bluuebunny/crossref_metadata_2025 huggingface dataset:
Botulinum Toxin Type a in the Treatment of Focal Hand Dystonia After Surgical Treatment for Thumb Duplication
Authors: Santamato Andrea , Panza Francesco , Solfrizzi Vincenzo , Frisardi Vincenza , Moretti Biagio , Notarnicola Angela , Neve Anna , Ranieri Maurizio , Fiore Pietro
Published: August 2009

Dystonia is a set of disorders characterized by abnormal postures and unwanted muscle spasms that interfere with motor performance. Focal dystonias, the most common, affect just 1 body part. A 25-year-old woman had a focal hand dystonia with pain and muscle spasms in the right hand after surgical treatment for thumb duplication. According to Wassel's classification, she was type II, with duplication of the distal phalanx. She had undergone Bilhaut-Cloquet surgery to remove a radial supernumerary thumb. During repetitive movements, she reported pain and muscle cramping in the right thumb and wrist. Force was rated, according to the Medical Research Council scale, from grades 0 to 5, and the patient had a score of 4. No sign of joint instability was found in her hand, and normal active and passive range of motion were found for interphalangeal or metacarpophalangeal joints of right thumb. However, right thenar muscle hypoplasia was found. Repetitive activity acted as an environmental trigger for the reconstructed thumb on thenar muscle hypoplasia as residual anatomical modification. Surface electromyography showed movements suggestive of dystonia. After 5 days of treatment with botulinum toxin type A, with both the flexor pollicis longus and the abductor pollicis brevis of right hand injected with a dose of 20 μM each, the patient reported a regression of most signs and symptoms. Two-month follow-up revealed that clinical effects of botulinum toxin type A were still present.
Treatment of Giant Cell Tumor of Long Bones: Clinical Outcome and Reconstructive Strategy for Lower and Upper Limbs
Authors: Muramatsu Keiichi , Ihara Koichiro , Taguchi Toshihiko
Published: August 2009

Giant cell tumor of bone is a rare and unpredictable lesion. Standard treatment ranges from surgical curettage to wide resection, with reports of varying oncological and functional results. Twenty-three consecutive cases of giant cell tumor of long bones were treated in 10 years. Fifteen men and 8 women had a mean age of 38 years (range, 17–82 years). Average follow-up was 45 months (range, 12–180 months). The most common tumor sites were the proximal tibia (10 cases), distal femur (8), and distal radius (3). All patients remained free of recurrence at the time of final follow-up. Functional outcomes as evaluated by the Musculoskeletal Tumor Society measure were successful, with an average score of 26.6 points (range, 22–30 points).

To avoid local recurrence around the knee joint, we recommend radical intralesional curettage with a high-speed drill burr, adjunctive therapy with cryosurgery, and filling with polymethylmethacrylate. Primary total knee arthroplasty is acceptable for older patients. For giant cell tumor of the upper limb or for young patients, biological reconstruction should be applied.
Posterior Versus Anterior Lumbar Interbody Fusion With Anterior Tension Band Plating: Retrospective Analysis
Authors: Freudenberger Curt , Lindley Emily M. , Beard Douglas W. , Reckling W. Carlton , Williams Allison , Burger Evalina L. , Patel Vikas V.
Published: August 2009

Over the past 2 decades, posterior lumbar interbody fusion (PLIF) with pedicle screw instrumentation has gained popularity. Anterior fusion techniques, however, have evolved over time and currently allow for minimally invasive anterior retroperitoneal diskectomy, interbody graft placement, and rigid instrumentation. A direct comparison of anterior lumbar interbody fusion (ALIF) with anterior tension band (ATB) plating to that of instrumented PLIF has not been previously reported.

This retrospective uncontrolled cohort comparison included 59 patients with low back pain and 1- or 2-level lumbar degenerative disk disease from L3 to S1 who underwent PLIF with pedicle screw instrumentation or ALIF with anterior tension band plating. Outcome measures included estimated blood loss, surgical time, radiographic evidence of fusion at 6 to 9 months postoperatively, and pre- and postoperative Oswestry Disability Index scores. Fusion rates for the 2 procedures were similar. Posterior lumbar interbody fusion patients had significantly higher estimated blood loss and longer surgical time than ALIF-ATB patients. Oswestry Disability Index scores were similar between the 2 groups at all postoperative time points, except at 3 months postoperatively when PLIF patients had lower scores than ALIF-ATB patients. These findings suggest that ALIF-ATB has similar fusion and functional outcomes as PLIF, but with shorter surgical time and decreased blood loss.
Hospitalist–Orthopedic Co-management of High-risk Patients Undergoing Lower Extremity Reconstruction Surgery
Authors: Pinzur Michael S. , Gurza Edward , Kristopaitis Theresa , Monson Rebecca , Wall Michael J. , Porter Anne , Davidson-Bell Victoria , Rapp Timothy
Published: August 2009

The introduction of the hospitalist co-management model represents an opportunity to improve care by changing the system as it applies to a small group of patients. Eighty-six consecutive patients with multiple comorbidities were selectively enrolled in an academic medical center hospitalist–orthopedic surgery co-management patient care program. Patients were stratified by all patient refined diagnosis-related groups, severity of illness, and risk of mortality. Hospital length of stay, cost of care, in-hospital mortality, complications, and intensive care unit admissions were compared with a retrospectively constructed control group of 54 patients undergoing similar surgery during the period immediately preceding initiation of the program. The University Health-System Consortium observed-to-expected ratio for hospital length of stay was 0.693 compared to 0.862 for the control group. The severity of illness and risk of mortality scores represented a relatively higher risk stratification in the study group. While the overall observed-to-expected cost of care remained virtually unchanged, the positive impact of the study model revealed an increased positive effect on the more severely affected severity of illness and risk of mortality patients.

