Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
World J Urol ; 39(10): 3861-3866, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33866401

RESUMO

PURPOSE: The aim of this study was to assess the post biopsy infection rate, feasibility and prostate cancer (PCa) detection rate (CDR) by performing transperineal MRI-TRUS fusion biopsy of the prostate (TPBx) under local anesthesia (LA) without antibiotic prophylaxis (AP). METHODS: We prospectively screened 766 men with suspicious lesions on mpMRI, an elevated PSA level or a suspect digital examination undergoing MRI-TRUS-TPBx in LA, from May 2019 to July 2020. Patients with the need for antibiotic prophylaxis or without a PI-RADS target lesion were excluded from final analyses. We reported CDR, perioperative pain (0-10) and postoperative complications. PCa with an ISUP grade ≥ 2 was classified as clinically significant PCa (csPCa). RESULTS: We included 621 patients with a median age of 68 years (IQR 62-74), a PSA of 6.43 ng/mL (IQR 4.72-9.91) and a prostate volume of 45 cc (IQR 32-64). In median, 4 targeted (TB) (IQR 3-4) and 6 (IQR 5-7) systematic biopsies (SB) detected in combination overall 416 (67%) PCa and 324 (52%) csPCa. Overall CDR of TB for PI-RADS 3, 4 and 5 was 26%, 65% and 84%, respectively. Patients reported a median perioperative pain level of 2 (IQR 1-3). Four patients (0.6%) developed a post biopsy infection, one experienced urosepsis. CONCLUSION: Our results demonstrate that transperineal MRI-TRUS fusion-guided prostate biopsy under LA without AP is feasible, safe and well tolerated.


Assuntos
Biópsia Guiada por Imagem/métodos , Neoplasias da Próstata/patologia , Sepse/epidemiologia , Infecção da Ferida Cirúrgica/epidemiologia , Infecções Urinárias/epidemiologia , Idoso , Anestesia Local , Antibioticoprofilaxia/métodos , Endossonografia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética Multiparamétrica , Períneo , Próstata/patologia , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/diagnóstico por imagem , Estudos Retrospectivos
2.
Sci Rep ; 10(1): 18897, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33144637

RESUMO

Traditional palaeontological techniques of disease characterisation are limited to the analysis of osseous fossils, requiring several lines of evidence to support diagnoses. This study presents a novel stepwise concept for comprehensive diagnosis of pathologies in fossils by computed tomography imaging for morphological assessment combined with likelihood estimation based on systematic phylogenetic disease bracketing. This approach was applied to characterise pathologies of the left fibula and fused caudal vertebrae of the non-avian dinosaur Tyrannosaurus rex. Initial morphological assessment narrowed the differential diagnosis to neoplasia or infection. Subsequent data review from phylogenetically closely related species at the clade level revealed neoplasia rates as low as 3.1% and 1.8%, while infectious-disease rates were 32.0% and 53.9% in extant dinosaurs (birds) and non-avian reptiles, respectively. Furthermore, the survey of literature revealed that within the phylogenetic disease bracket the oldest case of bone infection (osteomyelitis) was identified in the mandible of a 275-million-year-old captorhinid eureptile Labidosaurus. These findings demonstrate low probability of a neoplastic aetiology of the examined pathologies in the Tyrannosaurus rex and in turn, suggest that they correspond to multiple foci of osteomyelitis.


Assuntos
Dinossauros/classificação , Neoplasias/epidemiologia , Osteomielite/diagnóstico por imagem , Animais , Fíbula/diagnóstico por imagem , Fíbula/patologia , Fósseis/anatomia & histologia , Fósseis/diagnóstico por imagem , Funções Verossimilhança , Mandíbula/diagnóstico por imagem , Mandíbula/patologia , Neoplasias/diagnóstico por imagem , Neoplasias/veterinária , Osteomielite/etiologia , Osteomielite/veterinária , Filogenia , Tomografia Computadorizada por Raios X
3.
Knee Surg Sports Traumatol Arthrosc ; 26(12): 3667-3672, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29728742

