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R Andresen

Publications and source records attributed to R Andresen.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Bone density of spongiosa and cortical bone of the lumbar spine. Relations to sex, age and spinal deformities in a regional collective of the European Study of Vertebral Osteoporosis (EVOS)].

BACKGROUND AND METHOD: In an additional bone density measurement protocol to the European Vertebral Osteoporosis Study (EVOS) separate spongious and cortical density measurements (sQCT) were carried out at the first 3 lumbar vertebrae in 293 volunteers (92 men and 201 women) in 3 Berlin regional centers. RESULTS: The spongious mineral density decreases from proximal to distal (L1 to L3), the cortical density increases from proximal to distal, mainly in men. Men showed no significant decrease of cortical density and a lower decrease of spongious density with age compared to women. A comparison of bone mineral density with vertebral height indices of McCloskey/Kanis, Eastell/Melton and Felsenberg showed significant differences of spongious density between a group with normal vertebral height and a group with at least one pathologically degraded vertebra. Individuals with osteoporosis according to the WHO-definition showed a higher prevalence of vertebral deformities. No significant loss of cortical density was observed in these people.

Age Factors↗
PubMed1998

Testicular microlithiasis and concomitant testicular intraepithelial neoplasia.

We report a case of testicular microlithiasis developing during cancer follow-up in a previously normal testicle. Biopsy revealed testicular intraepithelial neoplasia which was treated with radiotherapy. We believe that especially in cancer follow-up newly developing microlithiasis must lead to biopsy to rule out otherwise undetectable germ cell neoplasia precursor.

Adult↗
PubMed1998

[The imaging of hamate fractures in the conventional X-ray and CT: experimental results and clinical experiences].

PURPOSE: Examination of the ability to image fractures of the body and hook of the hamate bone in conventional X-rays and HR-CT. MATERIAL AND METHODS: In an in vitro experiment on 18 cadaver hands, the hamate bone was fractured at different localisations. Before and after fracture, conventional x-rays were taken in different projectional planes: a.-p., lateral, oblique and carpal tunnel view, as well as an HR-CT with 2 mm layer thickness in the axial, sagittal and coronal plane. In addition, 15 clinically verified hamate bone fractures (two body and 13 hook of hamate fractures) were reviewed retrospectively to assess the value of the imaging procedures that led to diagnosis. RESULTS: Taking into account all conventional x-ray projections applied, the in vitro experiment yielded a sensitivity of 72.2%, a specificity of 88.8% and an accuracy of 80.5%. For CT, the sensitivity was 100%, the specificity 94.4% and the accuracy 97.2%. In retrospective clinical evaluation, 60% of the existing fractures were identified in the conventional x-ray images. The remaining fractures were detected by additional procedures like scintigraphy, conventional tomography and CT. CONCLUSION: For the diagnosis of fractures of the body and hook of the hamate HR-CT is the imaging procedure of choice, in which case an axial or sagittal plane should be chosen.

Adult↗
PubMed1998

Bone mineral density and spongiosa architecture in correlation to vertebral body insufficiency fractures.

OBJECTIVE: The clinical value of spinal quantitative CT (sQCT) and the structural patterns of the vertebral bone were studied. MATERIAL AND METHODS: sQCT was performed on 246 patients with a mean age of 57 years for whom conventional lateral radiographies of the thoracic and lumbar spine were available. All patients were suffering from back pain of unknown etiology. The bone mineral density (BMD) of the midvertebral section of 3 lumbar vertebral bodies was determined by means of single-energy-(SE)-weighted QCT (85 kV). Spongiosa architecture and density profile analyses were made in the axial images. This was contrasted to BMD values ascertained in SE QCT. The mean BMD was compared to the number of fractures and the patients were divided into three groups: group I--no fracture; group II--one fracture; and group III > 1 fracture. RESULTS: The mean BMD was: 134.3 (74.1-187.5) mg hydroxyapatite (HA)/ml in group I; 79.6 (58.6-114.3) mg HA/ml in group II; and 52.4 (13.1-79.1) mg HA/ml in group III. A significant deterioration in spongiosa structure was found with increasing demineralization: strongly rarefied patterns predominated in the fracture groups II and III. CONCLUSION: sQCT provides a good risk assessment of the occurrence of vertebral body insufficiency fractures.

Adult↗
PubMed1998

Intra- and infrahepatic agenesis of the inferior vena cava with azygos continuation accompanied by duplication of the postrenal segment.

Agenesis of one or more segments and duplication of the infrarenal segment are, individually, rare abdominal variants of the inferior vena cava (IVC). In this article, the authors report on a case in which these two anomalies occurred concurrently. Details of the embryology are presented insofar as they are necessary for an understanding of this IVC variant. Spiral computed tomography makes it possible to define the vascular morphology and to make a differentiation from lymphadenopathy. Cavography gives an overall picture of the vascular morphology.

