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1.
Eur J Orthop Surg Traumatol ; 29(1): 169-173, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29931529

RESUMO

The absence of osseous consolidation of a fracture for 9 or more months with no potential to heal is defined as nonunion. Both for the patient and from a socioeconomic point of view, nonunions represent a major problem. Hypertrophic, vital nonunions are distinguished from atrophic avital ones. Risk factors for a delayed fracture healing are insufficient immobilisation, poor adaptation of the fracture surfaces or residual instability, interposition of soft tissue within the fracture gap, as well as circulation disturbances and infections. The incidence of nonunions after fractures of the long bones lies between 2.6 and 16% depending on the surgical technique used. In human and animal studies, a positive effect of parathyroid hormone (PTH) on fracture healing has been shown. PTH has a direct stimulatory effect on osteoblasts and osteoclasts. In addition, it appears to influence the effect of osseous growth factors. In this prospective study, 32 patients with nonunions were treated with teriparatide to investigate the effects of PTH on fracture healing. Definitive healing of the nonunions following PTH treatment could be observed in 95% of the cases.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Consolidação da Fratura/efeitos dos fármacos , Fraturas não Consolidadas/tratamento farmacológico , Teriparatida/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Uso Off-Label , Estudos Prospectivos , Adulto Jovem
2.
Unfallchirurg ; 119(11): 929-935, 2016 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-25681131

RESUMO

INTRODUCTION: Sacral insufficiency fractures are often overlooked and lead to severe therapy-resistant pain. These fractures can be most sensitively detected with magnetic resonance imaging (MRI). Similar to balloon kyphoplasty, sacroplasty provides fixation of these fractures with cement. OBJECTIVES: This study was carried out to investigate whether pain is reduced using this method and whether computed tomography (CT)-guided cement application results in less cement extravasation and fewer complications than C-arm controlled application. MATERIAL AND METHODS: In a retrospective multicenter study, 46 patients (41 female, 5 male) with an average age of 75 years were treated by sacroplasty. The procedure was performed with CT-guidance for 25 patients and with C-arm control for 21 patients. Pain was evaluated using a visual analog scale. Patients were followed up for 6 months. RESULTS: The average operation time was 35 min and postinterventional hospital stay averaged 4 days. In the CT group pain decreased from an average score of 8.8 ± 0.7 preoperatively to 2.6 ± 0.6 postoperatively (p < 0.001) and in the C-arm group pain decreased from 8.2 ±1.0 to 2.2± 1.4 (p < 0.001). There were no cases of cement extravasation in the CT group (0 out of 25 = 0 %) and 8 asymptomatic cases in the C-arm group (8 out of 21 = 38 %). In addition, there were two injuries to the superior gluteal artery with hematoma in the area of puncture, one requiring operative treatment. There were two mortalities in the CT group from lung disease and stroke during the study but this was unrelated to the operation. CONCLUSION: Balloon sacroplasty results in a reliable and significant reduction in pain for sacral insufficiency fractures. The C-arm controlled cement application resulted in more frequent extravasation and complications than CT-guided application.


Assuntos
Fraturas de Estresse/terapia , Cifoplastia/métodos , Dor Lombar/prevenção & controle , Sacro/lesões , Fraturas da Coluna Vertebral/terapia , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Fraturas de Estresse/complicações , Fraturas de Estresse/diagnóstico por imagem , Humanos , Dor Lombar/diagnóstico , Dor Lombar/etiologia , Masculino , Pessoa de Meia-Idade , Sacro/diagnóstico por imagem , Sacro/cirurgia , Fraturas da Coluna Vertebral/complicações , Fraturas da Coluna Vertebral/diagnóstico por imagem , Cirurgia Assistida por Computador/métodos , Resultado do Tratamento
3.
Z Gastroenterol ; 51(7): 635-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23839916

RESUMO

We present a case of late breast cancer metastasis over 15 years since the initial diagnosis which was highly unusual because of its solitary aspect with no other evidence of the disease and its uncommon localization in the esophagus. With a history of breast cancer, several differential diagnoses for suspicious space-occupying masses need to be considered, like radiation-induced cancer or multiple neoplasm. A multimodal diagnostic approach can lead to the correct diagnosis. Endoscopy, endoscopic ultrasound (EUS) including EUS-guided fine-needle aspiration (FNA), CT and PET/CT findings are provided.


