Three-dimensional reconstruction of neuroradiological data within a stereotactic frame of reference for surgery of visible targets

Three-dimensional information obtained with neuroradiological exams performed under stereotactic conditions is displayed on a surgical console within the graphic reconstruction of the geometry of stereotactic frames. Planning of convenient probe trajectories can be carried out taking into account all data derived from different diagnostic techniques.     

Deep brain stimulation for neurologic and neuropsychiatric disorders

In the 1960s, ablative stereotactic surgery was employed for a variety of movement disorders and psychiatric conditions. Although largely abandoned in the 1970s because of highly effective drugs, such as levodopa for Parkinson's disease (PD), and a reaction against psychosurgery, the field has undergone a virtual renaissance, guided by a better understanding of brain circuitry and the circuit abnormalities underlying movement disorders such as PD and neuropsychiatric conditions, such as obsessive compulsive disorder. High-frequency electrical deep brain stimulation (DBS) of specific targets, introduced in the early 1990s for tremor, has gained widespread acceptance because of its less invasive, reversible, and adjustable features and is now utilized for an increasing number of brain disorders. This review summarizes the rationale behind DBS and the use of this technique for a variety of movement disorders and neuropsychiatric diseases.     

Update on thoracic paravertebral blocks

Thoracic paravertebral block was widely practised at the beginning of the 20th century. It has enjoyed a renaissance in the past decade. This form of afferent blockade is the technique of injecting local anaesthetic into the thoracic paravertebral space. Thoracic paravertebral analgesia is mostly indicated for unilateral surgical procedures of the thorax and abdomen. Compared to the other available regional techniques such as epidural, intercostal and interpleural, paravertebral blocks offer comparable or better analgesia with less side effects. Thoracic paravertebral blocks deserve greater consideration and investigation.     

Therapeutic Strategies for Localized Prostate Cancer II: Perineal Prostatectomy, X-Rays, Protons, Neutrons, and Combination Brachytherapy

Application of improved imaging, diagnostic, and computer techniques is beginning to have an impact on the management of localized prostate cancer. It is possible to perform a range of surgical and radiation procedures with less morbidity than in the past. The changes in therapy for patients with localized disease derive from better knowledge of anatomy for invasive procedures and optimization of virtual planning for noninvasive methods. Perineal prostatectomy and combinations of beam and seed radiation offer both patient and physician reasonable therapeutic options.     

Stereotactic interstitial brachytherapy--current concepts and concerns in twenty patients

Recent advances in imaging and stereotactic techniques have resulted in wider application of interstitial brachytherapy (IBT) for brain tumors. The advantages of brachytherapy alone or in combination with teletherapy have been detailed, and may be responsible for increasing survival time. We report the preliminary results of 20 patients who underwent CT stereotactic IBT for malignant brain tumors. Despite both old and recent evidence about the efficacy of IBT, concerns remain about the proper grade neoplasm, the target, the dose, and the timing for treatment. Current usage of IBT should be limited to centers with both stereotactic and radiotherapeutic expertise, and where the risks and benefits are being investigated.     

Magnetic resonance imaging in the assessment and surgical management of epilepsy and functional neurological disorders

Magnetic resonance imaging (MRI) offers significant advantages over computerized tomography (CT) and teleradiographic techniques when used for the evaluation and management of epilepsy and functional neurological disorders. Depth recording and radiofrequency electrodes can be more accurately positioned within structures such as the amygdala and hippocampus. The extent of corpus callosum section, lobectomy, topectomy, and radiofrequency stereotactic lesions can now be readily confirmed and related with seizure, neurological, and behavioral outcome. Occult, usually low grade, intraparenchymal neoplasms not visualized on CT scans can be located by MRI and biopsied or excised by MRI stereotactic techniques.     

A message emerging from development: the repression of mitochondrial β-F1-ATPase expression in cancer

Mitochondrial research has experienced a considerable boost during the last decade because organelle malfunctioning is in the genesis and/or progression of a vast array of human pathologies including cancer. The renaissance of mitochondria in the cancer field has been promoted by two main facts: (1) the molecular and functional integration of mitochondrial bioenergetics with the execution of cell death and (2) the implementation of ¹⁸FDG-PET for imaging and staging of tumors in clinical practice. The latter, represents the bed-side translational development of the metabolic hallmark that describes the bioenergetic phenotype of most cancer cells as originally predicted at the beginning of previous century by Otto Warburg. In this minireview we will briefly summarize how the study of energy metabolism during liver development forced our encounter with Warburg’s postulates and prompted us to study the mechanisms that regulate the biogenesis of mitochondria in the cancer cell.     