RESUMO

PURPOSE: Failure to reconstruct the natural footprints of the ruptured anterior cruciate ligament (ACL) may lead to premature graft-failure. Therefore, precise analyses of insertion site anatomy and inter-individual variations of the morphology of the ACL are highly important to facilitate optimal individualized graft placement. Therefore, the purpose of this study was to analyze the inter-individual variation of the morphology of the femoral and tibial ACL footprints. METHODS: Thirty subjects with an intact ACL were included in this study for MR imaging of their knee joint. A three-dimensional (3D) dual-echo steady-state sequence with near 0.8 mm isotropic resolution was acquired on a 3 T system with a 15-channel knee-coil. The ACL was subsequently manually segmented using dedicated medical imaging software (VitreaAdvanced®, Vital Images). The lengths and widths of the footprints were measured after reconstructing an axial oblique (tibial footprint) or coronal oblique (femoral footprint) section at the bone-ligament junction and descriptive analysis was conducted to describe morphology orientation of the footprint. RESULTS: The femoral footprint measured on average 14 mm ± 2 mm (range 8-19 mm) in length and 5 mm ± 1 mm (range 3-8 mm) in width. The mean value of the tibial footprint measured 10 mm ± 2 mm (range 5-14 mm) in length and 7 mm ± 2 mm (range 5-13 mm) in width. Descriptive analysis showed a stretched, ribbon-like appearance of the femoral footprint, while the tibial footprint revealed larger variability, stretching from anterolateral to posteromedial around the anterior horn of the lateral meniscus. CONCLUSION: 3D imaging of the ACL footprints reveals a distinct difference in insertion site morphology and fiber bundle orientation between the femoral and tibial footprint. This questions the concept of strict anatomical separation of the ACL into an anteromedial and posterolateral bundle.


Assuntos
Ligamento Cruzado Anterior/diagnóstico por imagem , Fêmur/diagnóstico por imagem , Articulação do Joelho/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Adulto , Feminino , Voluntários Saudáveis , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino
4.
Aktuelle Urol ; 47(5): 383-7, 2016 09.
Artigo em Alemão | MEDLINE | ID: mdl-27680189

RESUMO

BACKGROUND: A revised version of the PI-RADS scoring system has been introduced and score-related variability between version 1 and 2 may be suspected. This study aimed to assess the PI-RADS scores derived from version 1 (v1) and the updated version 2 (v2). MATERIAL AND METHODS: 61 patients with biopsy-proven prostate cancer (PCa) and 90 lesions detected on pre-biopsy 3-Tesla multiparametric MRI were included in this retrospective analysis. 2 experienced radiologists scored all lesions in consensus. Lesion scores differing between PI-RADS v1 and v2 were further analyzed. Histology data from radical prostatectomy (RP) were included when available. RESULTS: The PI-RADS v1 and v2 score differed in 52% of patients (32/61) and in 39% of lesions (35/90). On a lesion basis, the reason for the differences were related to sum score in v1 vs. categorical system in v2 in 51% (18/35) of lesions, cutoff between PI-RADS 4 and 5 based on lesion size in v2 as opposed to the sum score in v1 in 31% (11/35) and were inconclusive in 17% (6/35). The RP subgroup indicates enhanced detection of PCas with GS 3+3 and GS 3+4 in v2. CONCLUSION: PI-RADS scores of prostatic lesions frequently differed between v1 and v2, the major reasons for these differences being score-related. In men undergoing RP, PI-RADS v2 improved detection of low risk PCa, but did not increase accuracy for discrimination of GS 3+4 vs. GS≥4+3 compared to v1. Urologists should be aware of the system-related differences when interpreting PI-RADS scores.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Idoso , Biópsia , Humanos , Masculino , Pessoa de Meia-Idade , Próstata/diagnóstico por imagem , Próstata/patologia , Prostatectomia , Neoplasias da Próstata/cirurgia , Estudos Retrospectivos
5.
Radiologe ; 55(12): 1088-96, 2015 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-26515285

