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H Schicha

Publications and source records attributed to H Schicha.

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

Long-term follow-up of 82 patients with chronic disease of the thoracic aorta using spin-echo and cine gradient magnetic resonance imaging.

The objective of this study to examine the clinical impact of magnetic resonance imaging in long-term follow-up of patients (pts) with chronic disease of the thoracic aorta such as coarctation of the aorta, chronic aortic dissection and true aortic aneurysm. A total of 322 magnetic resonance examinations obtained in 82 pts with chronic disease of the thoracic aorta (31 pts with coarctation of the aorta (CoA), 29 pts with chronic aortic dissection and 22 pts with true aneurysm) over a period of 0.25 to 13.5 (mean +/- SD: 6.5 +/- 3.4) years were retrospectively reviewed. Diameters of the thoracic aorta were measured at predefined levels and morphological and functional parameters of special interest were analysed in each patient group. Pts were classified as having constant or progressive disease and clinical end-points were defined as (re-)operation or death. 43 pts (52%) (CoA 15 pts, chronic dissection 16 pts, true aneurysm 12 pts) had constant findings. None of them underwent (re-)operation and seven patients (16%) died, three of them from their aortic disease more than five years later after their last magnetic resonance examination, one from an arrhythmogenic event, and in the remaining 3 pts the cause of death could not be definitely established. 39 pts (48%) (CoA 16 pts, chronic dissection 13 pts, true aneurysm 10 pts) had progressive disease as demonstrated by repetitive magnetic resonance imaging. Of these 39 pts 24 pts underwent (re-)operation, in 15 pts operation was postponed. Four pts died from their aortic disease. Repetitive magnetic resonance imaging is a clinically feasible technique for long-term follow-up of pts with chronic disease of the thoracic aorta because it can detect progressive disease in a large subset of pts requiring elective surgery. The results of magnetic resonance imaging provided the rationale for either (re-)operation or conservative management, thus guiding patient management.

Adolescent↗
PubMed2000

Head to head comparison of dobutamine-transoesophageal echocardiography and dobutamine-magnetic resonance imaging for the prediction of left ventricular functional recovery in patients with chronic coronary artery disease.

AIMS: A substantial number of patients with dysfunctional but potentially viable myocardium cannot be accurately evaluated by transthoracic echocardiography due to a poor acoustic window. This study compares the diagnostic value of alternative functional imaging techniques, such as dobutamine-transoesophageal echocardiography (dobutamine-TEE) and dobutamine magnetic resonance imaging (dobutamine-MRI) for the detection of viable myocardium and the prediction of left ventricular functional recovery in patients with chronic coronary artery disease following successful revascularization procedures. METHODS AND RESULTS: Rest and low-dose (5, 10 microg dobutamine x min(-1) x kg(-1)) multiplane dobutamine-TEE and ultrafast cine-MRI studies were performed in 103 patients. Contractile recovery of an infarct region was predicted if a dobutamine contraction reserve could be assessed visually by TEE or MRI in > or =50% of infarct-related a- or dyskinetic segments. Revascularization of the infarct-related vessel was successful in 88 patients, and 4.9 +/- 0.7 months later 52 patients still had an angiographically controlled open target vessel. These patients underwent another rest MRI study to assess left ventricular functional recovery. A dobutamine contraction reserve was observed in 27/52 (52%) patients by TEE and in 26/52 (50%) patients by MRI. Functional improvement of the infarct region was diagnosed in 28/52 (54%) patients. The positive and negative predictive accuracy of dobutamine-TEE and dobutamine-MRI for the prediction of left ventricular functional recovery was not significantly different (85% vs 92%, ns and 80% vs 85%, ns). Diagnosis of a predominantly viable infarct region by TEE and MRI predicted a significant increase in left ventricular ejection fraction (TEE: 12 +/- 8% vs 2 +/- 7% P<0.001, MRI: 13 +/- 7% vs 2 +/- 7%, P<0.001) compared to infarct regions graded as scar. CONCLUSION: A qualitative visual analysis of TEE and MRI viability studies is highly accurate for the prediction of left ventricular functional recovery in patients with dysfunctional myocardium and proved to be a clinically valuable alternative if transthoracic dobutamine-echocardiography is unsuitable. To date, TEE is cardiologists' preferred choice for the assessment of myocardial viability but MRI may become significantly more attractive with increasing local availability and experience.