The results of this study suggest that a proactive, cooperative, co-management model for the perioperative management of high-risk patients undergoing complex surgery can improve the quality and efficiency metrics associated with the delivery of service to patients.
Two Different Types of Bowler's Thumb
Authors: Muramatsu Keiichi , Yoshida Koji , Taguchi Toshihiko
Published: August 2009

Two rare cases of bowler's thumb (traumatic neuropathy of the ulnar digital nerve of the thumb) were treated surgically with encouraging results. These had different types of lesion, involving nodular neuroma and epineural mass, which were distinguished by magnetic resonance imaging. The surgical outcome for active bowlers is unclear and postoperative protection from the repetitive trauma of throwing is important. Possible technical solutions include changing the size and weight of the ball, the spacing between holes, the fitting of thumb to ball, and the slope and size of thumb holes. It is important that both bowlers and clinicians are sufficiently aware of bowler's thumb to allow early diagnosis and treatment of this lesion.
Peroneal Nerve Palsy Resulting From Fibular Head Osteochondroma
Authors: Mnif Hichem , Koubaa Mustapha , Zrig Makram , Zammel Nizar , Abid Abderrazek
Published: August 2009

This article describes a case of an 11-year-old boy with an osteochondroma of the peroneal head causing peroneal nerve palsy. Physical examination disclosed large exostoses palpated at the right fibular head. Neurological examination revealed paresis of the tibialis anterior, lateral peroneal, and extensor digitorum muscles with a muscle strength grade of 2. Electrophysiological studies confirmed denervation of the muscles supplied by the right peroneal nerve. Radiological examination showed an osteochondroma in the head of the right fibula. The patient underwent surgical decompression of the right peroneal nerve after resection of the bone tumor. At 36-month follow-up, there was a complete recovery of the deficits.

Peroneal mononeuropathy in children is uncommon. Osteochondroma is a benign tumor consisting of projecting bone capped by cartilage. These tumors may be solitary or multiple and occur in hereditary multiple exostoses syndrome. The conjunction of this lesion with peroneal nerve palsy has been exceptionally reported for children, usually linked to hereditary multiple exostoses syndrome. Most peroneal nerve trauma occurs at the fibular head, where the common nerve has not yet divided into its deep and superficial peroneal nerve and where most peroneal nerve lesions, therefore, involve both branches, although motor deficits are more frequently involved than sensory ones. Surgical treatment should not be delayed because neurological improvement may be achieved if surgery is performed before severe neurological deficits become irreversible.
Posterior Subtalar Dislocation
Authors: Camarda Lawrence , Martorana Umberto , D'Arienzo Michele
Published: August 2009

A subtalar dislocation of the foot is an uncommon injury, and cases of posterior subtalar dislocation are even rarer. This injury is characterized by a simultaneous dislocation of talocalcaneal and talonavicular joints while tibiotalar and calcaneocuboid articulations remain intact. Subtalar dislocation is commonly accompanied by fractures of the malleoli, talus, or fifth metatarsal and by a rotational component of the subtalar joint. Subtalar dislocation can occur in any direction and produces significant deformity.

This article presents a case of pure posterior subtalar dislocation in an 80-year-old man who presented with pain and deformity in his left ankle following a motorcycle accident. Radiographs demonstrated dislocation of both the talonavicular and talocalcaneal joints. The calcaneus was displaced posteriorly without medial or lateral displacement. No rotational component of the calcaneus was noted, suggesting the trauma was in pure hyperplantar flexion.

We hypothesize that pure hyperplantar flexion could lead to a progressive subtalar ligament weakening that may result in a complete ligament rupture if the plantar flexion force is prolonged. This could be observed in the presence of good bone quality and if the force is applied distally at the navicular bone.
Cervicothoracic Giant Cell Tumor Expanding Into the Superior Mediastinum: Total Excision by Combined Anterior-Posterior Approach
Authors: Yoshioka Katsuhito , Kawallara Norio , Murakami Hideki , Demura Satoru , Kawaguchi Masahito , Oda Makoto , Matsumoto Isao , Tomita Katsuro
Published: August 2009