Assuntos
Neoplasias da Mama/diagnóstico , Carcinoma/diagnóstico , Carcinoma/secundário , Neoplasias Esofágicas/diagnóstico , Imagem Multimodal/métodos , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X/métodos , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/métodos , Feminino , Humanos , Pessoa de Meia-Idade
4.
J Clin Densitom ; 15(4): 443-453, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22521540

RESUMO

This study reports gender-specific vertebral area gain data from children and adolescents. Vertebral area was measured on lateral and anteroposterior thoracic and lumbar spine radiographs from 100 female and 100 male subjects aged 7-28 yr. T9, T11, T12, L1, and L2 X-ray area calculation was based on calculation of the area of the geometric figure of a trapezoid whose 2 nonparallel sides were equal in length, taking account of the waisted shape of the vertebrae. Both the boys and girls of our study population showed statistically significant dependence (p<0.001) of vertebral area gain on chronologic age, height, and weight right through the end of puberty, and especially so up to age 15 yr. However, height and weight were clearly better predictors of lateral and anteroposterior vertebral area gain than was chronologic age. Once vertebral growth is complete by age 18 yr or so, the lateral vertebral areas of the male subjects-regardless of body weight and height-are, on average, 25% larger, and the anteroposterior areas up to 30% larger than those of their female counterparts. After adjusting for chronologic age, height, and weight however we did not find significant differences, between gender, in vertebral area of male and female subjects, neither among children younger than 11 yr nor adolescents ages of 12-14 yr and young adults older than 18 yr.


Assuntos
Absorciometria de Fóton/métodos , Envelhecimento/fisiologia , Estatura , Peso Corporal , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/crescimento & desenvolvimento , Adolescente , Adulto , Densidade Óssea , Criança , Feminino , Humanos , Masculino , Valores de Referência , Fatores Sexuais , Adulto Jovem
5.
Unfallchirurg ; 114(11): 1035-40, 2011 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-21909733

RESUMO

Kyphoplasty is an established procedure for the treatment of osteoporotic vertebral compression fractures. Developments in instrumentation and techniques have facilitated its use also for other localizations. In the hands of experienced practitioners smaller working cannulas and balloons have made successful treatment of high thoracic and cervical fractures and metastases possible. Balloon kyphoplasty performed for sacral insufficiency fractures in older patients plagued by chronic pain leads to marked pain reduction as well as faster weight-bearing. There are also early research results regarding the repair of tibial head defects and reinforcement with resorbable cement. These new procedures, which are currently applied by only a few surgeons, will be introduced and described in a case-specific manner.


Assuntos
Medicina Baseada em Evidências , Fraturas por Compressão/terapia , Cifoplastia/tendências , Osteoporose/terapia , Fraturas da Coluna Vertebral/terapia , Humanos
6.
Science ; 225(4658): 177-9, 1984 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-17837931

RESUMO

The payload complement on Spacelab 1 included a spectrometer for observations of the brighter cosmic x-ray sources. The primary scientific objective was to study the detailed spectral features of cosmic x-ray sources and their associated temporal variations over a wide energy range from about 2 to 80 kiloelectron volts. The instrument, based on the gas scintillation proportional counter, had a geometrical area of some 180 square centimeters with an energy resolution of about 9 percent at 7 kiloelectron volts. The results presented here show new results from two galactic binary x-ray sources, Cygnus X-3 and Centaurus X-3, and from the Perseus cluster of galaxies. The excellent energy resolution of the instrument permits line features to be identified in these sources with unprecedented quality.