Aged↗
PubMed2000

Glucose metabolism of the thyroid in autonomous goiter measured by F-18-FDG-PE.

The radiolabeled glucose analogue F-18-Fluoro-Deoxyglucose (F-18-FDG) and Positron Emission Tomography (PET) were used to measure glucose metabolism of the thyroid in vivo. We evaluated patients with autonomous goitre before therapy with radioiodine in comparison to patients with normal thyroids. 30 patients with autonomous goitre underwent scanning the day before radioiodine therapy. 19 patients with head or brain tumours and normal thyroids were the controls. Overall F-18-FDG uptake was determined for all thyroids and proved to be significantly higher in autonomy patients compared to controls and in disseminated autonomous goitre slightly but not significantly higher than in focal autonomy. In autonomy patients F-18-FDG uptake increased with increasing radioiodine uptake and shorter radioiodine half-life. These results indicate that glucose metabolism is enhanced in the thyroids of patients with focal and disseminated autonomy. The negative correlation of radioiodine half-life and glucose metabolism as well as the positive correlation of radioiodine uptake and glucose metabolism suggest connections of glucose metabolism and iodine-dependent hormone synthesis in thyroid cells.

Adenoma↗
PubMed2000

2[F]-fluoro-2-deoxy-D-glucose positron emission tomography is a sensitive tool for the detection of occult primary cancer (carcinoma of unknown primary syndrome) with head and neck lymph node manifestation.

BACKGROUND: The neck lymph nodes are a common site of metastases from carcinoma of unknown primary (CUP syndrome). 2[(18) F]-fluoro-2-deoxy-D-glucose positron emission tomography (18-FDG-PET) has been shown to be a sensitive tool for detecting primary malignant lesions as well as metastatic spread. We have prospectively investigated the sensitivity of 18-FDG-PET in detecting occult primary carcinomas with manifestation in the head and neck lymph nodes. METHODS: From May 1994 to July 1998, in 723 patients a cancer of the head and neck was diagnosed at the University of Cologne ENT outpatient clinic. The routinely performed staging procedures were chest radiography; full blood count; cervical and liver ultrasound; endoscopy of the nasopharynx, oropharynx, hypopharynx, larynx, and esophagus; and laboratory analyses. After the staging workup, in 27 of 723 patients (3.7%) CUP syndrome had to be presumed because the primary cancer could not be detected. In these patients 18-FDG-PET was performed, and images were reconstructed with a transmission-emission fusion technique. RESULTS: In 7 of 27 patients (26%) 18-FDG-PET revealed an unknown primary: in 2 a bronchial carcinoma, in 2 a nasopharyngeal carcinoma, in 1 a squamous cell carcinoma of the parotid gland, in 1 a squamous cell carcinoma of the hypopharynx, and in 1 a carcinoma of the tonsil. In 4 of 7 patients the occult primary tumor was removed surgically. In 8 of 27 patients therapeutic strategy was changed as a result of the 18-FDG-PET findings. CONCLUSION: 18-FDG-PET should be performed in all patients with CUP syndrome after conventional diagnostic workup fails to identify the primary.

Adenocarcinoma↗
PubMed2000

Technetium 99m-MIBI-SPECT: A highly sensitive diagnostic tool for localization of parathyroid adenomas.

