Evaluation of articular cartilage thickness of the humeral head and the glenoid fossa by MR arthrography: anatomic correlation in cadavers

OBJECTIVE: To evaluate the accuracy of MR arthrography in determining the thickness of articular cartilage of the humeral head and glenoid fossa. DESIGN AND PATIENTS: MR arthrography of the glenohumeral joint was performed in 17 cadaveric shoulders. Articular cartilage thickness was measured on the MR arthrographic images and corresponding anatomic sections. RESULTS: The correlation coefficients for MR arthrographic measurement versus anatomic measurement of the cartilage thickness were 0.7324 and 0.8757 for humeral head and glenoid fossa, respectively. With regard to the humeral head, there was a tendency to overestimate regions of thin cartilage and underestimate regions of thick cartilage. This tendency was not found in the assessment of glenoid cartilage. The mean of the absolute value of MR-anatomic differences was similar on the glenoid side (0.27 mm) and the humeral side (0.29 mm). The accuracy of measurement was significantly better on the glenoid side (Fisher's r-to-Z transformation: Z=5.21, P=0.000001). CONCLUSION: MR arthrography causes a moderate degree of error in the naked-eye measurement of the cartilage of the glenohumeral joint. The accuracy is higher on the glenoid side than on the humeral side.     

MRI of patellar articular cartilage: evaluation of an optimized gradient echo sequence (3D-DESS)

OBJECTIVES: This study sought to examine the influence of time to reperfusion on myocardial salvage. BACKGROUND: Major trials of reperfusion therapy for myocardial infarction (MI) have demonstrated improved outcome for patients achieving earlier reperfusion. However, some patients experience significant benefit despite delayed reperfusion. METHODS: Fifty-five patients with a first anterior MI underwent successful reperfusion therapy (angioplasty or thrombolysis). Technetium-99m (Tc-99m) sestamibi was injected before reperfusion therapy and again at hospital discharge to determine the myocardial salvage index for each patient. Residual flow to the infarct territory was assessed by the nadir of the Tc-99m sestamibi count-profile curve. RESULTS: The salvage index showed wide variability (range -0.04 to 1.0), and extreme values were seen in 34.5% of the group (<0.10 in 9%, >0.90 in 25%). A high salvage index was associated with reperfusion therapy before 2 h (p=0.02) or good residual blood flow (p < 0.01). For the 10 patients who received reperfusion therapy within 2 h, residual blood flow was not correlated with salvage (p=0.12). For the 45 patients treated after 2 h, residual blood flow correlated significantly with salvage (r=0.57, p < 0.0001). There was a significant interaction (p < 0.05) between residual blood flow and time to therapy, indicating that the effect of each variable on salvage depended on the value of the other. Multiple historic and hemodynamic variables were examined, but none demonstrated any association with residual flow or myocardial salvage. CONCLUSIONS: In patients with acute MI, successful reperfusion therapy within 2 h is associated with the greatest degree of myocardial salvage. For patients treated after 2 h, residual blood flow to the infarct-related territory appears to be the most important determinant of myocardial salvage.     

A new 3-dimensional cephalometry model. A new 3-dimensional parameter analysis: the axis of inertia. A new idea: maxillofacial equilibrium

The authors propose a biomensurativ 3 D method based on the plotting of 8 anatomical landmarks situated on the trigeminal axis and the selection of teeth. In the analysis of this construction, we have employed mathematical tools unusual in developmental biology, the axis of inertia. The 3 D analysis allows to evidence the architectural, structural and functional balance of the dentomaxillofacial complex. This balance must be substituted to the normality concept to directly linked to cultural criterias and to the selection of mean parameters among culturally and ethnically homogeneous populations. Therapy does not have to lead to the normality of mean parameters but to the return or to the discovery of a real balance.     

