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Biomedical subjects

K Reichmann

Publications and source records attributed to K Reichmann.

At least 19 recordsLinked to original sources
PubMed2006

Therapy of hepatocellular carcinoma with iodine-131-lipiodol. Results in a large German cohort.

AIM: To evaluate the efficacy and tolerance of iodine-131-lipiodol ((131)I-lipiodol) for hepatocellular carcinoma (HCC) in German long term patients and comparison with medically treated controls. PATIENTS, METHODS: 38 courses of intra-arterial (131)I-lipiodol therapy with a total activity up to 6.7 GBq were performed in 18 patients with HCC (6 with portal vein thrombosis). Liver and tumour volume and lipiodol deposition were measured by computed tomography and (131)I activity by scintigraphy. Therapeutic efficacy was determined by tumour volume change and matched-pairs analysis in comparison to medically (i.e. tamoxifen or medical support) treated patients. RESULTS: Tumour volume decreased in 20/32 index nodules (63%) after the first course. Repeated therapy frequently resulted in further tumour reduction. Overall response to treatment was partial in 11 nodules, minor response in 4 nodules, and disease was stable in 12 and progressive in 5. Significant response was associated with pretherapeutic nodule volume up to 150 ml (diameter of 6.6 cm). Survival rate after 3, 6, 9, 12, 24 and 36 months was 78, 61, 50, 39, 17, and 6%. Matched-pairs analysis of survival revealed (131)I-lipiodol to be superior to medical treatment. The most important side effect was a pancreatitis-like syndrome whereas overall tolerance was good. CONCLUSION: The long term results confirm that HCC therapy with (131)I-lipiodol is effective and probably superior to medical treatment. Tumour nodules of up to 6 cm diameter are well suited for this therapy even in the presence of portal vein thrombosis.

Aged↗
PubMed2004

[PET/CT imaging in head and neck tumors].

AIM: To evaluate the usefulness of combined PET/CT examinations for detection of malignant tumors and their metastases in head and neck oncology. METHODS: 51 patients received whole body scans on a dual modality PET/CT system. CT was performed without i.v. contrast. The results were compared concerning the diagnostic impact of native CT scan on FDG-PET images and the additional value of fused imaging. RESULTS: From 153 lesions were 97 classified as malignant on CT and 136 on FDG/PET images, as suspicious for malignancy in 33 on CT and 7 on FDG-PET and as benign in 23 on CT and 10 on FDG-PET. With combined PET/CT all primary and recurrent tumors could be found, the detection rate in patients with unknown primary tumors was 45%. Compared to PET or CT alone the sensitivity, specifity and accuracy could be significantly improved by means of combined PET/CT. CONCLUSION: Fused PET/CT imaging with [F18]-FDG and native CT-scanning enables accurate diagnosis in 93% of lesions and 90% of patients with head and neck oncology.

Adult↗
PubMed2004

Neuroimaging and 5-HT2C receptor polymorphism: a HMPAO-SPECT study in healthy male probands using mCPP-challenge of the 5-HT2C receptor.

BACKGROUND: The human 5-HT (2C) receptor gene has been localized on the X chromosome and is expressed in two genetic variants. Whereas previous investigations have suggested that the 5-HT (2C) receptor gene polymorphism is critically involved in the pathogenesis of affective and eating disorders, as yet the functional consequences being associated with the rare serine variant of the 5-HT (2C) receptor in humans are unclear. METHODS: We explored by HMPAO-SPECT if a challenge with the serotonin agonist mCPP, that interacts mainly with the 5-HT (2C) receptor, provokes different patterns of regional cerebral bloodflow (rCBF) as a function of the genetic variant of the receptor. Thus we studied its action in 16 healthy male volunteers carrying the common 5-HT (2C)-cys-23 receptor gene and 16 healthy male volunteers carrying the less frequent 5-HT (2C)-ser-23 receptor gene. RESULTS: We found significant differences in rCBF between the two genotypes after mCPP infusion compared to placebo: In the cysteine group rCBF was increased in the left medial prefrontal cortex and decreased in the left anterior cingulate and right medio-temporal cortex, whereas the serine group showed an increase of rCBF in the left medio- and superior-temporal cortex and in cerebellum and a reduced rCBF in the right medial prefrontal cortex. In addition, there was a significant disordinal interaction of the genotype factors and challenge with an increase of rCBF in the serine group and a decrease in the cysteine group in the left motor cortex and calcarine cortex. Additionally, a decrease of rCBF in the serine-group and a simultaneous increase in the cysteine group was found in the right anterior and the left posterior cingulate cortex. CONCLUSION: These findings suggest that differences in the 5-HT (2C) receptor gene polymorphism has functional consequences due to a different responsiveness of the expressed 5-HT (2C) receptor variants.