Use of the Brown-Roberts-Wells stereotactic frame for functional neurosurgery

The Brown-Roberts-Wells (BRW) stereotactic unit has proven itself to be a highly accurate instrument for biopsying or locating pathologic intracranial lesions based on CT scan information. We utilized the BRW frame to select 18 target sites in 12 patients undergoing functional stereotactic procedures. Two patients had bilateral cingulumotomies, 5 had thalamotomies for movement disorders, and 5 underwent electrode implantations for the treatment of chronic pain. Stereotactic frame settings were determined using a positive contrast ventriculogram, orthogonal radiographs, and a computer program provided with the BRW system. In addition, attempts were made to select targets based on CT scan landmarks alone, and these were compared to those derived using ventriculography. We found the BRW frame to be a satisfactory device for performing functional neurosurgical procedures based on ventriculographic landmarks. Coordinates derived from CT scans were similar to those obtained with ventriculography, but were not accurate enough to permit the use of CT scanning as the sole means of target identification. Although future improvements in imaging techniques and computer software are likely to occur, our experience supports ventriculography as the current method of choice for the precise localization of functional targets with the BRW stereotactic system.     

A new stereotactic instrument for use with computerized tomography and magnetic resonance imaging

The new stereotactic instrument has the advantages of use with computerized tomography (CT) or magnetic resonance imaging (MRI) without special adaptations of instruments, brain targets transferred directly from CT or MRI to apparatus, and use with conventional stereotactic techniques. The apparatus is designed to meet present demands of neurosurgical facilities of good standards and capabilities, encompassing present and future developments towards more efficient and less invasive brain operations.     

A true 'advanced imaging assisted' skull-mounted stereotactic system

A stereotactic system has been designed based upon a series of interlocking discs secured to the skull with self-tapping screws. Unlike previous skull-mounted systems, this system is a true, advanced imaging based stereotactic device with the capabilities and accuracy of more traditional, frame based devices. It has been used in a range of applications, from simple biopsies to interstitial radiation implant procedures. Well tolerated by the patient, it allows reaccess to the intracranial target without rescanning. It is convenient for the physician to utilize, both mechanically and timewise, is adaptable to MRI, DSA, and conventional X-ray techniques without modification, and is affordable.     

Artificial contrasting of the hip joint in children and adolescents: X-ray anatomic study

The diagnostic capacities of currently available radiation diagnostic techniques in imaging some anatomic structures of the hip joint (HJ) were determined on the basis of studies of 70 sectional sets of HJs in children and adolescents aged 0 to 13 years through X-ray and anatomic comparisons. Magnetic resonance imaging (MRI) is the method of choice in visualizing the cartilaginous and soft-tissue structures of HJ in children and adolescents. MR-arthrography extends the capacities of the technique in imaging the articular surfaces and intraarticular structures of the joint. Contrast enhancement of the HJ cavity during X-ray study and computed tomography may be an alternative to MRI as it makes it possible to well visualize the cartilaginous head of the femur, the cartilaginous borders of the cotyloid cavity, the limbus, etc. Double contrasting enhances the capacities of detailed imaging of the articular surfaces, intraarticular structures, capsules, and ligamentous apparatus of HJ. The studies performed have specified the time course of anatomic changes during HJ growth and defined the method of choice or an alternative procedure of radiation techniques in the diagnosis of these changes, which is of great importance for early detection of pathological changes and for choice of therapeutic and diagnostic policy.     

Diagnostic imaging at its centennial: the past,the present and the future.

Since the discovery of x-rays by Wilhelm Conrad Röntgen 100 years ago, diagnostic imaging has profoundly influenced the practice of medicine. As a result of discoveries during this period, ultrasonography, nuclear imaging, computed tomography and magnetic resonance imaging, as well as conventional radiography, have assumed a major role in diagnostic medicine. In addition to their traditional role in diagnosis, imaging techniques are becoming an increasingly important factor in innovative treatment methods, and this role is likely to expand. In the current climate of rising health care costs, radiologists and other health care providers who use imaging must increasingly account to health care funders for the cost-effectiveness of imaging in relation to other diagnostic and interventional techniques. They must also assure minimum standards of quality and training, and determine the appropriate role for diagnostic imaging in health care systems of the future.     

