Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Anatomic Landmarks”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed2002

Meloplication of the malar fat pads by percutaneous cable-suture technique for midface rejuvenation: outcome study (392 cases, 6 years' experience).

The aging anterior midface is restored by reversing the contour undulations produced by sagging of the malar fat pad complex toward the nasolabial line. The convex irregularities include the exposed bulges of the post-septal fat, the unveiled malar bag, and the prominent nasolabial fold. The depressed irregularities are represented by the cresent-shaped hollow at the lid-cheek junction, the accentuated nasojugal groove, and the deepening nasolabial line. Repositioning of the ptotic malar fat pad, among other elements of meloplasty, represents a key procedure. In this study, the malar fat pad has been defined as a fan-shaped structure by external anatomic landmarks that correlate closely to the findings in cadaveric dissections and clinical cases, confirmed by the findings of spiral computed tomographic scanning. A simple but powerful adjustable and long-lasting percutaneous suture elevation technique was developed over the past 6 years by the senior author (G.H.S.) to reposition the fat pad in a superolateral direction. Through a dot incision within the nasolabial line, a permanent CV-3 Gore-Tex (or 4-0 clear Prolene) suspension suture, looped through a Gore-Tex anchor graft, suspends the malar fat pad in a direction perpendicular to the nasolabial line. A second suspension system is identically passed through another lower dot incision to broaden the repositioning vectors on the malar fat pad. Tension on each of the paired suture ends elevates the malar fat pad by 1 to 3 mm as measured from the nasolabial dot incisions. The sutures are fixed to the deep temporal fascia through a Gore-Tex tab, effectively stabilizing the soft-tissue repositioning. This maneuver may be performed in younger patients who present with an isolated malar fat pad ptosis without excess facial skin. The procedure may also be incorporated into open rhytidectomies to address this recalcitrant area along with superficial musculoaponeurotic system tightening. A total of 392 patients since 1995 underwent suture elevation of the malar fat pads. An outcome study indicated that the usage of two permanent sutures with Gore-Tex anchor grafts since 1998 resulted in improvement in midface rejuvenation of over 82 percent. Early and late complication rates were small and temporary. Patient acceptance was excellent, indicative of the benefits of anatomic repositioning of the malar fat pad complex.

Adipose Tissue↗
PubMed2005

Neuronavigation in skull base tumors.

OBJECTIVE: Computer-assisted neuronavigation was used in 87 cases of skull base lesions (SBLs). Preoperative planning and intraoperative identification of anatomic landmarks is especially important in SBLs since it helps to avoid or minimize surgical morbidity and mortality. In this study, we assessed the accuracy and the clinical usefulness of a frameless system based on the optical digitizer in SBLs. PATIENTS AND METHODS: Between April 2000 and March 2003, eighty-seven patients with SBLs were operated on in our department using cranial neuronavigation. A passive-marker-based neuronavigation system was used for intraoperative image guidance. There were 56 women and 31 men. The patient's ages ranged from 4 to 76 years (average: 45.7 year). The locations of the tumors reported in this series were as follows: frontobasal, 24 cases; sellar/parasellar, 32 cases; petroclival, 16 cases; tentorial/subtemporal, 15 cases. RESULTS: The computer-calculated registration accuracy ranged between 0.3 and 1.7 mm (mean, 1.1 mm). Gross total removal of the SBLs was accomplished in 82 out of 87 patients as was confirmed on postoperative CT and MRI scans. The follow-up period ranged from 1 month to 48 months (average: 20.1 months). Overall mortality and severe morbidity (meningitis, permanent cranial nerve deficits, and cerebrospinal fluid fistulae) rates were 4.6 % and 33.3 %, respectively. CONCLUSION: The image-guided surgery is a valuable aid for safe, helpful and complete removal of SBLs of the brain where accurate localization of the lesion is critical. Although our preliminary series is not large, interactive image guidance provides a constant display of surgical instrument position during surgery and its relationship with the SBLs components, surrounding normal brain, and vascular structures, providing valuable guidance to the surgeon during an operation. Our experience with the neuronavigation suggests that image guidance is helpful in this type of lesions, providing better anatomic orientation during skull base surgery, delineating tumor margins and their relation to critical neurovascular structures.