BACKGROUND: The aim of this study was to assess the value of technetium 99m-MIBI scintigraphy using the single photon emission computed tomography (SPECT) technique for preoperative localization of smaller (</= 1 g) parathyroid adenomas. METHODS: A total of 92 patients (34 men, 58 women; mean age, 60 +/- 13 years) with an established diagnosis of primary hyperparathyroidism and nondiagnostic ultrasonography (inclusion criteria) were scanned preoperatively. After a thyroid examination to check for other possible radionuclide-accumulating thyroid diseases, a planar technetium 99m-pertechnetate/technetium 99m-MIBI subtraction scintigraphy (15 minutes post injection) and tomographic images (120 minutes post injection) were acquired after intravenous injection of 740 MBq of technetium 99m-MIBI and using a 3-head gamma camera (Picker Prism 3000). Sensitivity was defined by the ability to predict the correct site of a parathyroid adenoma. RESULTS: All patients had parathyroid adenomas </= 1 g (53 patients, 0.5 -1.0 g; 39 patients, < 0.5 g). Correct localization of parathyroid adenomas to one side or the other was achieved in 87% of the patients using planar technetium 99m-pertechnetate/technetium 99m-MIBI subtraction scintigraphy. Sensitivity was increased to 95% by supplementary use of the SPECT technique and a 3-D display (volume-rendered reprojection for visualization). There was technetium 99m-MIBI accumulation in 11 benign thyroid nodes, but none of the healthy parathyroid glands were shown on the scan. CONCLUSIONS: This study indicates that technetium 99m-MIBI parathyroid scintigraphy is a sensitive and specific tool for topographic localization even of small parathyroid adenomas, especially with the use of SPECT. This method could help to improve the efficiency of parathyroidectomy (eg, by making unilateral exploration sufficient).

Adenoma↗
PubMed2000

Fluor-18-fluorodeoxyglucose positron emission tomography (FDG-PET) in malignant melanoma. Diagnostic comparison with conventional imaging methods.

PURPOSE: To assess the diagnostic value of fluor-18-fluorodeoxyglucose positron emission tomography (FDG-PET) in screening for melanoma metastases. MATERIAL AND METHODS: The case records of 94 melanoma patients who had been examined by whole-body FDG-PET between 1995 and 1999 were evaluated retrospectively. Forty patients showed evidence of lymphogenous and 42 of hematogenous metastasis. The maximal interval between PET and the diagnostic procedure under comparison was 2 weeks. Confirmation of the findings was based on histology or the clinical or radiological course. RESULTS: In 24 patients, all diagnostic examinations including CT had been performed within 2 weeks from PET. In no case did PET change the staging. In 13 patients, PET agreed with morphological diagnosis in the number of metastatically invaded organs. This included 3 patients without metastases. The estimated number of organs invaded by metastases was higher with PET in 5 patients and higher with morphological imaging techniques in 6 patients. Among the PET findings with higher or equivocal counts of organs with metastases there were 2 confirmed false-positive findings. CONCLUSION: In a selected patient population, FDG-PET was found to be inferior to CT for diagnosing lung and liver metastases. The supplementary use of FDG-PET is not generally of value once metastasis has been established.

Abdomen↗
PubMed2000

Hypothyroidism after therapy for larynx and pharynx carcinoma.

Early detection of local and regional recurrence is the main goal during follow-up of patients with larynx and pharynx cancer. Hypothyroidism occurring in those patients stays frequently undiagnosed as screening for hypothyroidism is not part of the routine follow-up. This study was performed to assess the prevalence of hypothyroidism in these patients. We included 120 patients (106 male, 14 female) with larynx or pharynx cancer treated more than 2 months earlier (mean = 41 months) in the study. Cancer treatment consisted of either surgery (n = 44), radiotherapy (n = 15), or surgery combined with postoperative radiotherapy (n = 61). In all patients, thyroid function studies (thyrotropin [TSH], free triiodothyronine [FT3], and free thyroxine [FT4]) were performed. Twenty-six of all patients (22%) were hypothyroid; in two patients hypothyroidism was diagnosed postoperatively and these two patients were on replacement therapy with thyroid hormones. The highest rate of hypothyroidism (34%) was present in patients treated with surgery combined with radiotherapy, whereas among patients treated with surgery only 7% were hypothyroid (p < 0.001). There was no difference in the duration of follow-up between therapy and inclusion in the study between those two groups. Two of 15 patients treated only with radiotherapy were diagnosed hypothyroid, but in this group the latency was shorter (p < 0.05). The results indicate that thyroid function studies should be routinely performed in the follow-up of head and neck cancer patients, especially if radiotherapy was part of the treatment.

