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M Galanski

Publications and source records attributed to M Galanski.

At least 37 records · Page 2Linked to original sources
PubMed2002

Advances in uroradiological imaging.

The development of new imaging techniques and the refinement of established methods in uroradiological imaging is proceeding rapidly. In the last few years several important developments have been implemented in the routine diagnostic evaluation of urological patients.A milestone is the recent advent of multidetector helical computed tomography (CT), enabling the radiologist to provide the clinician with high-quality three-dimensional (3-D) reconstructions of the urological organs. Powerful workstations are an indispensable tool in the post-processing of CT and magnetic resonance imaging (MRI)data. Significant advances in imaging were obtained in the fields of oncological imaging (e.g. prostate MRI and spectroscopic imaging), paediatric uroradiology(e.g. MR urography) and the evaluation of stone disease by unenhanced helical CT.

Abdomen, Acute↗
PubMed2002

Impact of magnetic resonance urography on preoperative diagnostic workup in children affected by hydronephrosis: should IVU be replaced?

PURPOSE: The aim of this study was to determine the role of magnetic resonance urography (MRU) in preoperative diagnostic workup of children with hydronephrosis in a prospective clinical study with comparison of MRU, standard diagnostic investigations, and intraoperative findings. METHODS: Thirty-one children with hydronephrosis secondary to different causes underwent ultrasound scan (US), intravenous urography (IVU), micturation cysto-urethrography (MCU), isotope nephrography (ING) and MRU. For MRU the authors performed sagittal and coronal halve-Fourier SSFSE scans in a 1.5 Tesla MR system. T1- and T2-weighted sequences were used in axial orientation to improve morphologic information. In 24 patients, preoperative data were compared with intraoperative findings. RESULTS: Comparison of the different imaging modalities proved MRU to be able to provide more detailed information about the correct localization of stenoses along the urinary tract and the morphology of renal parenchyma. MRU showed the highest concordance of all imaging modalities with intraoperative findings. CONCLUSION: As a reliable investigation, MRU has the potentials to replace IVU in preoperative diagnostic workup of hydronephrosis in childhood.

Adolescent↗
PubMed2002

[Interactive direct volume rendering of CT-data: technical principle and applications].

The advantages of interactive Volume Rendering Technique (VRT) for routine diagnostics of CT and particularly Multislice CT data are unquestionable. However, with apart from Virtual Endoscopy, where besides Shaded Surface Display, perspective Volume Rendering is used in some cases, VRT at present is only playing a minor role in routine diagnostics. One reason is time consuming calculation, so far requiring powerful computers. Due to the variety of possible parameter settings and the poorly predictable outcome of the resulting images, there also exists a certain discomfort in using the technique. In this paper the underlying principles of VRT are illustrated. Different parameter settings and their impact on the final images are explained. Possible pitfalls in VRT and also suitable parameter settings and indications for VRT are shown.

Angiography↗
PubMed2001

Use of Doppler ultrasonography to predict the outcome of therapy for renal-artery stenosis.

BACKGROUND: Prospectively identifying patients whose renal function or blood pressure will improve after the correction of renal-artery stenosis has not been possible. We evaluated whether a high level of resistance to flow in the segmental arteries of both kidneys (indicated by resistance-index values of at least 80) can be used prospectively to select appropriate patients for treatment. METHODS: We evaluated 5950 patients with hypertension for renal-artery stenosis using color Doppler ultrasonography, and we measured the resistance index ([1 - end-diastolic velocity divided by maximal systolic velocity] x 100). Among 138 patients who had unilateral or bilateral renal-artery stenosis of more than 50 percent of the luminal diameter and who underwent renal angioplasty or surgery, the procedure was technically successful in 131 (95 percent). Creatinine clearance and 24-hour ambulatory blood pressure were measured before renal-artery stenosis was corrected; 3, 6, and 12 months after the procedure; and yearly thereafter. The mean (+/-SD) duration of follow-up was 32+/-21 months. RESULTS: Among the 35 patients (27 percent) who had resistance-index values of at least 80 before revascularization, the mean arterial pressure did not decrease by 10 mm Hg or more after revascularization in 34 (97 percent). Renal function declined (defined by a decrease in the creatinine clearance; of at least 10 percent) in 28 (80 percent); 16 (46 percent) became dependent on dialysis and 10 (29 percent) died during follow-up. Among the 96 patients (73 percent) with a resistance-index value of less than 80, the mean arterial pressure decreased by at least 10 percent in all but 6 patients (6 percent) after revascularization; renal function worsened in only 3 (3 percent), all of whom became dependent on dialysis; and 3 (3 percent) died (P<0.001 for the comparison with patients with a resistance-index value of at least 80). CONCLUSIONS: A renal resistance-index value of at least 80 reliably identifies patients with renal-artery stenosis in whom angioplasty or surgery will not improve renal function, blood pressure, or kidney survival.

