bluuebunny/crossref_metadata_2025_split huggingface dataset:
Safety of magnetic resonance imaging of deep brain stimulator systems: a serial imaging and clinical retrospective study
Authors: Chhabra Vaninder , Sung Edward , Mewes Klaus , Bakay Roy A. E. , Abosch Aviva , Gross Robert E. 
Published: August 2009

Object
With the expanding indications and increasing number of patients undergoing deep brain stimulation (DBS), postoperative MR imaging is becoming even more important in guiding clinical care and practice-based learning; important safety concerns have recently emerged, however. Although phantom model studies have driven conservative recommendations regarding imaging parameters, highlighted by 2 recent reports describing adverse neurological events associated with MR imaging in patients with implanted DBS systems, the risks of MR imaging in such patients in clinical practice has not been well addressed. In this study, the authors capitalized on their large experience with serial MR imaging (3 times per patient) to use MR imaging itself and clinical outcomes to examine the safety of MR imaging in patients who underwent staged implantation of DBS electrodes for Parkinson disease, tremor, and dystonia.

Methods
Sixty-four patients underwent staged bilateral lead implantations between 1997 and 2006, and each patient underwent 3 separate MR imaging sessions subsequent to DBS placement. The first of these was performed after the first DBS placement, the second occurred prior to the second DBS placement, and third was after the second DBS placement. Follow-up was conducted to examine adverse events related either to MR imaging or to DBS-induced injury.

Results
One hundred and ninety-two MR images were obtained, and the mean follow-up time was 3.67 years. The average time between the first and second, and second and third MR imaging sessions was 19.4 months and 14.7 hours, respectively. Twenty-two MR imaging–detected new findings of hemorrhage were documented. However, all new findings were related to acute DBS insertion, whereas there were no new findings after imaging of the chronically implanted electrode.

Conclusions
Although potential risks of MR imaging in patients undergoing DBS may be linked to excessive heating, induced electrical currents, disruption of the normal operation of the device, and/or magnetic field interactions, MR imaging can be performed safely in these patients and provides useful information on DBS lead location to inform patient-specific programming and practice-based learning.
Levonorgestrel Intrauterine System Mirena: An Update
Authors: Siddiqui Maruf , Hossain Fawzia , Banu Lailaa 
Published: August 2009

Mirena is a levonorgestrel-releasing intrauterine system. Apart from being a reliable contraception, Mirena is now widely indicated for its non contraceptive benefits which include treatment of menorrhagia, dysmenorrhoea, premenstrual symptoms, fibroids, adenomyosis, endometriosis etc. It is now used even for hormone replacement therapy. This review article tries to explore different aspects of Mirena for treatment of menorrhagia compared to other available methods based on recent trials. doi: 10.3329/bjog.v23i1.3054 Bangladesh J Obstet Gynaecol, 2008; Vol. 23(1) : 25-31
Where Do We Go Wrong in Assessing Risk Factors, Diagnostic and Prognostic Tests?: The Problems of Two-by-two Association
Authors: Kraemer Helena Chmura , Gibbons Robert D. 
Published: August 2009

CME Educational Objectives

1.
Review two-by-two contingency tables.

2.
Express methods for assessing the strength of association between two binary variables.

3.
Explain design, sampling, and estimation issues in assessing risk, prognostic, and diagnostic factors.
Therapies for Pediatric Seborrheic Dermatitis
Authors: Poindexter Gabriele B. , Burkhart Craig N. , Morrell Dean S. 
Published: August 2009

CME Educational Objectives

1.
Describe the typical presentation of seborrheic dermatitis in infants and children.

2.
Restate the proposed etiology of seborrheic dermatitis.

3.
Recognize the different medications available for the treatment of seborrheic dermatitis and when it is best to use them.
Total Hip Arthroplasty After Periacetabular Osteotomy
Authors: Baqué François , Brown Antony , Matta Joel 
Published: August 2009