RESUMO

CLINICAL ISSUE: Prostate cancer is the most common form of cancer in men in Germany; however, there is a distinct difference between incidence and mortality. STANDARD TREATMENT: The detection of prostate cancer is based on clinical and laboratory testing using serum prostate-specific antigen (PSA) levels and transrectal ultrasound with randomized biopsy. DIAGNOSTIC WORK-UP: Multiparametric MR imaging of the prostate can provide valuable diagnostic information for detection of prostate cancer, especially after negative results of a biopsy prior to repeat biopsy. PERFORMANCE: In addition the use of MR ultrasound fusion-guided biopsy has gained in diagnostic importance and has increased the prostate cancer detection rate. ACHIEVEMENTS AND PRACTICAL RECOMMENDATIONS: The prostate imaging reporting and data system (PI-RADS) classification has standardized the reporting of prostate MRI which has positively influenced the acceptance by urologists.


Assuntos
Interpretação de Imagem Assistida por Computador/normas , Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética/normas , Guias de Prática Clínica como Assunto , Próstata/patologia , Neoplasias da Próstata/patologia , Algoritmos , Europa (Continente) , Humanos , Aumento da Imagem/métodos , Aumento da Imagem/normas , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
Rofo ; 187(9): 751-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26114251

RESUMO

UNLABELLED: New technical and clinical developments of sonography and magnetic resonance imaging include improved detection, localization and staging as well as active surveillance of prostate cancer. Multiparametric MRI can best answer these typical clinical questions. However, ultrasound elastography seems to be suitable for the detection of significant prostate cancer as well. The structured reporting system for multiparametric MRI of the prostate according to PI-RADS Version 1 led to improved and reproducible diagnosis of prostate cancer. The new PI-RADS Version 2 aims to minimize the limitations of Version 1 and make PI-RADS standardization more globally acceptable. KEY POINTS: The detection, staging, and active monitoring of prostate cancer are common clinical questions. The best method for answering these questions is multiparametric MRI. Ultrasound elastography also seems to be suitable for the detection of significant prostate cancer. The new PI-RADS Version 2 claims to eliminate the limitations of PI-RADS Version 1 and to allow globally recognized standardized diagnostic reporting.


Assuntos
Imageamento por Ressonância Magnética/normas , Imagem Multimodal/normas , Guias de Prática Clínica como Assunto , Neoplasias da Próstata/diagnóstico , Radiologia/normas , Ultrassonografia/normas , Alemanha , Humanos , Masculino , Oncologia/normas
7.
Dentomaxillofac Radiol ; 44(6): 20140416, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25734243

RESUMO

OBJECTIVES: We investigated artefacts caused from orthodontic appliances at 1.5-T MRI of the head and neck region and whether the image quality can be improved utilizing the artefact-minimizing sequence WARP. METHODS: In vitro tests were performed by phantom measurements of different orthodontic devices applying different types of MR sequences [echoplanar imaging (EPI), turbo spin echo (TSE) and TSE-WARP, gradient echo (GRE)]. Two independent readers determined after calibration the level of artefacts. Subsequently, the interobserver agreement was calculated. The measurement of artefacts was based on the American Society for Testing Materials Standard F 2119-07. For in vivo imaging, one test person was scanned with an inserted multibracket appliance. The level of artefacts for 27 target regions was evaluated. RESULTS: In vitro: ceramic brackets and ferromagnetic steel brackets produced artefact radii up to 1.12 and 7.40 cm, respectively. WARP reduced these artefacts by an average of 32.7%. The Bland-Altman-Plot indicated that maximum measurement differences of 3 mm have to be expected with two calibrated observers. In vivo: the EPI sequence for brain imaging was not analysable. The TSE sequence of the brain did not demonstrate artefacts except for the nasal cavity. Conversely, the TSE sequence of the cervical spine revealed severe artefacts in the midface region. The GRE sequence appeared to be more susceptible to artefacts than did the TSE sequence. CONCLUSIONS: In vitro measurements allow an estimation of the in vivo artefact size. Orthodontic appliances may often remain intraorally when performing MRI. WARP showed a more significant effect in vitro than in vivo.