Adult↗
PubMed2003

[Effectiveness of syringe shieldings using radionuclides in radiation synovectomy].

AIM: The radiation exposure in radiation synovectomy was investigated for technician and therapist using Erbium-169, Rhenium-186 and Yttrium-90 with and without syringe shieldings. METHODS: Dose rates were measured in relation to the distance of the syringe containing the radionuclide. Measurements were repeated using syringe shieldings which consist of plastic surrounded by a lead layer. RESULTS: The most relevant radiation exposure arises from Yttrium-90. Using syringe shieldings radiation exposure can be reduced by a factor of thousand. CONCLUSION: This kind of radiological protection is completely sufficient for the therapist. Concerning the technician preparing the radiopharmaceutics, the limit of the official German dosimetry service (500 mSv) might be exceeded if no special radiological protection is established. Thus, special dosimetry is recommended.

Humans↗
PubMed2002

Comparison of [18F]FDG-PET and L-3[123I]-iodo-alpha-methyl tyrosine (I-123 IMT)-SPECT in primary lung cancer.

OBJECTIVE: The aim of this study was to evaluate L-3[123I]-iodo-alpha-methyl tyrosine (IMT)-SPECT and FDG-PET in pulmonary lesions suspected to be lung cancer. METHODS: Whole body PET (measured transmission corrected emission scans) was performed 45 minutes after i.v. injection of 222-370 MBq (6-10 mCi) 18F-FDG on a Siemens PET scanner (ECAT EXACT 47) including 5-6 bed positions. 123I-IMT-SPECT (chest) was performed after injection of 370 MBq (10 mCi) with a dual head camera (Picker Prism 2000) and commercially available reconstruction algorithms. Ten patients (6 male and 4 female) with suspected lung cancer were investigated. The results were compared to histological findings after surgery or bronchoscopic biopsies and CT. RESULTS: 123I-IMT-SPECT and FDG-PET were able to detect all 9 cases of lung cancer (1-8 cm in diameter). One case was true negative. Both imaging methods were true positive with respect to mediastinal lymph node metastases in one patient. The tumor/background ratio was higher with PET (8.20 vs. 2.84). CONCLUSION: Despite the limited number of patients it may be concluded that IMT-SPECT as well as FDG-PET are suited to correctly diagnose lung cancer. Nevertheless, FDG-PET, if available, seems to be better suited because of the higher tumor/background ratio and better resolution.

Carcinoma, Non-Small-Cell Lung↗
PubMed2001

Clarification by TEM and SIMS of abnormal Ti depth distribution in chemical solution-deposited SrTiO3/La0.5Sr0.5CoO3.

A chemical solution-deposited multilayer system of SrTiO3 ("STO")/La0.5Sr0.5CoO3 ("LSCO") on a platinized wafer with a layer sequence Pt/TiO2/SiO2/Si(bulk) has been investigated by dynamic SIMS (secondary ion mass spectroscopy) and TEM (transmission electron microscopy); element determination was performed with EELS (electron energy-loss spectroscopy). The STO layer is intended to serve as a dielectric layer for a microelectronic capacitor; the conducting LSCO layer is a buffer layer intended to eliminate fatigue effects which usually occur at the STO/Pt interface. The SIMS depth profiles obtained for the main components revealed intense diffusion processes which must have occurred during the deposition/crystallization processes. Ti is found to diffuse from the (insulating) STO layer into the conductive LSCO layer where a region of constant concentration is observable. TEM-EELS experiments showed that these Ti plateaus are caused by precipitates approximately 20-80 nm in diameter.

Journal Article↗
PubMed2000

Liver perfusion scintigraphy prior to and after transjugular intrahepatic portosystemic shunts (TIPS) in patients with portal hypertension.

PURPOSE: This investigation was performed to compare the hemodynamic results of the transjugular intrahepatic portosystemic shunt, a new interventional treatment for portal hypertension, with those observed after the established surgical shunt interventions. METHODS: We examined 22 patients with portal hypertension due to liver cirrhosis before and after elective TIPS by liver perfusion scintigraphy. The relative portal perfusion was determined before and after the shunt procedure. Additionally, we measured the portal pressure gradient (PPG: portal-central venous pressure, mmHg). RESULTS: Prior to TIPS, the relative portal perfusion was significantly reduced to 22 +/- 9.1%. After the intervention we calculated values of 23.1 +/- 10.7% in the TIPS-group (p = 0.67; not significant). In spite of unchanged portal perfusion, the portal pressure was significantly (p < 0.001) reduced from 25.6 +/- 5.3 to 14.8 +/- 4 mm Hg. CONCLUSION: These results suggest that the reduction of portal hypertension by TIPS is effective. The portal perfusion is maintained by TIPS suggesting that liver perfusion is preserved to a higher degree.

