[Show abstract][Hide abstract] ABSTRACT: The present study aimed to analyse potential prognostic factors, with emphasis on tumour volume, in determining progression free survival (PFS) for malignancies of the nasal cavity and the paranasal sinuses.
Retrospective analysis of 106 patients with primary sinonasal malignancies treated and followed-up between March 2006 and October 2012. Possible predictive parameters for PFS were entered into univariate and multivariate Cox regression analysis. Kaplan-Meier curve analysis included age, sex, baseline tumour volume (based on MR imaging), histology type, TNM stage and prognostic groups according to the American Joint Committee on Cancer (AJCC) classification. Receiver operating characteristic (ROC) curve analysis concerning the predictive value of tumour volume for recurrence was also conducted.
The main histological subgroup consisted of epithelial tumours (77%). The majority of the patients (68%) showed advanced tumour burden (AJCC stage III-IV). Lymph node involvement was present in 18 cases. The mean tumour volume was 26.6 ± 21.2 cm
Radiological tumour volume proofed to be a statistically reliable predictor of PFS. In the multivariate analysis, T-, N- and overall AJCC staging did not show significant prognostic value.
Radiology and Oncology 09/2015; 49(3). DOI:10.1515/raon-2015-0028 · 1.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
Venous malformations of the limbs are congenital low-flow vascular anomalies. A treatment is reasonable if they are symptomatic or if a progressive lesion may affect functional structures.
The purpose of this work is the presentation of clinical results after treatment of venous malformations of the limbs according to the standard algorithm used at the University Hospital of Tuebingen, Germany.
Patients and methods:
Between January 2008 and June 2015, patients with venous malformations of the limbs were subjected to either percutaneous sclerotherapy or surgical excision according to this treatment algorithm. Remaining symptoms such as pain level and disturbing appearance before and after treatment as well as overall satisfaction was assessed the earliest 3 months after last treatment.
Thirty-nine patients with venous malformations of the limbs were subjected to either 1 or more percutaneous sclerotherapies (n = 19) or surgical excision (n = 21). There were no serious complications that needed surgical revision. There was a statistically significant reduction in the pain level and disturbing appearance after both sclerotherapy and surgical excision (p < .05) in 30 cases in total. The overall treatment satisfaction was rated 7.9/10 and 8.8/10 after sclerotherapy and surgical excision, respectively.
A low complication rate with a high patient satisfaction could be achieved after this treatment algorithm for venous malformations of the limbs.
Dermatologic Surgery 09/2015; 41(10). DOI:10.1097/DSS.0000000000000469 · 2.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Intraoperative magnetic resonance imaging (iMRI) has dramatically expanded and nowadays presents state-of-the-art technique for image-guided neurosurgery, facilitating critical precision and effective surgical treatment of various brain pathologies. Imaging hardware providing basic imaging sequences as well as advanced MRI can be seamlessly integrated into routine surgical environments, which continuously leads to emerging indications for iMRI-assisted surgery. Besides the obvious intraoperative diagnostic yield, the initial clinical benefits have to be confirmed by future-controlled long-term studies.
[Show abstract][Hide abstract] ABSTRACT: PURPOSE:
This study was performed to investigate any bilateral differences in the vascular pattern and microsurgical relevant parameters of the superficial temporal artery (STA) in vivo.
Digital subtraction angiographies of the STA of 38 individuals were retrospectively analyzed. A bilateral comparison of the branching pattern as well as of surgically relevant diameters and lengths of the main branches of the STA was performed. Moreover, gender-specific differences were assessed.
Only 10 cases (26 %) demonstrated an identical type and subtype of the STA pattern bilaterally. The diameters of the STA at its origin and bifurcation level as well as of its parietal branch were statistically significant wider on the right than on the left side (p o = 0.0009, p b = 0.006, p p = 0.030). Moreover, the diameters of the STA at its origin level on the right side, at its bifurcation level on both sides and of the frontal branch on both sides were statistically significant wider in males than females. No statistically significant differences of the lengths of the STA and its main branches between the right and the left side were identified.
The occurrence of the vascular pattern of the STA in vivo is random for each side of the same person and cannot be predicted by the vascular pattern of the opposite side. The calibers of the main branches of the STA are gender specific and commonly larger on the right than on the left side.