A new volumetric CT machine for dental imaging based on the cone-beam technique: preliminary results

The objective of this paper is to present a new type of volumetric CT which uses the cone-beam technique instead of traditional fan-beam technique. The machine is dedicated to the dento-maxillo-facial imaging, particularly for planning in the field of implantology. The main characteristics of the unit are presented with reference to the technical parameters as well as the software performance. Images obtained are reported as various 2D sections of a volume reconstruction. Also, measurements of the geometric accuracy and the radiation dose absorbed by the patient are obtained using specific phantoms. Absorbed dose is compared with that given off by spiral CT. Geometric accuracy, evaluated with reference to various reconstruction modalities and different spatial orientations, is 0.8-1% for width measurements and 2.2% for height measurements. Radiation dose absorbed during the scan shows different profiles in central and peripheral axes. As regards the maximum value of the central profile, dose from the new unit is approximately one sixth that of traditional spiral CT. The new system appears to be very promising in dentomaxillo-facial imaging and, due to the good ratio between performance and low cost, together with low radiation dose, very interesting in view of large-scale use of the CT technique in such diagnostic applications.     

Chondrocyte-seeded hydroxyapatite for repair of large articular cartilage defects. A pilot study in the goat

The aim of this study was to evaluate the potential for restoration of a large cartilage defect in the goat knee with hydroxyapatite (HA) loaded with chondrocytes. Isolated chondrocytes were suspended in fibrin glue, seeded on top of the HA, and then the composite graft was implanted in the defect. After transplantation, cell behaviour, newly synthesised matrix and the HA-glue interface were assessed histologically after 2, 4, 12, 26 and 52 weeks. Special attention was paid to the incorporation process of HA in the subchondral bone and interactions between this biomaterial and the fibrin-glue-chondrocyte suspension. Chondrocytes in the glue proved to survive the transplantation procedure and produced new metachromatically stained matrix two weeks after implantation. The glue-cell suspension had penetrated the superficial porous structure of the HA. Four weeks after surgery, islands of hyaline-like cartilage were observed at the HA-glue interface. A layer of fibrous tissue was formed surrounding the HA graft, resulting in a relatively instable fixation of the HA in the defect. This instability of the graft in the defect, possibly together with early weight bearing, resulted in a gradual loss of the newly formed hyaline cartilage-like repair tissue. Progressive resorption of the HA occurred without any sign of active bone remodelling from the host site. One year after surgery part of the defect which extended down to the cancellous bone had been predominantly restored with newly formed lamellar bone. Only small HA remnants were still present at the bottom of the original defect. Resurfacing of the joint had occurred with fibrocartilaginous repair tissue. The absence of adequate fixation capacity of the HA near the joint space resulted in a relative instability of the graft with progressive resorption. Therefore, HA is not a suitable biomaterial to facilitate the repair of large articular cartilage defects.     

Social psychology of creativity: A consensual assessment technique.

States that both the popular creativity tests, such as the Torrance Tests of Creative Thinking, and the subjective assessment techniques used in some previous creativity studies are ill-suited to social psychological studies of creativity. A consensual definition of creativity is presented, and as a refinement of previous subjective methods, a reliable subjective assessment technique based on that definition is described. The results of 8 studies testing the methodology in elementary school and undergraduate populations in both artistic and verbal domains are presented, and the advantages and limitations of this technique are discussed. The present methodology can be useful for the development of a social psychology of creativity because of the nature of the tasks employed and the creativity assessments obtained. Creativity assessment is discussed in terms of the divergent aims and methods of personality psychology and social psychology. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Toward articulatory-acoustic models for liquid approximants based on MRI and EPG data. Part II. The rhotics

Magnetic resonance images of the vocal tract during sustained production of [symbol: see text] by four native American English talkers are employed for measuring vocal-tract dimensions and for morphological analysis of the 3D vocal tract and tongue shapes. Electropalatography contact profiles are used for studying inter- and intra-talker variabilities. The vocal tract during the production of [symbol: see text] appears to be characterized by three cavities due to the presence of two supraglottal constrictions: the primary one in the oral cavity, and a secondary one in the pharyngeal cavity. All subjects show a large volume anterior to the oral constriction, which results from an inward-drawn tongue body, an anterior tongue body that is characterized by convex cross sections, and a concave posterior tongue body shape. Inter-subject variabilities are observed in the oral-constriction location and the way the constriction is formed. No systematic differences are found between the 3-D vocal tract and tongue shapes of word-initial and syllabic [symbol: see text]s. Tongue-shaping mechanisms for these sounds and their acoustic implications are discussed.     

