Macintosh LAN, of 15 computers, allowing the entire image acquisition, processing, interpretation, documentation and archiving to be performed on the same comfortable menu-guided surface. Complete patient management is accomplished by a specific commercially available data base to which a specially developed image and document archive was connected. The system described provides complete digital management without the conventional filing systems at the moderate price of approximately DM 11 x 10(4) plus the cost of the new camera computers.

Computer Graphics↗
PubMed1995

Reduction of exercise-induced myocardial perfusion defects by isosorbide-5-nitrate: assessment using quantitative Tc-99m-MIBI-SPECT.

BACKGROUND: Although nitrates were introduced more than 100 years ago and have been used for the treatment of angina pectoris, there are still some open questions concerning the mechanism of their action on myocardial ischemia. There are also insufficient data regarding the influence of any anti-ischemic medication on the results of myocardial perfusion scintigraphy. METHODS: To assess the influence of a mononitrate, 30 patients with stable angina pectoris, coronary stenosis > or = 70% and normal left ventricular function were examined using quantitative Tc-99m-MIBI exercise-single photon emission computed tomography (SPECT). On the same day, 5 h after a randomized double-blind dose of 60 mg sustained-release isosorbide-5-nitrate or placebo, SPECT was repeated with identical stress protocol. The results were analyzed using a semi-automatic polar coordinate program that allows definition of areas with significant decreased blood flow expressed as a percentage of standard vessel area. RESULTS: In the vessel areas with the largest perfusion defects, the mean defect size decreased after isosorbide-5-nitrate from 38.2 +/- 31.0% to 29.1 +/- 33.8% (reduction by 24%; P < 0.05) and increased from 35.2 +/- 27.6% to 36.6 +/- 27.4% after placebo (increase by 4%; P = NS). The difference between defect size changes was also significant (P < 0.05). CONCLUSION: Acute administration of sustained-release isosorbide-5-nitrate significantly reduces the size of exercise-induced perfusion defects as assessed using quantitative Tc-99m-MIBI-SPECT.

Adult↗
PubMed1993

Iodine-123 labelling of atrial natriuretic peptide and its analogues: initial results.

Receptors for atrial natriuretic peptide (ANP) are known to be present in many organs, e.g. brain, liver and kidney. The aim of this study was to optimize the labelling method for ANP analogues with iodine-123 and to describe their pharmakokinetics. ANP 99-126, atriopeptin III, Tyr-atriopeptin II and urodilatin were labelled by the Iodogen method. Of the various labelling conditions tested, the Iodogen procedure with 10 micrograms Iodogen, 10 micrograms peptides in 100 microliters phosphate buffer (pH 7.2) and a reaction time of 60 min proved to be optimal. Separation was performed using a Sep-pak reversed-phase extraction cartridge. In all cases quality control by thin-layer chromatography resulted in a radiochemical purity higher than 98%. After intravenous administration of 15 MBq/kg kinetic profiles of various organs in rabbits were investigated by whole-body scintigraphy with a gamma camera. Organ kinetics showed accumulation and excretion via the kidney. No bowel accumulation was observed. Interestingly, increasing tracer uptake in the head region was registered with three of the four tested tracers. Liver accumulation decreased rapidly during the first 40 min. No tracer degradation was registered over the whole time period, as shown by the low thyroid accumulation with a maximum of only 1%. Thus, labelling of ANF and its analogues is possible. These compounds seem to be of interest for further experiments and perhaps clinical studies because of their potential for brain receptor imaging.

Animals↗
PubMed1993

Abnormal ventricular contraction patterns in patients with arrhythmogenic substrates using three-dimensional phase analysis.

Arrhythmogenic substrate diagnosis has been achieved by electrophysiological studies and best localized by successful radiofrequency ablation. Pre-invasive localization procedures have been based on surface ECGs and more recently on biomagnetism, but in addition to these electric and magnetic signals a mechanical signal may be utilized: the initial site of contraction may be detected by phase analysis during radionuclide ventriculography. Generation of three-dimensional data set of phases is achieved by incorporating the new emission tomography technique. The performance of this modified phase analysis has been investigated for the detection of the normal contraction pattern during sinus rhythm, the arrhythmogenic substrate of the WPW syndrome and ventricular tachycardia, and further, to define the limitations of the method in experimental studies on pigs. In 30 out of 44 patients with normal sinus rhythm and no ventricular lesion, a characteristic phase pattern was found. Physiologically, the initial site of contraction appeared to be paraseptal and in the anterior wall of the right ventricle close to the apex. In 13 patients with WPW syndrome and in seven with ventricular tachycardia, the phase data were compared to the electrophysiological study. In 14 of 20 there was a complete match, in 3 of 20 a mechanical focus was found in the area adjacent to the electric focus. From experimental pig studies with simulated stimulation, a spatial precision of at least 20 mm was found at a pre-excitation of 20 ms.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Non-invasive three-dimensional localisation of arrhythmogenic foci in Wolff-Parkinson-White syndrome and in ventricular tachycardia by radionuclide ventriculography: phase analysis of double-angulated integrated single photon emission computed tomography (SPECT).

A new tomographic technique combined with phase analysis was used to detect premature and ectopic ventricular contraction patterns in 15 patients with Wolff-Parkinson-White syndrome and during ventricular tachycardia in seven patients. Data generated by gated single-photon emission computed tomography (SPECT) were analysed by backprojection of the Fourier coefficients, double-angulation, and integration to thick slices containing the ventricles, thus allowing visualisation of the contraction patterns in three perpendicular views. The results were compared with those of catheter mapping. In nine patients with Wolff-Parkinson-White syndrome the site of initial contraction detected was identical with the site of the accessory pathway found by catheter mapping. The sites of origin of the ventricular tachycardias determined by catheter mapping were within 3 cm of the sites detected by the new technique. This new technique seems to be a promising non-invasive method for localising ectopic ventricular activity that will considerably shorten the time required for subsequent invasive procedures.

Adult↗
PubMed1993

[Imaging procedures in preoperative lymph node staging of invasive bladder cancer. Necessary or superfluous?].

A staging programme for detection of lymph node involvement before radical cystectomy has been carried out in 22 patients. The programme includes: intravenous pyelography, chest X-ray, abdominal sonography, bone scan, CT and MRI. Also an immunoscintigraphic examination using monoclonal anti-CEA antibody (TUMAK BW 421/26) was done in every patient. Preoperative lymph node staging using CT, MRI and immunoscintigraphy was compared with post-operative histological staging: a total of 5 patients were found to have lymph node involvement. In none of them had lymph node involvement been predicted on the basis of CT, MRI or immunoscintigraphy.

Aged↗