7.
Sportverletz Sportschaden ; 23(1): 35-40, 2009 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-19306235

RESUMO

AIM: Also after bagatelle trauma, some patients can develop a complex regional pain syndrome (CRPS). The limb concerned usually shows a marked temperature difference to the contralateral side. Apart from a doughy swelling, the patient is impaired in particular by burning pain and a restricted range of motion. The objective of the present study was to examine the influence of early thoracic sympathetic nerve blockade on the basis of clinical and quantified blood flow parameters. METHODS: In 7 young patients (average age 17.7 [15 - 21] years) with a clinically developing type 1 CRPS after sport injuries (mountain bike, bike, skateboard, hockey and go-kart accidents), occult injury and ligament lesions were ruled out using conventional imaging and MRI. In addition to pain-adapted physiotherapy and pharmacotherapy with analgesics and calcitonin, sympathetic nerve blockade was performed three times at two-day intervals. The CT-assisted puncture was performed in the prone position at the level of the intervertebral space of the 2nd/3 rd thoracic vertebral bodies. In the correct paravertebral position, a 10-cm long, 22 G Seibel-Grönemeier needle was used for the successive injection of 6 - 10 ml Carbostesin 0.5 %. By adding a small amount of contrast medium, it was possible to visualise clearly the distribution of the sympathicolytic agent in the control scan in each case. Before and after the intervention, colour-coded duplex sonography (CCDS) of the affected limb arteries was performed on all patients. RESULTS: The injection needle was correctly placed in all patients, without complications. The medication mixture was observed to have distributed properly. After the intervention, all patients reported the immediate onset of marked pain relief, whereby they recovered fully over the further course. The increase in peripheral blood flow was shown by a significant improvement in flow in the CCDS. CONCLUSION: Outpatient CT-assisted temporary sympathetic nerve blockade is an effective and low-complication therapeutic option for the supportive treatment of patients with CRPS.


Assuntos
Anestésicos Locais , Traumatismos em Atletas/terapia , Bloqueio Nervoso Autônomo , Bupivacaína , Traumatismos da Mão/terapia , Cirurgia Assistida por Computador , Tomografia Computadorizada por Raios X , Adolescente , Feminino , Mãos/irrigação sanguínea , Humanos , Masculino , Medição da Dor , Distrofia Simpática Reflexa , Fluxo Sanguíneo Regional/efeitos dos fármacos , Vértebras Torácicas , Adulto Jovem
9.
Handchir Mikrochir Plast Chir ; 38(5): 273-82, 2006 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-17080342

RESUMO

PURPOSE: Hamate hook fractures can be treated conservatively or surgically, whereby fragment and fracture position, age of the fracture, associated injuries, and individual needs of the patient all influence the choice of the therapeutic procedure. Acute non-displaced fractures are frequently treated conservatively, while displaced fractures and nonunions undergo surgical treatment. We report our experience in diagnostic and therapeutic management of 14 hamate hook fractures. CLINICAL MATERIAL AND METHOD: During a three-year period, 14 patients (eleven men and three women) 21 to 73 years old (42.0 +/- 17.9 years) with fractures at the base of the hamate hook were treated at three hand surgery units. The retrospective study of all patients included a chart review, postoperative radiological imaging after one year, and clinical examinations with grip strength measurements after 18 to 34 months (27.8 +/- 4.9 months). In six patients (43 %), the acute fracture was immobilized in a lower arm cast for six weeks, while eight patients (57 %) were operated primarily. In five cases (36 %) excision of the fragment and in three cases (21 %) open reduction and internal fixation using a screw were performed. Of six patients treated conservatively, five developed nonunion after two to five months (3.0 +/- 1.2 months) with persistent pain and underwent secondary surgery. One patient was asymptomatic despite a nonunion and declined surgical treatment. In three cases the fragment was excised, while two patients underwent open reduction and internal fixation with a screw. RESULTS: All patients operated primarily were free of complaints three months after surgery. The success rate of surgical treatment (8/8) was therefore significantly higher than that after conservative treatment (1/6). CONCLUSION: Compared to conservative treatment of acute non-displaced hamate hook fractures, which is associated with a high risk of developing symptomatic nonunion, primary surgical treatment reliably yields a good clinical outcome. Here, results after fragment excision and open reduction and internal fixation are comparable.


