Robotic Assistance System for Cone-Beam Computed Tomography-Guided Percutaneous Needle Placement

CardioVascular and Interventional Radiology - The study aimed to evaluate a new robotic assistance system (RAS) for needle placement in combination with a multi-axis C-arm angiography system for...     

UMMPerfusion: an Open Source Software Tool Towards Quantitative MRI Perfusion Analysis in Clinical Routine

To develop a generic Open Source MRI perfusion analysis tool for quantitative parameter mapping to be used in a clinical workflow and methods for quality management of perfusion data. We implemented a classic, pixel-by-pixel deconvolution approach to quantify T1-weighted contrast-enhanced dynamic MR imaging (DCE-MRI) perfusion data as an OsiriX plug-in. It features parallel computing capabilities and an automated reporting scheme for quality management. Furthermore, by our implementation design, it could be easily extendable to other perfusion algorithms. Obtained results are saved as DICOM objects and directly added to the patient study. The plug-in was evaluated on ten MR perfusion data sets of the prostate and a calibration data set by comparing obtained parametric maps (plasma flow, volume of distribution, and mean transit time) to a widely used reference implementation in IDL. For all data, parametric maps could be calculated and the plug-in worked correctly and stable. On average, a deviation of 0.032 ± 0.02 ml/100 ml/min for the plasma flow, 0.004 ± 0.0007 ml/100 ml for the volume of distribution, and 0.037 ± 0.03 s for the mean transit time between our implementation and a reference implementation was observed. By using computer hardware with eight CPU cores, calculation time could be reduced by a factor of 2.5. We developed successfully an Open Source OsiriX plug-in for T1-DCE-MRI perfusion analysis in a routine quality managed clinical environment. Using model-free deconvolution, it allows for perfusion analysis in various clinical applications. By our plug-in, information about measured physiological processes can be obtained and transferred into clinical practice.     

Cognitive change on the repeatable battery of neuropsychological status (RBANS) in parkinson's disease with and without bilateral subthalamic nucleus deep brain stimulation surgery

Cognitive change following bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) surgery in those with Parkinson's disease (PD) has led to equivocal results. The current study applied a standardized regression-based (SRB) method based on 20 medically managed PD patients and 20 STN DBS PD surgical patients who were administered the Repeatable Battery of Neuropsychological Status (RBANS). Of the medically managed PD participants, 94% remained stable compared to 73% of the DBS group. In the DBS group cognitive change was noted on the Total scale and the Immediate Memory Index. A secondary analysis also revealed reliable change on several subtest scores. Although preliminary, the current study provides change parameters for post DBS surgery on this brief battery.     

Single-Port Cholecystectomy Versus Multi-Port Cholecystectomy: A Prospective Cohort Study with 222 Patients

Background

The aim of this study was to compare single-port access cholecystectomy (SPA) with the standard laparoscopic technique (LC) regarding the duration of the operation, complications, learning curve, late postoperative quality of life (QoL) and the incidence of incisional hernias.

Methods

Between June 2009 and December 2011, a total of 122 SPA cholecystectomies were performed in our hospital. Simultaneously, 310 patients were operated on with the LC technique. In the LC group, 100 patients met the same criteria defined for SPA surgery. The two groups (SPA and LC) were compared by multivariable regression analysis. Endpoints of this study were quality of life (QoL) after 6 months by the EQ-5D questionnaire 5L and the incidence of incisional hernia 1 year after surgery. Operating time, hospital stay, and perioperative complications were also measured and compared. The median follow-up was 9.2 months (3–25 months).

Results

The patients in the SPA group were younger and more often female. The mean operating time for group SPA was 73 min (35–136 min)—significantly longer than that for group LC with 60 min (33–190 min) (p < 0.001). Additional trocars were used in 8 of 122 (6.5 %) SPA patients. A conversion to open cholecystectomy was not necessary in SPA patients. The conversion rate in the LC group to open cholecystectomy was 2 % (2/100). The perioperative and postoperative complications and incisional hernia (5.5 %) were the same in both groups. QoL was significantly better in the SPA group in terms of mobility (p = 0,002), usual activity (p = 0.036), and overall anxiety (p = 0.026).

Conclusions

SPA cholecystectomy is safe, although the operation is significantly longer. No differences in terms of major complications or the incidence of incisional hernia were seen after 1 year. QoL was significantly better in patients operated on with the SPA technique.     