The New Health Practitioner — The Past as Prologue

The training and utilization of New Health Practitioners (NHP''s) has moved within a decade from a small tentative beginning in the mid-1960''s to a major health manpower policy issue. Its discussion transcends a number of important and emotionally charged areas including the role of various professions in providing health care services, the renaissance of primary care, the geographic and economic maldistribution of medical services, and the cost of care. It is valuable to highlight what is known, what is professed and what needs to be studied further about this issue.     

In vivo biomicroscopy of the skin with high-resolution magnetic resonance imaging and high frequency ultrasound.

Noninvasive imaging and characterization of the skin is of great interest in dermatology. In order to get relevant diagnostic information, high-resolution imaging techniques have to be applied. Ultrasonic imaging is a potential method for this purpose where the special requirements concerning the spatial resolution make it essential to apply high frequency ultrasound (HFUS). Alternatively, magnetic resonance imaging (MRI), being a very promising imaging modality, also shows the perspective of becoming a valuable diagnostic tool in dermatology. However, to account for the small dimensions of the structures under observation, very specialized system designs have to be developed. In this paper, a HFUS imaging system working in the 50 MHz and 100 MHz range is applied for high-resolution skin imaging. Furthermore, a commercial MRI-system was equipped with specially designed low noise rf (radio frequency) coils with minimized volume, and customized imaging sequences were applied to optimize the signal-to-noise ratio. With HFUS and high-resolution magnetic resonance (HR-MR) imaging complementary imaging techniques for in vivo biomicroscopy of the skin are available.     

Present and future developments of stereotactic technology

Incorporation of a surgical computer system into stereotactic methodology provides the facility for efficient utilization of the multiple data bases at the disposal of the modern stereotactician. Computed tomography, magnetic resonance imaging, and digital fluoroscopy data gathered in stereotactic conditions are digitized into a stereotactic surgical matrix for surgical planning and interactive surgical procedures. The advantages of this system are illustrated in stereotactic biopsy, interstitial irradiation, and laser resections of intracranial tumors.     

Computer-interactive stereotactic resection of deep-seated and centrally located intraaxial brain lesions

The carbon dioxide laser has been incorporated into a computer-interactive stereotactic system for precision resection of deep-seated intraaxial neoplasma defined by stereotactic computed tomography and magnetic resonance imaging. One hundred and ninety-seven procedures were performed on 191 patients having deep-seated lesions. Postoperative results have been satisfactory as regards the postoperative condition of the patient in consideration of the completeness of tumor removal achieved.     

CT Perfusion Imaging as an Early Biomarker of Differential Response to Stereotactic Radiosurgery in C6 Rat Gliomas

Background

The therapeutic efficacy of stereotactic radiosurgery for glioblastoma is not well understood, and there needs to be an effective biomarker to identify patients who might benefit from this treatment. This study investigated the efficacy of computed tomography (CT) perfusion imaging as an early imaging biomarker of response to stereotactic radiosurgery in a malignant rat glioma model.

Methods

Rats with orthotopic C6 glioma tumors received either mock irradiation (controls, N = 8) or stereotactic radiosurgery (N = 25, 12 Gy in one fraction) delivered by Helical Tomotherapy. Twelve irradiated animals were sacrificed four days after stereotactic radiosurgery to assess acute CT perfusion and histological changes, and 13 irradiated animals were used to study survival. Irradiated animals with survival >15 days were designated as responders while those with survival ≤15 days were non-responders. Longitudinal CT perfusion imaging was performed at baseline and regularly for eight weeks post-baseline.

Results

Early signs of radiation-induced injury were observed on histology. There was an overall survival benefit following stereotactic radiosurgery when compared to the controls (log-rank P<0.04). Responders to stereotactic radiosurgery showed lower relative blood volume (rBV), and permeability-surface area (PS) product on day 7 post-stereotactic radiosurgery when compared to controls and non-responders (P<0.05). rBV and PS on day 7 showed correlations with overall survival (P<0.05), and were predictive of survival with 92% accuracy.

Conclusions

Response to stereotactic radiosurgery was heterogeneous, and early selection of responders and non-responders was possible using CT perfusion imaging. Validation of CT perfusion indices for response assessment is necessary before clinical implementation.     

