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PubMed2000

[In Process Citation]

The shoulder joint takes a special position among all the||| other joints of the human body because of its special requirements of stability||| and mobility. Knowledge of the biomechanics of the shoulder joint forms the||| basis for the development of modern concepts of reconstructive surgery and||| arthroplasty. Most of the biomechanical findings are the result of research||| performed on cadaver shoulders using increasingly sophisticated methods of||| measurement. These studies elucidate the interaction of the static and dynamic||| factors which contribute to the delicate balance of the glenohumeral joint.||| Recently performed research is increasingly being focussed on more detailed||| analyses of muscle forces and stress distribution in the subchondral bone and||| periarticular soft tissues. The efficiency of the computer systems now||| available has enabled the development of complex, virtual shoulder models and||| three-dimensional finite element analyses. In the future a pure mechanical||| understanding has to be modified to extend to a concept which includes more||| data obtained from living subjects, especially with regard to muscle activity||| under varying loads and neuromuscular feedback systems which currently are||| difficult to assess.

Journal Article↗

PubMed2000

Risk management methodology for HIPAA security standard.

The Health Insurance Portability and Accountability Act (HIPAA) security standard requires a formal security management process that includes risk management. Risk management is a detailed process used to identify and assess risk, identify and accept mediation for risk, and maintain an acceptable level of risk. This chapter explains the risk management methodology developed by Providence Health System for HIPAA compliance. Providence risk management methodology includes risk analysis and assessment for both hard and soft assets.

Computer Security↗

PubMed2001

Extragonadal retroperitoneal endodermal sinus tumor in an eight-month-old female infant.

We describe a rare case of an extragonadal retroperitoneal endodermal sinus (yolk sac) tumor in the minor pelvis. Radiologic investigation, which included abdominal ultrasound and computed tomography (CT), showed a large soft tissue mass occupying the pelvic cavity. Radionuclide bone scans demonstrated bone metastases. The serum alpha fetoprotein was elevated. Pathologic examination of the surgical specimen revealed extragonadal yolk sac tumor. Immunohistochemically, the tumor was positive for a-feto-protein and cytokeratins. After postoperative combination therapy, follow-up CT showed decreasing tumoral disease, while serum alpha fetoprotein returned to normal.

Endodermal Sinus Tumor↗

PubMed2003

Restoring soft and hard dental tissues using a removable implant prosthesis with digital imaging for optimum dental esthetics: a clinical report.

Currently, most dental implants are placed in the esthetic zone with a delayed surgical protocol. This delay can result in loss of both soft and hard oral tissues following the healing period, necessitating guided tissue regeneration, distraction osteogenesis, or bone expansion and grafting procedures either prior to or at the time of implant placement. If a delayed placement protocol is used, or if grafting procedures are ineffectual, the prosthetic phase of implant dentistry must restore the missing structures artistically and functionally to integrate with the patient's existing dentition. This article presents the option of using a removable implant prosthesis for an esthetic anterior restoration of soft and hard tissues. A computer-assisted camera was used to record speaking, smiling, and active facial positions, with digital imaging to achieve realism for tooth position during the prosthetic phase. The captured patient images with the esthetic setups were transmitted by e-mail for direct viewing by both dentist and dental technician prior to case completion. These images were viewed as reference files during laboratory construction of the prosthesis to achieve the desired esthetic and functional results.

Adult↗

PubMed1991

[Primary malignant lymphoma of the skull presenting as a growing mass in the forehead; a case report].

A rare case of primary malignant lymphoma of the skull was reported. A 74-year-old woman was admitted to our hospital complaining of a growing mass in her forehead where she had had minor trauma one month previously. On admission, neurological findings were normal and an elastic hard tumor (6 x 6 x 2 cm) was found in the right frontal region. Computed tomography (CT) showed a large soft tissue mass in the subcutaneous tissue and a small mass in the ethmoid sinus, with erosion at the inner and outer tables of the frontal bone. Magnetic resonance imaging revealed a low intensity area in the bone marrow beneath the tumor. Right carotid angiography showed that the tumor was fed by branches of the ophthalmic artery in the arterial phase and stained in the capillary phase. Partial excision of the tumor was performed, but the affected bone was left because of her advanced age, even though thinning and spicular formation of the frontal bone were observed beneath the tumor in places. Pathological examination showed the tumor to be a malignant lymphoma of non-Hodgkin and diffuse mixed type. Postoperatively, systemic examinations were performed by 99mTechnetium-MDP bone scanning, 67Gallium citrate scanning, bone marrow puncture, and CT scanning, without any evidence of systemic lymphoma. The patient received postoperative chemotherapy with Cyclophosphamide, Doxorubicin HCl, Vindesine Sulfate, Prednisolone, and complete remission has been achieved for the 8 months since the operation.

