Levobupivacaine vs. racemic bupivacaine in peribulbar anaesthesia: a randomized double blind study in ophthalmic surgery.

AIMS: The Authors examine the employement of a new anaesthetic agent, levobupivacaine 0.50% (S - enantiomer of racemic mixture of bupivacaine), for peribulbar anaesthesia in a randomized double blind study vs. racemic bupivacaine 0.50% alone or in association with hyaluronidase 10 IU x ml(-1). MATERIALS AND METHODS: 120 patients were divided into four groups of 30 each: group L (levobupivacaine 0.50%), group B (racemic bupivacaine 0.50%), group LH (levobupivacaine-hyaluronidase 10 IU x ml(-1)), group BH (racemic bupivacaine-hyaluronidase 10 IU x ml(-1)). RESULTS: The onset-time (14 +/- 3.2 min vs. 13 +/- 4.8 min) and the duration of anaesthesia (195 +/- 34.2 vs. 204 +/- 37.6) were similar. The ocular akinesia was evaluated with an 8 point system: it was considered sufficient for surgery with values of less than 5 points. The association with hyaluronidase increased the spread of local anaesthetics (76.6% of group LH, 73.3% of group BH) with local anaesthetics alone (60% of group L, 56.6% of group B). Moderate hypotension (<30% baseline) was reported in 3 patients (10%) of group L, 2 (6.6%) of group B, 1 (3.3%) of group LH and 2 (6.6%) of group BH. Statistical analysis (Student-Newman-Keuls test) was significant between group L vs. BH, B vs. BH and LH vs. BH as regards onset-time of anaesthesia; between group B vs. LH, B vs. BH and L vs. LH for the duration of anaesthesia. Chi square test for the general akinesia score showed significant results in group L vs. LH (p=0.043) and B vs. LH 8P =0.018); as regards the score 0, test reported significant values between groups B vs. LH (p=0.004) and B vs. BH (p=0.017). CONCLUSIONS: In conclusion levobupivacaine, a longlasting local anaesthetic with limited cardio and neurotoxicity, might be useful for vitreoretinal surgery in elderly patients, compared with general anaesthesia.

Carotid intimal-media thickness and endothelial function in young patients with history of myocardial infarction.

AIM: The aim of the study was to evaluate the prevalence of carotid atherosclerosis and endothelial dysfunction in 45 young patients (38 mens and 7 females) with myocardial infarction (MI), age 29-45, mean age 42+/-3 years, to verify its possible role as a marker of coronary atherosclerosis. METHODS: Vascular echography was performed to verify the presence of carotid atherosclerosis and/or endothelial dysfunction in 45 young patients with MI and in 45 healthy control subjects well matched for age and sex. RESULTS: We observed a normal intima media thickness (IMT) only in 30% of patients with juvenile myocardial infarction (JMI) compared with 66% in the control group (P<0.0001) and 34% of patients showed an increased IMT compared with 24% of healthy subjects (P<0.0001). Compared with control subjects, patients with JMI had lower flow-mediated reactivity of the brachial arteries (P<0.05). There was a negative linear relationship between flow-mediated dilation and IMT (P<0.001). The severity of coronary artery disease (CAD) was correlated with increased IMT and with a lower flow-mediated dilation. Finally, multiple regression analysis, demonstrated that both brachial-artery reactivity and carotid IMT were significantly and independently correlated with severity of CAD. CONCLUSIONS: Structural (carotid atherosclerosis) and functional changes (endothelial dysfunction) were present at an early age in the arteries of persons with history of JMI.

Optimization neural networks for the segmentation of magnetic resonance images.

The application of the Hopfield neural network for the multispectral unsupervised classification of MR images is reported. Winner-take-all neurons were used to obtain a crisp classification map using proton density-weighted and T(2)-weighted images in the head. The preliminary studies indicate that the number of iterations needed to reach ;good' solutions was nearly constant with the number of clusters chosen for the problem.

The influence of the resolution and contrast on measuring the articular cartilage volume in magnetic resonance images.

The progression of OA in patients may be followed by measuring the volume of articular cartilage from MR images. We attempted to determine the reproducibility of volume measurements of articular cartilage made from magnetic resonance images of the knees and the dependence of the reproducibility on image resolution and contrast-to-noise. A fat-suppressed 3D technique was used to generate four image sets with different image resolution. Each patient was imaged twice to obtain image pairs at each resolution. To assess the dependence of reproducibility on noise we generated six image sets for each patient by adding noise to the original images and repeating the comparison. On each image set, the femoral, tibial, and patellar cartilage were outlined by a combination of computer and manual methods, and the images were used to calculate the volume of each cartilage plate. Comparing the coefficient of variance between the volume measurements made from the two visits, the volume measurements made from images with the highest resolution (0.275 x 0.275 x 1.0 mm) had the highest reproducibility. The high resolution images of the tibia and femur had the least partial-volume averaging and, as a result, better defined the boundaries between cartilage and adjacent tissues. A different trend was evident for the patella. For studies of osteoarthritis therapies, we recommend using MR images with the highest possible in-plane spatial resolution to provide the most reproducible volume measurements of knee cartilage.