Assuntos
Fraturas Ósseas/cirurgia , Fraturas Cominutivas/cirurgia , Hamato/lesões , Adulto , Idoso , Parafusos Ósseos , Feminino , Fixação Interna de Fraturas , Consolidação da Fratura/fisiologia , Fraturas Ósseas/diagnóstico por imagem , Fraturas Cominutivas/diagnóstico por imagem , Hamato/diagnóstico por imagem , Hamato/cirurgia , Força da Mão/fisiologia , Humanos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
10.
Rofo ; 188(10): 926-32, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27529397

RESUMO

PURPOSE: The exact etiology of mesenteric panniculitis (MP) is still unknown and has been discussed in relation to different causes. The aim of this retrospective study was to evaluate a coherence between MP and malignancy. MATERIALS AND METHODS: Retrospective analysis of consecutive CT abdomen examinations of 5595 patients in terms of MP over a period of 3 years was performed. To make the diagnosis of MP, three of five typical signs were obligatory: hyperdense mass lesion with intercalated nodules, a "fat-ring sign" or halo sign, a hyperdense pseudocapsule and displacement of bowel loops. The patient cohort (mean age: 64.7 years) consisted of 1974 (35.2 %) patients with histologically confirmed cancer and 3621 patients (64.8 %) without known underlying oncological disease. RESULTS: A total of 143 cases were diagnosed with MP (2.55 %). The average age of patients was 69.9 years with a male to female ratio of 2:1. In this group oncological disease was confirmed in 107 patients (74.8 %). In 36 patients with MP (25.2 %), no malignancy was present. In the group of patients with an underlying oncological disease, the prevalence of MP was 5.42 % and was significantly higher (p < 0.005) than in the patients with MP and without an oncological disease. The highest prevalence of MP (29 cases) was observed in non-Hodgkin lymphoma (22.6 %). The statistically calculated risk of a tumor disease in this collective is about 5 times higher if MP was demonstrated (p < 0.001). CONCLUSION: Based on the data of the collective, the risk of malignancy is five times higher in the presence of MP than in an inconspicuous mesentery. MP seems to frequently occur with non-Hodgkin lymphoma. MP can be seen on the basis of typical morphological features on the CT image. MP must be differentiated from a wide range of benign and malignant diseases of the mesentery. KEY POINTS: • Mesenteric panniculitis can be diagnosed with CT.• In the case of accidentally diagnosed mesenteric panniculitis, a possible malignant cause should be ruled out in the differential diagnosis. Citation Format: • Scheer F, Spunar P, Wiggermann P et al. Mesenteric Panniculitis (MP) in CT - A Predictor of Malignancy?. Fortschr Röntgenstr 2016; 188: 926 - 932.


Assuntos
Paniculite Peritoneal/diagnóstico por imagem , Paniculite Peritoneal/epidemiologia , Neoplasias Peritoneais/diagnóstico por imagem , Neoplasias Peritoneais/epidemiologia , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Causalidade , Criança , Pré-Escolar , Comorbidade , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Adulto Jovem
11.
Invest Radiol ; 33(2): 113-6, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9493727

RESUMO

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.


Assuntos
Anormalidades Múltiplas/diagnóstico por imagem , Veia Ázigos/anormalidades , Rim/irrigação sanguínea , Fígado/irrigação sanguínea , Veia Cava Inferior/anormalidades , Anormalidades Múltiplas/cirurgia , Adulto , Veia Ázigos/diagnóstico por imagem , Veia Ázigos/cirurgia , Diagnóstico Diferencial , Feminino , Humanos , Flebografia , Tomografia Computadorizada por Raios X , Veia Cava Inferior/diagnóstico por imagem , Veia Cava Inferior/cirurgia
12.
Invest Radiol ; 34(1): 46-50, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9888053