Aged↗

PubMed1990

[A case of delayed radiation lumbo-sacral plexopathy].

We report a 47-year-old woman who developed a slowly progressive lumbosacral plexopathy with mixed sensorimotor losses in the lower extremities. The symptoms were apparent 8 years after x-ray irradiation for an ovarian carcinoma. Neurological examination showed mild weakness and absent deep tendon reflexes of bilateral lower extremities, and hypesthesia to all modalities in anterior aspects of bilateral lower thighs, in dorsum pedis and soles. Extensive investigations regarding the possibility of tumor recurrence were negative. Computed tomography of pelvis showed abnormal soft tissue densities around the lumbosacral plexus. Intravenous pyelography showed bilateral hydronephrosis and narrowed ureters at the first sacral vertebra level. These findings are consistent with radiation-induced fibrosis rather than tumor infiltration. The results suggest the entrapment lumbosacral plexopathy due to surrounding fibrosis after irradiation. We speculated the sensorimotor losses caused by entrapment of the lumbosacral plexus.

Female↗

PubMedDate not supplied

[Otitis externa maligna and cranial neuropathy].

Malignant external otitis (MEO) is a disease of the external auditive channel (EAC) due to Pseudomonas aeruginosa which usually involves individuals with diabetes mellitus. It may result in the invasion of the cranial base with cranial neuropathy and a high mortality rate despite therapy. We report the clinical features, diagnostic procedures, evolution and therapy of 8 patients with MEO, seven of which had cranial neuropathy. All patients have diabetes except one who had acquired immunodeficiency syndrome. All had otalgia, otorrhea and headache lasting for several months. Six patients had homolateral (as related to the MEO) facial palsy. One patient with bilateral MEO developed bilateral facial palsy and lesion of the cranial nerves VI (unilaterally) and IX through XII (bilaterally). In all patients P. aeruginosa was cultured from the EAC exudate scintigraphy with 99Tc showed uptake at medium ear and mastoid level in all 8 patients, suggesting a possible osteomyelitis. Scintigraphy with 67Ga was positive in the 6 cases where it was carried out, showing uptake in the soft tissues of the cranial base. Computed tomography was carried out in 6 patients, and it was useful to define the anatomical extent of the disease. The patients received different therapeutic schedules, particularly the combination of a betalactamic and aminoglucoside antibiotics. Follow up was characterized by common recurrences, and one patient died. The importance of early diagnosis and treatment to prevent the extension and recurrence of MEO are discussed. Cranial neuropathy is considered as a poor prognostic finding.

Acquired Immunodeficiency Syndrome↗

PubMed1987

[Magnetic resonance imaging in the diagnosis of soft cervical disk hernia. Evaluation report on 20 cases previously examined by x-ray computed tomography].

Twenty successive patients were examined using CT scanning followed by M.R.I. Thirteen were subsequently operated upon. The results are reported in detail, specifying which signals were used to make the diagnosis of cervical disc prolapse. Short sequences were used for degeneration in the herniated disc, disc protrusion into the spinal canal and compression of the spinal cord. Long sequences were used for indentations or blocks in the cerebro-spinal fluid column at the level of the disc prolapse. Ordinary disc degenerations and associated stenoses are also shown. The reliability of the method was established by comparison with radiographs and surgical findings which were shown to be positive in all the 13 cases treated surgically. The report discusses the difficulties and current limitations of magnetic resonance imaging such as the scarcity of machines, the supine position, the length of the examination, the mediocre quality of horizontal axial sections and difficulties in transmitting magnetic resonance information. There is expected to be rapid and decisive progress with the use of rapid imaging, the preferential choice of sequences, the use of scout views and closer collaboration between radiologist and clinician. A final section is devoted to a discussion of the relative merits of CT scanning and M.R.I. The latter has the advantage of providing total three-dimensional information, particularly in the sagittal plane with a better appreciation of the relationship between container and contents and a method which is strictly non-invasive with the use neither of contrast medium nor X-rays. The authors conclude that M.R.I. provides a positive contribution to the diagnosis of cervical disc protrusions and that this technique can, from now onwards, be considered the examination of choice.