Adolescent↗
PubMed2006

Superficial surgical landmarks for identifying the posterior interosseous nerve.

OBJECT: There is a paucity of information in the neurosurgical literature regarding the surgical anatomy surrounding the posterior interosseous nerve (PIN). The goal of the current study was to provide easily recognizable superficial bone landmarks for identification of the PIN. METHODS: Thirty-four cadaveric upper extremities obtained from adults were subjected to dissection of the PINs, and measurements were made between this nerve and surrounding superficial bone landmarks. In all specimens the main radial trunk was found to branch into its superficial branch and PIN at the level of the lateral epicondyle of the humerus. Proximally, the PIN was best identified following dissection between the brachioradialis and extensor carpi radialis longus and brevis muscles. At its exit site from the supinator muscle, the PIN was best identified after retraction between the extensor carpi radialis longus and brevis and extensor digitorum communis muscles. This site was a mean distance of 6 cm distal to the lateral epicondyle of the humerus. No compression of the PIN by the tendon of origin of the extensor carpi radialis brevis muscle was seen. One specimen was found to have a proximally split PIN that provided a previously undefined articular branch to the elbow joint. The mean diameter of the PIN proximal to the supinator muscle was 4.5 mm. The leash of Henry crossed the PIN in all but one specimen and was found at a mean distance of 5 cm inferior to the lateral epicondyle. The PIN exited the distal edge of the supinator muscle at a mean distance of 12 cm distal to the lateral epicondyle of the humerus. Here the mean diameter of the PIN was 4 mm. The exit site from the distal edge of the supinator was found to be at a mean distance of 18 cm proximal to the styloid process of the ulna. This exit site for the PIN was best identified following dissection between the extensor carpi radialis longus and brevis and extensor digitorum communis muscles. The distal articular branch of the PIN was found to have a mean length of 13 cm and the proximal portion of this terminal segment was located at a mean distance of 7.5 cm proximal to the Lister tubercle. CONCLUSIONS: The addition of more anatomical landmarks can help the neurosurgeon to be more precise in identifying the PIN and in avoiding complications during surgery in this region.

Aged↗
PubMed2001

Endocast of Sambungmacan 3 (Sm 3): a new Homo erectus from Indonesia.

A new fossil calvaria, Sambungmacan 3 (Sm 3), described in New Fossil Hominid Calvaria From Indonesia--Sambungmacan 3 by Márquez et al., this volume, yields one of the most advanced and complete endocasts yet recovered from Java. This communication provides a thorough interpretation of the external anatomical landmarks observable on Sm 3. Using computer tomography (CT) and traditional morphological measurements, our comparative paleoneurological analyses show that while Sm 3 has a mosaic of features that are similar to both Indonesian and Chinese H. erectus, it also possesses significant characters reminiscent of later hominins. These include a greater degree of asymmetry characterized by a possible left-occipital, right-frontal petalial pattern, left-right volumetric cerebral asymmetry, and marked asymmetry in Broca's cap. Moreover, the frontal lobe offers a more rounded, shortened appearance in contrast to the flat, elongated appearance of other Indonesian fossils (e.g., Sangiran 17). Another unique trait is exhibited in the transverse plane where the widest breadth of Sm 3 occurs more superiorly than in other Indonesian H. erectus. Thus, the endocast of Sm 3 presents a unique morphology not seen previously in the hominin fossil record. While the strong modern human characteristics in this endocast may not represent a particular ancestry, they do allow us to recognize a new dimension of the remarkable variation in Indonesian Homo erectus.

Animals↗
PubMed2002

Three-dimensional surface rendering reconstruction of scoliotic vertebrae using a non stereo-corresponding points technique.