Adult↗
PubMed1999

Regional cerebral blood flow single-photon emission tomography with 99mTc-HMPAO and the acetazolamide test in the evaluation of vascular and Alzheimer's dementia.

The diagnostic potential of technetium-99m hexamethylpropylene amine oxime (HMPAO) following systemic administration of the cerebral vasodilator acetazolamide (acetazolamide test) was evaluated by regional cerebral blood flow (rCBF) single-photon emission tomography (SPET) in patients with Alzheimer's disease (AD) or vascular dementia (VD). An initial, high-resolution SPET study was performed with 99mTc-HMPAO, and after 2 days the patients were re-evaluated with 99mTc-HMPAO following systemic administration of acetazolamide. Reconstructed SPET slices were evaluated visually and semiquantitatively by a semi-automatic rCBF map method. When 99mTc-HMPAO alone was used, bilateral hypoperfusion was found in the temporal and/or parietal regions in 33% (6/18) of the VD patients and in 70% (23/33) of the AD patients. The corresponding data obtained by quantitative evaluation were 41% (7/17) and 71% (15/21), respectively. The vascular reserve capacity, as determined with the acetazolamide test, was preserved visually in 22% (4/18) and quantitatively in 29% (5/17) of the VD patients, but in 73% (24/33) and 76% (16/21) of the AD patients. The differences in the perfusion patterns between the VD and AD patients were statistically significant (P<0.01, Fischer's exact test). Of the VD patients with hypoperfusion (bilateral temporal and/or parietal), 4/6 (67%, visual evaluation) and 4/7 (57%, quantitative evaluation) had a decreased vascular reserve capacity as determined with the acetazolamide test. In the AD group of patients the corresponding results were 3/23 (13%) and 4/15 (27%). It is concluded that the acetazolamide test is promising in rCBF SPET to differentiate VD from AD.

Acetazolamide↗
PubMed1998

rCBF SPECT and the acetazolamide test in the evaluation of dementia.

BACKGROUND: The diagnostic potential of 99mTc-HMPAO following systemic administration of the cerebral vasodilator acetazolamide (acetazolamide test) was evaluated using regional-cerebral-blood-flow (rCBF) SPECT in patients with Alzheimer's disease (AD) or with vascular-type of dementia (VD). METHODS: An initial, high-resolution SPELT study was performed with 99mTc-HMPAO, and after 2 days patients were re-evaluated with 99mTc-HMPAO following systemic administration of acetazolamide. Reconstructed SPELT slices were evaluated visually and semiquantitatively by a semiautomatic rCBF map method. RESULTS: Using 99mTc-HMPAO alone, a bilateral hypoperfusion was found in the temporal and/or parietal regions in 33% (6/18) of VD patients and in 70% (23/33) of AD patients. The vascular reserve capacity, as determined with the acetazolamide test, was not impaired in 22% of the VD patients but in 76% of the AD patients. The differences in the perfusion patterns between VD and AD patients were statistically different (p < 0.01, Fischer's exact test). Of the 6 VD patients with hypoperfusion (bilateral temporal and/or parietal), 4 had a decreased vascular reserve capacity as determined in the acetazolamide test. Decreased reserve capacity was found in only 4 out of 25 patients with AD. CONCLUSIONS: The acetazolamide test is helpful in rCBF SPECT to differentiate VD from AD.

Journal Article↗
PubMed1996

Interventional brain SPECT--a review.

Brain SPECT with HMPAO or ECD has-due to its short accumulation period--a rather high time resolution of approx 60 sec. Compared to isopropyl amphetamine (I-123) and FDG-PET, shortlasting interventions may be evaluated by SPECT. Usually, a two-step approach is used, injecting one third of the dose under baseline conditions and two thirds during intervention. The first study is then subtracted from the second study, resulting in a "difference" image which allows to calculate the effect of the intervention. These interventional procedures may include drug, mechanical, and mental intervention as well as ictal, blood pressure and receptor intervention. Moreover, the difference of pCO2 after hyperventilation or hypoventilation may also be used as a stimulus. The above mentioned procedures are described in detail.