Prospective study of osseous, articular, and meniscal lesions in recent anterior cruciate ligament tears by magnetic resonance imaging and arthroscopy.

Fifty-four patients with anterior cruciate ligament tears that were arthroscopically reconstructed within 3 months of initial injury were prospectively evaluated. Patients with grade 3 medial collateral ligament, lateral collateral ligament, or posterior cruciate ligament tears were excluded. Eighty percent of our patients had a bone bruise present on the magnetic resonance image, with 68% in the lateral femoral condyle. Two of the latter findings--an abnormal articular cartilage signal (P = 0.02) and a thin and impacted subchondral bone (P = 0.03)--had a significant relationship with injury to the overlying articular cartilage. Meniscal tears were found in 56% of the lateral menisci and 37% of the medial menisci. A significant association was present between bone bruising on the lateral femoral condyle and the lateral tibial plateau (P = 0.02). Results of our study support the concept that the common mechanism of injury to the anterior cruciate ligament involves severe anterior subluxation with impaction of the posterior tibia on the anterior femur. Determination of the significance of bone bruising, articular cartilage injury, or meniscal tears will require a long-term followup that includes evaluation for arthritis, stability, and function. These 54 patients represent the first cohort evaluated in this ongoing prospective clinical study.

Transient osteoporosis of the hip: clinical and imaging features.

Transient osteoporosis of the hip is a form of reflex sympathetic dystrophy characterized by pain, limping, limitation of hip joint motion, and delayed radiographic patchy osteoporosis of the proximal femur. Spontaneous resolution is usually paralleled by radiographic recovery, usually within a few months. We present clinical and imaging features in seven cases of unilateral transient osteoporosis of the hip. In the appropriate clinical setting, conventional radiography will support the diagnosis. The role of more sensitive imaging techniques such as bone scintigraphy and magnetic resonance imaging in the early diagnosis of this disease has yet to be defined.

A fast and accurate method for registration of MR images of the head.

This paper proposes a new fully automated technique that can be used for the registration of medical images of the head. The method uses Chebyshev polynomials in order to approximate and then minimize a novel multiresolutional, signal intensity independent disparity function, which can generally be defined as the mean squared value of the mean weighted ratio of two images. This function is explicitly computed for n Chebyshev points in a geometric transformation parameter interval [-A, +A] transformation units and is approximated using the Chebyshev polynomials for all other points in the interval. For 3D T2-T1 weighted MR registration, 120 experiments with studies from ten patients were performed and showed that n = 4 Chebyshev points for A = 18 transformation units give mean rotational error 0.36 degrees and a mean translational error 0.36 mm. The different noise conditions did not affect the performance of the method. We conclude that the method is suitable for routine clinical applications and that it has significant potential for future development and improvement.

Special diagnostic procedures in sports medicine.

In summary, there are a number of imaging procedures available to support the physician in his or her evaluation of sports injuries. Conventional radiographs remain the primary imaging examination. Specialized radiographic projections will often provide additional pertinent information. A fluoroscopic examination or conventional tomography may provide a cost-effective method of clarifying subtle post-traumatic changes. The use of the more sophisticated and costly imaging procedures should be reserved for those cases in which a diagnosis cannot be made with simpler technology. CT scanning, by virtue of its ability to image in the axial plane, has proved to be an effective method of documenting injuries particularly in complex bony anatomy such as the spine, wrist, elbow, and hips. CT arthrography provides diagnostic information about intra-articular structures. MRI is emerging as an excellent method of noninvasively imaging injuries to soft-tissue structures such as tendons, ligaments, and cartilage. The advancements in MRI technology that are projected for the future may expand the range of usefulness of this modality and decrease the current high cost of these procedures. Radionuclide scanning with Tc99m diphosphonate compounds has proved to be an efficient method of localizing subtle bone pathology and providing a "road map" for further analysis with additional imaging techniques. The cost-effective use of all of these imaging procedures is predicated on an understanding of their usefulness in the diagnosis of each clinical problem and the judicious use of each procedure to fit the needs of the individual patient.

Imaging modalities for study of the distal ulnar region.

Judicious use of diagnostic imaging maximizes the diagnostic capabilities of the surgeon treating the distal radio-ulnar joint (DRUJ). A good clinical history and clinical examination are necessary to direct the selection of appropriate imaging studies. Plain radiographs are almost always the first imaging examination. More advanced imaging techniques are costly and may provide only limited information. This article discusses imaging modalities useful for assessment of the DRUJ and the area around it.

A new automated method for three-dimensional registration of MR images of the head.