Assuntos
Artefatos , Imageamento por Ressonância Magnética/métodos , Aparelhos Ortodônticos , Calibragem , Imagem Ecoplanar , Humanos , Técnicas In Vitro , Imagens de Fantasmas
8.
Aktuelle Urol ; 46(1): 34-8, 2015 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-25519051

RESUMO

BACKGROUND: Magnetic resonance imaging (MRI)/ultrasound (US) fusion-guided biopsy detects more prostate cancer (PCa) than transrectal US (TRUS)-guided biopsy in patients with an indication for prostate re-biopsy. The aim of this study was a) to compare the detection rates of MRI/US fusion-guided biopsy with conventional TRUS in a double centre cohort and b) to investigate the influence of the number of pre-biopsies on the PCa detection rate. MATERIAL AND METHODS: In the period from January 2012 to July 2014, 310 consecutive patients gave written informed consent and underwent 3 Tesla MRI scans of the prostate. All patients had at least one PCa suspicious lesion in the MRI and were biopsied by MRI/US fusion followed by a conventional 10-core biopsy of the prostate. Detection rates based on technique, Gleason score and number of pre-biopsies were calculated. RESULTS: The overall detection rate of the study was 51% (158 patients). Among these 158 patients a histopathological Gleason score of 6 was detected in 60 patients (38%), a Gleason score of 7 in 54 patients (34%) and a Gleason score≥8 in 44 patients (28%). MRI/US fusion-guided biopsy detected 110 (69.7%) of the overall detected 158 PCa. TRUS-guided biopsy detected a higher rate of Gleason score 6 (54%) and a lower rate of Gleason score≥8 (15%) lesions in comparison to 38% Gleason 6 and 28% Gleason≥8 in the MRI/US fusion-guided biopsy, respectively. Furthermore, a lower Gleason score was observed in patients with more than one pre-biopsy. The detection rate in biopsy-naïve patients undergoing MRI/US fusion was 75% (40 patients) among 75% detected Gleason score≥7. CONCLUSION: MRI/US fusion-guided biopsy detected more PCa and also more clinically significant cancer than conventional TRUS. In our cohort patients with more than one pre-biopsy showed lower Gleason scores. The included patients with an initial MRI/US fusion-guided biopsy should be further investigated.


Assuntos
Biópsia Guiada por Imagem/métodos , Imagem por Ressonância Magnética Intervencionista/métodos , Imageamento por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Neoplasias da Próstata/patologia , Ultrassonografia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estudos Prospectivos , Próstata/patologia , Sensibilidade e Especificidade
9.
Anat Histol Embryol ; 43(2): 90-102, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23551141

RESUMO

Temnospondyls, the largest group of Palaeozoic and Mesozoic amphibians, primitively possess rhachitomous vertebrae with multipartite centra (consisting of one horse-shoe-shaped inter- and paired pleurocentra). In a group of temnospondyls, the stereospondyls, the intercentra became pronounced and disc-like, whereas the pleurocentra were reduced. We report the presence of congenital vertebral malformations (hemi, wedge and block vertebrae) in Permian and Triassic temnospondyls, showing that defects of formation and segmentation in the tetrapod vertebral column represent a fundamental failure of somitogenesis that can be followed throughout tetrapod evolution. This is irrespective of the type of affected vertebra, that is, rhachitomous or stereospondylous, and all components of the vertebra can be involved (intercentrum, pleurocentrum and neural arch), either together or independently on their own. This is the oldest known occurrence of wedge vertebra and congenital block vertebra described in fossil tetrapods. The frequency of vertebral congenital malformations in amphibians appears unchanged from the Holocene.


Assuntos
Anfíbios/anormalidades , Fósseis , Coluna Vertebral/anormalidades , Animais
10.
Rofo ; 186(3): 260-6, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23999784

