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Biomedical subjects

K Verstraete

Publications and source records attributed to K Verstraete.

At least 19 recordsLinked to original sources
PubMed2006

Analysis of image quality in digital chest imaging.

An evaluation of the image quality of an amorphous silicon flat-panel detector system and a computed radiology system compared with a screen-film system was performed by means of contrast-detail phantom images. Hard and soft copy images were evaluated. Although patient dose at clinical settings was strongly decreased with the amorphous silicon system, the low-contrast visibility with this system was still significantly better than with the screen-film system. For the computed radiology system, low-contrast visibility was comparable to the screen-film system. Best results were obtained by soft copy reading at full resolution with adaptation of contrast and brightness. Changing tube voltage (102-133 kV), or additional filtration, did not significantly affect image quality. However, low-contrast visibility improved significantly with increasing exposure. It was clearly demonstrated that, in chest imaging, the amorphous silicon system has superior imaging characteristics compared to the screen-film and the computed radiology system.

Calibration↗
PubMed2005

Arthroscopic meniscus repair in the ACL-deficient knee.

Between 1985 and 1995, 45 patients underwent closed meniscus repair. There were 30 men and 15 women with a mean age of 32.5 years. In 23 patients, the anterior cruciate ligament was intact (group 1) whereas it was deficient in 22 patients (group 2). All patients were managed with the same postoperative program of partial weight bearing, immediate motion and rehabilitation of the knee. Five patients had a failed meniscal repair and underwent a repeat arthroscopy and a partial meniscectomy. These patients were considered as failures and excluded from the final scoring. After a mean follow-up of more than 9 years, all patients were subjected to a clinical examination using the Hospital for Special Surgery (HSS) knee rating system. Seven patients in group 2 had episodes of frequent giving way and had their anterior cruciate ligament (ACL) reconstructed 6 and 7 years after the initial meniscus repair. None of the other patients had any clinical symptoms or signs of a meniscal tear. In group 1, 20 patients and in group 2, 14 patients, all had a satisfactory knee score. Even though the failure rate of meniscus repair may be greater in an unstable knee, it is concluded that meniscal repair is not contraindicated in a knee with a deficient ACL.

Adult↗
PubMed2004

[Bio-artificial implants in orthopedics].

Aging of the population and thus of loadbearing cartilage produces a number of degenerative symptoms. At the knee, considerable macroscopic asymmetry of the joint underlies these degenerative changes, were it not for two menisci that somewhat neutralize this discongruency. Microscopically, cartilage is a structure within the knee joint that allows for low friction and congruent movement. Repetitive microtrauma rather than macrotrauma can affect its integrity. Both microscopically and macroscopically reconstruction of a cartilage-like structure is achieved through implantation of cultured cells or auto- and allografts either by minimally invasive or classical surgery, which theoretically could have a beneficial effect on the natural course of degeneration.

Aged↗
PubMed2003

Psammomatoid ossifying fibroma of the ethmoid.

We present a 16 year-old girl who suffered since one year of a painless slow growing mass on the left medial orbital rim causing globe displacement. CT-scan and MRI of the orbit with T1 and T2 weighted images showed the presence of a large mucocoele in the frontal sinus. This occurred secondary to the obstruction of the sinonasal tract by a bony tumour. Histopathology showed a lesion consisting of fibrous tissue and ossicles or psammomatoid bodies. The diagnosis of a psammomatoid ossifying fibroma (POF) was made.

Adolescent↗
PubMed2003

[Long-term assessment of arthroscopic meniscus repair].

PURPOSE OF THE STUDY: A prospective study was set up to evaluate meniscal suturing using an inside-out technique. MATERIALS AND METHODS: Of an initial group of 20 patients who underwent closed meniscus repair between 1985 and 1988 using an inside-out technique, 13 were studied. All patients were subjected to a clinical examination and an magnetic resonance imaging (MRI) investigation. The findings were compared with those of their previous follow-up examination (1994). The Hospital for Special Surgery (HSS) knee rating system was used. The study included 7 men and 6 women, ranging in age from 29 years to 50 years (mean age: 35 years 6 months). The mean follow-up was 13 years 2 months (11 years 11 months-15 years 4 months). Six left and 7 right knees were involved. Seven patients also had an anterior cruciate ligament (ACL) injury of which one was repaired 6 years after meniscal repair. RESULTS: All patients obtained an HSS score of more than 75%. In all patients the site of the previous suture was still visible on MRI mainly by small metal artefacts in the meniscus. Patients with an unrepaired ACL lesion had an early onset of arthrosis and cartilage degeneration. CONCLUSION: Meniscal suturing gives good clinical long-term results. Magnetic resonance imaging, however, showed signs of mucoid degeneration or scar tissue in 46% of the patients.

Adult↗
PubMed2001

Neurofibromatosis, gigantism, elephantiasis neuromatosa and recurrent massive subperiosteal hematoma: a new case report and review of 7 case reports from the literature.

The authors report the case of a 13-year-old patient with neurofibromatosis (NF-I), who suffered blunt trauma to the left tibia in 1993. The diagnosis of subperiosteal hematoma was made. Treatment consisted of temporary rest. There was a recurrence in 1996, and the subperiosteal hematoma was drained. In 1997, a shortening osteotomy of the left tibia was performed. However, massive gigantism with elephantiasis of the left leg remained, causing a serious functional and cosmetic problem. In 1999, the leg was amputated above the knee. The literature is reviewed and 7 case reports are compared. The pathogenesis of subperiosteal hematoma is discussed.

Adolescent↗
PubMed2001

Repair of chronic ruptures of the anterior cruciate ligament using allograft reconstruction and a ligament augmentation device.