Angioplasty, Balloon↗
PubMed2001

Reaction monitoring of platinum(II) complex--5'-guanosine monophosphate adduct formation by ion exchange liquid chromatography/electrospray ionization mass spectrometry.

Cisplatin and four structurally related platinum(II) complexes were incubated with guanosine 5'-monophosphate (5'-GMP) in water at 37 degrees C. The adduct formation reactions were monitored with cation- and anion-exchange liquid chromatography/electrospray ionization mass spectrometry. In addition to mono- and bis-adducts of guanosine 5'-monophosphate with the platinum(II) complexes, other molecular species, presumably with a binuclear structure (two platinum(II) centres), were detected in the reaction mixtures, which have not been reported previously, indicating an unexpected complexity of adduct formation. Anion-exchange chromatography revealed the presence of isomers of two complexes which presumably result from the restricted rotation at the platinum-- N-7 (5'-GMP) bonds. All reaction products were characterized in both the positive and negative ion modes. Furthermore, preliminary kinetics and half-times of complex formation were investigated for cisplatin and two other platinum(II) complexes, monitoring the relative concentrations of free 5'-GMP and of mono- and bis-GMP adducts as a function of time (250 h) using an internal standard protocol with thymidine 5'-monophosphate.

Journal Article↗
PubMed2001

[Concepts for optimizing stent graft treatment of abdominal aortic aneurysms based on results of animal experiments].

PURPOSE: In the endoluminal therapy of abdominal aortic aneurysms, a short proximal aneurysm neck, endoleaks and the large size and stiffness of the introducer systems are responsible for many of the complications and sub-optimal outcomes. The purposes of the present review article is to to suggest strategies to minimize these complications based on the results of experimental studies in animals. MATERIAL AND METHODS: After implanting various types of stents across the renal artery origins, the functional and morphological changes in the kidneys and renal vessels were studied by various authors. In order to prevent progressive widening of the proximal aneurysmal neck and graft dislocation, Sonesson et al. performed a laparoscopic banding around the proximal neck in pigs. To study the effects of endoleaks, Marty, Schurink and Pitton carried out pressure measurements in experimental aneurysms with and without endoleaks. Sakaguchi und Pavcnik developed the "Twin-tube endografts" (TTEG) and the "Bifurcated drum occluder endografts" (BDOEG) and tested them in dogs. RESULTS: Up to 3 months after suprarenal stent placement, Chavan et al. detected no significant fall in the mean inulin clearance in sheep (140 +/- 46 ml/min before, 137 +/- 58 ml/min after). Nasim et al. and Malina et al. reported similar observations with respect to renal function. Suprarenal fixation may result in isolated thrombotic occlusions of the renal arteries and microinfarcts in the kidneys. Mean aortic diameters at the level of banding were significantly smaller in the animals with aortic banding as opposed to those in the control group without banding (8 mm vs 11 mm, p = 0.004). The banding caused a secure proximal fixation of the stent-graft. Persistent endoleaks resulted in significantly higher intraaneurysmal pressures. Although the TTEG and the BDOEG stent-grafts required smaller sheaths, occlusions were observed in 8% (TTEG) and 60% (BDOEG) of the graft limbs. DISCUSSION: Supra-renal fixation of the stent-graft does not significantly affect renal function. Depending partly on the stent-graft-Design, isolated microinfarcts in the kidneys or thrombotic occlusions of the renal arteries may occur. A laparoscopic banding of the aorta at the proximal neck after graft implantation could prevent widening of the proximal neck and graft dislocation with the passage of time. To reduce the incidence of endoleaks, embolization of large branches, particularly those arising from aneurysms without mural thrombus is advisable. Due to the relatively high rate of occlusion of the graft limbs, the TTEG and the BDOEG stent-graft designs still require refinement. A rational application of the results of these animal experimental studies in clinical practice could markedly improve the long-term results of endoluminal stent grafting of abdominal aortic aneurysms.

Aortic Dissection↗
PubMed2001

Precise determination of aortic length in patients with aortic stent grafts: in vivo evaluation of a thinning algorithm applied to CT angiography data.