Abnormalities, Multiple↗
PubMed1998

Imaging modalities in Peyronie's disease. An intrapersonal comparison of ultrasound sonography, X-ray in mammography technique, computerized tomography, and nuclear magnetic resonance in 20 patients.

OBJECTIVE: Peyronie's disease is an ill-understood condition afflicting men in their 40s with the reported age ranging from 18 to 68 years. It is characterized by a plaque in the tunica albuginea which leads to penile deformity making sexual intercourse difficult if not impossible and is often accompanied by severe pain upon erection in the early stage; erectile dysfunction is present in about 2% of cases. Diagnosis rests upon medical history, clinical examination with plaque palpation and autophotography in two planes. These diagnostic steps are not plaque-specific and therefore we wanted to assess which imaging modalities would allow for an objective determination of the plaque status. MATERIALS AND METHODS: We evaluated 20 patients with Peyronie's disease. All patients underwent clinical examination including autophotography and the subsequent use of the following imaging techniques: (1) ultrasound (US) using a 7.5-MHz transducer with a profile for semiquantitative density analysis; (2) X-ray in mammography technique in two planes; (3) computerized tomography (CT) with a density profile, and (4) magnetic resonance imaging (NMR). RESULTS: (1) Degree of deviation: Penile deviation ranged from 15 degrees to 63 degrees. It was best assessed using radiography in mammography technique reflecting the results obtained by autophotography. (2) Calcifications: Plaque calcifications were seen in 12 patients, 8 had no calcifications but thickening of the tunica albuginea only, 2 also had a fibrosis of the corpus cavernosum distant to the plaque. Calcifications were visualized using ultrasound sonography (12/12), radiographically (12/12), CT (12/12), NMR (9/12). Thickening of the tunica albuginea only was visualized using ultrasound sonography (7/8), radiographically (0/8), CT (2/8), NMR (6/8). (3) Morphological pattern in ultrasound: Three distinct patterns could be detected: (type 1) the plaque appeared as a thickening of the tunica albuginea without acoustic shadowing and only minimal density increase in the histogram profile; (type 2) moderately calcified plaque with typical ultrasound shadow but minimal density increase in the density profile; (type 3) severely calcified plaque with typical acoustic shadowing and density increase in the histogram profile. (4) Plaque inflammation: Only NMR with gadolinium DTPA showed periplaque inflammation. CONCLUSIONS: High-resolution ultrasound sonography is the best imaging modality in assessment of plaques. NMR is the modality of choice to monitor the inflamed plaque. X-ray in mammography technique and CT are not necessary in daily routine.

Calcinosis↗
PubMed1998

Contribution of the cortical shell of vertebrae to mechanical behaviour of the lumbar vertebrae with implications for predicting fracture risk.

In the diagnosis of osteoporosis using single energy quantitative CT (SE-QCT) on the axial skeleton, only spongy bone mineral density (BMD) is used at present. Although the density of cortical bone is also determined by most QCT methods, it is not used for evaluation. The objective of this study was to determine the extent to which the cortical bone of the lumbar vertebral bodies accounts for their load-bearing capacity and failure behaviour, and to use this information to suggest improvements in the differential diagnosis of osteoporosis. Investigations were conducted in a clinical, theoretical-numerical and biomechanical-experimental context. Cortical (BMDC) and spongy (BMDS) bone mineral density was measured by SE-QCT/85 kV on 179 patients (68 males, 111 females). These bone densities were matched with the vertebral body fractures previously determined from conventional X-rays. A finite element model was used to study the variation in structural and material parameters of the vertebral body. 19 vertebral bodies that had been removed post-mortem were available for the biomechanical-experimental investigations. Spongy and cortical bone densities were also determined by SE-QCT on these vertebral bodies. Their failure load was then measured in the axial compression test. These investigations show that, in addition to the spongiosa, the cortical shell plays an important role in the load-bearing capacity of the vertebral body. If the spongiosa is weakened due to a loss of BMD, the residual load-bearing capacity of the vertebral bodies is increasingly shouldered by the cortical bone. The lower susceptibility to fracture in men compared with women when spongy bone mineral density is reduced can thus be attributed to the lack of a reduction in cortical bone mineral density. It is recommended that the BMDC also be evaluated in future, especially in the diagnosis of bone mass losses in women, to improve the estimation of the individual fracture risk.

Adult↗
PubMed1998

Noninvasive assessment of stiffness and failure load of human vertebrae from CT-data.