This article describes a case of cervicothoracic giant cell tumor expanding into the superior mediastinum treated by total spondylectomy. A 42-year-old-man presented with back pain and paraparesis. Magnetic resonance imaging revealed the collapse of the T2 vertebral body. The spinal cord was severely compressed by the tumor mass. The tumor had spread from T2 to the mediastinum, so that the tumor was in contact with many vital structures. To resect the tumor completely, total spondylectomy from T1 to T3 was performed through a combined anterior-posterior approach. The tumor was dissected from the vital structures using an anterior low cervical approach and splitting one-third of the sternum. En bloc vertebral resection from Th1 to Th3, including the tumor pseudocapsule, was possible through a posterior approach. The tumor around the nerve roots or dura was resected piece by piece since it was possible to separate the capsulated tumor from the dura. Splitting one-third of the sternum allowed separation of the tumor from the anterior vital structures, under direct vision. This allowed en bloc vertebral resection of the tumor that had spread to the mediastinum from T2 and in the craniocaudal direction from T1 to T3. Although giant cell tumor is benign, it can be locally aggressive. Complete excision of a giant cell tumor is the best treatment option even for the cervicothoracic spine, to protect the vital structures or neural function.
Juxta-articular Myxoma Within the Suprapatellar Pouch Masquerading as a Ganglion Cyst
Authors: Kosty John W. , Moore Jeffrey G.
Published: August 2009

This article presents the case of a 63-year-old man who noted painless swelling within the suprapatellar pouch, which he attributed to an effusion. Small-magnet, lower-extremity magnetic resonance imaging (MRI) and subsequent arthroscopy missed the lesion. On MRI with gadolinium contrast, the lesion was defined but misdiagnosed as a suprapatellar pouch ganglion cyst. Following resection of the 6×5×1.8-cm lesion, histology confirmed a lobular benign tumor with cystic elements recognized in the pathology and radiology literature as juxta-articular myxoma. Such lesions are characteristically multilobulated and contained within a capsular rim that enhances with gadolinium venous contrast. Otherwise, they appear hyperintense to fat on T2-weighted images and hypointense to muscle on T1-weighted images. This is an uncommonly encountered but known cystic lesion around the knee that is most often confused with ganglion cyst, synovial lipoma, lipoma arborescens, or pigmented or non-pigmented villonodular synovitis. Given its more cellular nature and thicker encapsulation, it should be able to be differentiated from ganglion cyst on MRI with a high index of suspicion, and should be recognized because of its high rate of recurrence. Unusual in this case was its location within the suprapatellar pouch, demonstrating the ease with which such lesions can be missed arthroscopically despite significant mass.
Lumbar Disk Herniation: What Are Reliable Criterions Indicative for Surgery?
Authors: Cakir Balkan , Schmidt Rene , Reichel Heiko , Käfer Wolfram
Published: August 2009

Educational Objectives

As a result of reading this article, physicians should be able to:

1.

List the indications for surgical intervention in lumbar disk disease and the level of support for each indication as documented in the available literature.

2.

Describe the clinical diagnosis that would benefit most from urgent surgical decompression compared to nonoperative management to best optimize clinical outcomes.

3.

Discuss the role and duration of nonoperative therapy in the treatment of lumbar herniated disk disease.
OCT Imaging of Capsular Block Syndrome With Crystalline Cortical Remnants in the Capsular Bag
Authors: Mastropasqua Leonardo , Toto Lisa , De Nicola Giulio , Nubile Mario , Carpineto Paolo
Published: August 2009

A 72-year-old woman with cataract had phacoemulsification and intraocular lens implantation in the capsular bag with continuous curvilinear capsulorrhexis in the right eye. One day postoperatively, cortical remnants were noted between the posterior capsule and the intraocular lens optic located inferiorly. Uncorrected visual acuity was 1.0 and the patient was emmetropic. At a control visit 6 years postoperatively, the patient showed a hyperopic shift compared with the refraction of the first postoperative period with a best-corrected visual acuity of 0.4. A transparent liquefied substance that accumulated between the lens optic and the fibrotic capsule and surrounding the residual cortical masses was clearly visible using slit-lamp biomicroscopy and anterior segment optical coherence tomography. A surgical revision with aspiration of the cortical masses and the fluid was performed, resolving the capsular block syndrome. A neodymium:YAG laser posterior capsulotomy followed to clear the visual axis.
[Ophthalmic Surg Lasers Imaging 2009;40:399–402.]
Use of Voriconazole in the Surgical Management of Chronic Postoperative Fungal Endophthalmitis
Authors: Vasconcelos-Santos Daniel V. , Nehemy Márcio B.
Published: August 2009

Management of postoperative mycotic endophthalmitis remains challenging. This study reports successful management of postoperative chronic fungal endophthalmitis with vitrectomy surgery and voriconazole. A retrospective interventional case series of four eyes of four patients with chronic fungal endophthalmitis treated with pars plana vitrectomy and oral and intravitreal voriconazole is described. Pars plana vitrectomy, en bloc capsulectomy, and explantation of the intraocular lens were then performed combined with one to four intravitreal injections of voriconazole and oral voriconazole for up to 5 weeks. Identified fungal species included
Aspergillus
,
Acremonium
,
Penicillium
, and
Verticillium
. Voriconazole may have affected the clinical and surgical management of fungal endophthalmitis.
[Ophthalmic Surg Lasers Imaging 2009;40:425–431.]
Use of Physical Restraint in Institutional Elderly Care in Finland: Perspectives of Patients and Their Family Members
Authors: Saarnio Reetta , Isola Arja
Published: August 2009