RESUMO

RATIONALE AND OBJECTIVES: To examine the ability to image fractures of the body and hook of the hamate bone in conventional X-rays and high-resolution computed tomography (HR-CT). MATERIALS AND METHODS: In an in vitro experiment using 18 cadaver hands, the hamate bone was fractured at different places. Before and after fracture, conventional X-rays were taken in different planes (anteroposterior, lateral, oblique, and carpal tunnel), and HR-CT was performed with 2-mm layer thickness in the axial, sagittal, and coronal plane. RESULTS: Taking into account all the conventional X-ray projections applied, the in vivo experiment revealed a sensitivity of 72.2%, a specificity of 88.8%, and an accuracy of 80.5%. For the HR-CT, the sensitivity was 100%, the specificity was 94.4%, and the accuracy was 97.2%. CONCLUSIONS: Fractures of the body and hook of the hamate cannot always be detected with certainty in the conventional X-ray image, even if different projectional planes are used. The HR-CT is the imaging procedure of choice for further clarification, and an axial or sagittal plane should be selected.


Assuntos
Ossos do Carpo/diagnóstico por imagem , Ossos do Carpo/lesões , Fraturas Ósseas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Cadáver , Reações Falso-Negativas , Reações Falso-Positivas , Traumatismos da Mão/diagnóstico por imagem , Humanos , Pessoa de Meia-Idade , Variações Dependentes do Observador , Sensibilidade e Especificidade
13.
Invest Radiol ; 34(9): 572-8, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10485072

RESUMO

RATIONALE AND OBJECTIVES: Osteoporosis is characterized by a loss of bone mineral density and deterioration of structure. The authors present a structural parameter for the quantitative assessment of osteoporotic changes in vertebral bone. METHODS: In 40 patients without or with known osteoporotic fractures, spongiosa and cortical bone mineral density was measured in lumbar vertebrae 1 to 3 by quantitative CT. Additional axial high-resolution CT slices were obtained for the structural analysis. In the spongiosa, the gray-value profile along a horizontal line in the CT slice was used, whereas in the cortical shell a profile was obtained from the cortical ridge. Both profiles were intersected with a horizontal line of variable position, and the maximum number of intersections was determined. RESULTS: The maximum number of intersections is significantly higher in cases with fractures (spongiosa 48.6, cortical shell 77.3) than in cases without fractures (spongiosa 42.1, cortical shell 62.4). It also correlates with bone mineral density and age. CONCLUSIONS: The presented method shows significantly different numeric results for patients with and without osteoporotic fractures. The analysis is easy to perform and provides additional information on the bone structure that may be used in combination with bone mineral density measurements.


Assuntos
Doenças Ósseas Metabólicas/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Osteoporose/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Densidade Óssea , Doenças Ósseas Metabólicas/metabolismo , Feminino , Humanos , Vértebras Lombares/metabolismo , Pessoa de Meia-Idade , Osteoporose/metabolismo , Índice de Gravidade de Doença
14.
Psychiatry Res ; 83(2): 75-84, 1998 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-9818733

RESUMO

A new method is introduced to project the sulcal pattern of the brain surface onto a 2D plane. Twin brains are compared against each other using the planar representation. We obtained T1-weighted Flash-3D MRI volumes from 14 male twins (seven monozygotic, seven dizygotic) with 3 mm-thick coronal slices. The projection is based on potential theory: A virtual electrostatic field is calculated between the area of the segmented brain and a surrounding spherical electrode. Field lines starting from each border point of the segmented brain follow the gradient towards the sphere, leading to field line concentrations due to the underlying sulci. The unwrapped sphere surface with the number of field lines per area unit is used as the 2D representation of the sulcal pattern. The resulting brain projections show a distinctive pattern, and a visual assignment of the twin pairs from the unsorted set is possible because of a high similarity of the patterns between twin pairs. Global correlation coefficients for each pair of maps yield significantly higher values for matching monozygotic twin pairs (mean = 20.2, range 12.3-25.6) than for unmatched pairs (mean = 13.0, range 1.1-28.5). As a conclusion, our method allows us to map the location and depth of the sulci on a 2D plane. The resulting maps allow quantitative inter-individual comparisons on the entire brain or parts of the brain surface.


