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Biomedical subjects

K F Gratz

Publications and source records attributed to K F Gratz.

At least 37 records · Page 2Linked to original sources
PubMed1994

Bone scintigraphy in the evaluation of bone grafts used for mandibular reconstruction.

Bone scintigraphy was applied in the follow-up of 24 patients who received bone grafts for reconstruction of the mandible after partial resection. Semiquantitative assessment of the grafts was done with a six-grade scoring system, based on comparison of tracer uptake in the graft and in the calvarium (as an internal control). Sixty-nine bone scans were evaluated. Late planar imaging was carried out in all cases, and single-photon emission tomography (SPET) was performed additionally in 34 of these cases. Complications were observed in four grafts. They occurred less frequently in revascularized grafts than in non-revascularized grafts. Planar scintigrams performed within 14 days after reconstruction showed a significantly higher tracer uptake in grafts with an uncomplicated further course than in those which developed complications. Follow-up scintigrams after 1 and 3 months revealed a significant increase in tracer uptake in grafts with an uncomplicated course. This was not apparent in grafts which developed complications. The tracer uptake was estimated to be higher on the basis of the SPET scans as compared with the planar scintigrams. It is concluded that bone scintigraphy is of prognostic value in the evaluation of bone grafts used for mandibular reconstruction. SPET seems to be more sensitive than planar imaging for the assessment of graft viability.

Bone Transplantation↗
PubMed1994

[Quality control of fractionated port scintigraphy in patients with head and neck neoplasms].

The purpose of this study was to evaluate the precision of a technique for shunt measurement and to quantify its relevant influencing factors. Therefore, 10 patients underwent firstly an intraarterial injection of 100 MBq 99mTc-MAA and secondly a fractionated intravenous injection of 4 x 10 MBq 99mTc-MAA. Calculations of the shunt volumina were done with Wheeler's algorithm. In addition the relative shunt volumina for all applications were computed and corrected for (a) tracer retention, (b) biological degradation, (c) physical decay, (d) remaining activities and (e) the combination of (a)-(d). The coefficient of variation was 9.4%. The influence of (a), (b) and (d) was significant and that of (c) not significant. If all influencing factors were ignored (e), no significant differences could be seen, compared to the fully corrected results. Therefore, fractionated shunt scintigraphy is a simple and rapid technique for precisely determining relative shunt volumina in patients under local chemotherapy.

Adult↗
PubMed1994

123I-IBZM SPECT: reconstruction methodology and results in parkinsonism and dystonia.

In 58 patients with Parkinsonism or dystonia striatal dopamine D2 receptors were investigated using 123I-iodobenzamide (123I-IBZM) single-photon emission computed tomography (SPECT). The influence of SPECT reconstruction methodology on semiquantification and the clinical value of 123I-IBZM SPECT were evaluated. Delineation of the striatal uptake and striatum/frontal cortex (ST/FC) ratios were improved by the use of compensation procedures for scatter and attenuation as well as the choice of an adequate filter. Satisfactory results were achieved using a Metz prefilter with a comparatively high order number (i.e. high cut-off and low suppression of higher frequencies via roll-off). Regarding clinical diagnoses it was not possible to differentiate between advanced idiopathic Parkinson's disease (IP) and Parkinsonism of other aetiology (OP) on the basis of 123I-IBZM SPECT. But patients with IP and favourable response to L-Dopa showed significantly higher ST/FC ratios than those with fluctuating response. In patients with dystonia ST/FC ratios were significantly higher compared to patients with IP or OP.

Adult↗
PubMed1994

[Scintigraphy using 131I in oxyphilic carcinomas of the thyroid gland].

The aim of the study was to ascertain the role of 131I scintigraphy (RIS) in the follow-up of oxyphilic thyroid carcinomas (OTC). It is discussed that metastases (M) and local recurrencies (LR) are incapable of accumulating 131I sufficiently; therefore, the usual strategy of RIS cannot be used for follow-up. The re-examination of 91 patients suffering from OTC showed that 10/20 patients with M/LR did have a positive uptake of 131I, which could be used for therapy in 8 patients. An ablation of M using high-dose 131I therapy could be demonstrated in three younger patients who had cervical lymph node M 3 months after thyroidectomy as an early manifestation of their disease. In three patients RIS first led to the metastatic site. The clinical course of patients with distant M that developed at a later stage was unfavourable, even though they did accumulate 131I. Patients with positive uptake of 131I in M/LR were significantly younger (55a) than patients who had no uptake (67a) and belonged more often to stage I and II of UICC, namely 7/10 vs 2/10. RIS should be used especially in an early interval after thyroidectomy and individually for follow-up: as a diagnostic method and therapeutic instrument.

Adult↗
PubMed1993

[Functional scintigraphy in the follow-up of transplants].