Adult↗

PubMed1995

[Diagnostic and surgical problems in a case of post-traumatic retention of a foreign body in the submandibular gland].

We report a particular case of a traumatically introduced foreign body in the sub-mandibular gland. A breaking object (plastic pen) penetrated, through the anterior oral floor, the submandibular gland. Such foreign bodies should be removed before suturing the wounds, as they can disturb healing and cause problems long after the accident. An adequate history, clinical and imaging studies should reveal the possibility of foreign body penetration and its localization, when it isn't previously removed. We compare the use of ultrasound detection of foreign bodies in soft tissue and conventional plain radiography, computed tomography, and magnetic resonance imaging. The usefulness of US in this kind of research does not justify TC or RM studies and allows a less invasive surgical operation.

Child↗

PubMed1998

[A case of ureteral polyp prolapsing into bladder in a 3-year-old boy].

A 3-year-old boy was referred to us with a diagnosis of bladder tumor. On cystoscopy, a yellowish-white pedunculated tumor was found at the right trigone and biopsy revealed an inflammatory change. Computed tomographic (CT) scan showed a soft tissue density from the lower ureter to the bladder. Open surgery confirmed a ureteral polyp originating from the lower ureter prolapsing into the bladder, which mimicked bladder tumor. The need of open surgery in such cases is discussed.

Child, Preschool↗

PubMed2002

Are soft tissue composition of bone and non-bone pixels in spinal bone mineral measurements by DXA similar? Impact of weight loss.

Weight loss seems associated with a decrease in bone mineral density (BMD) as measured by absorptiometry, which may be the result of accuracy errors caused by differences in soft tissue between non-bone and bone pixels. The aim was to study the abdominal fat% and thickness in regions corresponding to non-bone, soft tissue-only and bone pixels for spinal BMD measurements by dual energy X-ray absorptiometry (DXA), and to calculate the theoretical errors in measurement of changes in BMD by DXA as a result of changes in soft tissue heterogeneity with weight loss. Abdominal computed tomography (CT) and DXA scans were performed in 34 obese subjects (42.1+/-10.1 years (mean +/- SD), wt: 102.1+/-12.8 kg and BMI: 36.6+/-3.8 kg m(-2)) before and after weight loss (11.3+/-6.9 kg after 1 year). There were some significant differences in fat% and thickness of soft tissue between abdominal regions corresponding to non-bone and bone pixels, respectively, for spinal BMD measurements by DXA, both before and after weight loss. With weight loss there were some changes in the soft tissue heterogeneity, which caused a minor theoretical error (apparent, but false decrease of 1-2%) of borderline significance for the anterior-posterior (AP) spinal BMD by DXA.

Absorptiometry, Photon↗

PubMed2006

[Secondary midfacial reconstruction using different surgical techniques and computer assisted surgery].

AIM: Aim of this retrospective study was to assess the outcome after secondary midfacial reconstruction using different operation techniques and computer assisted surgery. Functional and aesthetic aspects as well as experiences are reported. PATIENTS AND METHODS: 18 patients were assessed for enophthalmos, diplopia, and aesthetics during a follow-up period of up to 2.5 years. RESULTS: In 40% of the patients several techniques for soft and hard tissue reconstruction were used. In 5 of the 9 patients diplopia was improved; in 4 patients there was no change. A significant enophthalmos was corrected in 8 out of 12 patients. After additional surgery 6 patients had a good aesthetic result, 7 a satisfactory and 5 a poor. CONCLUSION: For secondary midfacial reconstruction often a combination of different surgical techniques is necessary. Bony asymmetries and enophthalmos were successfully corrected, however, functional and aesthetic impairment due to bad soft tissue condition are difficult to correct. Computer assisted surgery is helpful for dissection within the orbit, for graft placement, and for positioning of osteotomized segments.