MRI evaluation of the brain in infantile neuronal ceroid-lipofuscinosis. Part 2: MRI findings in 21 patients

The purpose of this study was to demonstrate the course of infantile neuronal ceroid-lipofuscinosis with brain magnetic resonance imaging (MRI) in children aged 3 months to 11 years. Twenty-one patients and 46 neurologically normal controls of the same age were examined. The images were evaluated visually; then signal intensities were measured and related to those of references. MRI abnormalities were detectable before clinical symptoms. The radiologic picture of the brain varied with the duration of the disease. Pathognomonic MRI findings in the early stage of the disease were generalized cerebral atrophy, strong thalamic hypointensity to the white matter and to the basal ganglia, and thin periventricular high-signal rims from 13 months onward on T2-weighted images. In patients over 4 years old, cerebral atrophy was extreme, and the signal intensity of the entire white matter was higher than that of the gray matter, which is the reverse of normal. This study showed that the abnormalities seen on MRI progress rapidly during the first 4 years of life, then stabilize, in conformity with the clinical and histopathologic pictures of infantile neuronal ceroid-lipofuscinosis.     

In vivo kinematics of the cervical spine. Part I: Development of a roentgen stereophotogrammetric technique using metallic markers and assessment of its accuracy

A technique for simultaneous roentgen stereophotogrammetry (RS) was developed, and its accuracy was assessed. In vitro models fabricated from dried cadaveric C4 and C5 vertebrae were used to simulate the motion behavior of the cervical spine. Metallic markers made of Vitallium beads (diameter < 0.3 mm) were implanted into the posterior and anterior surfaces of each vertebra at surgically accessible locations to simulate the bead placement for both posterior and anterior surgical approaches to the cervical spine. A series of roentgen stereo pairs were obtained to systematically assess the accuracy (validity) of displacement measurements in anteroposterior (AP) translation, axial rotation, and flexion/extension. In addition, the effects of soft tissue density on the accuracy of the system were investigated by obtaining a series of roentgen stereo pairs with the experimental model immersed in a water bath. The coordinates of the metallic markers on the radiographs were then digitized by two raters who were not informed of the actual motion (i.e., blind study). The results indicated a high accuracy throughout the study. Overall root mean square errors were 0.07 mm for AP translation, 0.08 degrees for axial rotation, and 0.14 degrees for flexion/extension. The corresponding accuracy estimates (R2 values by linear regression analysis) were very high (0.992, 0.998, and 0.995) when the measurement results were compared with the actual displacements. The water bath did not affect measurement accuracy, indicating that soft tissue density should have little effect on the accuracy of the technique for in vivo applications. This system appears to be an accurate and reliable method for assessment of simulated in vivo cervical spine motion, regardless of the rater. The technique has been further used in in vivo assessment of cervical spine kinematics in one patient to confirm the efficacy of the developed technique.     

A mathematical model of aluminum depth filtration with ceramic foam filters: Part I. Validation for short-term filtration

This work presents a mathematical model to compute the efficiency of depth filtration of molten aluminum using ceramic foam filters. In the model, the porous structure of foam filters was represented by a unit cell that takes into account the convergent-divergent nature of the flow field. The steady, two-dimensional, and fully developed flow field within the unit cell was obtained from the numerical solution of the continuity and Navier-Stokes equations. The assessment of the proper assumptions for the model was carried out by comparing the computed velocity field with that experimentally determined for a physical model of the unit cell with scale 10:1 and containing an aqueous solution of CaCl₂. The measurements were done using the particle image velocimetry (PIV) technique. The efficiency and the coefficient of initial filtration for foam filters were obtained from the determination of the particle limiting trajectory, resulting from a force balance on a spherical inclusion. This balance included the buoyancy and the viscous drag forces. The last force took into consideration the wall effect on the particle motion. The values of the computed initial filtration coefficient show an excellent agreement with the corresponding measured ones reported for laboratory and plant tests for short-term filtration. This comparison involves several combinations of particle sizes and downward fluid superficial velocities. This model is further extended to study long-term filtration in the second part of the article.     

Modified coronally positioned flap for obtaining new attachment in Class 2 and 3 furcation defects. Part I: Rationale and surgical technique

A new technique, the modified coronally positioned flap procedure, is described for treatment of Class 2 and Class 3 molar furcation defects in conjunction with barrier membranes. This technique is designed to minimize barrier exposure during the healing phase and to cover and protect the newly formed granulation tissue following barrier removal. Examples are presented and discussed, and modifications for varying situations are described. The modified coronally positioned flap technique is applicable for use with nonresorbable and resorbable membranes.     