Surgical and Radiologic Anatomy 08/2015; DOI:10.1007/s00276-015-1538-0 · 1.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hybrid magnetic resonance (MR)-positron emission tomography (MR-PET) is a novel technology with advantages over sequential MR and PET imaging, allowing maintain full individual diagnostic performance with negligible mutual interference between the two hardware settings. Obvious synergies between MR and PET in acquisition of anatomical, functional, and molecular information for neurological diseases into one single image pave the way for establishing clear clinical indications for hybrid MR-PET as well as addressing unmet neuroimaging needs in future clinics and research. Further developments in attenuation correction, quantification, workflow, and effective MR-PET data management might unfold the full potential of integrated multimodality imaging.
[Show abstract][Hide abstract] ABSTRACT: With further increase of CT numbers and their dominant contribution to medical exposure, there is a recent quest for more effective dose control. While re-introduction of iterative reconstruction (IR) has proved its potential in many applications, a novel focus is placed on more noise efficient detectors. Our purpose was to assess the potential of IR in combination with an integrated circuit detector (ICD) for aggressive dose reduction in head CT.
Non-contrast low-dose head CT (190 mAs, CTDIvol 33.2 mGy) was performed in fifty consecutive patients, using a new noise efficient detector and IR. Images were assessed in terms of quantitative and qualitative image quality and compared with standard dose acquisitions (320 mAs, CTDIvol 59.7 mGy), using a conventional detector and filtered-back-projection.
By combining IC detector and IR in low-dose exams, signal-to-noise was improved by about 13% above baseline level in the standard-dose control group. Both, contrast-to-noise ratio (2.02±0.6 vs. 1.88±0.4; p=0.18) and objective measurements of image sharpness (695± 84 vs.705± 151 Change in HU/Pixel; p=0.79) were fully preserved in the low-dose group. Likewise, there was no significant difference in the grading of several subjective image quality parameters when both noise reducing strategies were used in the low-dose exams.
Combination of noise efficient detector with IR allows for meaningful dose reduction in head CT without compromise of standard image quality. Advances in knowledge: Our study demonstrates the feasibility of almost 50% dose reduction in head CT (1.1 mSv per scan) through combination of novel dose reducing strategies.
The British journal of radiology 04/2015; 88(1050):20140404. DOI:10.1259/bjr.20140404 · 2.03 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background/Study Aims Percutaneous radiofrequency trigeminal rhizotomy (RTR) is a standardized treatment for trigeminal neuralgia, yet it has been associated with serious complications related to the cannulation of the foramen ovale. Some of these complications, such as carotid injury, are potentially lethal. Neuronavigation was recently proposed as a method to increase the procedure's safety. All of the techniques described so far rely on pre- or intraoperative computed tomography scanning. Here we present a simple method based on magnetic resonance imaging (MRI) (radiation free) used to target the foramen ovale under navigation guidance. Patients/Material and Methods We retrospectively analyzed nine patients who had undergone navigated percutaneous RTR based solely on preoperative MRI and compared them with 35 patients who underwent conventional RTR guided by fluoroscopy. We analyzed immediate and late outcome and categorized the results into pain free, > 70% pain reduction, and persistent pain. We also compared groups in terms of the duration of the procedure and the complication rates. Here we describe the navigation method in detail and review the anatomical landmarks for target definition. Results The duration of the surgical procedure was similar in both groups (32.1 in the standard technique versus 34.5 minutes with navigation; p = 0.5157). There was no significant difference between groups regarding pain reduction at the immediate (p = 1.0) or late follow-up (p = 0.6284) time points. Furthermore, no serious complications were observed in the navigated group. Conclusions We present a simple radiation-free method for neuronavigation-assisted percutaneous RTR. This method proved to be safe and effective, and it is especially recommended for young, inexperienced neurosurgeons.
Georg Thieme Verlag KG Stuttgart · New York.
Journal of Neurological Surgery. Part A: Central European Neurosurgery 01/2015; 76(02). DOI:10.1055/s-0034-1394190 · 0.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background and purpose:
Treatment of symptomatic intracranial atherosclerotic disease by angioplasty and stenting (PTAS) is limited by a high rate of periinterventional strokes. We performed a detailed analysis of these strokes at our center in order to identify strategies to reduce the risk of periinterventional complications.
Case records and imaging data of 80 patients with a symptomatic 70-99% stenosis of a major intracranial artery treated with PTAS between July 2007 and December 2013 were reviewed. All patients had a sufficient response to aspirin and clopidogrel. Periinterventional strokes were categorized as either ischemic (perforator territory, distal embolic or delayed stent thrombosis) or hemorrhagic (intraparenchymal, subarachnoid).