A prospective study was performed to determine the effect of a ligament augmentation device (LAD) on the replacement of the anterior cruciate ligament (ACL) using tendon allografts. Twenty-five patients were followed for 66 to 98 months after tendon allograft replacement with LAD reinforcement for ACL rupture. The evaluation was done using the form of the International Knee Documentation Committee (IKDC), the Lysholm score and the Tegner scale. Two patients sustained a rerupture after major injury. Three other multiply-injured patients scored poorly because of associated injuries and fractures (IKDC grade D). Four patients scored normal (grade A), 12 patients nearly normal (grade B), and 5 patients abnormal (grade C). The Lysholm score showed 14 excellent (average 96), 5 good (average 86) and 4 fair results (average 76). Three patients with excellent results were IKDC grade C, solely because the xrays showed slight narrowing of the medial joint line, which might indeed indicate future problems. On the Tegner scale, the sports level decreased by an average of 1.4 points (from 7.25 to 5.83). Only five patients showed an anteroposterior displacement of more than 3 mm, of which only one was in the grade C group.

Adult↗
PubMed2001

Parosteal osteosarcoma of the humerus.

The authors report the case of a 50-year-old man who presented with nontraumatic swelling of the left upper arm. The diagnosis of parosteal osteosarcoma of the humerus was made after diagnostic workup. A long diaphyseal segment of the humerus containing the tumor was resected with a healthy margin of soft tissues and was irradiated extracorporeally with a single dose of 30 Gray. The bony segment was then reimplanted after removal of the tumor using plate and screw fixation. Loosening of the proximal screws after one year required additional fixation and autologous cancellous bone grafting. The patient has a nearly three-year-follow-up and there are no signs of tumor recurrence or metastasis. The proximal osteotomy has healed nicely; the distal fixation osteotomy exhibits delayed healing. The pathogenesis of parosteal osteosarcoma is discussed.

Bone Neoplasms↗
PubMed2000

MR imaging of clear cell sarcoma (malignant melanoma of the soft parts): a multicenter correlative MRI-pathology study of 21 cases and literature review.

OBJECTIVE: To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts). DESIGN AND PATIENTS: MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, signal intensities on T1- and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study. RESULTS: On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody. CONCLUSIONS: Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well-defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images.

Adolescent↗
PubMed2000

Cervical chordoma with vertebral artery encasement mimicking neurofibroma: MRI findings.

A case of cervical chordoma in a 36-year-old white man with hypoesthesia in the neck and right shoulder, neck pain, and restricted neck mobility is presented. Plain radiographs of the cervical spine showed radiolucency of the body of C2 on the right side and enlargement of the right intervertebral foramen at C2-C3 level. Tumor encasement of the vertebral artery was demonstrated by MR imaging and confirmed by conventional arteriography. This proved to be particularly important for preoperative assessment.

Adult↗
PubMed2000

Venous congestion and blood flow in free transverse rectus abdominis myocutaneous and deep inferior epigastric perforator flaps.

A series of 240 deep inferior epigastric perforator (DIEP) flaps and 271 free transverse rectus abdominis myocutaneous (TRAM) flaps from two institutions was reviewed to determine the incidence of diffuse venous insufficiency that threatened flap survival and required a microvascular anastomosis to drain the superficial inferior epigastric vein. This problem occurred in five DIEP flaps and did not occur in any of the free TRAM flaps. In each of these cases, the presence of a superficial inferior epigastric vein that was larger than usual was noted. It is therefore suggested that if an unusually large superficial inferior epigastric vein is noted when a DIEP flap is elevated, the vein should be preserved for possible use in flap salvage. Anatomical studies with Microfil injections of the superficial venous system of the DIEP or TRAM flap were also performed in 15 cadaver and 3 abdominoplasty specimens to help determine why venous circulation (and flap survival) in zone IV of the flaps is so variable. Large lateral branches crossing the midline were found in only 18 percent of cases, whereas 45 percent had indirect connections through a deeper network of smaller veins and 36 percent had no demonstrable crossing branches at all. This absence of crossing branches in many patients may explain why survival of the zone IV portion of such flaps is so variable and unpredictable.

Abdomen↗
PubMed1997

Magnetic resonance imaging of localized giant cell tumour of the tendon sheath (MRI of localized GCTTS).

The objective of this study was to evaluate the appearance of localized giant cell tumour of the tendon sheath (GCTTS) on unenhanced and Gd-enhanced MR images. MR images of 13 histologically proven cases of localized GCTTS were evaluated for mean size, location, homogeneity and signal intensity (SI) on both T1- and T2-weighted images, and enhancement pattern. All lesions except 1 affected young adults. On T1- and T2-weighted images, lesions showed predominantly low SI equal to or slightly higher than skeletal muscle. On Gd-enhanced T1-weighted images, strong homogeneous enhancement was seen. These findings reflect the underlying histological composition of the lesion; haemosiderin deposition in xanthoma cells, shortening T2-relaxation time, and abundant collagenous proliferation are responsible for low SI on T1- and T2-weighted images. Strong homogeneous enhancement originates from numerous proliferative capillaries in the collagenous stroma. We conclude that these characteristic MR features, together with clinical information, are a valuable diagnostic tool in offering a correct preoperative diagnosis.

Adolescent↗
PubMed1993

Magnetic resonance imaging in tracheal compression by the innominate artery.

Tracheal compression by the innominate artery is frequently suspected in infants with noisy breathing and no obvious aortic arch anomalies or pulmonary artery sling. However the diagnosis is difficult to confirm. The findings after using magnetic resonance imaging in two infants with tracheal compression syndrome are presented.

Brachiocephalic Trunk↗