Overlooked physical diagnoses in chronic pain patients involved in litigation, Part 2. The addition of MRI, nerve blocks, 3-D CT, and qualitative flow meter

This study followed 120 chronic pain patients referred to a multidisciplinary pain center. The referral diagnosis for many patients, such as "chronic pain," "psychogenic pain," or "lumbar strain," was frequently found to be incomplete or inaccurate (40%) following a multidisciplinary evaluation that used appropriate diagnostic studies, including magnetic resonance imaging, computed tomography, nerve blocks, and qualitative flowmeter. Significant abnormalities were discovered in 76% of the diagnostic tests. An organic origin for pain was found in 98% of these patients. The patients were discharged with objective verification of diagnoses including facet disease, nerve entrapment, temporomandibular joint disease, thoracic outlet syndrome, and herniated discs.     

Bioethics of the refusal of blood by Jehovah''s Witnesses: Part 2. A novel approach based on rational non-interventional paternalism

Due to costs in using and disposing of radiochemicals and to health considerations, we have been developing applications which include non-isotopic detection of DNA and proteins using chemiluminescence. Our major interests are in the detection of viral nucleic acids and in the analysis of transgenic plants. Generally, probes were labelled with digoxigenin, either by the random priming method or by PCR, and then detected with CSPD or CDP-Star. We routinely use a tissue blotting protocol for diagnosing TYLCV, a plant virus becoming a post in the Mediterranean region. Test results were comparable with those using the same radiolabelled probe. When total nucleic acids are extracted from the plant samples and used in dot-blot or Southern blot assays, viral DNAs are promptly detected by chemiluminescence. In transgenic plants, chemiluminescence was used to detect the transgene on genomic Southern blots, the transgenic mRNAs on Northern blots, and the transgenic protein on Western blots. In Southern and Northern blots, the quality of the results obtained was usually satisfactory, but not as good as with a radiolabelled probe, the main problem being the signal-to-background ratio. Our goal is now to improve the quality of results in demanding applications such as genomic Southern blots, by reducing the background on membranes.     

A biographical inventory for students: II. Validation of the instrument.

Scores on the BIS (see 31: 3079) were correlated, for samples of college freshmen, with 5 scholastic ability and achievement measures, 2 personality inventories, 2 values inventories, and vocational choice (major field of study). The magnitude and significance of the correlations between these 10 criteria and the 10 subscale scores of the BIS are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oligodendrogliomas. Part II: A new grading system based on morphological and imaging criteria

Myocardial perfusion scintigraphy is a noninvasive diagnostic method for the evaluation of patients with suspected or proven coronary artery disease (CAD). We utilized case-based reasoning (CBR) methods to develop the computer-based image interpretation system SCINA which automatically derives from a scintigraphic image data set an assessment concerning the presence of CAD. We compiled a case library of 100 patients who underwent both perfusion scintigraphy and coronary angiography to document or exclude the presence of CAD. The angiographic diagnosis of the retrieved nearest neighbor match of a scintigraphic input case was selected as the CBR diagnosis. We examined the effects of input data granularity, case indexing, similarity metric, and adaptation on the diagnostic accuracy of the CBR application SCINA. For the final prototype, sensitivity and specificity for detection of coronary heart disease were 98% and 70% suggesting that CBR systems may achieve a diagnostic accuracy that appears feasible for clinical use.     

A technique for determining the spatial relationship between the rotator cuff and the subacromial space in arm abduction using MRI and 3D image processing

An MR imaging-based technique for three-dimensional determination of subacromial space width in relation to the rotator cuff in arm abduction is presented. Five volunteers were examined in an open MRI in seven arm positions, and coronal images were obtained with a gradient-echo sequence. 3D reconstruction of the bones and the supraspinatus was performed, and the minimal spatial distances between acromion, clavicle, and humerus were calculated. The closest contact between the supraspinatus and the anterior inferior part of the acromion occurred at 90 degrees abduction in internal rotation. The technique presented allows investigation of the morphological basis of the impingement syndrome.