The purpose of this qualitative study was to describe the use of physical restraint and the perspectives of elderly patients and their family members on the use of physical restraint in long-term institutional care. Data were collected in three elderly care units through participant observation and theme interviews. The results revealed that in addition to traditional means of restraint, such as restraint belts and raising the sides of the bed, the nursing staff used indirect methods of restraint as well. These included a mode of operation that promoted passivity, such as removing the patient's mobility aid and keeping the patient inadequately clothed. The results also revealed that the patients felt so unsafe in the nursing environment that they voluntarily locked themselves in their rooms. Another interesting finding was that patients' family members were active in restraint situations. The study findings provide information that can be applied in the development of long-term institutional care.
Georadar and seismic investigations over the Glacier de la Girose (French Alps)
Authors: Sénéchal G. , Rousset D. , Salomé A.‐L. , Grasso J.‐R.
Published: August 2009

Several ground penetrating radar (GPR) acquisitions have been performed on a temperate glacier (glacier de la Girose, southern French Alps) in order to determine the ability of this method in terms of penetration and resolution. The final goal of these experiments is to constrain the structural context on an area where 3‐C wide‐band seismic recorders have been deployed for icequake analysis. Radar data have been recorded using 50 MHz antennae in order to get information about the glacier thickness, and 250 and 500 MHz frequency antennae have been used for shallow high resolution structural images. For comparison, thickness of the glacier has been independently evaluated from seismic data. Local determination of the electromagnetic wave velocities has been obtained from a CMP acquisition. Several hyperbolas can be picked up to 1600 ns, the strongest one being interpreted as the reflection from the ice‐bedrock interface, at 1150 ns (around 90 m depth). This result is well correlated to the seismic data which show on the unmigrated time section a strong dipping reflection between 50 (West) to 70 ms (East) (between 90 and 120 m after migration and depth conversion).

Where the radar profiles cross crevasses, the unmigrated sections obtained with 250 and 500 MHz antennae show shallow diffraction patterns associated with low amplitude strip. On the migrated sections, one can observe deeper diffraction points, probably generated by rock material or water feeders. The high resolution data provided with radar allow to distinguish several periodic arrivals between 1150 and 1600 ns. These are interpreted as multiple reflections due to a thin water layer separating the base of the glacier and the bedrock. The lower resolution of seismic data doesn't allow to detect this thin layer.

In terms of resolution, deep radar resolution is one order of magnitude better than the seismic one and shallow radar resolution is two orders of magnitude more accurate than seismics. Shallow radar appears as the only efficient tool for imaging the shallow glacier structures.
Resistivity imaging to determine clay cover and permeable units at an ex‐industrial site
Authors: Vickery Anna , Hobbs Bruce A
Published: August 2009

A previous geophysical and invasive site investigation over an ex‐industrial site near the Forth Estuary, Edinburgh, identified a network of subsurface oil‐pipes and shallow contaminants. A subsequent resistivity survey has now been conducted to determine possible contaminant migration pathways. Resistivity images measured along 28 profiles have been inverted to obtain resistivity models and their collation has enabled a pseudo three‐dimensional resistivity image of the site to be constructed. Shallow subsurface resistivities indicate that the majority of the site is covered by a layer of clay, approximately 5‐10 m thick, typically regarded as sufficient for containing contaminants within the near surface. However in one region the clay layer is shown to be thin and underlain by permeable sandstone thus presenting a possible pathway for downward migration of fluids. Resistivity values at greater depths infer the existence of several sandstone units and faults that may aid the transportation of contaminants away from the site. There is particular concern that pathways may exist that allow the transportation of contaminants towards the Forth Estuary. A revision of the local geology for the site to include the faulted sandstone has been suggested.
Assessing reliability of 2D resistivity imaging in mountain permafrost studies using the depth of investigation index method
Authors: Marescot L. , Loke M.H. , Chapellier D. , Delaloye R. , Lambiel C. , Reynard E.
Published: August 2009

2D electrical resistivity tomography has been applied within a mountain permafrost environment to assist in ice location. In the context of climate change, a warming process could partially thaw this permafrost and thereby increase the risk of slope instabilities. The extent and location of permafrost are therefore of considerable interest to civil engineers.

The most challenging aspect of resistivity surveys on mountain permafrost concerns the surface layer, which mainly consists of large blocks with air voids. To overcome the very poor electrical contact, long steel stakes and sponges soaked in salt water are used as electrodes. Nevertheless, only a weak current can be injected. Another challenging aspect is the high resistivity contrast between frozen and unfrozen material, which makes inversion and interpretation difficult and problematic. In order to assess whether features at depth, indicated by the data, are real or are artefacts of the inversion process, a special inversion algorithm was applied to process depth of investigation (DOI) index maps. This method carries out two inversions of the same data set using different values of the reference resistivity. The two inversions give the same resistivity values in areas where the data contain information about the resistivity of the subsurface. On the other hand, the final result depends on the reference resistivity in areas where the data do not constrain the model.