RESUMO

PURPOSE: To introduce a novel in-vivo three-dimensional multifrequency magnetic resonance elastography (3D-MMRE) method for high-resolution mechanical characterization of the liver and spleen. MATERIALS AND METHODS: Ten healthy volunteers were examined by abdominal single-shot 3D-MMRE using a novel patient-activated trigger system with respiratory control. 10 contiguous slices with 2.5  mm cubic voxel resolution, 3 wave components, 8 time steps, and 2 averages were acquired at 7 mechanical excitation frequencies from 30 to 60  Hz. The total imaging time was approximately 15  min. For postprocessing, multifrequency dual elasto-visco (MDEV) inversion was used to calculate high-resolution mechanical parameter maps of the abdomen including the liver and spleen. RESULTS: Two parameters maps were generated from each image slice to capture the magnitude and the phase angle of the complex shear modulus. Both parameters depicted the mechanical structures of the abdomen with unprecedented high spatial resolution. Spatially averaged group mean values of the liver and spleen are 1.27 ±â€Š0.17 kPa and 2.01 ±â€Š0.69 kPa, indicating a significantly higher asymptomatic stiffness of the spleen compared to the liver. CONCLUSION: Patient-activated respiratory-gated 3D-MMRE combined with MDEV inversion provides highly resolved mechanical maps of the liver and spleen that are superior to previous elastograms measured by abdominal MRE.


Assuntos
Biorretroalimentação Psicológica/instrumentação , Técnicas de Imagem por Elasticidade/instrumentação , Imageamento Tridimensional/instrumentação , Fígado/anatomia & histologia , Técnicas de Imagem de Sincronização Respiratória/instrumentação , Autocuidado/instrumentação , Baço/anatomia & histologia , Adulto , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Masculino , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Rofo ; 185(9): 830-7, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23888471

RESUMO

PURPOSE: Generally, high-resolution MRI of the eye is performed with small loop surface coils. The purpose of this phantom and patient study was to investigate the influence of magnetic field strength and receiver coils on image quality in ocular MRI. MATERIALS AND METHODS: The eyeball and the complex geometry of the facial bone were simulated by a skull phantom with swine eyes. MR images were acquired with two small loop surface coils with diameters of 4 cm and 7 cm and with a multi-channel head coil at 1.5 and 3 Tesla, respectively. Furthermore, MRI of the eye was performed prospectively in 20 patients at 1.5 Tesla (7 cm loop surface coil) and 3 Tesla (head coil). These images were analysed qualitatively and quantitatively and statistical significance was tested using the Wilcoxon-signed-rank test (a p-value of less than 0.05 was considered to indicate statistical significance). RESULTS: The analysis of the phantom images yielded the highest mean signal-to-noise ratio (SNR) at 3 Tesla with the use of the 4 cm loop surface coil. In the phantom experiment as well as in the patient studies the SNR was higher at 1.5 Tesla by applying the 7 cm surface coil than at 3 Tesla by applying the head coil. Concerning the delineation of anatomic structures no statistically significant differences were found. CONCLUSION: Our results show that the influence of small loop surface coils on image quality (expressed in SNR) in ocular MRI is higher than the influence of the magnetic field strength. The similar visibility of detailed anatomy leads to the conclusion that the image quality of ocular MRI at 3 Tesla remains acceptable by applying the head coil as a receiver coil.


Assuntos
Olho/patologia , Aumento da Imagem/instrumentação , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/instrumentação , Interpretação de Imagem Assistida por Computador/métodos , Campos Magnéticos , Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/métodos , Melanoma/diagnóstico , Imagens de Fantasmas , Neoplasias Uveais/diagnóstico , Adulto , Idoso , Animais , Artefatos , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Suínos
14.
Rofo ; 184(11): 1013-9, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22893489