Patients with hip dysplasia often endure multiple surgical interventions, first in attempts to preserve their biologic hips and later for total hip arthroplasty (THA). Each different surgical approach traumatizes the musculoligamentous complex of the hip. These cumulative insults can significantly affect THA success.
We retrospectively reviewed 8 patients who underwent THA after previous periacetabular osteotomy via the same anterior approach. Acetabular bone stock required no augmentation for implant coverage. No complication occurred during surgery. All patients increased their functional score at last follow-up. No dislocation or implant loosening occurred. Leg-length restoration was excellent.
Periacetabular osteotomy is a proven conservative procedure in dysplastic hips that can be realized through a Smith-Petersen incision. Restoration of the acetabular anatomy is achieved with limited muscle detachment. Good results have been achieved with periacetabular osteotomy; however, some patients develop increasing pain from progression of osteoarthritis and require a THA to allow relief of symptoms. The anterior-approach THA is a well-established procedure using the same Smith-Petersen interval as periacetabular osteotomy. Using this approach for both procedures optimizes the patient's immediate and ultimate functional recovery and hip stability. Instead of compromising subsequent THA, periacetabular osteotomy may improve THA results in dysplastic hips.
Classification of Pelvic Fractures: Analysis of Inter- and Intraobserver Variability Using the Young-Burgess and Tile Classification Systems
Authors: Furey Andrew J. , O'Toole Robert V. , Nascone Jason W. , Sciadini Marcus F. , Copeland Carol E. , Turen Clifford 
Published: August 2009

Classification systems for pelvic ring injuries have been developed to assist in understanding the anatomy of the injury, predicting prognosis, and helping define treatment. Despite the frequent clinical use of the Young-Burgess and Tile classification systems, to our knowledge little work has been conducted to validate either system. We assessed the degree of inter- and intraobserver variability when using both the Young-Burgess and Tile classification systems and thereby assessed their validity for clinical use.
Eighty-nine isolated pelvic ring disruptions were selected. Sets of injury images were randomly ordered and distributed to 5 orthopedic trauma surgeons blinded to the patients' names, attending surgeons, dates of injury, and eventual treatments. The surgeons were asked to independently classify each pelvic ring disruption based on the Young-Burgess and Tile classifications. Eight weeks later, the same images were randomly ordered and redistributed to the same 5 surgeons, who were again asked to classify the pelvic injuries. A kappa analysis was conducted to analyze agreement among surgeons. A moderate degree of agreement was shown among orthopedic trauma surgeons when using both the Young-Burgess and Tile classification systems. Intraobserver agreement was found to be substantial for the Young-Burgess classification and moderate for the Tile classification. The degree of inter- and intraobserver variability may limit the usefulness of the 2 classification systems, both clinically and for research purposes.
The Use of a Biplanar Construct in Pelvic External Fixation
Authors: Noda Mitsuaki , Yamakawa Takayoshi , Fujii Tsuyoshi 
Published: August 2009

Inserting pins at a single location of the iliac crest temporarily provides an effective splint for emergency patients with pelvic ring fractures. For a longer application, however, this procedure frequently causes infection and pin loosening and does not effectively stabilize the pelvic construct. We presumed biplanar pelvic constructs may provide better stability than a uniplanar construct.
Two patients were treated with inserting pins at the lateral side of the supra-acetabulum as well as the iliac crest. Postoperatively, they demonstrated significant improvement in pain relief. The biplanar pelvic constructs showed sufficient stability during the procedure and at the time of pin removal several months postoperatively. Another pinning location for pelvic external fixation is the anteroinferior iliac spine toward the posteroinferior iliac spine. Inserting pins from this spot and the iliac crest does not create a biplanar construct, since anatomically these pins share a similar plane. Thus, the biplanar method in which pins were introduced at the lateral side of the supra-acetabulum and at the iliac crest was selected.
Despite the pins' application for several months, pin-site infection was not critical in our cases. We concluded that stability of the biplanar construct helped minimize pin-site infection.
A Rare Case of Intraosseous Benign Notochordal Cell Tumor of the Coccyx
Authors: Uglialoro Anthony D. , Beebe Kathleen S. , Hameed Meera , Benevenia Joseph 
Published: August 2009