The medical imaging techniques that allow a three-dimensional (3D) surface rendering reconstruction, which is usually required by the clinician when dealing with scoliotic patients, are computed tomography (CT) and stereoradiography. However, CT cannot provide a 3D rendering of the whole spine because of the high irradiating dose, while the stereoradiographic 3D reconstruction techniques, which use an algorithm derived from the direct linear transformation (DLT), are usually limited in accuracy because of the small number of corresponding anatomical landmarks identifiable on both radiographs. The purpose of the present study is to validate a recent biplanar 3D surface rendering reconstruction technique on scoliotic vertebrae. This technique, called "non stereo-corresponding points" (NSCP), has already been tested on non-pathologic dry cervical vertebrae and frozen lumbar specimens, and the results have proved very encouraging. Since scoliosis is a 3D deformity of the vertebrae and of the global spine, such a technique could be a very useful clinical tool for the diagnostic, follow-up and surgical planning when dealing with scoliotic patients. The validation of the NSCP technique on scoliotic patients was performed on 58 scoliotic vertebrae in 14 patients, by comparison with the CT scan 3D rendering technique. The results of this study show mean errors of 1.5 mm. On the basis of this study, we can conclude that the NSCP 3D reconstruction technique is a definite improvement over existing techniques, and can serve as a useful diagnosis tool in scoliosis. However, the results of the technique still need to be optimized for use in geometrical modeling.

Adolescent↗
PubMed2006

[Femoral shaft bowing in valgus knees: an anatomic study].

PURPOSE OF THE STUDY: In a previous anatomic study of healthy knees, we observed that femoral valgus cannot be attributed to hypoplasia of the lateral femoral condyle. In the present study, in an attempt to determine the site of the femoral deformation, we examined femoral shaft bowing in the frontal plan. MATERIAL AND METHODS: This cadaver study included 41 lower limbs of healthy Caucasian subjects aged over 65 years. The following anatomic landmarks were identified: center of the femoral head (H), center of the intercondylar notch (K), center of the talar dome (A), center of the femoral shaft half way between the apex of the greater trochanter and the middle of the intercondylar notch (S), the tangent line of the femoral condyles (I). Three angles were analyzed: HKA, HKI and SKI. There were 23 normal knees (HKA = 179.1 +/- 1.6 degrees) and 18 valgus knees (HKA = 182.7 +/- 0.8 degrees). Skeletal analysis (the skeleton of an object being defined as the median points of the object) was used to describe the morphology of the femoral shaft then to shape it with a second degree function (y = fx2 + bx + c). The protocol was repeated seven times to achieve accurate measurement. Accuracy was 1 degrees for the HKA angle and 0.45 degrees for the HKI and SKI angles. This accuracy was comparable to that reported in the literature. The Mann and Whitney U test was used to compare means. Spearman's t test was used to search for correlations. The first order risk was set at 0.05. RESULTS: The HKI angle of valgus knees (95.5 +/- 1.1 degrees) was greater than for the normally aligned knees (93.6 +/- 2.4 degrees), confirming the femoral origin of the valgus. The form parameter f for the normal knees (1.33 10(-5) +/- 1.41 10(-5)) was greater than for the valgus knees (5.71 10(-6) +/- 5.27 10(-6)). There was a correlation between the form parameter f and the HKI angle for valgus knees, reflecting a relationship between frontal bowing of the femoral shaft and femoral valgus in this group. DISCUSSION: The difference observed between the two groups of knees regarding the form parameter f and the correlation between f and the HKI angle in the valgus knees led us to consider that a considerable part of constitutional valgus knees can be attributed to the femoral shaft. Thus for equivalent anatomic valgus (SKI), minimal bowing (f) of the femoral shaft in valgus knees leads to greater mechanical valgus (HKI). These results confirm those obtained in our earlier study where we concluded that hypoplasia of the lateral femoral condyle does not contribute to constitutional valgus knees. We hypothesize that the same could be true for degenerative disease of constitutional valgus knees. For surgical cure, the origin of the misalignment in valgus knees dictates the rotation position of the femoral component of total knee arthroplasty and the lengthening technique for the lateral structures.