The aim of this study was to develop a technique for precise determination of the aortic length using volumetric CT data for potential use prior to endovascular stent-graft placement. The study population consisted of 20 patients (38 measurements) with already performed endoluminal grafting. This allowed for in vivo evaluation of our technique. Its length according to the graft specifications served as a gold standard for our own measurements. The implemented graft length varied between 120 and 195 mm. Computed tomography angiography was performed with 3-mm slice collimation, 5-mm table feed and a reconstruction interval of 2 mm. Following semi-automatic segmentation of the aorta and its large side branches, the median centerline (skeleton) of the vessels was determined employing a modified three-dimensional thinning algorithm. The algorithm was validated by comparing the calculated length of the resulting skeleton with the specifications of the grafts. The calculated length was sufficiently precise despite the limiting reconstruction interval of 2 mm of our CT data which only permitted an assessment of stent length in 2-mm steps. The differences in the measured length and graft length were in the range between 0 and 8 mm (< 5%) with a mean fractional error of 2.46 +/- 2.37 mm. The use of an intelligent region growing algorithm capable of coping with variable arterial enhancement significantly reduced operator post-processing time. The average time necessary for segmentation was 7 min (range 3-10 min). Our algorithm provides a non-invasive method for objective and precise measurement of aortic length apparently even in tortuous vessels. It has the potential to replace angiography for aortic and iliac length measurements with calibrated catheters prior to endovascular intervention.

Algorithms↗
PubMed2001

Correlation of MRI and CT findings with histopathology in hepatic angiomyolipoma.

Hepatic angiomyolipomas are rare and often mimic other liver tumors. The aim of our study was to describe the CT and MRI findings and to correlate imaging features with histopathology. The CT and/or MR images were available for retrospective analysis in seven patients. Patients had non-enhanced as well as enhanced CT (n = 6) or MRI (n = 4) before and after administration of Gd-DTPA (n = 2) or MnDPDP, a liver specific contrast agent, (n = 3). In three patients CT and MRI did not detect fat, and in two patients the angiomyolipomas were also histopathologically devoid of fat. Vascularity ranged from hypervascular (n = 4) with arteriovenous shunts (n = 1) to equal (n = 1) or less (n = 2) postcontrast enhancement compared with the normal liver parenchyma. No uptake of the liver specific contrast agent, MnDPDP, was observed (n = 3). Predominantly, CT and MRI did not include angiomyolipoma in the differential diagnosis, and the initial histopathological evaluation was inconclusive in more than half the cases. Hepatic angiomyolipomas frequently manifest as solitary well-circumscribed heterogeneous masses in patients with no underlying liver disease or elevation of serum tumor markers. If present, the demonstration of intratumoral fat is helpful in the diagnosis of angiomyolipoma. The final diagnosis can be obtained by immunohistochemistry.

Adult↗
PubMed2000

Kinetics of binding properties of 5'-GMP with cisplatin under simulated physiological conditions by capillary electrophoresis.

Kinetics of the adduct formation of cisplatin and its hydrolysis products with 5'-GMP was investigated using capillary electrophoresis (CE) under 'simulated physiological conditions'. Therefore, chloride ion and phosphate concentration as well as the pH were chosen comparable to intracellular conditions. Furthermore, the influence of the sulfur-containing alpha-amino acids L-methionine and L-cysteine on the kinetics of the adduct formation have been studied. Both amino acids increased the half-time of the reaction significantly but did not influence the formation of the major adduct cis-[Pt(NH3)2(N7-GMP)2]2-. The reaction products were separated using CE, and characterised using UV and NMR spectroscopy.

Chlorides↗
PubMed2000

[Basic principles of data acquisition and data processing for construction of high quality virtual models].

Creating models for virtual reality subdivides into several steps. The aim of the data acquisition is the extraction of nearly isotropic (same solution in all three axes) data sets with low noise content. An approximate isotropy can be achieved by suitable choice of scan parameters. For raw data reconstruction, the application of high-resolution reconstruction algorithms is prohibited due to increased noise. A missing isotropy can computationally be approximated by interpolation. Further noise suppression is achieved by applying filters. Additionally, the contrast of the object for segmentation can be increased by image processing operators. The correct choice of the segmentation method and the editing tools is essential for a precise segmentation with minimal user interaction. Prior to visualization, smoothing the shape of the segmented model (shape-based or morphological interpolation, polygon reduction of wire frame model) further improves the visual appearance of the 3D model.

Algorithms↗
PubMed2000

[Bone manifestations in non-Hodgkin's lymphoma in childhood and adolescence].