Aged↗
PubMed2000

Follow-up of differentiated thyroid cancer: comparison of multiple diagnostic tests.

The radioablation of thyroid remnants improves the prognosis of differentiated thyroid cancer. In our prospective study an activity of 3.7 GBq 131I failed to completely ablate the remnants in 46 out of 101 patients, but a 3-year follow-up period was uneventful. One other patient had a recurrence early after thyroidectomy. In view of possible stunning effects of 131I it might be advantageous to visualize such remnants by imaging modalities which do not emit beta-particles. Our data have revealed that neither magnetic resonance imaging (MRI), nor ultrasonography (US), nor 99Tcm-sestamibi scintigraphy, nor positron emission tomography could detect or reliably exclude minimal remnants. Such remnants did not produce thyroglobulin (Tg). A 123I and 131I uptake of> 10% after thyroidectomy was associated with about a 90% probability of persistent remnants. On the other hand, MRI was helpful in the patient group (n = 32) with Tg>4ng x ml(-1) at the second whole-body scintigraphy (TSH>30 mU x l(-1)) for planning the management of lymph node metastases (n = 15 patients): 12 patients had subsequent surgery and three patients radioiodine therapy. We recommend that MRI be used early in follow-up care when Tg is elevated. The decision of whether or not to treat persistent thyroid remnants should not be made on the basis of MRI, US or nonspecific scintigraphic methods. Complete ablation did not appear to have any clinical benefit in our study group.

Adolescent↗
PubMed2000

Single-channel activity and expression of atrial L-type Ca(2+) channels in patients with latent hyperthyroidism.

Patients with "latent hyperthyroidism" (suppressed thyroid-stimulating hormone and normal circulating thyroid hormones) are at risk to develop atrial fibrillation. In animal models, hyperthyroidism is associated with increased cardiac L-type Ca(2+) current. Therefore, we assessed L-type channel function and expression in right atria from patients undergoing cardiac surgery. Single L-type channels were studied in the cell-attached condition. Voltage dependence of gating was similar in patients with and without latent hyperthyroidism. With use of a pulse protocol leading to maximum channel availability, single-channel activity was further analyzed. Average peak current was significantly enhanced in latent hyperthyroidism, mainly because of an increased channel availability (P < 0.05). Protein expression was analyzed by Western blot. In latent hyperthyroidism, expression of Ca(2+) channel alpha(1)-subunits was increased more than threefold (P < 0.01). In contrast, sarco(endo)plasmic reticulum Ca(2+)-ATPase and phospholamban levels were not significantly changed. We only observed a trend toward increased sarco(endo)plasmic reticulum Ca(2+)-ATPase expression (P = 0.085). Function and expression of human atrial L-type Ca(2+) channels are increased in latent hyperthyroidism. These endocrine effects on the heart may be clinically relevant.

Blotting, Western↗
PubMed2000

[Sonographic determination of thyroid volume--comparison with surgical data].