Periinterventional complications occurred in 6/80 (7.5%) patients, consisting of 2 ischemic strokes (2.5%, both perforator territory), 3 hemorrhagic strokes (3.8%, 2 intraparenchymal due to reperfusion injury, 1 subarachnoid due to vessel rupture) and one death (1.3%) unrelated to stroke. All strokes occurred within 24h after PTAS.
Our retrospective data analysis suggests that the risk of periinterventional stroke after PTAS of symptomatic intracranial atherosclerotic disease might be reduced by sufficient antiplatelet therapy and optimized management of patients with high risk for reperfusion injury or perforator strokes, including selection of a stenting device adapted to individual vessel morphology.
European Journal of Radiology 09/2014; 83(12). DOI:10.1016/j.ejrad.2014.08.018 · 2.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rationale and Objectives: A new computed tomography (CT) detector with integrated electric components and shorter conducting pathways has recently been introduced to decrease system inherent eleotronic noise. The purpose of this study was to-assess the potential benefit of Such integrated circuit detector (ICD) in head CT by comparing objective and subjective image quality in low dose examinations with a conventional detector design. Materials and Methods: Using a conventional detector, reduced-dose noncontrast head CT (255 mAs; effective dose, 1.7 mSv) was performed in 25 consecutive patients. Following transition to ICD; 25 consecutive-patients were scanned using identical imaging parameters. Images in both groups were reconstructed with iterative reconstruction (IR) and filtered back projection (FBP) and assessed in terms of quantitative and qualitative image quality. Results: Acquisition of head CT using ICD increased Signal-to-noise ratio of gray and white matter by 14% (10.0 +/- 1.6 vs. 11.4 +/- 2.5; P = .02) and 17% (8.2 +/- 0.8 vs. 9.6 +/- 1.5; P = .000). The associated improvement in contrast-to-noise ratio was 12% (2.0 +/- 0.5 vs. 2.2 +/- 0.6; P = .121). In addition, there was a 51% increase in objective image sharpness (582 +/- 85 vs. 884.5 +/- 191; change in HU/Pixel; P < .000). Compared to standard acquisitions, subjective grading of noise and overall image quality scores were significantly improved with ICD (2.1 +/- 0.3 vs. 1.6 +/- 0.3; P < .000; 2.0 +/- 0.5 vs. 1.6 +/- 0.3; P = .001). Moreover, streak artifacts in the posterior fossa were substantially reduced (2.3 +/- 0.7 vs. 1.7 +/- 0.5; P = .004) Conclusions: At the same radiation level, acquisition of head CT with ICD achieves superior objective and subjective. image quality and provides potential for significant dose reduction.
[Show abstract][Hide abstract] ABSTRACT: Purpose:
A new method for diffusion-weighted imaging (DWI) using independent parallel transmission technique resulting in zoomed DWI was applied in four patients suffering from acute spinal cord ischemia.
Four patients with clinical symptoms of acute spinal cord ischemia were examined on a 3 T MR-system equipped with a two-channel transmit array. Scans included T2-weighted turbo spin echo, conventional DWI, and zoomed DWI. Image evaluation was performed with regard to overall image quality, anatomic delineation of the spinal cord, and the level of confidence to establish the diagnosis of spinal cord ischemia.
Through spatially selective excitation, zoomed DWI allows for acquisition of high-resolution images with reduced scan time due to a reduced field of view in phase-encoding direction, resulting in zoomed images. In all cases the ischemia was demonstrated in conventional DWI as well as zoomed DWI.
Compared to conventional DWI, zoomed DWI enables a faster image acquisition and allowed a more detailed analysis of the spinal lesion which may be critical to attribute the lesion to a particular vessel territory.