Assuntos
Mapeamento Encefálico/métodos , Córtex Cerebral/anatomia & histologia , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Adulto , Anatomia Transversal/métodos , Biometria/métodos , Humanos , Masculino , Análise por Pareamento , Modelos Neurológicos , Gêmeos Dizigóticos , Gêmeos Monozigóticos
15.
Br J Radiol ; 71(847): 759-65, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9771387

RESUMO

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.


Assuntos
Fraturas Espontâneas/fisiopatologia , Vértebras Lombares/lesões , Vértebras Lombares/fisiopatologia , Fraturas da Coluna Vertebral/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Fenômenos Biomecânicos , Densidade Óssea , Feminino , Fraturas Espontâneas/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Osteoporose/complicações , Osteoporose/diagnóstico , Fatores de Risco , Fatores Sexuais , Fraturas da Coluna Vertebral/etiologia , Suporte de Carga
16.
Br J Radiol ; 72(858): 569-78, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10560339

RESUMO

In addition to the pure measurement of bone mineral density (BMD) in osteodensitometry, the investigation of bone structure is becoming increasingly important for estimating fracture risk. In a clinical study, a risk score was proposed which separately assesses BMD and structural parameters for spongious and cortical bone and aggregates them into a single diagnostic parameter. In 120 lumbar vertebrae from 40 patients, BMD was determined separately for spongious and cortical bone by means of quantitative CT using a single energy procedure (SE-QCT/85 kV). In addition, structural parameters based on high resolution CT were calculated for the spongiosa and cortical bone. For all patients the number of osteoporosis-related fractures was determined on the entire skeletal system. According to WHO criteria, the patients were subdivided into four groups: 1, normal; 2, osteopenic; 3, osteoporotic without fractures; 4, severely osteoporotic. Weighting factors were determined by means of multivariate least-squares analysis and used to calculate a risk score of all parameters. The ability of the individual parameters and of the sum of discriminate between the individual groups was tested. If one considers the individual parameters (BMD and the fractal structural values for spongious and cortical bone), they allow a statistically significant separation of the four groups, although there is overlapping in the value ranges. In patients with fractures, there was a significant reduction in the cortical mineral density, accompanied by a deterioration in structural properties. The following individual values were obtained (minimum-mean-maximum): spongiosa BMD (mg ml-1), unfractured: 62-112-163, fractured: 9-48-77; cortical BMD (mg ml-1), unfractured: 190-287-405, fractured: 133-191-269; spongiosa structural parameter, unfractured: 0.35-0.73-1.01, fractured: 0.95-1.24-1.58; cortical structural parameter, unfractured: 18-31-65, fractured: 21-44-66. Above 77 mg ml-1 CaHA in the spongiosa and 270 mg ml-1 CaHA in cortical bone, no fractures were observed. By appropriately selecting the weighting factors, the score is free of overlapping between the groups with and without fractures (values: unfractured 1-9-15, fractured 16-21-29). With higher score values, the fracture risk is increasing.


Assuntos
Densidade Óssea , Fraturas Ósseas/etiologia , Osteoporose/complicações , Osteoporose/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Feminino , Fractais , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Osteoporose/fisiopatologia , Medição de Risco
17.
Br J Radiol ; 70(834): 586-93, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9227251

RESUMO

Combining the measurement of bone mineral density (BMD) and the classification of the trabecular structure in cancellous bone improves the estimation of the degree of osteoporosis. A fractal method for the automatic quantitative classification of the trabecular structure in midvertebral slices of lumbar vertebrae is introduced. This method is based on the computation of the fractal dimension (box counting method) for varying binarization thresholds. Radiographic images from 30 lumbar vertebrae and CT images from an additional 16 lumbar vertebrae were analysed by calculating the dimension D in dependency of the threshold value T. The function D(T) was normalized by the average image grey value, eliminating the bone mineral density from the computations. The results show that the images of the lumbar vertebrae have fractal properties, and the function D(T) has a typical behaviour that allows the discrimination of the degree of osteoporosis. With two parameters extracted from the function D(T) the correlation coefficients with BMD were both -79% for the radiographic images, and -93% and -91% for the CT data, respectively.