As can be deduced from field data from the Swiss Alps and the Jura Mountains, this methodology prevents over‐interpretations or misinterpretations of inversion results in mountain permafrost studies. From the DOI calculations, it is evident that little reliable information on the bedrock under the massive ice can be obtained and that the resistivity within the high resistivity zones cannot be determined accurately. The DOI map also helps to explain the occurrence of erratic and non‐geological structures at depth and indicates to what depth an inverted resistivity profile can provide results.
Properties and effects of measurement errors on 2D resistivity imaging surveying
Authors: Zhou Bing , Dahlin Torleif
Published: August 2009

Electrode spacing errors and errors correlated with the magnitude of the observed potential are two key factors that affect the data quality for DC resistivity imaging measurements. This paper investigates the properties and effects of these two kinds of error on 2D resistivity imaging or inversion for practical applications. By analytic analysis and numerical simulations, the off‐line and in‐line electrode spacing errors were quantitatively estimated for all common electrode arrays (pole‐pole, pole‐dipole, pole‐bipole, Wenner, Schlumberger, dipole‐dipole, γ‐array, Wenner‐β) in 2D resistivity imaging surveys. Meanwhile, the spreading patterns of the spacing errors in the pseudosection and the possible artefacts in the imaging (inverted model) are evaluated. We show that the magnitude of the spacing errors are quite different with these arrays, being largest for dipole‐dipole, Wenner‐β and γ‐array surveys, for which a 10% in‐line spacing error may cause twice as large an error (>20%) in the observed resistance or apparent resistivity, which in turn will produce some artefacts in the inverted model. The observed potential errors obtained with the reciprocity principle and collected from different sites and with different electrode arrays, were analysed to show the properties of the potential error caused by many aspects in the field. Using logarithmic plots and error pseudosections, we found that with different electrode arrays and at different sites the potential errors demonstrate a general property, which may be regarded as a negative‐power function of potential reading. Power net transients, background telluric variation and instrument malfunction are possible sources that may cause the large errors present as outliers deviating from this function. We reaffirm the fact that the outliers are often correlated with high contact resistances for some of the electrodes used in a measurement, but this may also be caused by an unsatisfactory connection between the electrode and the cable due to, for example, dirt or oxide on the connectors. These outliers are often the main part of the errors affecting the imaging results. Furthermore, a robust inversion and a smoothness‐constrained inversion were applied to the investigation of the effects of the measurement errors. Using two real data sets, we show that the smoothness‐constrained least‐squares inversion is much more sensitive to the potential errors than the robust inversion, but the two inversion schemes produce very similar models with a high data quality. Artefacts or indefinite parts in the inverted models correlate with the distribution zones of the outliers in the potential error pseudosection.
GPR abilities for the detection and characterisation of open fractures in a salt mine
Authors: Grégoire Colette , Halleux Lucien , Lukas Volker
Published: August 2009

Ground‐penetrating radar is widely used for mapping fractures in resistive rocks such as salt. In operating mines, fractures are often induced by the mining activity itself. Knowledge of the position and the characteristics of the fractures, and their evolution in space and time, are very important for mine safety. In the salt mine discussed in this paper, radar profiles are carried out daily to detect fractures in the roof of the galleries. For this study, radar measurements are carried out using two different systems at two different sites in the mine. Dynamic and static data are obtained at various antenna–roof distances. A supplementary profile is registered at 500 MHz. At the two sites, 15 boreholes are available and the fracture openings are measured. Most of the fractures observed in the boreholes can be observed on the radar profiles, except for the very thin fractures and the fractures of complex fracture systems, which cannot be resolved. The detectability of the fractures is analysed for the dynamic as well as the static data. Fractures larger than 10 mm can be detected at least up to a depth of 2 m (length of the boreholes). For fractures smaller than 10 mm, the detectability depends on the depth into the salt and the antenna–roof distance. These results may be site specific. In order to characterize the fracture opening, the frequency content of the radar reflection is analysed. Synthetic signals show that in order to obtain reliable results, the analysis has to be performed over a broad frequency range and not at one frequency. For the real data, a reference signal is required and some corrections have to be applied to the reflected wave to take into account the propagation, the geometry and the reflectivity of the roof. If the signal quality is good, the estimation of the openings by inversion is mostly satisfactory. For signals where this is not the case, the differences from the real openings can be explained by a spatial variation of the fractures, irregularities of the opening, the presence of fractures very close to each other or by the quality of the reference signal. It can also be due to the method itself, which is less efficient in some opening ranges. Although the estimation of the fracture opening is not perfect, the uncertainty about the opening is reduced. A statistical analysis should further improve the results.
Cone penetration logging for the direct detection of LNAPLs contamination
Authors: Kvapil Jiri , Mares Stanislav
Published: August 2009