Are Mammographic Changes in the Tumor Bed More Pronounced After Intraoperative Radiotherapy for Breast Cancer? Subgroup Analysis from a Randomized Trial (TARGIT‐A)

Intraoperative radiotherapy (IORT) with low‐energy x‐rays is increasingly used in breast‐conserving therapy (BCT). Previous non‐randomized studies have observed mammographic changes in the tumor bed to be more pronounced after IORT. The purpose of this study was to reassess the postoperative changes in a randomized single‐center subgroup of patients from a multicenter trial (TARGIT‐A). In this subgroup (n = 48) 27 patients received BCT with IORT, 21 patients had BCT with standard whole‐breast radiotherapy serving as controls. Overall 258 postoperative mammograms (median follow‐up 4.3 years, range 3–8) were retrospectively evaluated by two radiologists in consensus focusing on changes in the tumor bed. Fat necroses showed to be significantly more frequent (56% versus 24%) and larger (8.7 versus 1.6 sq cm, median) after IORT than those in controls. Scar calcifications were also significantly more frequent after IORT (63% versus 19%). The high incidence of large fat necroses in our study confirms previous study findings. However, the overall higher incidence of calcifications in the tumor bed after IORT represents a new finding, requiring further attention.     

Management of Urologic Complications in Renal Transplantation: A Single-Center Experience

Introduction

Ureterovesical complications subsequent to renal transplantation are associated with a high morbidity leading to graft loss or even death. In the present study, the management of these complications by using interventional and surgical procedures (native pyeloureterostomy [NPUS]/ureteroureterostomy [NUU] vs ureteroneocystostomy [UNC]) was evaluated retrospectively.

Patients and Methods

Between 1994 and 2012, a total of 780 kidney transplantations (690 deceased and 90 living donors) were performed at our institution. Demographic, clinical, and laboratory data from patients with urologic complications were analyzed and compared.

Results

Fifty patients (6.4%) exhibited ureterovesical complications, and 18 patients (36%) were operated on immediately. In 32 (64%) of 50 patients, an interventional procedure was initially performed, with 21 patients (66%) undergoing operation due to therapy failure. NPUS/NUU and UNC were performed in 26 (66.6%) and 13 (33.3%) patients, respectively. Indications for an operation were ureteral stenosis in 12 patients (30.8%), ureteral necrosis and urine leakage in 19 patients (48.7%), and symptomatic vesicoureteral reflux in 8 patients (20.5%). Long-term results were comparable between all groups.

Conclusions

Surgical revision of ureteral complications should be the standard therapy. NPUS/NUU, UNC, and the successful interventional procedures did not differ significantly in terms of long-term results.     

23Na-magnetic resonance imaging of the human lumbar vertebral discs: in vivo measurements at 3.0 T in healthy volunteers and patients with low back pain

Background context¹H magnetic resonance imaging (MRI) of the spine can rule out common causes of low back pain (LBP), such as disc protrusions or nerve root compression; however, no significant causal relation exists between morphology and the extent of symptoms. Functional MRI techniques, such as ²³Na, may provide additional information, allowing indirect assessment of vertebral glycosaminoglycan concentrations, decreases in which are associated with early degenerative changes.PurposeTo evaluate ²³Na-MRI of asymptomatic healthy volunteers and symptomatic patients with LPB and correlate the results to the Pfirrmann classification of MRI disc morphology.Study designRetrospective cohort study at an academic medical center.Patient sampleTwo groups were studied: (1) 55 healthy volunteers (31 men, 24 women; mean age 28.8 years) and (2) 12 patients (6 men, 6 women; mean age: 35.3 years) with a recent history of LBP.MethodsLumbar spines of the aforementioned groups were examined on a 3.0 T MRI scanner with morphological ¹H and ²³Na imaging. Intervertebral disc (IVD) ²³Na at each level was normalized (²³Na_norm). Distribution and differences between mean ²³Na_norm corresponding to each Pfirrmann classification were evaluated in the two study groups (analysis of variance). Linear correlations between ²³Na_norm, body mass index (BMI), and age were assessed (Pearson correlation coefficient). Gender-dependent differences were evaluated (paired t test).Outcome measuresPhysiological measure: IVD ²³Na_norm as determined by ²³Na-MRI.ResultsA normal distribution of ²³Na_norm was confirmed for both groups (p=.072 and p=.073, respectively). The mean Pfirrmann score statistically significantly differed between them (p<.0001). ²³Na_norm was statistically significantly reduced in degenerated IVDs (Pfirrmann scores 4+5) (p<.0001). No statistically significant differences were seen for the mean ²³Na_norm of IVDs with the same Pfirrmann score in healthy volunteers and patients (.469<p<.967). Age (0.007<R²<0.202) and BMI (0.074<R²<0.288) showed either weak or no correlation to ²³Na_norm. Mean ²³Na_norm was significantly (p=.0002) greater in women relative to men.ConclusionsThe results underline the feasibility and robustness of ²³Na-MRI of human IVDs and affirm, in a large cohort, decreases in ²³Na IVD content seen with disc degeneration.