Aged↗
PubMed1999

Surgical planning of computer-assisted repositioning osteotomies.

Repositioning osteotomies are frequently used in orthopedic surgery and traumatology to correct malpositions. Computed tomography (CT), stereolithographic models, and x-rays are used in planning. However, the precision achieved in the planning phase is usually not translated to patients. The Surgical Segment Navigator (SSN) is a navigation system that allows computer-assisted correction of malpositions. It consists of an infrared positioning device, two dynamic reference frames (DRF), an infrared pointer, and an infrared camera. All data are displayed numerically and graphically on the monitor of the SSN workstation. The Laboratory Unit for Computer-Assisted Surgery (LUCAS) is used for planning surgery in the laboratory. LUCAS requires only a native CT scan. A preparatory operation to implant bone markers that will be visible in x-rays and a further planning CT scan showing the bone markers, which were necessary with previous systems, are not required for the LUCAS and SSN system. This significantly reduces the radiation exposure of the patient and the costs of surgical planning. Measuring anatomical landmarks in the surgical site, which is time-consuming and reduces accuracy, is not required with the SSN system because the position of the infrared transmitters is known during surgical planning on the LUCAS workstation. This makes the surgical approach faster and much more precise. The surgical planning data are transferred to the surgical site using a data file and an individual surface pattern that fits the surface of the navigated bone segment. The data file is exported from the LUCAS-workstation to the SSN workstation. The planned spatial displacement of the infrared transmitters is saved in this file. The individual surface pattern carries the infrared transmitters. This pattern is the mechanical interface between infrared transmitters and navigated bone segment. The individual surface pattern can be polymerized directly on a small stereolithographic model of the navigated bone segment. The surface pattern can also be generated as negative form from a CT data set using a computer-assisted design/manufacture system. In summary, LUCAS and SSN allow for the computer-assisted correction of malpositions and positioning of artificial joints and implants. In principle, the systems can be used in all fields of surgery.

Biomechanical Phenomena↗
PubMed2006

[Individual 3-D image prototyping models for orbital reconstruction].

OBJECTIVE: To fabricate a rapid prototyping (RP) 3-D image models for individual reconstruction of orbital bony loss. METHODS: The skull was placed on a helical CT scanner table and the Frankfort plane was perpendicular to the table. The CT data was obtained by a Aquilion (TOSHIBA, Japan) with 1 mm thickness section in spiral mode. By adjusting of CT threshold value and pixels in order to stack the segmental defects, we obtained an approximate 3-dimension visual model of the scanned skull using MedGraphics software. An orbital RP model based on the dataset of the 3-dimension visual model was fabricated by RP machine. Both 3-dimension visual model and RP model were measured against the skull with several anatomic landmarks to examine the accuracy of the models, and the errors were analysed. RESULTS: Integrity precision rapid RP models of the orbital region were reconstructed. The anterior orbital rim, middle orbital section and posterior orbital section were all fabricated. Optic foramen, superior orbital fissure, infraorbital foramen, inferior orbital fissure, lacrimal sac socket and naso-lacrimal duct were shown clearly. But some fine hole and slot, such as the anterior ethmoidal foramen, posterior ethmoidal foramen and zygomaticofrontal suture were not obviously seen. The mean difference between the 3-dimension visual model and the skull was 0.10 +/- 1.02mm. For the RP and dry skull, the mean difference was 0.22 +/- 1.04mm. There were no statistical differences between them. CONCLUSIONS: Integrity precision orbital RP models were fabricated which fulfilled the requirements of the individual reconstruction with bony orbital pathologic changes. The keys to fabricate the precision orbital RP models included a closer cooperation between the surgeon and engineer, thin CT slice in 1mm thick and an appropriated threshold value. Better results for the orbital deformities should be achieved for the contour of orbital region or eye function.