This article presents a case of a 53-year-old woman who presented with intermittent, dull, poorly localized lower back and buttock pain. The pain worsened in a seated position or after long periods of standing. A T1-weighted magnetic resonance image (MRI) of the sacrum and coccyx revealed a well-demarcated intraosseous lesion with homogeneous low signal intensity, while T2-weighted MRIs demonstrated homogeneous high signal intensity. An excisional biopsy revealed benign notochord cell tumor. The biopsy proved to be effective, as it relieved the patient's coccydynia.
Due to the rarity of intraosseous benign notochordal cell tumors, it is essential to document and review this type of tumor. Only 2 benign notochordal cell tumors involving the coccyx have been previously reported, both of which presented with the same clinical symptoms of chronic coccydynia as our patient, likely due to the location of the involved lesion. The other leading diagnosis in our patient was chordoma, a malignant and locally aggressive neoplasm that is important to consider and exclude. Although chordomas have been well characterized in the surgery, pathology, and radiology literature, the benign notochordal cell tumor is a relative newcomer.
Ceramic Hemi-unicondylar Arthroplasty in an Adolescent Patient With Idiopathic Tibial Chondrolysis
Authors: Dombroski Derek , Garino Jonathan , Lee Gwo-Chin 
Published: August 2009

Despite recent advances in cartilage regeneration and restoration procedures, isolated, large, full-thickness cartilage lesions in young patients continue to pose significant challeneges to patients and orthopedic surgeons. Treatment options for this difficult problem have traditionally included arthrodesis, osteotomy, osteochondral allograft, and prosthetic reconstruction. We present a case of an adolescent patient with isolated idiopathic lateral tibial chondrolysis treated with a custom ceramic hemi-unicondylar hemiarthroplasty.
Preoperatively, a 3-dimensional computed tomography scan of the patient's knee was obtained to begin manufacturing a conforming custom ceramic insert that would articulate between the tibial base plate and the patient's native lateral femoral cartilage. Through a lateral parapatellar approach, the tibial preparation was carried out using the Zimmer M/G unicompartmental knee system (Warsaw, Indiana), and the tibial base plate was cemented into position in the standard fashion. A custom, conforming, prefabricated ceramic insert (CeramTec, Memphis, Tennessee) was then inserted onto the tibial base plate.
At 5-year follow-up, this salvage procedure was successful in relieving pain and restoring function in this young patient. There were no signs of implant loosening or lysis. Magnetic resonance imaging of the knee at last follow-up revealed that the cartilage thickness of the patient's lateral femoral condyle remained unchanged.
Unicondylar hemiarthroplasty performed in patients with large unipolar lesions in the knee can provide durable and reliable pain relief. Ceramic is a viable material that can be considered for articulation with native cartilage.
Transpedicular Bone Grafting Following Short-Segment Posterior Instrumentation for Acute Thoracolumbar Burst Fracture
Authors: Liao Jen-Chung , Fan Kuo-Fon , Chen Wen-Jer , Chen Lih-Hui , Kao Hsuan-Kai 
Published: August 2009

Posterior short-segment instrumentation for thoracolumbar burst fracture is known for a high implant failure rate because of the lack of anterior support. Anterior body augmentation by transpedicular bone grafting has been developed as an alternative to overcome this failure. However, the efficacy of transpedicular bone grafting remains debatable.
Between August 2002 and August 2006, 31 patients with a single-level thoracolumbar fracture underwent insertion of posterior short-segment pedicle screws and transpedicular bone grafting. Twenty-one men and 10 women had a mean age of 39.7 years at the time of surgery. All patients were followed up for at least 2 years; the mean follow-up period was 52.7 months. Preoperative computed tomography showed that the mean canal encroachment was 48.1%. The kyphotic angle improved from 20.9° to 3.7° immediately postoperatively. Loss of kyphosis correction was 2.7° before implant removal and 6.2° at final follow-up. The anterior body height was corrected from 50.9% to 86.9% by surgery, but collapsed to 82.2% before implant removal and became 78.1% at final follow-up. The failure of the surgery was defined as an increase of ⩾10° in local kyphosis and/or implant breakage. At last follow-up, no implants had failed, but 3 patients had a loss of correction >10°; the failure rate was 9.7%. According to the Dennis functional scales, the mean pain score was 1.7, and the mean work score was 2.2 at final follow-up. All 8 patients with partial neurological deficit initially had improvement.
Analysis of the results indicated that this technique effectively corrects deformities, restores vertebral height, prevents early implant failure, and provides satisfactory clinical results.
New logging tool for measuring azimuth of the ground‐water flow
Authors: Mares Stanislav , Henzl Tomas , Woltaer Leo , Lux Karl‐Norbert , Stump Uwe 
Published: August 2009