AIM: Objective of this prospective study was to find out, if especially the volume of large nodular goitres can be determined accurately by using ultrasonography and the ellipsoid model. METHODS: 100 patients with different thyroid disorders, who all underwent a thyroid resection, were examined by a single experienced investigator. The preoperative thyroid volume was determined by ultrasonography and correlated to the sum of surgically removed and postoperative thyroid volume determined by ultrasound. RESULTS: Patients included had thyroid volumes between 12 and 450 ml (mean value 89 ml). Within the whole study group, coefficients of correlation and variation were r = 0.90 and CV = 0.29, respectively. The mean difference between the thyroid volume determined preoperatively by ultrasonography and the sum of surgically removed and postoperative thyroid volume was 3 +/- 27 ml or 13 +/- 38%. Excluding patients with retrosternal goitres or cysts with a diameter > 2 cm, the correlation coefficient increased to r = 0.95 (CV = 0.21) and mean differences decreased to 2 +/- 20 ml and 9 +/- 30%. Further subdivision according to thyroid volume (< or = 50 ml, < or = 100 ml, > 100 ml) revealed no significant influence of thyroid volume on the accuracy of ultrasound volume determination. Subdividing the study collective according thyroid disorders, relevant deviations of preoperative sonographic thyroid volume from the sum of surgically removed and postoperative thyroid volume were observed in case of retrosternal goitre (19 +/- 62%), cystic degeneration (41 +/- 52%) and Graves' disease (23 +/- 29%). CONCLUSION: These results show, that even large suprasternal goitres > 100 ml can be sufficiently determined by ultrasound by an experienced examiner.

Adult↗
PubMed2000

[Effect of iodine application during radioiodine therapy in patients with impending therapy failure].

AIM: We investigated whether additional application of "cold" iodine after therapy with radioiodine could result in a prolongation of the effective half life of iodine-131 and would thus lead to an increase of the effective thyroid radiation dose. METHODS: Time-activity-curves after therapy with radioiodine were analysed in 25 patients (16 women, 9 men). Nine patients suffered from autonomously functioning thyroid nodules, 5 from autonomous multinodular goiter and 11 from Graves' disease. These patients had an effective half life shorter than 4 days resulting in an undertreatment of > 20% with respect to the desired effective thyroid radiation dose. 2-4 days after therapy with radioiodine all patients received "cold" iodine for three days in a dose of 3 x 200 micrograms per day. RESULTS: In 14 of the 25 patients an increase of the effective half life was observed. Patients with an autonomously functioning thyroid nodule showed a mean increase of the effective thyroid radiation dose of 40 +/- 44 Gy, patients with toxic multinodular goiter of 29 +/- 30 Gy and patients with Graves' disease of 37 +/- 37 Gy. CONCLUSION: Additional application of "cold" iodine after therapy with radioiodine can prolong the effective half life in selected patients. We suspect a correlation with the thyroid iodine pool. This will be the basis for further investigations hopefully resulting in a better patient preselection to determine who might respond to this therapy.

Adult↗
PubMed1999

[Clinical value of magnetic resonance tomography in imaging coronary stenoses. A comparison with coronary angiography and myocardial scintigraphy].

BACKGROUND AND OBJECTIVE: The development of ultra-rapid gradient-echo sequence magnetic resonance imaging (MRI) makes it possible to visualize coronary arteries. But the clinical value of coronary artery MRI (MRCA) still needs to be established. It was the aim of this study to determine whether MRCA can demonstrate proximal parts of the coronary arteries and visualize haemodynamically relevant stenoses. PATIENTS AND METHODS: MRCA was performed, using segmented 2D sequences and a navigator pulse, in 29 patients (22 men, seven women, mean age 60 +/- 10 years) in whom coronary heart disease (CHD) was suspected or who, with proven CHD (> or = 50% stenosis) further treatment was to be established. Exercise myocardial scintigraphy with single proton emission tomography (SPECT) was additionally performed in 20 of the patients. RESULTS: Seven of 87 coronary arteries (8%) could not be demonstrated because the patients' claustrophobia necessitated premature termination of the investigation: these vessels were excluded from the final analysis. The mean length of the visualized coronary arteries was 12 +/- 4 mm for the main stem (LM), 36 +/- 14 mm for the left interventricular branch (LAD), 18 +/- 12 mm for the circumflex branch (CX) and 67 +/- 23 mm for the right coronary artery (RCA). Of 37 stenoses demonstrated by coronary angiography 29 were also visualized by MRCA: 13 of 18 LAD stenoses, two of three CX stenoses and 14 of 16 RCA stenoses. Mean sensitivity of MRCA was 78%, mean specificity 86%. In patients who had undergone exercise SPECT, coronary angiography demonstrated 26 stenoses, of which 16 (six LAD, two CX and eight RCA stenoses) were haemodynamically significant. Of these 16 stenoses MRCA demonstrated 13, but three stenoses (one RCA and two LAD stenoses) were not visualized, because the stenoses were distal to the demonstrated segments. CONCLUSION: MRCA can visualize moderately severe stenoses, especially of the proximal coronary arterial segments. This method represents an new approach to noninvasive diagnosis of CHD, but additional technical improvements will have to be made.