Humans↗
PubMed1996

[Computer assisted pedicle screw installation. Our first 3 cases].

Pedicle screw fixation is sometimes a difficult surgical procedure relying on anatomical landmarks that may be modified by vertebral asymmetries. A significant incidence of cortex penetration and neuro-vascular complications have been documented. Our study evaluates the usefulness of a computer-aided pedicle installation system and analyses the results for our first 3 clinical cases. The system was used for 3 adolescent patients with idiopathic scoliosis undergoing surgical correction and instrumentation. In all cases, selected vertebrae were reconstructed in 3D pre-operatively. At surgery, the surgeon compared the computer-suggested pedicle location to his own opinion. After pedicular hole drilling was done in the usual fashion, hole positions were confirmed per-operatively with the computer software. Post-operatively, software hole positions were measured and compared to the actual screw axis using CT-Scans. Three dimensional models produced for all selected vertebrae allowed visualization of asymmetrical deformations of the scoliotic vertebrae. All pedicles were correctly detected by the software. Pedicular hole measurements agreed with the actual screws positions on post-op CT-Scans. The computerized surgical assistant can be of value in a clinical situation. These initial results warrant a large scale trial in order to establish accuracy and reliability.

Adolescent↗
PubMed1997

[Prevention of hemorrhagic complications in the lateral retinacular section of the patella. A study of the lateral arteries of the knee applied to the prevention of knee hemarthrosis].

PURPOSE OF THE STUDY: Arthroscopic lateral retinacular release is one of the most employed procedures for patellar chondromalacia. A literature review show a complication rate of 10 to 18 p. 100 of postoperative hemarthrosis. This work aims to study the vessels anatomy of the lateral side of the knee in order to find anatomical landmarks allowing to avoid or coagulate them. MATERIAL AND METHODS: Thirty-three cadaver knees were dissected. Measures were made related to the lateral superior genicular artery and the lateral inferior genicular artery. A study using tracing-paper was also carried out. The main part of the work was more descriptive, studying anastomosis between the different arteries and veins location. RESULTS: Concerning the lateral superior genicular artery, measure analysis showed that this artery was always cut in lateral patellar retinaculum. This artery never runs more than one centimeter proximally to the base of patella, which is too insufficient to escape from lateral retinacular release. We noted the possibility of locating 90 p. 100 of lateral superior genicular arteries in a minimal distance of 15 mm, in front of the lateral proximal angle of the patella. Concerning the lateral inferior genicular artery, only a few arteries, protected in the meniscal wall in its early course, can remain intact. Two thirds of these arteries are very vulnerable running across the lateral side of the knee. The study of the tracing-papers confirmed topographic study measurements. The descriptive study emphasized the number and the importance of anastomoses between these different arteries. Each artery is flanked by two large satellite veins, which also attribute a veinous origin to a possible bleeding. DISCUSSION: The topographic study of the lateral inferior genicular vessels shows that their course varies. It seems necessary to avoid their division by performing the standard anterior lateral inferior arthroscopic portal proximally to these vessels. This can be realized at the beginning of the procedure through cutaneous transillumination. The lateral superior genicular vessels are always cut. They are nevertheless reachable through a small lateral incision of about 10 mm, distally to the lateral superior angle of the patella. 90 p. 100 at least of these arteries could be coagulated in such a way. We also emphasize the use of classical methods for the prevention of excessive venous bleeding, such as a compression dressing. CONCLUSION: Following this anatomical study, we suggest, as a supplementary precaution, a selective hemostasis of the lateral superior genicular vessels through a small incision associated with the location of the lateral inferior genicular vessels by cutaneous transillumination.

Arthroscopy↗
PubMed1999

Assessment of geometric and mechanical parameters in wheelchair seating: a variability study.