Adolescent↗

PubMed1994

Combined and three-dimensional rendered multimodal data for planning cranial base surgery: a prospective evaluation.

Magnetic resonance (MR), X-ray computed tomography (CT), and angiographic images best depict soft tissue, bone, and blood vessels respectively. No one on its own is sufficient in the preoperative assessment of cranial base lesions. We have developed and evaluated a computational technique for the three-dimensional (3D) combination and display of multimodality images for planning cranial base surgery. This evaluation was prospective and performed in such a way that the results could be quantified. Eight patients (three acoustic neuromas, four subfrontal and suprasellar meningiomas, and one petrous apex meningioma) underwent MR, CT, and MR angiographic investigations. These images were registered with anatomical landmarks rather than an external frame. Two techniques were used to display the resulting combined images: multiple slices in which bone from CT was overlaid on soft tissue from registered MR and pseudo-3D-rendered movie sequences showing bone from CT, lesions and optic nerves from MR, and blood vessels from MR angiography. The advantages of the combined displays compared with those of conventional methods of viewing were assessed prospectively by the operating surgeon and by an independent surgeon, and the results were compared with operative findings. The preoperative assessment showed a significant improvement (P < 0.05, sign test) in the depiction of both individual structures (lesion and bone from overlaid slices and lesion and vasculature from 3D-rendered displays) and structural relationships (tumor-bone relationships from overlaid slices and of tumor-vasculature relationships from 3D-rendered displays). The operative findings indicated that a more accurate interpretation of this information was possible from the combined images.

Adult↗

PubMed1987

Role of computed tomography in selecting patients for hindquarter amputation.

Nine patients with soft tissue sarcomas close to the pelvic girdle and one patient with a primary malignant bone tumour of the pelvis were referred for consideration of hindquarter amputation. Patients were considered unsuitable for hindquarter amputation on clinical grounds if malignant disease infiltrated into the perineum or across the sacro-iliac joint. If disease in the femoral triangle extended above the inguinal ligament the tumour's operability was seriously questioned. Buttock tumours which had passed through the greater sciatic notch to become palpable on pelvic examination were also considered likely to be inoperable. On computed tomographic (CT) examination, tumours were considered inoperable if the psoas muscle was involved above the inguinal ligament, or if malignant disease involved the sacro-iliac joint, sacrum or perineal structures. Soft tissue tumours of the buttock extending significantly through the greater sciatic notch were also considered likely to be inoperable. Five patients thought suitable for hindquarter amputation on clinical assessment had no excluding features on CT; four undergoing hindquarter amputation were proven on histological examination to have good clearance of their tumours. In another patient, considered suitable for hindquarter amputation on clinical grounds, CT suggested that en bloc wide excision of the tumour was feasible enabling the affected limb to be preserved. Four patients after clinical examination were considered unsuitable for hindquarter amputation and in all cases inoperability was confirmed by CT. CT complements clinical examination and provides an objective and reliable means of selecting patients for hindquarter amputation which should avoid unnecessary surgical exploration.

Adult↗

PubMed2003

A surgical simulator for cleft lip planning and repair.

