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Biomedical subjects

M C Freund

Publications and source records attributed to M C Freund.

17 recordsLinked to original sources

[Diagnostic imaging in acute neurological status in childhood].

The diagnostic imaging of children with acute, non-traumatic, neurologic symptoms enables a fast and non-invasive localization and diagnosis. A spectrum of typical disorders will be described dependent on the location of neurologic symptoms (central, spinal, or peripheral nervous system). Different non-invasive imaging modalities e.g. US with colour-coded doppler, CT, MRI are utilized dependent on age of the patient and neurologic symptoms. The purpose of this article is to describe the spectrum of diagnostic imaging for each of these common disorders.

Acute Disease↗

[Long-term follow-up MRI in children with craniocerebral trauma].

PURPOSE: A prospective study was initiated for the correlation of the findings in the initial cranial CT with the long-term follow-up MRI in children with severe head injury. Another aim was the evaluation of frequency and location of lesions, found only in MRI. METHODS: 70 children with severe head injury and initially performed pathological CCT were followed up (mean time 3 years) by MRI. RESULTS: 71% of the children had a pathological MRI. In 43% of the children with subdural bleeding could be found parenchymal lesions in the underlying cortex. All 15 children with epidural bleeding had unsuspicious findings at the former hematoma. All of the contusions were found as parenchymal residual lesions. 44% of the children had evidence of parenchymal lesions in the follow-up MRI initially and retrospectively not revealable. 16 lesions in the corpus callosum were only revealed by MRI. CONCLUSION: This study shows the higher sensitivity of magnetic resonance imaging in non-hemorrhagic parenchymal lesions and in "diffuse axonal injury". A MRI-examination is recommended in children with severe head injury, especially in patients with normal CCT and posttraumatic neurological deficits.

Adolescent↗

Arteriovenous fistula of the thyroid gland associated with spontaneous bleeding from a flow-induced aneurysm of the inferior thyroid artery.

A case of acute, spontaneous cervical hemorrhage caused by a ruptured aneurysm of the inferior thyroid artery is described. This lesion was accompanied by an arteriovenous fistula within the thyroid gland that caused a flow-induced aneurysm. Diagnosis and treatment were successfully performed by selective angiography with endovascular occlusion and embolization. Both diagnostic and therapeutic management are discussed, and the related literature is reviewed. To our knowledge, this is the first reported case of an aneurysm of a thyroid artery in conjunction with an intraparenchymatous arteriovenous fistula of the thyroid gland.

Aged↗

[Management of injuries of the thoracic and lumbar vertebrae in children].

Traumatic injuries of the thoracic and lumbar spine are rare in children and differ in pathomorphology, healing process and prognosis from those in adults. Before growth arrest the vertebral epiphysis has an important role in pathomorphology and prognosis; therefore, treatment should recognize the age-dependent potential for growth and remodelling. This study demonstrates the different anatomic and pathomorphologic characteristics of traumatic spinal injuries in 40 children. Additionally, prognosis and the various forms of treatment are discussed in the context of the recent literature. In total we observed 85% compression-type injuries and 15% distraction- and rotation-type injuries. Vertebral body fractures were treated conservatively and segmental disruptions by fusion. Long-term follow-up was performed on average 8 years after the accident in 26 patients clinically and in 21 patients radiologically. Most patients had no physical complaints or clinical symptoms. Additionally, the radiographs did not demonstrate any post-traumatic defects. In summary, spinal injuries up to the age of 12 without initial neurologic symptoms have a favorable prognosis.

Age Factors↗

Bone bruise of the knee: histology and cryosections in 5 cases.

We evaluated the histopathologic and cryosectional appearance of bone bruise injuries of the knee detected on MRI. Histologic evaluation of bone biopsies from 3 patients revealed microfractures of cancellous bone, edema and bleeding in the fatty marrow. Between intact lamellar bone trabecules, fragments of hyaline cartilage mixed with highly fragmented bone trabecules were found. Postmortem specimens were obtained from 2 more patients, killed in motor vehicle accidents. MRI revealed bone bruise injuries of the lateral femoral condyle and of the lateral tibial plateau in 1 knee and anterior cruciate ligament disruption, a medial meniscus tear and bone bruise injury of the tibial plateau and of the lateral femoral condyle in the other specimen. The specimens were embedded in physiologic saline solution and frozen to -30 degrees C. By rotationcryotomy, 1 mm slices were removed from the surface of the specimens and documented on photographs. Subchondral lesions and bleeding were found, corresponding to the MR images.

Adult↗

[The smart-scan procedure of spiral computed tomography. A new method for dose reduction].

PURPOSE: In this article a new method - the Smart-Scan-Technique - for dose reduction during spiral computed tomography is described. This technique allows a dynamical adaptation of the tube current according to the measured local density structure form and absorption values of the object of interest. Its clinical applicability for dose reduction is investigated. In addition, changes in image quality are evaluated. METHODS: Specially designed, water filled plexiglas-phantoms, an Alderson-Rando phantom, and 20 patients were used to simulate possible measures of patients within the thoracic and abdominal region. For those two regions the dose reduction, the modulation transfer function, and the pixel noise were measured. RESULTS: Depending on patient geometry dose reduction up to 20% could be achieved with the Smart-Scan-Technique. This technique also enabled a decrease of the modulation transfer function and an increase of the pixel noise by 8%. CONCLUSION: Relevant dose reductions can be achieved by applying the Smart-Scan-Technique in spiral computed tomography.