ABSTRACTIn hydrogeological research for ground water as well as in many contamination studies, the direction of the subhorizontal ground water flow is an important information influencing further decisions in exploitation of the ground water resources or in application of remediation measures.New construction of the logging tool for determining azimuth of the ground water flow in a single well and its laboratory and field testing is presented. The sophisticated logging tool ‐ combination of an electronic compass with a special circular photometric sensor detecting the time changes of the tracer plume in the measuring slot ‐ offers the information on direction of subhorizontal ground water flow in a single well for velocities ranging between 10‐6 to 10‐1 m/s. The diameter of the tool is 76 mm, length 1.12 m and weight 13 kg. The tool is operating together with current logging systems.
Geophysical Study of an Landslide in Northern Sicily
Authors: Cosentino P. , Martorana R. , Perniciaro M. , Terranova L.M. 
Published: August 2009

ABSTRACTThe San Fratello area in the Nebrodi Mountains (northern Sicily) is a region of high instability. It has suffered many devastating occurrences, which have hit and destroyed the village of San Fratello. At present the area is still subject to a high landslide risk.A series of geophysical surveys have been carried out with the aim of determining the thickness and dimensions of the landslide body as well as some tectonic features, in order to gain insight into the evolution of the landslide. The following geophysical techniques have been used: borehole seismic tomography, i.e. down‐hole tomographic seismic soundings (DH TSS), time‐domain electromagnetic (TDEM) soundings and georadar profiling (GPR). An additional objective was to compare the efficiency of the geophysical methods used in real geological, morphological and logistic situations.The data obtained using seismic tomography outlined the shape and the thickness of the body of the landslide in the scar and track area, as well as some mechanical characteristics of the formations involved in the movement. TDEM soundings provided a little additional information on the upper 5–10 m. Georadar profiles supplied some information about the locations of some lateral lithological changes.Finally the information obtained with the various geophysical techniques was used to provide an outline of the history of the area.
Two‐dimensional electrical imaging for detection of hydrocarbon contaminants
Authors: Godio A. , Naldi M. 
Published: August 2009

ABSTRACTThe effects of a long‐term diesel oil pollution due to leakage from buried tanks have been investigated using electrical resistivity tomography. The reliability of 2D electrical resistivity imaging of the subsoil was assessed using a numerical modelling approach that simulated the different behaviour of the contaminated zone. The effects of inversion parameters, such as the damping factor and smoothing matrix, have been studied in order to evaluate the optimal parameters to process real data.The results of the field test indicated that highly conductive anomalies can be related to the biological degradation of hydrocarbons: geochemical analysis performed on several groundwater samples confirmed the presence of biodegradation activity. Chemical analysis pointed out an anomalous concentration of iron and manganese cations dissolved in the groundwater. Very low values of resistivity can be associated with a marked modification of the cation exchange capacity of the soil mixture due to degradation of these hydrocarbons. Chemical and physical interactions due to hydrocarbon pollution affect the electrical properties of soils and groundwater.
Investigation of a fractured limestone cliff (Chartreuse Massif, France) using seismic tomography and ground‐penetrating radar
Authors: Dussauge‐Peisser Carine , Wathelet Marc , Jongmans Denis , Hantz Didier , Couturier Bernard , Sintes Michel 
Published: August 2009