A calculational method based on noninvasively derived data for the assessment of the mechanical quality of individual vertebrae is presented. Dimensional data obtained from serial, segmented CT scans were used as the geometric input for a newly developed finite element model designed to calculate stiffness and failure load of these complex bone structures. Mechanical, structural data for cancellous bone was obtained by measurements of the compressive strength and failure load of actual vertebral specimens obtained at autopsy. The stiffness and failure load calculated by the newly developed finite element model were compared with the data obtained from mechanical measurements of vertebral specimens. A high correlation between measured and calculated failure load was found (r = 0.89, p < 0.001, n = 16). The correlation between the failure load and bone mineral density (BMD) was significant (r = 0.82, p < 0.001, n = 16). A similar correlation between calculated and measured stiffness (r = 0.81, p < 0.001, n = 15) was also found using the finite element model described herein. Thus the newly developed calculation methodology has been verified and can be used to predict the failure load and stiffness of osteoporotic vertebrae using data obtained non-invasively from CT scans.

Adult↗
PubMed1998

Detection of ankle effusions: comparison study in cadavers using radiography, sonography, and MR imaging.

OBJECTIVE: The purpose of this study was to compare radiography, sonography, and MR imaging in revealing ankle effusions in cadaveric specimens. MATERIALS AND METHODS: Known quantities of saline solution were instilled in increments into the ankle joints of three cadaveric specimens. Imaging was completed after each injection with the ankle in dorsiflexion, plantar flexion, and a neutral position. Imaging included radiography, sonography, and MR imaging. Three observers who were aware of possible joint fluid evaluated the images by consensus and determined the presence or absence of joint effusion. RESULTS: MR imaging revealed 1 ml of fluid within the anterior recess of the ankle in a neutral position and in plantar flexion and within the posterior recess in dorsiflexion. Sonography revealed 2 ml of fluid within the anterior recess in a neutral position and in plantar flexion. Radiography revealed 5 ml of fluid within the anterior recess in a neutral position. CONCLUSION: MR imaging, sonography, and lateral radiography, in order of decreasing sensitivity, revealed ankle effusion. The power to reveal with each technique is influenced by the precise position of the ankle.

Adipose Tissue↗
PubMed1998

[Right-sided double inferior vena cava and common iliac vein: imaging with spiral computerized tomography].

Duplications of the inferior vena cava (IVC) are rare variants of the abdominal vessels and are normally located on both sides of the abdominal aorta. The rare case of a rightsided infrarenal duplication of the IVC with involvement of the common iliac vein is reported. Details of the embryology are presented for the understanding of this IVC variant. The spiral CT with multiplanar reconstructions makes it possible to define the vascular morphology and to differentiate it from lymphoma.

Adult↗
PubMed1997

Lung torsion--a rare postoperative complication. A case report.

Lung or lobe torsion is a rare condition that must be included in the differential diagnosis when a partial or complete shadow is detected on the lung. We report a case of this rare complication after chest surgery. The bedside radiograph provided initial evidence of torsion. CT verified the diagnosis of lower lobe torsion. Prompt recognition and intervention is imperative in order to save the affected lung.

Aged↗
PubMed1997

Assessment of the penile vascular system with color-coded duplex sonography and pharmacocavernosometry and -graphy in impotent men.

OBJECTIVE: To examine the extent to which color-coded duplex sonography permits complete clarification of vessel-dependent erectile dysfunction (ED). MATERIAL AND METHODS: A total of 215 patients with ED were examined. All patients underwent pharmacocolor-coded duplex sonography (PHCCDS; 20 micrograms of prostaglandin E1, PGE1, intracavernosally) as well as pharmacocavernosometry and -graphy (PHCM and PHCG; 20 micrograms of PGE1 intracavernosally). The penile vessels were visualized, i.e. the dorsal arteries, the cavernosal arteries, and the anastomoses between them, as well as the venous pathways. Peak flow and end-diastolic flow in all arteries and, when present, anastomoses were determined after stimulation. Induction flow to achieve maximal tumescence/rigidity as well as maintenance flow were determined during PHCM. Finally, for the morphological visualization of the cavenous body and possible venous insufficiencies, a radiography in 2 planes was produced with infusion of a water-soluble contrast medium. RESULTS: In 145 patients with a grade 0-III tumescence after stimulation with 20 micrograms of PGE1, PHCCDS revealed an end-diastolic flow of > 5 cm/s, with a peak flow velocity > 25 cm/s in the 2 cavernosal and 2 dorsal arteries. The deep dorsal vein of the penis was visualized in 110 of these 145 patients with a blood flow > 5 cm/s, and in 35 cases with a blood flow < 5 cm/s. Venous drainage to the corpus spongiosum was visualized in 80 patients with a blood flow > 10 cm/s. All patients had a pathologically increased induction (normal value < 100 ml/min) and maintenance venous flow (normal value < 10 ml/min) in the PHCM as well as venous drainage in the PHCG. Sixty patients with a tumescence grade of IV-V (rigidity) had a peak flow velocity clearly > 25 cm/s, an end-diastolic flow < 5 cm/s in the 2 cavernosal and 2 dorsal arteries in the PHCCDS, as well as induction values < 100 ml/min and maintenance flow values < 10 ml/min in the PHCM, without visible insufficient efferent venous pathways on the PHCG. In 29 patients (13.5%) hemodynamically active anastomoses perforating the tunica albuginea could be detected. Ten patients with a tumescence grade of III had a peak flow velocity < 25 cm/s and an end-diastolic flow < 5 cm/s without venous leakage in PHCM and PHCG. CONCLUSION: PHCCDS allows for the assessment of arterial flow disorder as well as of venous leakage in ED. PHCM and PHCG should only be carried out in patients in whom surgical or radiological interventional procedures at the efferent venous pathways are planned.