RESUMO

PURPOSE: Despite advantages in antiviral therapy of hepatitis C (HCV) in recent years, progressing liver fibrosis remains a major problem for patients suffering from hepatitis C after liver transplantation. Therefore, effective non-invasive methods for the assessment of liver fibrosis are needed in order to guide treatment decisions and predict prognosis in these patients. The aim of this study was to prospectively assess the diagnostic accuracy of viscoelasticity-based magnetic resonance (MR) elastography for the assessment of liver fibrosis in HCV patients after liver transplantation. MATERIALS AND METHODS: After IRB approval, a total of 25 patients, who had received a liver graft due to chronic hepatitis C underwent both liver biopsy and MR elastography. Two viscoelastic constants, the shear elasticity µ and the powerlaw exponent α were calculated by fitting the frequency function of the complex shear modulus with the viscoelastic springpot-model. RESULTS: A strong positive correlation between shear elasticity µ and the stage of fibrosis could be found (R = 0.486, p = 0.0136). The area under the receiver operating curve (AUROC) of MR elastography based on µ for diagnosis of severe fibrosis (F ≥ 3) was 0.87 and 0.65 for diagnosis of significant fibrosis (F ≥ 2). The powerlaw exponent α did not correlate with the stage of fibrosis. CONCLUSION: MR elastography represents a promising non-invasive procedure for the assessment of higher grades of fibrosis in HCV patients after liver transplantation. The poor correlation for lower grades of fibrosis suggests unknown mechanical interactions in the transplanted liver.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/cirurgia , Cirrose Hepática/diagnóstico , Cirrose Hepática/cirurgia , Transplante de Fígado/patologia , Complicações Pós-Operatórias/diagnóstico , Estudos de Coortes , Seguimentos , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/patologia , Hepatite C Crônica/patologia , Humanos , Biópsia Guiada por Imagem/métodos , Fígado/patologia , Cirrose Hepática/patologia , Testes de Função Hepática , Complicações Pós-Operatórias/patologia , Prognóstico , Estudos Prospectivos , Sensibilidade e Especificidade
15.
Rofo ; 182(9): 793-802, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20517819

RESUMO

PURPOSE: To compare the direct costs of two diagnostic algorithms for pretherapeutic TNM staging of rectal cancer. MATERIALS AND METHODS: In a study including 33 patients (mean age: 62.5 years), the direct fixed and variable costs of a sequential multimodal algorithm (rectoscopy, endoscopic and abdominal ultrasound, chest X-ray, thoracic/abdominal CT in the case of positive findings in abdominal ultrasound or chest X-ray) were compared to those of a novel algorithm of rectoscopy followed by MRI using a whole-body scanner. MRI included T 2w sequences of the rectum, 3D T 1w sequences of the liver and chest after bolus injection of gadoxetic acid, and delayed phases of the liver. The personnel work times, material items, and work processes were tracked to the nearest minute by interviewing those responsible for the process (surgeon, gastroenterologist, two radiologists). The costs of labor and materials were determined from personnel reimbursement data and hospital accounting records. Fixed costs were determined from vendor pricing. RESULTS: The mean MRI time was 55 min. CT was performed in 19/33 patients (57%) causing an additional day of hospitalization (costs 374 euro). The costs for equipment and material were higher for MRI compared to sequential algorithm (equipment 116 vs. 30 euro; material 159 vs. 60 euro per patient). The personnel costs were markedly lower for MRI (436 vs. 732 euro per patient). Altogether, the absolute cost advantage of MRI was 31.3% (711 vs. 1035 euro for sequential algorithm). CONCLUSION: Substantial savings are achievable with the use of whole-body MRI for the preoperative TNM staging of patients with rectal cancer.


Assuntos
Algoritmos , Endossonografia/economia , Imageamento por Ressonância Magnética/economia , Proctoscopia/economia , Neoplasias Retais/patologia , Tomografia Computadorizada Espiral/economia , Ultrassonografia/economia , Imagem Corporal Total/economia , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste/economia , Custos e Análise de Custo , Feminino , Gadolínio DTPA/administração & dosagem , Gadolínio DTPA/economia , Alemanha , Custos Hospitalares/estatística & dados numéricos , Humanos , Tempo de Internação/economia , Fígado/patologia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Pulmão/patologia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Programas Nacionais de Saúde/economia , Estadiamento de Neoplasias , Recursos Humanos em Hospital/economia , Estudos Prospectivos
16.
Rofo ; 181(6): 536-42, 2009 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-19353483