Brain↗
PubMed1996

[123I]IBZM SPECT for imaging of striatal D2 dopamine receptors in 56 schizophrenic patients taking various neuroleptics.

OBJECTIVE: The purpose of this study was to compare the binding of various typical and atypical neuroleptics to striatal D2 dopamine receptors in schizophrenic patients. METHOD: Fifty-six inpatients with schizophrenia, including 14 with schizoaffective disorder and one with schizophreniform disorder, were evaluated. Fourteen patients were neuroleptic free. Single photon emission computed tomography (SPECT) was performed 90 minutes after intravenous injection of [123I]benzamide ([123I]IBZM). Subsequent semiquantitative analysis of D2 receptor binding was done with the use of the basal ganglia (striatum)/frontal cortex (BG/FC) ratio of activity. Clinical symptoms were rated with the Positive and Negative Syndrome Scale and the Hamilton Depression Rating Scale. RESULTS: The BG/FC ratios in patients taking typical neuroleptics were significantly lower than those in the neuroleptic-free subjects but not lower than those in the patients taking atypical neuroleptics (clozapine, remoxipride). For atypical antipsychotics, a dose-dependent relationship with striatal D2 receptor binding could not be demonstrated. BG/FC ratios were not significantly correlated with clinical symptoms or with duration of illness. CONCLUSIONS: The results indicate that [123I]IBZM SPECT is useful for semiquantitative imaging of striatal D2 dopamine receptors and for estimating their blockade by neuroleptics. Thus, it may improve drug monitoring in psychiatric patients. Furthermore, the findings suggest a complex relationship between the antipsychotic effect of atypical neuroleptics and D2 receptor blockade.

Adult↗
PubMed1996

[Pain therapy with rhenium-186 HEDP in multiple bone metastases].

AIM: Therapeutic means for patients with painful bony metastases are strongly limited. In these patients, a systemic therapy with isotopes can be helpful. The aim of this study was to evaluate the efficacy of rhenium-186 HEDP for pain palliation in patients with disseminated bone metastases. METHODS: 30 patients taking analgesics because of bone pain received one or more injection of 1295 MBq 186Re HEDP for pain palliation. RESULTS: In 70% of the patients, therapy resulted in a significant reduction of pain. The average duration of pain relief was 4 weeks (1 week-2.5 months). The main side effects of therapy were a decrease of platelets (aver. 30000/microliters) and an increase of pain for 1-2 days (flare-phenomenon). CONCLUSION: Therapy with rhenium-186 HEDP can be used complementarily to analgesic therapy in patients with painful, disseminated bone metastases.

Bone Neoplasms↗
PubMed1995

The relevance of interictal rCBF brain SPECT in temporal lobe epilepsy: diagnostical value and effects of spatial resolution.

Interictal rCBF-SPECT is frequently being used as an adjunctive method for localization of an epileptogenic area during presurgical evaluation of patients suffering from medically refractory temporal lobe epilepsy. This study retrospectively evaluates interictal rCBF-SPECT using Tc-99m-HMPAO in comparison to the results of MRI. The final results of surface EEG and ECoG and the postsurgical clinical results as to seizure frequency were used a a 'gold-standard' for the evaluation of both imaging procedures. As spatial resolution is discussed to be the major reason for higher sensitivity of F-18-DG-PET compared to rCBF-SPECT, special attention has been paid to the spatial resolution of the different SPECT systems being used in this study. In 55 patients the complete data set could be obtained retrospectively, 36 of them being evaluated using SPECT systems with relatively low spatial resolution (Picker Dyna 2000, Elscint Helix) and 19 pt. being evaluated using moderate- to high-resolution SPECT systems (ADAC Genesys, DSI Ceraspect). Overall sensitivity of the interictal rCBF-SPECT was 75%, with 69% for low-resolution systems and 84% for high-resolution systems. Approximately at the same time when our institution installed the ADAC Genesys, the MRI equipment was changed form the 1.5 T Philips Gyroscan S15 to the 1.5 T Philips Gyroscan ACS II, the latter allowing superior imaging opportunities. Overall sensitivity of MRI was 60%, with 56%, for the Gyroscan S15 and 68% for the Gyroscan ACS II. The overall positive predictive value (PPV) was 87% for the interictal rCBF-SPECT and 87% for the MRI. Due to the lack of true negative studies in this population specificity was not calculated. False lateralization using rCBF-SPECT occurred in 5 pts. (9%), however, in 3 pts. the area of hypoperfusion correlated with a detectable MRI pathology, yet EEG/ECoG revealed the epileptogenic focus to be elsewhere. In conclusion, the interictal rCBF-SPECT revealed reasonable sensitivity and PPV in pt. suffering from focal temporal lobe epilepsy and modern SPECT systems showed significantly improved results. Since there is a variety of possible reasons for regional cortical hypoperfusion, the interictal SPECT could add significant information prior to the application of ECoG. This specially appeared to be useful in patients with abnormal MRI scan. Furthermore, in patients presenting with a clear pathology on MRI and a corresponding EEG focus, ECoG could be avoided if the interictal rCBF-SPECT additionally showed localized and singular involvement of the affected temporal lobe. ECoG was mainly applied in those patients with relatively wide-spread hypoperfusion additionally involving frontal or parietal cortical areas.