Assuntos
Densidade Óssea , Fractais , Osteoporose/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiopatologia , Osteoporose/fisiopatologia , Tomografia Computadorizada por Raios X
18.
Br J Radiol ; 73(865): 69-72, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10721323

RESUMO

The box counting dimension is a frequently applied tool for the classification of trabecular bone structure. The algorithm requires a binarization of the gray value data, for example that acquired by high resolution CT (HRCT). We recently proposed a method to eliminate bone mineral density (BMD) by applying a linear normalization scheme. Further consideration has shown that full BMD independence has not been achieved, and the structural parameter proposed was therefore difficult to interpret. In this study we present an alternative approach to obtain a structural parameter that is independent of BMD. HRCT volume data was acquired on 21 lumbar vertebrae from five cadavers. In the segmented spongiosa, thresholding was based on different quantiles of the gray value histogram, yielding invariance over linear and non-linear transformations. Thresholding at high gray value levels (80% quantile) shows the highest level of significance when discriminating between osteoporotic and non-osteoporotic cases. As an addition to the measurement of BMD alone, the determination of structural properties allows an improvement of the assessment of the individual fracture risk.


Assuntos
Algoritmos , Fractais , Vértebras Lombares/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Densidade Óssea , Cadáver , Computação Matemática
19.
Br J Radiol ; 70(840): 1222-8, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9505840

RESUMO

The structural classification of trabecular bone is of considerable clinical importance for the diagnosis of osteoporosis. Assessment of the cortical bone mineral density (BMD) and analysis of cortical structure is necessary because the cortex is also affected by osteoporosis. We describe a method for the automatic classification of the cortex from its structure on high resolution (HR) CT images. The method is based on the distribution of areas with low BMD in the cortex. Two different approaches are presented; one uses the grey scale profile of the cortical ridge, and the other one evaluates the distribution of connected regions (clusters) of low BMD. i.e. areas that lie below a certain threshold value. In HRCT images from 22 lumbar vertebrae, the number of intersections of the cortical intensity profile with a horizontal line was determined at various positions of this threshold line. At a certain position, there was a local maximum in the number of intersections which was 38% higher in the osteoporotic cases. The maximum shows a moderate correlation with the cortical BMD of rni = -0.72 (p < 0.0001). The number nc of connected regions (clusters) with pixel values below a certain threshold value was determined in relation to the threshold value T. The resulting function nc(T) shows a relative maximum slightly below the average grey scale value of the respective image. The curve depends on the degree of osteoporosis: the height of the maximum (i.e. the maximal number of clusters ncmax) allows distinction to be made between different degrees of osteoporosis, and ncmax shows a correlation with the cortical BMD of rnc = -0.84 (p < 0.0001).


Assuntos
Densidade Óssea , Processamento de Imagem Assistida por Computador/métodos , Vértebras Lombares/diagnóstico por imagem , Osteoporose/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Estudos de Avaliação como Assunto , Feminino , Humanos , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Osteoporose/fisiopatologia
20.
Rofo ; 159(6): 541-7, 1993 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-8298114

RESUMO

The present study proposes a new MRI-specific staging of chondromalacia patellae (CMP) which is based on cartilage thickness decrease and signal intensity behaviour under compression as well as cartilage morphology in the plain image. The investigation was performed in 30 patients with varying knee complaints who underwent arthroscopy after MR imaging. It was demonstrated that three CMP stages can already be differentiated by MRI under compression in arthroscopically healthy cartilage. This proves a marked improvement in the early diagnosis of CMP.


Assuntos
Artroscopia , Doenças das Cartilagens/diagnóstico , Cartilagem Articular/patologia , Imageamento por Ressonância Magnética/instrumentação , Patela/patologia , Adolescente , Adulto , Idoso , Doenças das Cartilagens/classificação , Diagnóstico Diferencial , Estudos de Avaliação como Assunto , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade
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