Light non‐aqueous phase liquids (LNAPLs), such as crude oil and by‐product fuels, represent a common source of organic contamination in the environment. Successful remediation of contaminated sites requires knowledge of the LNAPL distribution in the subsurface. The delineation and monitoring of the LNAPL plume carried out using fluid sampling in monitoring wells can differ from the reality because the residual LNAPLs are trapped in the pores of the soil. Surface geophysical techniques, such as GPR and ERT, can be used only for indirect LNAPL detection. This study suggests the use of cone penetration logging (a combination of cone penetration tests and geophysical logging) as a tool for detecting total hydrocarbon content (residual and movable) in shallow unconsolidated soil materials.
Moisture assessment with small‐scale geophysics‐the Interurban project
Authors: Müller Martin , Mohnke Oliver , Schmalholz Jürgen , Yaramanci Ugur
Published: August 2009

Urban soils are subject to strong variations in environmental conditions, such as water flow, solute transport and heat budget. The INTERURBAN research project has been set up to investigate the dynamics of water and solutes at urban locations with particular attention to spatial heterogeneity, organic soil substance, and soil‐biological transformation processes in the unsaturated zone. The objectives of INTERURBAN also define the tasks for geophysics: the development of non‐invasive procedures to map water distribution, water dynamics and important structural parameters at small scales. This paper focuses on the development of a geophysical methodology as a tool for soil research. Approaches to adapting geophysical methods for particular objectives in the framework of the project have been successful. Soil moisture could be derived from ground‐penetrating radar (GPR) in combination with timedomain reflectometry (TDR), high‐resolution direct‐current geoelectrics (DC on a dm scale) could be realized and a newly developed direct‐push spectral induced‐polarization (SIP) probe delivered high‐quality data. The resistivities and phases derived from the direct‐push SIP data correlate very well with the water content and decay times derived from nuclear magnetic resonance (NMR) measurements performed in the laboratory on a core from the same site. For DC geoelectrics and SIP, the layout of the sensors was a customized high‐resolution multi‐electrode configuration (a comb of electrodes with an electrode spacing of 5 cm) and the influence of the short electrode spacing (line electrode) was corrected for. For GPR metal plates were buried at a known depth to allow monitoring of the traveltime by means of water content. Furthermore, the ground wave has been used to determine the shallow water content which correlates well with TDR measurements. For surface NMR (SNMR), smaller loops and excitation intensities were used to enhance the resolution of the method for shallow depths.
Cone penetration logging for the direct detection of LNAPLs contamination
Authors: Aaltonen Jaana
Published: August 2009

It is becoming increasingly important to carry out efficient geophysical investigations into the hydrogeological conditions in larger esker areas. These investigations are aimed at mapping the prerequisites for groundwater or mineral take‐out or conditions for artificial infiltration. Today most of these investigations are carried out based solely on a few geo‐technical borings, giving only a small amount of information about the subsurface conditions.

We show that the combination of ground‐penetrating radar (GPR) and continuous vertical electrical sounding (CVES) measurements will, in a relatively fast manner, cover larger areas of investigation, and thus provide a large quantity of information about the subsurface. The combination of GPR and CVES will give detailed information about the top layers (down to 10–20 m), and will also provide good characteristics of layers down to 50–60 m.
GPR using an array antenna for landmine detection
Authors: Sato Motoyuki , Hamada Yusuke , Feng Xuan , Kong Fan‐Nian , Zeng Zhaofa , Fang Guangyou
Published: August 2009

We propose a new ground‐penetrating radar (GPR) methodology for buried land‐mine detection. A GPR system using an antenna array was used for common‐midpoint (CMP) data acquisition. This system uses an array of ten Vivaldi antennae and operates from 30 MHz to 6 GHz. The moveout of the CMP data was corrected and the data were stacked to suppress ground clutter. The system was tested in the laboratory and we showed that it images buried mine‐like targets with a high resolution. A model of a plastic land‐mine of Type‐72 was buried in soil consisting of a mixture of gravel and crushed rocks and could be detected by the proposed technique. CMP processing applied to the array signal effectively suppresses the clutter from rough ground surfaces and inhomogeneous soil. We found that the migration algorithm is effective in suppressing ground clutter, but it is even more effective if it is combined with the CMP technique.
Material response analysis of georadar reflection data
Authors: Fokkema Jacob T. , Slob Evert C. , Fokkema Emile , Beekman Sicco
Published: August 2009

Understanding the nature of the ground‐penetrating radar (GPR) reflection response in terms of the dielectric permittivity and conductivity contrast is an important factor in interpretation. This is the reason for the present study, which aims to carry out an experiment in a controlled fashion, so that the relationship between measurements and the relevant physical parameters can be established. Accurate modelling of the subsurface parameter distribution is hampered by lack of both knowledge of the source signature and an appropriate model. We have therefore constructed a controlled environment in which to carry out measurements that can be modelled with sufficient accuracy in a 1D setting, under the constraint that subsurface conditions can be changed without disturbing the overburden. We present the results of such measurements, an analysis of the data and an interpretation based upon a 1D model, which is sufficiently realistic to accommodate sophisticated physical parameter models.
A comparison of segmentation techniques for target extraction in ground‐penetrating radar data
Authors: Shihab S. , Al‐Nuaimy W.
Published: August 2009