Adolescent↗
PubMed1994

Brain single-photon emission tomography using technetium-99m bicisate (ECD) in a case of complex partial seizure.

The clinical application of technetium-99m bicisate (ethyl cysteinate dimer, ECD) for ictal and interictal studies of regional cerebral blood flow (rCBF) in a patient suffering from medically intractable simple and complex partial seizures is reported. The interictal study was performed 60 min p.i. and the ictal studies were performed at 60 min p.i. using an annular crystal single photon emission tomography (SPET) system dedicated for high-resolution brain SPET imaging. Visual evaluation of the studies was carried out, as well as semiquantitative measurement of regional tracer uptake. Magnetic resonance imaging (MRI) scans revealed atrophy of almost the complete left frontal lobe and the ventral parts of the left temporal lobe, including in part the temporomesial structures. The left parietal and occipital structures and the right hemisphere were normal. The interictal study showed a large perfusion defect involving the whole left frontal lobe as well as the left temporal lobe with remaining small areas of normal cortical tracer uptake. The ictal studies detected circumscribed hyperperfusion within the left mesial temporal lobe (ventral part of the hippocampus). Additionally an increase in perfusion could be seen within the entire remaining left temporal lobe. Semiquantitative evaluation of tracer uptake comparing both studies detected markedly increased uptake within the focus compared to the remaining left temporal lobe. On this basis the newly available tracer for studies of rCBF, 99mTc-bicisate, seems to be of value for the detection of epileptogenic foci. Additionally, the value of ictal rCBF studies in the presurgical evaluation of those patients presenting severe morphological alterations on MRI is clearly underlined by this case.

Adult↗
PubMed1994

Ictal and interictal brain SPECT imaging in epilepsy using technetium-99m-ECD.

UNLABELLED: The aim of this study was to evaluate the use of 99mTc-ethyl cysteinate dimer (ECD), also known as 99mTc-bicisate, in the presurgical evaluation of patients suffering from medically intractable epilepsy. METHODS: Twenty-three brain SPECT studies (8 ictally and 15 interictally) were performed on 16 patients with a high-resolution annular SPECT system (CERASPECT). For the ictal studies, the tracer was injected in the very early phase of the seizure. The delay between seizure onset and 99mTc-ECD injection was 2-20 sec. RESULTS: Interictally, all patients showed circumscribed hypoperfusions. In four patients, the SPECT lesion represented only structural defects. Circumscribed increased tracer uptake was observed in all ictal studies. For all patients with temporal lobe epilepsy without significant mass lesion, in whom an interictal and ictal 99mTc-ECD-SPECT study could be obtained, the asymmetry index was 0.88 +/- 0.03 for the interictal and 1.23 +/- 0.08 for the ictal studies. CONCLUSION: The data suggest that 99mTc-ECD is an effective marker of cerebral perfusion imaging in epilepsy. In comparison to other tracers, it has a high in vitro stability and is therefore particularly useful for ictal studies in the very early phase after seizure onset.

Adolescent↗
PubMed1993

[Brain SPECT with 123I-labelled iodobenzamide (IBZM): aspects of semiquantitative evaluation].

The striatal dopamine-D2-receptor uptake of 123I-IBZM in 32 patients (18 without and 14 under therapy with typical neuroleptics) was measured semiquantitatively using different ROI techniques. The aim of the study was to evaluate the influence of these techniques on the different ratios (striatum/cortex) found by various examiners. Using the same SPECT system no major differences were found between rectangular and manually drawn ROIs of the same size. All ROI techniques could differentiate between patients with and without therapy on a highly significant level. Therefore, the resulting ratio is mainly dependent on the spatial resolution of the camera system and only to a relatively minor extent on the ROI technique. Ratios obtained by different observers are not comparable quantitatively.

Adult↗