A measurement method has been developed to quantify the posture of able-bodied subjects seated in their wheelchair. Fourteen geometric parameters were measured in order to represent the pelvis, trunk and lower limbs orientations. They were defined by digitizing the three-dimensional (3-D) position of 23 anatomical landmarks using a mechanical articulated arm (Microscribe3D, Immersion Corporation). Mechanical parameters were used to measure the maximum pressure, mean pressure and peak pressure gradient on the seat and the back of the wheelchair using a force sensing array (Vista Medical, Inc.). A third set of parameters combining mechanical and geometric measurements were defined to represent pelvic tilt and ischial pressure orientations. However, different types of errors are associated to the measurement of these geometric and mechanical parameters. The purpose of this study was to evaluate these errors and their impact on the precision of the various parameters on a sample group of five able-bodied subjects. Results showed that variability of most of the geometric parameters is below 2 degrees with the sagittal rotation of the pelvis presenting the highest variability (3.8 degrees) and the thigh angle the lowest one (0.5 degrees). The variability of the mechanical parameters were respectively equal to 4.9% for the mean pressure, 9.3% for the peak pressure gradient and 16.9% for the maximum pressure under ischial tuberosities. It is suggested that the method proposed in this paper could be used as an accurate procedure to characterize the posture of subjects sitting in a wheelchair.

Adult↗
PubMed1990

An anatomy-based coordinate system for the description of the kinematic displacements in the human knee.

The effects and interaction of the anatomical displacements in the human knee are a prerequisite to an accurate assessment and communication of the kinematic data. For the kinematic information to be used to improve diagnosis and treatment, and for better prosthetic design and installation, there must be clear, concise, and universal definitions of the displacements. In general, the displacements are defined as three translations and three rotations. In this paper, anatomic landmarks on the femur and on the tibia are used to define the locations and orientations of the six displacement axes; i.e. three translational and three rotational displacement axes. The most commonly accepted kinematic representation of the knee joint, in the literature, is a special geometry three-cylindric open chain in which the axes of the cylindric joints are defined according to the rotational displacement axes. The sequentially adjacent joint axes are assumed to not only intersect but to intersect at right-angles. The open chain permits a total of six degrees of freedom between a Cartesian reference frame attached to the femur and a Cartesian reference frame attached to the tibia. In this paper, the three rotational axes are shown to be skewed and off-set from each other, therefore, a three-cylindric open chain with skewed joint axes is proposed to measure the six displacements between the two reference frames. The authors believe that the proposed open chain is the most general to date and provides a more realistic representation of the displacements in the knee. To illustrate the significance of the reference frames on the interpretation of measured data, the anterior/posterior drawer is plotted against per cent gait cycle for three existing open chains and the proposed open chain.

Biomechanical Phenomena↗
PubMed1995

Comparison between planned prosthetic trajectory and residual bone trajectory using surgical guides and tomography--a pilot study.

Implant treatment is a highly technical and complex form of dentistry. Research and experience have shown that the success of dental implant treatment relies on a well-developed treatment plan approach that takes into account factors such as systemic condition, anatomical landmarks, occlusion, shape and density of the jawbone, and type of implant system. Historically, once the tissue was reflected, implant placement was guided by residual bone height and width, using the trajectory that was compatible with the location and direction of available bone, at times compromising prosthetic needs. The purpose of this study was to measure the amount of deviation between planned prosthetic trajectory (PPT), perpendicular to the plane of occlusion, and residual bone trajectory (RBT) in different areas of the maxillary and mandibular dental arches, using tomography in conjunction with surgical guides. Twenty-five patients with a total of 66 implant sites were selected for this study. A surgical guide with a radiopaque indicator was constructed to determine the PPT. Cross-sectional tomograms were taken through the indicator at each implant site. The outlines of the available bone, PPT and RBT, were traced, and the difference in the angulation between the two trajectories was determined. Results showed discrepancies between the PPT and the RBT to be greater in the mandibular molar areas. Further study of such pre-implant diagnostic procedures is needed to understand the relation between the PPT and RBT, thus increasing the predictability of implant success.