In a typical GPR survey, only a small fraction of the collected data actually represent useful data (i.e. target data), whereas the majority of the data is considered redundant. The first of the post‐processing stages, which relies heavily on a skilled operator, involves indicating those areas that may contain targets and suppressing others. Consequently, this process consumes considerable amounts of time and effort, apart from the fact that the existence of the human factor at this critical stage invariably introduces inconsistency and error into the interpretation. In this paper, automatic detection and segmentation techniques for GPR data are discussed and compared. The techniques rely on the computation of certain features from which a neural network is then able to arrive at a decision whether to classify the data segments in question as targets or otherwise. The first technique is based on extracting statistical features from A‐scan segments while the second technique computes statistical features from B‐scan regions. In the third technique, some regional properties of B‐scan segments are used to achieve discrimination not only between targets and non‐targets, but also between hyperbolic‐shaped and non‐hyperbolic‐shaped targets. All the techniques were tested on different types of GPR data collected from a variety of sites, and they proved to be very efficient in forming a robust automatic technique for data reduction and segmentation. In addition, these techniques are carried out in near real‐time enabling on‐site processing and interpretation of collected data.
Combined high‐resolution magnetics and GPR surveys of the roman town of Flavia Solva
Authors: Seren S. , Eder‐Hinterleitner A. , Neubauer W. , Groh S.
Published: August 2009

High‐resolution magnetics and ground‐penetrating radar (GPR) prospecting methods are both employed over large areas (125 000 and 45 000 m2) at the Roman town of Flavia Solva in Austria. High‐resolution magnetics using a multisensor caesium gradiometer were used in a survey in a raster of 0.5 x 0.125 m. GPR measurements using a PulseEKKO 1000 device applying 450 and 900 MHz antennae were carried out in a raster of 0.5 x 0.05 m. The collected data are evaluated and visualized in grey scale, using the self‐developed software, APMAG and APRADAR. In addition, the small prospected areas are combined automatically into one coherent image and transformed into global coordinate system (geo‐referencing) for archaeological interpretation in the Geographical Information System (GIS). The magnetic prospecting shows very clearly the extent of the Roman town of Flavia Solva. The Roman streets and walls appear in the magnetics as negative anomalies (black). The positive magnetic anomalies could be due to brick walls, which did not show up as structures in the GPR. On the other hand, GPR provides a lot of detailed three‐dimensional information about the archaeological structures.
Study of saltwater intrusion using 1D, 2D and 3D resistivity surveys in the coastal depressions at the eastern part of Matruh area, Egypt
Authors: Gemail K. , Samir A. , Oelsner C. , Mousa S.E. , Ibrahim S.
Published: August 2009

Saltwater intrusions into shallow aquifers near the coast are an important environmental problem along the whole coastal strip of the western desert of Egypt. This phenomenon was studied in two selected coastal depressions on the eastern side of the Matruh area by a geoelectrical survey which comprised several 1D sounding points as well as 2D and 3D resistivity‐imaging surveys.

For the 2D and 3D field surveys, pole‐dipole (both forward and reverse) and pole‐pole arrays were used, respectively. The spacing between adjacent electrodes was 10 m for the 2D resistivity surveys. A 5 × 5 grid of electrodes was used for the 3D survey. The spacing between electrodes was 10 or 20 m, depending on the expected depth of freshwater in each respective area. The choice of electrode spacing was based on the results of interpretation of the depth of the freshwater–saltwater boundaries, as derived from 1D resistivity soundings using a Schlumberger array. The sounding points were distributed over the study areas and the soundings were conducted prior to the 2D and 3D survey.

The data sets were inverted using the smoothness‐constrained least‐squares method. The inversion results indicate that the subsurface resistivity distributions in the whole area are highly inhomogeneous and change rapidly within a short distance. However, from the resulting models, it was possible to correlate the ranges of resistivity with subsurface geological information available from shallow boreholes. The horizontal and vertical sections presented illustrate the configuration of the subsurface conditions that would have been, most probably, insufficiently accurate in the case of 1D modelling.
Using airborne electromagnetics surveys to investigate the hydrogeology of an area near Nyborg, Denmark
Authors: Smith Richard S. , O’Connell Michael D. , Poulsen Lene Hjelm
Published: August 2009

A time‐domain airborne electromagnetic survey was flown in the County of Fyn, Denmark, immediately west of the city of Nyborg as a quick and efficient means of providing resistivity information for the development of a hydrogeological model. The bedrock geology is typified by a thick limestone overlain by a sequence of marine marl and a Quaternary moraine of variable thickness and composition. The limestone is the largest aquifer within the area and is used to supply water for Nyborg. The upper 100 m or so of the limestone generally contain fresh water and below that the groundwater is saline. The boundary between the resistive fresh water and the conductive saline water was the target of the airborne electromagnetic survey.

Man‐made structures can strongly impact electromagnetic measurements; however, they can be minimized using two tactics: (1) masking the results around large power lines, and (2) non‐linear filtering of any perturbations in the interpretation that are the consequence of these or other structures. The latter strategy is possible because of the dense areal coverage provided by the airborne survey, and is particularly useful when a regional overview is required.