[Show abstract][Hide abstract] ABSTRACT: Several studies evaluated the predictive value of dynamic susceptibility contrast enhanced (DSC) imaging and arterial spin labeling (ASL) with regard to histological grade. Yet still less is known about their significance in terms of patients prognosis. Our purpose was to evaluate the agreement between them and the prognostic value of ASL- and DSC-CBF measurements for time-to-recurrence (TTR). Sixty nine cases of WHO Grade 3-4 gliomas underwent both DSC- and ASL-MRI. Normalized ASL and DSC-based cerebral blood flow (CBF) maps as well as DSC-derived cerebral blood volume maps (CBV) were analyzed. Wilcoxon test and Bland-Altman plot analysis were applied in order to compare DSC-rCBF and ASL-rCBF. Spearman's rank correlation coefficients were determined for all perfusion parameters. Receiver operating characteristic (ROC) curve and survival curve analyses were performed. The median values of ASL-rCBF, DSC-rCBF, and DSC-rCBV were 5.3, 6.9, and 8.0, respectively. There was neither significant correlation nor difference between ASL-rCBF and DSC-rCBF. Slight proportional bias was demonstrated in the Bland-Altman plot analysis of ASL-rCBF and DSC-rCBF values. Unlikely to DSC-rCBV, DSC- and ASL-based rCBF parameters demonstrated moderate sensitivity and specifitity for tumor recurrence but no statistical significance regarding their prognostic values for TTR in the Kaplan-Meier analysis. There were neither correlation nor interchangeability between the DSC-rCBF and ASL-rCBF estimations, which demonstrated comparable, though not significant prognostic value for the prediction of TTR. rCBV measurements seem to provide the best sensitivity and specificity to predict tumor recurrence and survival time in these patients.
Journal of Neuro-Oncology 08/2014; 120(3). DOI:10.1007/s11060-014-1586-z · 3.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The period of event-free survival (EFS) within the same histopathological glioma grades may have high variability, mainly without a known cause. The purpose of this study was to reveal the prognostic value of quantified tumor blood flow (TBF) values obtained by arterial spin labeling (ASL) for EFS in patients with histopathologically proven astrocytomas independent of WHO (World Health Organization) grade. Twenty-four patients with untreated gliomas underwent tumor perfusion quantification by means of pulsed ASL in 3T. The clinical history of the patients was retrospectively extracted from the local database. Six patients had to be excluded due to insufficent follow-up data for further evaluation or histopathologically verified oligodendroglioma tumor components. Receiver operating characteristic (ROC) curves were used to define an optimal cut-off value of maximum TBF (mTBF) values for subgrouping in low-perfused and high-perfused gliomas. Kaplan-Meier curves and Cox proportional hazard regression model were used to determine the prognostic value of mTBF for EFS. An optimal mTBF cut-off value of 182 ml/100 g/min (sensitivity = 83%, specificity = 100%) was determined. Patients with low-perfused gliomas had significantly longer EFS compared to patients with high-perfused gliomas (p = 0.0012) independent of the WHO glioma grade. Quantified mTBF values obtained by ASL offer a new and totally non-invasive marker to prognosticate the EFS, independently on histopathological tumor grading, in patients with gliomas.
PLoS ONE 06/2014; 9(6):e99616. DOI:10.1371/journal.pone.0099616 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: The maneuver of transmeatal drilling carries the risk of injuring inner ear structures, which may cause immediate or delayed hearing loss. OBJECTIVE: To describe the changes in petrous bone anatomy caused by the tumor and to analyze both the incidence and the risk pattern for violation of the endolymphatic system in a surgical series. METHODS: One hundred patients operated on for vestibular schwannoma were included in this prospective study. Thin-slice computed tomography was performed before and after surgery. We assessed topographic measurements on both the pathological and healthy sides. Postoperatively, we evaluated anatomic and functional values. RESULTS: The diameter of the internal auditory canal was significantly larger (P < .001) in the petrous bones of the affected sides than in the contralateral healthy sides. An average of 5.6 ± 1.8 mm of the internal auditory canal was drilled, and the distance from the medial border of the sigmoid sinus to the drilling line (tangential to the drilled surface of the posterior lip of the internal auditory canal) was 9.8 ± 2.9 mm. A postoperative violation of the vestibular aqueduct (VA) was detected in 41 cases; the VA was intact in 55 cases; and the VA could not be clearly defined in 4 cases. The incidence of VA injury increased with increasing tumor size. In the patient group with good preoperative and postoperative hearing function, a VA injury occurred in 26% of cases, whereas the incidence increased to 67% in preoperatively deaf patients. CONCLUSION: Vestibular schwannomas cause significant distortion of the petrous bone anatomy. Detailed preoperative knowledge of the topography is necessary for the preservation of function. ABBREVIATIONS: IAC, internal auditory canal VA, vestibular aqueduct VS, vestibular schwannoma