Alveolar Bone Loss↗
PubMed1996

Quantitative assessment of radiation-induced lung changes by computerized optical densitometry of routine chest x-rays.

PURPOSE: To develop a quantitative assay of radiological lung changes after postmastectomy radiotherapy applicable for analysis of routine chest x-rays. METHODS AND MATERIALS: The assay relies on measurement of the optical density of chest x-rays by means of a standard personal computer-controlled film densitometer used for scanning dosimetry films. Density profiles were recorded at 1 mm steps along two reference lines in each lung. The crossing between the clavicula and the first rib in the x-ray projection was used as an easily identifiable anatomical landmark and was used to establish two parallel cranio-caudal reference lines separated by 20 mm. The starting point for recording optical densities was 5 mm below a line perpendicular to the reference lines and tangent to the top of the lung. Data were stored in a computer file for subsequent processing. The optical film densities in the apex of the lungs were converted into equivalent absorber thickness (EAT). To minimize the dependency on technical factors, the unirradiated lung was used as a control. Lung density changes were quantified by the relative change in EAT (REAT), which was evaluated as the difference between the summed EATs along the reference lines in the two lungs, corrected for any pretreatment difference in lung density, and taken as a percentage of the pretreatment EAT value of the lung. RESULTS: Four different test were carried out to investigate the reproducibility and validity of the proposed assay. (a) An anthropomorphic phantom was used to test the relationship between REAT and the layer of plastic absorber placed in front of one lung. A linear relationship was found with a correlation coefficient of 0.9993. (b) A series of 10 repeat measurements of the same arbitrarily chosen x-ray showed a mean REAT value of 9.8%, with a standard deviation of 0.21%. (c) Forty-three chest x-rays exposed on the same day were available from the clinical series. These were treated as double determinations of REAT values, and the standard deviation was estimated at 1.35%. (d) REAT values estimated with this assay were significantly correlated with the scores of two experienced specialists, an oncologist and a radiologist (Spearman's rank correlation coefficient being 0.605, p < 10(-8)). CONCLUSION: This assay quantifies radiation-induced lung injury from routine chest x-rays. Thus, it is possible to take advantage of the very large retrospective materials available in most oncological institutions. The assay has been validated in a phantom experiment and shown to be reproducible. Furthermore, it is technically easy to perform.

Female↗
PubMed2004

Change in thrombus length on venous ultrasound and recurrent deep vein thrombosis.

BACKGROUND: Despite successful treatment, deep vein thrombosis may not fully resolve in some patients. Consequently, in patients with new symptoms in a previously affected leg, noncompressibility on ultrasound cannot be assumed to be due to recurrent thrombosis; therefore, we sought to determine interobserver agreement on ultrasound measurements of thrombus length and identify the change in length that is likely to indicate thrombus extension. METHODS: Cross-sectional study of patients with previous proximal deep vein thrombosis and residual ultrasound abnormalities, but without symptoms suggestive of recurrence. The patients had a standardized series of measurements of thrombus length independently performed by 2 ultrasonographers. The outcome measure was the agreement between the ultrasonographers on the distance of thrombus margins from 4 anatomical landmarks. RESULTS: There was good interobserver agreement on thrombus length when measured from the saphenofemoral junction, mid-popliteal fossa, and mid-patella (93% or more of the variance was accounted for by the paired measurements). Using these landmarks, the 95th percentile for the absolute difference between paired measurements was 8.9 cm for the saphenofemoral junction, 8.5 cm for the mid-popliteal fossa, and 8.4 cm for the mid-patella. CONCLUSIONS: When 2 ultrasound examinations are compared, an apparent increase in thrombus length of 9 cm or greater is likely to be supportive of a diagnosis of recurrent deep vein thrombosis. Increases in thrombus length of less than 9 cm appear to be within the bounds of measurement error.

Adult↗
PubMed1977

Three-dimensional computerized tomographic scans of brain. A new approach to intracranial diagnosis.