Nuclear medicine procedures have special indications in the follow-up of transplanted patients: In case of renal transplantation perfusion, function (glomerular filtration) and urinary flow measured by bolus application of 99mTc-DTPA is an important tool to detect and monitor acute tubular necrosis, rejection, urinary leakage, obstruction or vascular complications. This method is used for pancreatic grafts, too. To exclude rejection in case of heart transplantation more than one year after operation the antimyosin antibody scintigraphy is introduced avoiding biopsies. The radionuclide ventriculography is able to monitor heart function by determining the ejection fraction. Cholescintigraphy in liver transplants is sensitive to detect complications of bile flow. In case of an auxiliary liver transplantation a competition between two livers has been described. This method allows a distinction of functional performance of donor and recipient liver. The same problem is solved by ventilation-perfusion scan in lung transplants. Bone scintigraphy is of prognostic value for graft viability. Other radionuclide examinations have been developed to measure perfusion, glucose-, fat-metabolism to detect rejection episodes, abscesses or tumor recurrencies.

Bone Transplantation↗
PubMed1992

[The clinical course of oxyphilic carcinoma of the thyroid].

In a total of 1665 patients with malignant thyroid neoplasms 90 oxyphilic thyroid carcinomas (OTC) were found of whom 55 could be re-examined and newly classified. Morphological and clinical parameters influencing the clinical course were determined. During a mean follow-up period of 6.5 y metastases or local recurrent disease occurred in 12 patients (24%). Apart from 3 early manifestations of metastases, 9 patients developed recurrent disease within, on average, 4.7 y after thyroidectomy: local lymph node metastases and local recurrences occurred within an average of 5.4 y, distant metastases after only 2.7 y. Thyroglobulin proved to be reliable for follow-up with a sensitivity of 88% on levothyroxine and 75% on endogenous TSH-stimulation (specificity: 98%). The frequency of metastases and local recurrences correlated with age at the time of tumor diagnosis, the degree of invasiveness and the local tumor extension (pT4 vs. pT1-3), whereas other factors such as the absolute diameter of the tumor or patient's sex had no influence on the clinical course. The survival probability for 5 and 10 years was 95 and 75%, respectively. All OTC patients should be examined regularly at least once a year by cervical sonography and thyroglobulin measurement. Because 18% recurrences occurred within 4.7 y such examinations should be repeated beyond year 5 after thyroidectomy.

Aged↗
PubMed1991

[Multiple organ failure. Reflection of generalized cell damage of all organs following severe trauma].

Multiple organ failure (MOF) is presently recognized as the most severe, and often lethal, complication after multiple trauma. Causal factors and pathomechanisms remain unclear, however. Generalized inflammatory cell tissue injury with a subsequent increase in permeability in all organs has been suggested. For this reason, 38 polytraumatized patients were examined in a prospective study. Organ function was analyzed, and specific clinical and histological studies were performed to check for generalized cell tissue damage and increased respiratory permeability. In all organs we found signs of tissue damage immediately after trauma. Disturbances of organ function were seen consistently, starting precisely from day 4. It was not possible to confirm an influence of blunt organ trauma on organ function during follow-up. The severity of injury (especially intrathoracic and intraabdominal) and massive bleeding increases the risk of MOF. MOF was not always associated with the onset of sepsis, and no temporal dependence could be shown. Histological studies demonstrated an inflammatory change in organ tissues, which is probably the result of toxic substances (endotoxin, TNF, oxygen radicals, proteases and eicanosoids) released into the blood circulation after trauma. Insufficient neutralization of these toxic metabolites leads to generalized permeability damage and consequently to progressive organ failure. Therefore, even with optimized initial treatment of multiple trauma patients, MOV and mortality can only be reduced with a causal approach to therapy.

Adolescent↗
PubMed1991

Noninvasive measurement of lung carbon-11-serotonin extraction in man.

The fraction of serotonin extracted on a single passage through the lungs is being used as an early indicator of lung endothelial damage but the existing techniques require multiple arterial blood samples. We have developed a noninvasive technique to measure lung serotonin uptake in man. We utilized the double indicator diffusion principle, a positron camera, 11C-serotonin as the substrate, and 11CO-erythrocytes as the vascular marker. From regions of interest around each lung, we recorded time-activity curves in 0.5-sec frames for 30 sec after a bolus injection of first the vascular marker 11CO-erythrocytes and 10 min later 11C-serotonin. A second uptake measurement was made after imipramine 25-35 mg was infused intravenously. In three normal volunteers, the single-pass uptake of 11C-serotonin was 63.9% +/- 3.6%. This decreased in all subjects to a mean of 53.6% +/- 1.4% after imipramine. The rate of lung washout of 11C was also significantly prolonged after imipramine. This noninvasive technique can be used to measure lung serotonin uptake to detect early changes in a variety of conditions that alter the integrity of the pulmonary endothelium.

Carbon Radioisotopes↗
PubMed1990

[Early and late HMPAO-SPECT during an epileptic seizure].

For presurgical evaluation of epilepsy a 44-year old patient with complex-partial seizures underwent HMPAO-SPECT. The morphology of the seizures, the MRI-scan, psychometry and ictal as well as interictal EEGs showed a left temporal origin of the seizures. Early images were obtained 20 min and late images 24 h following injection. On both scans a marked hyperperfusion was observed in the left temporal area. A crossed cerebellar diaschisis was also seen on both SPECTs. It could be shown that during ictal examinations there is no bloodflow-dependent wash-out from brain tissue.