Absorption↗

[Dose reduction in computerized tomography with a new scan procedure].

A new investigation technique in computed tomography--the Smart Scan process--and the associated reduction in tube current are discussed. In addition, the reduced dosage values resulting from the reduced current values are compared with those of a standard measurement and image characteristics such as picture unit noise are evaluated. By means of three special water phantoms with dimensions corresponding to those of actual patient geometries and a pool of 183 patients, the Smart Scan process was tested by the control algorithm implemented on a spiral computer tomograph. The dosage values with and without the Smart Scan being activated were determined. Dosage reductions of up to 18% can be realized with this new examination technique. In particular, patients with transverse oval head profiles will benefit from this modality.

Adolescent↗

[Thoracic radiographs with the AMBER system. A comparison of the diagnostic image quality of film-screen and storage-phosphor radiographs on the grid-partition stand and the AMBER system].

Since April 1990, chest radiographs in the Mannheim clinic have been performed with a slit technique (Kodak AMBER System). In this study, image quality from conventional film/screen combination and from storage phosphor radiography was compared with that from the AMBER system. Phantoms were used to measure spatial resolution and to determine the detectability of nodules. Image quality affecting various structures within the thorax was evaluated on 200 p.a. and 48 lateral radiographs by three radiologists from Mannheim and four from Berlin. In the retrocardiac, retrodiaphragmatic, mediastinal and peripheral portions the best image quality was obtained by film/screen with the AMBER system. Compared with conventional film/screen images, there was no improvement from the AMBER system within the lung parenchyma. The use of storage phosphor plates with the AMBER system did not lead to any further improvement in image quality.

Evaluation Studies as Topic↗

[MR tomography of the bone marrow in malignant systemic diseases. Diagnosis and therapeutic follow-up control].

This paper presents a short survey of the current status of bone marrow diagnosis in systemic neoplastic disease by means of MR imaging. The different patterns of bone marrow infiltration from lymphomas and leukaemias are presented and the differential diagnoses are discussed. Apart from the primary diagnosis the relevance of conventional MRI and chemical shift imaging for therapy follow up and after-care is discussed.

Bone Marrow↗

Bioabsorbable polyglyconate interference screw fixation in anterior cruciate ligament reconstruction: a prospective computed tomography-controlled study.

PURPOSE: It was the purpose of the study to evaluate a new polyglyconate bioabsorbable interference screw for graft fixation in anterior cruciate ligament (ACL) reconstruction. TYPE OF STUDY: Prospective randomized. MATERIALS AND METHODS: Forty patients who underwent endoscopic ACL reconstruction were included in the study and randomized intraoperatively. Group A consisted of 20 patients (6 women, 14 men; mean age, 29.6 years) who had femoral bone block fixation with a bioabsorbable interference screw and tibial fixation with a titanium interference screw. Group B included 20 patients (5 women, 15 men; mean age 29.6 years) who had fixation of both femoral and tibial bone blocks with titanium interference screws. There was no significant difference between the groups with regard to age, gender, height, weight, time from injury to surgery, activity level, and concomitant injuries. RESULTS: Clinical results (using IKDC, Lysholm, Tegner scores) of the 2 groups as well as instrumented laxity measurements (KT-1000) did not show significant (P >.05) differences at any stage of follow-up. No complications with respect to graft fixation could be found. Computed tomography scans, performed within the first postoperative week, at 6 weeks, and at 3, 6, 12, and 24 months postoperatively revealed a uniform picture for all patients within the groups, showing completed screw degradation at 12 months in group A. CONCLUSION: Polyglyconate interference screw fixation for patellar tendon grafts has not been found to be associated with increased clinical complications or significant osteolysis. It provided equivalent fixation and clinical results compared with titanium screws. However, replacement of the screw with bone did not take place for up to 3 years postoperatively.

Absorbable Implants↗

US of the spinal cord in newborns: spectrum of normal findings, variants, congenital anomalies, and acquired diseases.

Ultrasonography (US) of the spinal cord is performed in newborns with signs of spinal disease (cutaneous lesions of the back, deformities of the spinal column, neurologic disturbances, suspected spinal cord injury due to traumatic birth, and syndromes with associated spinal cord compression). The examination is performed with high-frequency linear- and curved-array transducers in the sagittal and axial planes from the craniocervical junction to the sacrum. Normal variants such as transient dilatation of the central canal and ventriculus terminalis can be demonstrated with US. US allows detection of congenital malformations, such as myelocele or myelomeningocele, spinal lipoma, dorsal dermal sinus, tight filum terminale syndrome, diastematomyelia, terminal myelocystocele, lateral meningocele, caudal regression syndrome, and hydromyelia or syringomyelia. Acquired intraspinal diseases following birth trauma and transient alterations after lumbar puncture can also be detected with US. US can demonstrate the entire spectrum of intraspinal anatomy and pathologic conditions with high geometric resolution. Therefore, US should be considered the initial imaging modality of choice for investigating the spinal cord in newborns.

Birth Injuries↗