Resistivity sections derived from the airborne electromagnetic data indicate a resistive zone of till, diluvial sand and freshwater limestone of variable thickness above a deeper conductive zone of saline water. A conductive layer within the moraine, assumed to be clay or marl, is also occasionally indicated. We used a two‐layer model to estimate the depth to the freshwater/saline‐water interface. Where ground soundings have been made, the depth estimates from the ground and airborne data agree. The depth estimates from the airborne data can be used to infer the thickness of the freshwater aquifer, either locally or regionally.
Advanced signal processing tools for dispersive waves
Authors: Mars J. I. , Glangeaud F. , Mari J. L.
Published: August 2009

Two field examples are presented, showing the advantages of using multicomponent sensors for surface‐wave studies. Multicomponent sensors allow the use of specific signal‐processing tools such as the multicomponent singular value decomposition filter and the multicomponent polarization filter, which are both very efficient at separating surface waves from the other waves that comprise a seismic field record.

Firstly, some signal‐processing tools for studying surface waves are described. The various filters range from classical to advanced techniques. For processing single‐component data, the filters are the filter and filters based on singular value decomposition and on spectral matrix decomposition. For processing multicomponent data, the filters are the 4C‐singular value decomposition filter and the classical or high‐order polarization filter.

Secondly, processing sequences that can be applied to the field data are described and the single‐component processing sequence and the multicomponent processing sequence are compared. Two field examples are presented. The first data set is a land seismic data recording on 2C sensors. The second data set was obtained from a marine acquisition with OBS (4 components). The results obtained illustrate the advantages of using multicomponent filters. The efficiency of the 4C‐SVD filter and the high‐order statistic polarization filter is demonstrated.
Imaging scattered seismic surface waves
Authors: Campman X. , van Wijk K. , Riyanti C.D. , Scales J. , Herman G.
Published: August 2009

Surface‐wave analysis is a key tool for seismologists, ranging from near‐surface characterization in geotechnical applications to global seismology. Even in exploration seismology, where surface waves are regarded as a kind of noise, the fact that they typically represent the bulk of the recorded energy makes an understanding of surface‐wave propagation important. On the other hand, the heterogeneity of the near surface can make such analyses difficult since the heterogeneity is responsible for scattering and mode conversion.

Here, we show how multichannel seismic records of scattered surface waves can be used to obtain spatial images of the heterogeneity. We discuss both data processing and imaging and illustrate our method on laboratory‐scale data. Further, synthetic examples show that we can locate individual scatterers accurately, even when many scatterers produce interfering surface waves. Our laboratory results show that the method has the potential to locate near‐surface heterogeneities in the field.
Estimating seismic velocities below the sea‐bed using surface waves
Authors: Shtivelman V.
Published: August 2009

Seismic data acquired in shallow offshore surveys often display well‐defined dispersion patterns related to two types of surface wave, propagating in shallow subwater layers. The waves of the first type propagate as normal modes and are represented by a low‐velocity, low‐frequency wavetrain identified with Scholte waves. The phase velocities of Scholte waves are related to the shear‐wave velocities below the water‐bottom and can be inverted to estimate in the subwater layers. The waves of the second type propagate as leaking modes and are characterized by a number of distinctive features: their dispersion patterns have a resonant frequency‐tuned appearance, they have relatively high cut‐off frequencies and their phase velocities exceed the velocity in the water. When the subwater layers are composed of relatively soft saturated rocks with high Poisson’s ratio, the leaking modes can be closely approximated by acoustic waves. By inverting the approximating dispersion curves, the vertical distribution of the compressional‐wave velocity in the shallow subwater layers can be estimated.

Estimation of and below the sea‐bottom using the two types of surface wave is illustrated by examples from shallow offshore surveys conducted at several sites in the eastern Mediterranean area.
Combination of 1D laterally constrained inversion and 2D smooth inversion of resistivity data with a priori data from boreholes
Authors: Wisén Roger , Auken Esben , Dahlin Torleif
Published: August 2009

Resistivity imaging in combination with borehole information is a powerful tool for site investigation. We show that the combination of 1D laterally constrained inversion (1D‐LCI) with the use of a priori information from borehole data and 2D smooth inversion adds significant value to the interpretation of continuous vertical electrical sounding (CVES) data. The 1D‐LCI offers an analysis of the resolution of the model parameters. This is helpful when evaluating the integrity of the model. Furthermore, with the 1D‐LCI it is possible to constrain model parameters with a priori information, e.g. depth‐to‐layer interfaces, based on borehole information.

We show that 2D smooth inversion resolves lateral changes well, while 1D‐LCI results in well‐defined horizontal layer interfaces. In geological environments where the lateral variations are not too pronounced, the 1D‐LCI contributes to a geological interpretation of the resistivity measurements. Depths to layers can be interpreted with greater certainty than if using results from 2D smooth inversion only. The inclusion of a priori information in the inversion reveals further details and enhances the geological interpretation significantly.