多功能磁共振造影剂研究进展

磁共振成像技术因对人体无创、任意方向断层扫描三维图像且分辨率较高、提供形态与功能两方面诊断评价等突出优点,成为了临床上用于疾病诊断的重要手段之一。临床上使用磁共振造影剂可以提高成像的分辨率和灵敏度,提高图像质量,增强对比度和可读性。但是,各种成像技术由于实现原理不同,具有各自的优势和缺陷,靠传统单一的诊断模式无法提供疾病的全面信息,因而在对各种复杂疾病进行诊断时会受到一定的限制。因此,将磁共振成像与其他成像技术如CT成像、超声成像等联合起来使用,则可以达到优势互补的效果,能为疾病的临床诊断提供更快捷精确的信息,同时可将磁共振成像与各种治疗方式结合在一起,即开发基于磁共振成像的诊断治疗一体化试剂,以实现对疾病的即时治疗和实时监控。本文主要介绍了磁共振成像造影剂的原理和种类,并且综述了目前国内外在基于磁共振成像的多功能造影剂/诊疗制剂这一领域的研究进展,最后就未来可能的研究方向进行了展望。     

Single-scan stereotactic tumor biopsy and brachytherapy

Stereotactic tumor biopsy and brachytherapy catheter implantation can be accomplished with targets derived from computed axial tomography and magnetic resonance scans. Computer manipulation of image data allows both diagnostic and therapeutic procedures to be carried out from a single set of scan slices. This eliminates the need for repeat scanning as part of the surgical procedure. Microcomputer technology is sufficiently advanced to handle the images and graphics necessary for stereotactic neurosurgery. A system based on the IBM PC/AT designed for this purpose uses readily available graphics software and custom-designed imaging programs. Direct loading of computed axial or magnetic resonance scan images from magnetic tape can be accomplished. Determination of points, contours and volumes in three-dimensional space allows intraoperative alignment of image data and patient landmarks within the stereotactic head frame using pattern recognition overlays. Three-axis scaling for magnification correction along with rotational and linear data transformations provide the basis for single-scan stereotaxis. Interactive computer graphics integrate image, patient and frame coordinates for target determination. This method eliminates the need to design and fabricate nonmagnetic or radiolucent scanner-compatible devices.     

Optical endomicroscopy and the road to real-time, in vivo pathology: present and future

ABSTRACT: Epithelial cancers account for substantial mortality and are an important public health concern. With the need for earlier detection and treatment of these malignancies, the ability to accurately detect precancerous lesions has an increasingly important role in controlling cancer incidence and mortality. New optical technologies are capable of identifying early pathology in tissues or organs in which cancer is known to develop through stages of dysplasia, including the esophagus, colon, pancreas, liver, bladder, and cervix. These diagnostic imaging advances, together as a field known as optical endomicroscopy, are based on confocal microscopy, spectroscopy-based imaging, and optical coherence tomography (OCT), and function as "optical biopsies," enabling tissue pathology to be imaged in situ and in real time without the need to excise and process specimens as in conventional biopsy and histopathology. Optical biopsy techniques can acquire high-resolution, cross-sectional images of tissue structure on the micron scale through the use of endoscopes, catheters, laparoscopes, and needles. Since the inception of these technologies, dramatic technological advances in accuracy, speed, and functionality have been realized. The current paradigm of optical biopsy, or single-area, point-based images, is slowly shifting to more comprehensive microscopy of larger tracts of mucosa. With the development of Fourier-domain OCT, also known as optical frequency domain imaging or, more recently, volumetric laser endomicroscopy, comprehensive surveillance of the entire distal esophagus is now achievable at speeds that were not possible with conventional OCT technologies. Optical diagnostic technologies are emerging as clinically useful tools with the potential to set a new standard for real-time diagnosis. New imaging techniques enable visualization of high-resolution, cross-sectional images and offer the opportunity to guide biopsy, allowing maximal diagnostic yields and appropriate staging without the limitations and risks inherent with current random biopsy protocols. However, the ability of these techniques to achieve widespread adoption in clinical practice depends on future research designed to improve accuracy and allow real-time data transmission and storage, thereby linking pathology to the treating physician. These imaging advances are expected to eventually offer a see-and-treat paradigm, leading to improved patient care and potential cost reduction. Virtual Slide The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5372548637202968.