The objective of this project was to develop a computer-based surgical simulation system for cleft lip planning and repair. This system allows the user to interact with a virtual patient to perform the traditional steps of cleft-lip repair. The system interfaces to force-feedback (haptic) devices to track the user's motion and provide feedback during the procedure, while performing real-time soft-tissue simulation. An eleven-day old unilateral cleft-lip and palate patient was previously CT scanned for ancillary diagnostic purposes using standard imaging protocols and 1mm slices. High-resolution 3D meshes were automatically generated from this data using the ROVE software created in our lab. The resulting 3D meshes of bone and soft-tissue were instilled with physical properties of soft tissues for purposes of simulation. Once these preprocessing steps were completed, the patient's bone and soft-tissue data are presented on the computer screen in stereo and the user can freely view, rotate, and otherwise interact with the patient's data in real-time. The user is prompted to select anatomical landmarks on the patient data for preoperative planning purposes, then their locations are compared against that of a "gold standard" and a score, derived from their deviation from that standard and time required, is generated. The user can then move a haptic stylus and guide the motion of the virtual cutting tool. The soft tissues can thus be incised using this virtual cutting tool, moved using virtual forceps, and fused in order to perform any of the major procedures for cleft-lip repair. Real-time soft tissue deformation of the mesh realistically simulates normal tissues and haptic-rate (>1kHz) force-feedback is provided. The surgical result of the procedure can then be immediately visualized and the entire training process can be repeated at will. A short evaluation study was also performed. Two groups (nonmedical and plastic surgery residents) of six-people each performed the anatomical marking task of the simulator four times. Results showed that the plastic surgery residents scored consistently better than the people without medical background. Every person's score increased with practice, and the length of time needed to complete the eleven markings decreased. The data was compiled and showed which specific markers consistently took users the longest to identify as well as which locations were hardest to accurately mark. Our findings suggest that the simulator is a valuable training tool, giving residents a way to practice anatomical identification for cleft lip surgery without the risks associated with training on a live patient. Educators can also use the simulator to examine which markers are consistently problematic, and modify their training to address these needs.

Cleft Lip↗

PubMed1999

Comparison of soft tissue profile changes in serial extraction and late premolar extraction.

To assess soft tissue profile changes through time, a comparison was made of patients treated by serial extraction without subsequent orthodontic treatment (n=28), patients treated with serial extraction and orthodontic treatment (n=30), and patients treated orthodontically with late extraction (n=30). Cephalometric radiographs were traced and digitized; linear and angular measurements were made with a custom computer program that allowed digitization of specific soft tissue points. Maxillary, mandibular, and overall cephalometric superimpositions and linear measurements of change from the superimpositions were done by hand. Statistical analyses were made to determine if significant differences existed within each group at each time period and between groups at each time period, as well as between males and females at each time period. Data were also analyzed to determine if significant correlations existed between any hard tissue variable and any soft tissue variable, or between any soft tissue variable and any other soft tissue variable. It was found that in those patients treated with late premolar extraction, the most labial point of the mandibular incisor was more posterior from pretreatment to posttreatment than in the serial extraction group. While a great number of associations existed between variables, no significant differences were found between the soft tissue profiles of these three groups of patients. The gender differences that were found to exist were most likely due to normal maturational changes, not the treatment itself.

Adolescent↗

PubMed1998

Mixed and Penalty Finite Element Models for the Nonlinear Behavior of Biphasic Soft Tissues in Finite Deformation: Part II - Nonlinear Examples.

This two-part paper addresses finite element-based computational models for the three-dimensional (3-D) nonlinear analysis of soft hydrated tissues, such as articular cartilage in diarthrodial joints, under physiologically relevant loading conditions. A biphasic continuum description is used to represent the soft tissue as a two-phase mixture of incompressible inviscid fluid and a hyperelastic, transversely isotropic solid. Alternate mixed-penalty and velocity-pressure finite element formulations are used to solve the nonlinear biphasic governing equations, including the effects of strain-dependent permeability and a hyperelastic solid phase under finite deformation. The resulting first-order, nonlinear system of equations is discretized in time using an implicit finite difference scheme, and solved using the Newton-Raphson method. Details of the formulations were presented in Part I [1]. In Part II, the two formulations are used to develop two-dimensional (2-D) quadrilateral and triangular elements and three-dimensional (3-D) hexahedral and tetrahedral elements. Numerical examples, including those representative of soft tissue material testing and simple human joints, are used to validate the formulations and to illustrate their applications. A focus of this work is the comparison of the alternate formulations for nonlinear problems. While it is demonstrated that both formulations produce a range of converging elements, the velocity-pressure formulation is found to be more efficient computationally.

Journal Article↗

PubMed1983

Computed tomography of lambdoid calvarial defect in neurofibromatosis. A case report.

A patient with neurofibromatosis is reported in whom cranial computed tomography (CT) revealed a calvarial defect with an associated soft-tissue mass in the region of the left lambdoid suture. This defect has been the subject of several previous reports, having been demonstrated by means of conventional skull radiography. It should be included in the differential diagnosis when a lytic calvarial lesion is found on CT.

Adult↗