Adult↗
PubMed1999

Magnetic resonance imaging of ductus arteriosus Botalli apertus in adulthood.

Ductus arteriosus Botalli apertus is a congenital cardiovascular malformation usually diagnosed in childhood by echocardiography and/or cardiac catheterization. Reports about magnetic resonance imaging of ductus arteriosus Botalli apertus are rare. We report about three adult female patients and one adult male patient in whom magnetic resonance imaging was able to demonstrate the pathology. In all four patients quantitative data about right ventricular function were calculated. Pulmonary hypertension with Eisenmenger syndrome detected by cardiac catheterization had developed in three of the four patients excluding operative closure of the ductus. The patient in whom pulmonary hypertension had not developed underwent successful operative closure of the ductus. Magnetic resonance imaging is a non-invasive tool that can be used for diagnosis of ductus arteriosus Botalli apertus and it allows to quantify right ventricular function. Magnetic resonance imaging can be used repetitively in patients with Eisenmenger syndrome which may be helpful for better timing of combined heart-lung transplantation as ultimate therapeutic strategy because deterioration of right ventricular function can be monitored.

Adult↗
PubMed1999

Economic evaluation studies in nuclear medicine: the need for standardization.

The guidelines for publishing economic evaluations require a statement of the economic importance of the analysis and the viewpoint from which it has been carried out, as well as specification of at least two alternative programmes or interventions, the form of economic evaluation, the outcome measure, the method of costing, the time horizon and adjustment for timing of costs and benefits (e.g. by a discount factor), and the allowance for uncertainties (e.g. by implementation of a sensitivity analysis). The decision analysis can be based on clinical trial data, on retrospective or administrative databases, or on modelling. The choice of outcome measures is the key issue in an economic evaluation. In cost-effectiveness analysis, benefits are usually measured in natural units. This is the form of economic evaluation most frequently used in nuclear medicine. Endpoints of effectiveness applied in studies in this field have been procedures avoided, procedures initiated, cardiac events, survival probability, morbidity, quality of life and protracted or failed surgical procedures. In other instances, surrogate endpoints have been used such as metastases detected, staging, viability or tumour response. This, however, limits comparability of cost-effectiveness considerably, as proof of a change in the health outcome cannot be obtained. Measures of utility such as QALYs (quality-adjusted life years) have so far only been applied for decision tree analysis. Useful examples of economic evaluation studies in nuclear medicine are presented here for fluorodeoxyglucose positron emission tomography (FDG-PET) in the preoperative staging of non-small cell lung cancer, for FDG-PET in differentiating indeterminate solitary pulmonary nodules, for somatostatin receptor scintigraphy in detecting metastases of carcinoid tumours, for routine preoperative scintigraphy with sestamibi in patients with parathyroid adenoma, for periodic measurement of thyroid-stimulating hormone in detecting mild thyroid failure, for diagnostic algorithms including a lung scan in patients with suspected pulmonary embolism, for myocardial perfusion imaging as an incremental prognostic factor in patients with coronary artery disease, and for the use of radioiodine as first-line therapy of Graves' hyperthyroidism and of toxic nodular goitres. Further evaluations of effectiveness or utility should be carried out within a multidisciplinary framework to ensure that nuclear medical procedures are included in the general management guidelines.

Cost-Benefit Analysis↗