ABSTRACTEvaluating the stability state of a rock slope is a complex problem, mainly due to the lack of knowledge of the real state of the rock mass. Geophysical methods appear to be useful for investigating the deep discontinuity pattern, which may be poorly interpreted from surface observations. However, they have seldom been applied on steep rock slopes. The aim of this study is to test seismic tomography and ground‐penetrating radar on near‐vertical cliffs, and assess the quality of information that they can provide when investigating the characteristics of the fracture pattern inside the massif.The test site is located in the Chartreuse massif, 20 km north‐west of Grenoble, France. It is a 15 m high limestone cliff, characterized by one main near‐vertical discontinuity set, including some wide open fractures.Seismic tomography has been conducted between the vertical free surface and the plateau above, along three parallel profiles. Results show strong velocity gradients, from 800 to 3500 m/s. Some triangular low‐velocity zones can be correlated with field observation of open fractures, but different tests on synthetic models and on real data show that the method is too sensitive to such heterogeneous conditions to provide accurate information on the fracture pattern.Ground‐penetrating radar surveys have also been acquired along vertical profiles on the cliff. We used three different antennae with centre frequencies of 35, 120 and 500 MHz. The penetration depth varied from 10 m (500 MHz) to about 20 m (35 MHz). The main reflectors are near‐vertical and most of them can be correlated with fractures observed on the site. The reflectivity varies strongly along one single reflector, indicating changes in the aperture and/or filling characteristics.
Seismic reflection imaging of an ultrashallow interface from a P‐wave data set with a poor signal‐to‐noise ratio
Authors: Balia Roberto , Gavaudo Enrico 
Published: August 2009

ABSTRACTIt is well known that pitfalls are commonly encountered in the acquisition and processing of shallow reflection data. Although they can often lead to misinterpretations, the obsession with these difficulties can generate an excessively pessimistic attitude and ultimately lead to rejecting data that contain genuine reflections. The authors revisited a data set acquired during an ultrashallow P‐wave reflection experiment conducted in December 1996 on a subsurface model characterized by one main, complex interface. The model had been purpose‐built to control acquisition and processing decisions, and to contribute to clarifying at least some of the critical aspects inherent in the ultrashallow seismic reflection method. For the experiment, the acquisition geometry was purposely designed regardless of the known characteristics of the model, considering only a target depth of less than ten metres. The data, which had been acquired with CMP techniques, were generally characterized by a poor signal‐to‐noise ratio and had been considered completely useless. Initially, inexperience in acquiring and, above all, processing ultrashallow reflection data, in conjunction with mise‐valuations, had led to disappointing failures. Velocity analysis on reflection data had proved very difficult and standard processing sequences were inadequate. However, in this case a good result was obtained by modelling the near‐surface velocity using direct‐wave traveltimes analysis and by adopting a simple but segregated processing sequence, which proved necessary due to significant velocity gradients and large relative variations of the reflector depth. Time‐to‐depth conversion afforded a more than acceptable result.
Three‐dimensional GPR imaging in the horizontal wavenumber domain for different heights of source and receiver antennae
Authors: van der Kruk J. 
Published: August 2009

ABSTRACTFor imaging ground‐penetrating radar (GPR) data, three of the most important parameters are the wave speed, polarization and amplitude of the propagating electromagnetic wave‐field. Choosing an appropriate forward model that incorporates these three parameters is a critical aspect of imaging. Also, the height of the antennae above the surface influences the scattered field significantly and should be taken into account. As the height of the antennae above the surface is increased, the widths of the antenna patterns decrease, resulting in decreasing horizontal spatial bandwidths of the scattered electric fields. Imaging is carried out in the horizontal wavenumber domain using the spatial bandwidths of the scattered data. Decreased spatial resolution is obtained for increasing heights. The far‐field expressions do not account for geometrical spreading in air above the surface, resulting in anomalously low image amplitudes for elevated antennae. Experimental data measured with 900 MHz antennae also show reductions in spatial bandwidth as the height of the source and receiver antennae is increased. For heights and , similar spatial bandwidths as predicted by the synthetic results are obtained. For , this reduction in bandwidth is not as strong as predicted by the synthetic results, primarily because of limitations of the far‐field expressions. For stability reasons, the imaging could only be carried out using the limited bandwidth for the forward far‐field model. Images of a spherical metal sphere for measurements at and were almost identical, whereas those at were similar to those at low heights. In one direction, a higher spatial resolution was observed for the antennae with zero height and decreasing spatial resolution for increasing height. In the other direction, the difference in spatial resolution was not very obvious.