Alprostadil↗
PubMed1997

Dual-energy X-ray absorptiometric densitometry in osteoarthritis of the hip. Influence of secondary bone remodeling of the femoral neck.

PURPOSE: The aim of this study was to evaluate the influence of buttressing on bone densitometry measurements in the femoral neck, in Ward's triangle, and in the greater trochanter. In addition, we attempted to establish the length of the femoral axis (FAL) and the true length of the femoral neck (FNL) as potential correlates with osteoarthritis (OA) or with buttressing. MATERIAL AND METHODS: Our study comprised 101 hips in 68 adult patients. Conventional radiographs of the hip joints were obtained in order to assess the presence and extent of OA by means of the 6-step grading system introduced in 1990 by CROFT et al., and in order to measure the cortical thickness at the medial aspect of the femoral neck. In addition, FAL and FNL were measured. All patients underwent dual energy x-ray absorptiometry so that bone density could be assessed in the femoral neck, in Ward's triangle, and in the greater trochanter. The Spearman rank correlation was used to compare the measurements. RESULTS: Statistical analysis showed a significant positive correlation between cortical thickness and bone density in the femoral neck and in Ward's triangle. No correlation was found between cortical thickness and bone density in the greater trochanter, nor between cortical thickness and OA, FNL, and FAL, nor between OA and bone density, FNL, and FAL. CONCLUSION: Buttressing influenced our bone density measurements in the femoral neck and in Ward's triangle. It did not affect the region of the greater trochanter which may therefore be the best region of interest for a long-term follow-up of bone density in patients with OA.

Absorptiometry, Photon↗
PubMed1997

Intravenous urography revisited in the age of ultrasound and computerized tomography: diagnostic yield in cases of renal colic, suspected pelvic and abdominal malignancies, suspected renal mass, and acute pyelonephritis.

The aim of our study was to assess the diagnostic yield of intravenous urography (IVU) compared to ultrasound (US) and computerized tomography (CT) in cases of renal colic, suspected pelvic and abdominal malignancies, suspected renal mass, and acute pyelonephritis. We retrospectively analyzed the case charts of 216 consecutive patients. The patients had been referred to the Department of Radiology by different hospital departments and local general practitioners. All had undergone clinical examination, US and IVU, in that order. When deemed necessary, conventional tomography was performed. Patients with renal masses also underwent CT. In cases without renal colic and normal US examination, the subsequent IVU failed to detect any further important pathology. Hydronephrosis was equally well detected using US and IVU, however, the level of obstruction was better determined using delayed X-ray films. In 24% of cases of renal colics the initial US was normal, however, the IVU revealed ureteric obstruction. Repeat US 8-12 h later always showed hydronephrosis. In 6 of 34 solid renal masses, IVU and conventional tomography failed to make the correct diagnosis, but never could the patient be spared a subsequent CT. IVU is only indicated if US shows hydronephrosis. In cases of renal colic, repeat US is necessary to diagnose the possibly developing hydronephrosis. Clinical history, US and a plain abdominal image will suffice to make the diagnosis. Renal masses always require CT. In these cases, IVU is not necessary. There is no indication left for conventional renal tomographies.

Abdominal Neoplasms↗
PubMed1997

Leydig cell tumor--comparison of results of radical and testis-sparing surgery in a single center.

Between January 1981 and December 1995, 15 patients were treated for Leydig cell tumor at our institution -- 12 by radical orchiectomy, 3 by tumor enucleation. All patients were contacted to assess the long-term outcome depending on the treatment initially chosen. Follow-up ranged from 8 to 161 months (mean 56). In no case was progressive disease documented, in 1 case local recurrence was witnessed 4 months after tumor enucleation despite negative resection margins. We conclude that a small Leydig cell tumor can safely be managed by local enucleation alone.

Adult↗