A new method for displaying computerized tomographic cross sections of brain in the coronal and sagittal planes is described. These images are reconstructed from the original horizontal 3-mm thin slices. This method uses an Artronix scanner and has the advantage of completely eliminating the need to rescan the patient. These pictures are of excellent quality and have proved to be of significant value in demonstrating the special relationships between lesions and anatomical landmarks. This has proved to be of particular importance in the localization of surgical lesions preoperatively.

Brain↗
PubMed1998

Comparison of subperiosteal vs subgaleal elevation techniques used in forehead lifts.

OBJECTIVES: To compare eyebrow and forehead elevation and tension among the following 3 surgical techniques: subperiosteal dissection to the supraorbital rim, subperiosteal dissection with release (elevation, incision, and spread) of periosteum at the supraorbital rim, and subgaleal dissection to the supraorbital rim, and to determine the optimal method of elevation in an aesthetically accepted range for the endoscopic forehead lift. DESIGN: A randomized, self-controlled study using an open approach to the forehead in cadaver heads. Each half of head was compared with the other in the following 2 study groups: subperiosteal dissection without release vs subperiosteal dissection with release of periosteum (group 1) and subperiosteal dissection with release of periosteum vs subgaleal dissection. SETTING: Anatomy laboratory at a university medical center. SUBJECTS: Eight cadaver heads fixed with ethylene glycol in each group. INTERVENTION: Predissection distances in millimeters from fixed anatomic landmarks were measured. The forehead flaps were elevated using a coronal incision and divided with a midline incision for side-to-side comparison. Cadaver heads and side of surgical intervention were selected randomly. The flap tensions associated with incremental flap advancement of 0.5 and 1.0 cm were measured. Traction of 2.2 kg was then applied to each flap, and distances between the fixed landmarks were measured. MAIN OUTCOME MEASURES: Mean predissection and postdissection distance of brow and forehead elevation for each dissection type and mean distance and median tension of brow and forehead elevation within each group. RESULTS: The mean postdissection brow measurements at rest were significantly greater than the mean predissection measurements at most landmarks in all dissections for both groups (P<.05). The mean postdissection brow and forehead measurements with 2.2 kg of traction were significantly greater than the mean predissection measurements at all landmarks in all dissections for both groups (P<.05). The mean increase in distance from predissection to postdissection (at rest and with 2.2 kg of traction) did not significantly differ between the different dissection types (P>.05). For group 1, the median flap tension for subperiosteal dissection without release was greater than that for subperiosteal dissection with release (P>.05). For group 2, subperiosteal dissection with release had greater median flap tension than subgaleal dissection (P>.05). CONCLUSIONS: All 3 methods of dissection significantly elevated the brow at rest for most landmarks. All 3 methods of dissection significantly elevated the brow and forehead when traction was applied to the flap. Brow and forehead elevation at rest and with 2.2 kg of traction did not significantly differ between the dissections. Subgaleal dissection was associated with less flap tension compared with the subperiosteal dissection with or without release. The data support the use of all 3 methods of forehead dissection for brow elevation and subgaleal forehead dissection as the optimal approach for the forehead lift, whether performed endoscopically or open.

Aged↗
PubMed1983

Techniques to enhance utilization of advancement flaps.

Utilization of advancement flaps to cover facial defects is potentially limited by the secondary distortion of adjacent anatomical landmarks, expansion of any residual lesion, and the vascular embarrassment of wound closure under tension. In this study, advancement flaps are raised in piglets, and the first stage in the serial excision of a hypothetical skin lesion is simulated. It is demonstrated that undermining of the lesion-bearing skin results in expansion of the lesion and is counterproductive. If, however, a separate layer of hypodermis and fascia is mobilized deep to the lesion and sutured to the advancing flap, skin closure can be accomplished with minimal tension. This results in maximal recruitment of the advancement flap and minimal expansion of the residual lesion as the defect is bridged.

Animals↗