A new technique for three-dimensional image registration was developed and tested using T1 and T2 weighted Magnetic Resonance image studies of the head. The method uses the fuzzy c-means classification algorithm for outlining the surface contours and then minimizes iteratively the mean squared value of the voxel per voxel weighted ratio of the two trilinearly interpolated cubic voxel volumes. A total of 200 two-dimensional and 240 three-dimensional registration experiments were performed and showed that the method is signal intensity independent, it has registration accuracy better than 1 degree for rotations and 1 voxel for translations and it is not affected by the deterioration in the imaging resolution for voxel sizes up to 1.8 mms.

Image distribution in a multi-facility radiology practice.

The Cleveland Clinic Health System is a multifacility practice that distributes images electronically. Issues specific to the internal department at the main campus must be addressed with regard to the overall commitment to the healthcare system. Training for new and old employees on diagnostic and transcription equipment is a key issue. Interfacing different systems or different configurations of a system, either hospital or radiology information systems, is many times difficult and sometimes insurmountable. Issues of confidentiality have been addressed. In light of the impending new regulations from the Health Insurance Portability and Accountability Act, are the current system security practices enough?

Impact of digital radiography on clinical workflow and patient satisfaction.

Compared to traditional film radiography, digital radiography is believed to improve workflow and patient throughput. Digital radiography permits the technologist to immediately view the quality of the film directly at the modality. Additional workflow improvements, therefore, should be achieved with the integration of the radiology information system (RIS). To learn more about this proposed efficacy, a study was performed at The Cleveland Clinic Foundation (Cleveland, OH) comparing timings in three groups: traditional film radiography; digital radiography; and digital radiography with RIS integration. Our data validated a timesaving of digital radiography over traditional or standard films and an even greater timesaving in a digital radiography/RIS environment.

A web implementation: the good and the not-so-good.

E-commerce, e-mail, e-greeting, e-this, and e-that everywhere you turn there is a new "e" word for an internet or Web application. We, at the Cleveland Clinic Foundation, have been "e-nlightened" and will discuss in this report the implementation of a web-based radiology information system (RIS) in our radiology division or "e-radiology" division. The application, IDXRad Version 10.0 from IDX Corp, Burlington, VT, is in use at the Cleveland Clinic Foundation and has both intranet (for use in Radiology) and internet (referring physician viewing) modules. We will concentrate on the features of using a web browser for the application's front-end, including easy prototyping for screen review, easier mock-ups of demonstrations by vendors and developers, and easier training as more people become web-addicted. Project communication can be facilitated with an internal project web page, and use of the web browser can accommodate quicker turnaround of software upgrades as the software code is centrally located. Compared with other technologies, including client/server, there is a smaller roll out cost when using a standard web browser. However, the new technology requires a change and changes are never implemented without challenges. A seasoned technologist using a legacy system can enter data quicker using function keys than using a graphical user interface and pointing and clicking through a series of pop-up windows. Also, effective use of a web browser depends on intuitive design for it to be easily implemented and accepted by the user. Some software packages will not work on both of the popular web browsers and then are tailored to specific release levels. As computer-based patient records become a standard, patient confidentiality must be enforced. The technical design and application security features that support the web-based software package will be discussed. Also web technologies have their own implementation issues.

Implementation of an electronic teaching file using web technology.

The implementation of an electronic teaching file using web technology is discussed in this article. A web client server model is used for a standard web browser capable of displaying joint photographic Experts Group (JPEG) compression images. Like other web-based teaching files, this teaching file in a similar way uses a database containing information. This database section of the teaching file allows flexible database querying and viewing of pages generated by hypertext markup language (HTML). Because the browser client is so flexible, images types such as video and 3D representations with virtual reality markup language (VRML) can be displayed.

Tools to manage the enterprise-wide picture archiving and communications system environment.

The presentation will focus on the implementation and utilization of a central picture archiving and communications system (PACS) network-monitoring tool that allows for enterprise-wide operations management and support of the image distribution network. The MagicWatch (Siemens, Iselin, NJ) PACS/radiology information system (RIS) monitoring station from Siemens has allowed our organization to create a service support structure that has given us proactive control of our environment and has allowed us to meet the service level performance expectations of the users. The Radiology Help Desk has used the MagicWatch PACS monitoring station as an applications support tool that has allowed the group to monitor network activity and individual systems performance at each node. Fast and timely recognition of the effects of single events within the PACS/RIS environment has allowed the group to proactively recognize possible performance issues and resolve problems. The PACS/operations group performs network management control, image storage management, and software distribution management from a single, central point in the enterprise. The MagicWatch station allows for the complete automation of software distribution, installation, and configuration process across all the nodes in the system. The tool has allowed for the standardization of the workstations and provides a central configuration control for the establishment and maintenance of the system standards. This report will describe the PACS management and operation prior to the implementation of the MagicWatch PACS monitoring station and will highlight the operational benefits of a centralized network and system-monitoring tool.