Adult↗
PubMed1989

[Humoral and cellular changes of non-specific immune response following severe trauma].

The influence of trauma and hemorrhagic shock on the non-specific immune system has been pointed out in various experimental studies. Other investigations have also been able to find a relationship between these changes and a higher incidence of post-traumatic complications in the form of organ failure. Our aim was to demonstrate the potential changes in the cellular defense system in a clinical study on multiple trauma patients. The polymorphonuclear leukocytes (PMNL) are the main representative of the mobile, non-specific immune system. Our study revealed a significant deterioration of PMNL function after trauma. The metabolic activity and phagocytic function were mainly affected by a decrease in the concentration of so-called "opsonins." The opsonins are important for the identification and engulfment of debris (necrosis, fat emboli and thrombi) and bacterial substances (endotoxin). Next to the opsonin level, a change in the receptor configuration is important for phagocytosis. However, we could not find any substantial evidence of surface receptor alteration. The reticuloendothelial cells (RES), a stationary phagocytic system, also showed a significant reduction in clearance function in these polytraumatized patients. Similar to PMNL, these disturbances were based on the reduction of the opsonine concentration. We were able to demonstrate a significant disturbance in immune function in multiple trauma patients with post-traumatic complications compared to patients with a normal clinical course after injury. Disturbances in the PMNL function (seen after 4 days) were found to appear after the RES disturbances. Systemic interaction between these two phagocytic systems cannot be excluded and further investigation is therefore required.

Adolescent↗
PubMed1988

[Surgical therapy of sporadic and familial pheochromocytoma].

From 1975 through 1987, 54 patients underwent operations for pheochromocytoma (PCC): 37 patients for sporadic unilateral adrenal PCC, 9 for bilateral and familial PCC, and 4 patients for paraganglioma. In 4 additional patients, laparotomy failed to discover the reason for hypercatecholaminemia. There were no operative mortality and a low morbidity for unilateral (n = 43) as well as for bilateral adrenalectomy (n = 6). To avoid hormone replacement therapy after bilateral total adrenalectomy at least for some years, unilateral instead of bilateral adrenalectomy was preferred to be the initial surgical procedure of choice for familial and MEN-IIA-associated unilateral adrenal PCC. Autologous transplantation of the adrenal cortex were performed in 2 patients after bilateral adrenalectomy. 6 months postoperatively, the transplants were vital as proved by light-microscopy, but sufficiently functioning only in 1 patient.

Adolescent↗
PubMed1988

[Ulcer detection using 99m Tc-sucralfate].

Sucralfate is an agent commonly used in the therapy of gastrointestinal ulcers. It binds itself to proteins in the ulcer crater. A selective labeling with pure 99mTc-pertechnetate is possible. For an unequivocal ulcer localization or exclusion, images have to be taken in the upright and supine positions. Encouragement of gastric emptying is useful. Images should be taken at least twice, the last one 4 h after ingestion. The method might be used when endoscopy is difficult, incomplete or contraindicated, and for follow-up during therapy. We recommend it also in the search for the cause of intermittent bleeding.

Duodenal Ulcer↗
PubMed1985

[Dynamic reflux scintimetry for quantifying gastroesophageal reflux in patients with prolonged esophageal transit].

A combination of a radionuclide transit test and a dynamic gastroesophageal scan was evaluated in normal volunteers, in patients with achalasia treated by pneumatic dilatation (n = 34) or Heller myotomy (n = 21). Interpretation of 31 of 57 examinations done with usual scintiscan was not possible because of too high esophageal tracer retention. Only one case could not be interpreted with the modified technique. Gastroesophageal reflux was detected and quantified in this manner in 8 patients, 6 more than with the usual scintiscan. 7 of these 8 patients have had Heller procedure, 1 patient even combined with fundoplasty.

Adult↗
PubMed1985

[Nuclear medicine demonstration of esophageal bile reflux].

Biliary and pancreatic juice has been implicated as a cause of regional inflammation or carcinoma after gastric surgery. We studied 38 patients after gastrectomy using a modification of cholescintigraphy (185 mBq 99m-Tc-DESIDA i.v.). As soon as the tracer had reached the duodenum, a dynamic study (30 min, 120 frames) was started. Thereafter a static image of the epigastrium and thorax in the anterior view with more than 1000 cts/cm2 was recorded. This procedure was repeated after a meal. Of 29 patients without complaints only 4 had a reflux into the jejunal loop. By contrast in 7 of 9 patients with suggestive symptoms this examination demonstrated bile reflux which reached the oesophagus in 6 cases. A stenosis of the distal oesophagus prevented oesophageal reflux in one patient. 2 patients with oesophageal reflux had a history of oesophageal stenosis and oesophagitis confirmed by endoscopy. The remaining 2 patients without demonstrable reflux had neither oesophagitis nor radiologically verified reflux. Cholescintigraphy as modified by us may detect clinical relevant bile reflux into the oesophagus. This is important for surgeons selecting patients with potential benefit from a reoperation. Since most patients with complaints after gastrectomy have had demonstrable bile reflux, reflux-reducing surgical techniques should be used in all.

Bile Reflux↗