PURPOSE: Skeletal manifestation of Non-Hodgkin's lymphoma is rare in pediatric patients. Objective of the study was to determine imaging features, before and after treatment, and to correlate these features with clinical outcome. METHODS: A retrospective analysis of 1246 patients from two therapy studies (NHL-BMF-90 and 95) was performed. Imaging studies of 63 patients with bone involvement of lymphoma were reevaluated. RESULTS: Incidence of initial bone involvement in Non-Hodgkin's lymphoma was 6.8%. Distribution was best assessed by bone scan, MRI revealed larger areas of marrow involvement and detected additional lesions. Sites of predilection were long bones of the lower extremities with epiphyseal involvement in 39%. Residual signal alterations in MRI after successful therapy remained in 71%. Osteonecrosis after therapy was a common finding. Clinical outcome war not correlated to the presence of bone involvement. CONCLUSIONS: Since clinical outcome is not effected by bone involvement in childhood NHL, value of screening may be limited. Knowledge of imaging characteristics is mandatory for initial evaluation of primary osseous lymphomas and symptomatic lesions as well as for therapy controls.

Adolescent↗
PubMed2000

Role of the intra-arterial calcium stimulation test in the preoperative localization of insulinomas.

The aim of this study was determination of the significance of the arterial stimulation test with venous sampling (ASVS) in the preoperative localization of insulinoma. Eleven patients with endogenous hyperinsulinism underwent preoperative transabdominal US, spiral computer tomography (spiral CT), MRI, endoscopic ultrasound (EUS) as well as angiography (DSA) combined with ASVS. The results were compared with intraoperative findings, intraoperative ultrasound (IOUS) and histopathology. There were no complications related to the ASVS test. In 11 patients the tumor could be localized with the various modalities as follows: US 1 of 11 (9%), MRI 3 of 10 (30%), spiral CT 4 of 11 (36%), EUS 5 of 10 (50%), DSA 8 of 11 (73%), and ASVS 10 of 11 (91%). In 2 patients the tumors were intraoperatively neither palpable nor detectable by IOUS, and consequently the intraoperative management was governed by information provided by DSA combined with the ASVS test. Ten patients had solitary benign insulinomas and 1 patient with multiple endocrine neoplasia I had two tumors adjacent to each other in the pancreatic tail. Arterial stimulation test with venous sampling was the most sensitive preoperative test for regionalizing the insulinoma in our set of patients. It can be performed safely in the course of a regular DSA examination and may affect intra-operative management in patients in whom the tumors are not detectable by palpation or IOUS.

Adolescent↗
PubMed2000

Hepatic hemangiosarcoma: imaging findings and differential diagnosis.

Primary hepatic angiosarcoma is a rare mesenchymal tumor of the liver that usually presents with nonspecific symptoms in elderly men. We present four cases of hepatic hemangiosarcoma and discuss the imaging characteristics of this entity. Our series shows that this tumor is not uncommon in younger patients with no associated risk factors such as previous exposure to thorotrast or vinyl chloride. Our experiences on a limited number of patients suggests that the combined use of angiography and dual-phase helical CT provides a better identification of the tumor and its complications. Analysis of imaging studies in patients with hepatic hemangiosarcoma reveals hypervascular lesions. Common complications were portal vein thrombosis, Budd-Chiari syndrome, as well as arterio-venous or arterio-portal shunts. Due to the vascularity of the tumor, percutaneous liver biopsy is hazardous.

Adult↗
PubMed2000

Endoluminal grafting of abdominal aortic aneurysms: experience with the Talent endoluminal stent graft.

The aim of this study was to evaluate the Talent endoluminal stent graft (TESG) in treating abdominal aortic aneurysms (AAA). The TESG is a polyester-covered nitinol endograft (proximal diameters 20-38 mm and iliac limb diameters 8-22 mm). Twenty-two men were treated with the TESG via bilateral femoral arteriotomies. Pre-implantation, coil embolization of various vessels arising from the aneurysm was performed in 6 patients. Plain radiographs and spiral CT angiograms (CTA) were carried out at 7 days, 3, 6, and 12 months following TESG implantation or re-intervention. Median aortic and iliac diameters were 27 mm (range 20-34 mm) and 14 mm (range 10-19 mm). The corresponding graft diameters were 30 mm (range 24-38 mm) and 14 mm (range 12-20 mm). No patient was rejected purely on the basis of too large aortic or iliac diameters. Eight patients required custom-made grafts. Graft implantation was successful in all patients. There were no blood transfusions, distal embolic episodes, or conversions to open surgery. Re-intervention was necessary in 1 patient. Complications included one fatal myocardial infarction, one inguinal hematoma, and two superficial wound infections. The aneurysm thrombosed completely following implantation in 14 patients and at 3 or 6 months in 4 other patients. One patient with endoleak is awaiting his 3-month control and 2 patients show tiny endoleaks but reduction of aneurysm size. The mean aneurysm size decreased significantly from 58 +/- 10 to 53 +/- 13 mm (p < 0.0005). Due to the large sizes available and the option of custom-made grafts, the TESG helps widen the spectrum of patients who can be treated with endoluminal grafting. The treatment is associated with a significant reduction in aneurysm size.

Aged↗