RESUMO

PURPOSE: To investigate whether pharmacokinetic MRI parameters "perfusion, blood volume, mean transit time (MTT), interstitial volume, permeability, extraction coefficient, delay, and dispersion" allow the differentiation of low-grade (Gleason score < or = 6) and high-grade (Gleason score > or = 7) prostate cancer. MATERIALS AND METHOD: Forty-two patients with prostate cancer verified by biopsy (PSA 2.7 to 31.4 ng/ml) and scheduled for prostatectomy underwent MRI at 1.5 Tesla using the dynamic contrast-enhanced inversion-prepared dual-contrast gradient echo sequence (temporal resolution, 1.65 s) and a combined endorectal body phased array coil. Parametric maps were computed using a sequential 3-compartment model and the corresponding post-processing algorithms. A total of 41 areas of prostate cancer (15 low-grade, 26 high-grade cancers) in 32 patients were able to be correlated with the prostatectomy specimens and were included in the analysis. RESULTS: Low-grade prostate cancers had a higher mean blood volume (1.76 % vs. 1.64 %, p = 0.039), longer MTT (6.39 s vs. 3.25 s, p < 0.001), and lower mean permeability (2.57 min (-1) vs. 3.86 min (-1), p = 0.011) than high-grade cancers. No statistically significant difference was found for perfusion (p = 0.069), interstitial volume (p = 0.849), extraction coefficient (p = 0.615), delay (p = 0.489), and dispersion (p = 0.306). CONCLUSIONS: Blood volume, MTT, and permeability allow the differentiation of low-grade and high-grade prostate cancer. They may be used to detect cancer progression by MRI in patients managed by active surveillance.


Assuntos
Algoritmos , Meios de Contraste/farmacocinética , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/metabolismo , Adulto , Humanos , Aumento da Imagem/métodos , Masculino , Neoplasias da Próstata/classificação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
Rofo ; 180(12): 1104-9, 2008 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-18814103

RESUMO

PURPOSE: Recent magnetic resonance elastography (MRE) studies have reported the potential of this noninvasive method for diagnosing hepatic fibrosis based on the elastic properties of liver tissue. However, in many cases biological tissue responds to mechanical vibrations as a combined solid-liquid body causing MRE-derived elastic parameters to become functions of the applied vibration frequency. Therefore a multi-frequency MRE study of liver was performed and the potential of the method for separating healthy from fibrotic liver was investigated. The aim of this study was the increase of the accuracy of liver elastography by analyzing multi-frequency MRE examinations using the springpot model. MATERIALS AND METHODS: 18 healthy volunteers and 10 patients were examined by multi-frequency MRE of the liver in a frequency range between 25 Hz and 62.5 Hz. The liver was mechanically excited with four harmonic vibrations simultaneously. The measured dispersion of the complex modulus was analyzed using the springpot model which accounts for both elastic and viscous properties of a material with 2 independent parameters. RESULTS: The mechanical stimulation and the motion encoding according to the multi-frequency approach was implemented successfully. Significant differences (p < 0.05) were found in the hepatic viscoelasticities of normal livers. The separation of healthy volunteers and patients was achieved with a sensitivity and specificity of 80 and 100 %, respectively. CONCLUSION: Using the springpot model, multi-frequency MRE is sensitive to interindividual differences in the hepatic viscoelastic properties of healthy volunteers. The obtained accuracy of the technique in separating healthy from fibrotic livers opens the possibility of applying multi-frequency MRE as a noninvasive method for diagnosing liver fibrosis in the future.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Cirrose Hepática/diagnóstico , Adulto , Idoso , Fenômenos Biomecânicos , Elasticidade , Feminino , Humanos , Fígado/fisiopatologia , Cirrose Hepática/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valores de Referência , Sensibilidade e Especificidade , Vibração , Viscosidade
18.
Acta Radiol ; 49(4): 376-82, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18415778

RESUMO

BACKGROUND: Respiratory triggering allows the acquisition of high-resolution magnetic resonance (MR) images of the upper abdomen. However, the depiction of organs close to the gastrointestinal tract can be considerably impaired by ghosting artifacts and blurring caused by bowel peristalsis. PURPOSE: To evaluate the effect of gastrointestinal motion suppression by intramuscular butylscopolamine administration on the image quality of a respiratory-triggered T2-weighted turbo spin-echo (T2w TSE) sequence of the upper abdomen. MATERIAL AND METHODS: Images of 46 patients were retrospectively analyzed. Twenty-four patients had received intramuscular injection of 40 mg butylscopolamine immediately before MR imaging. Fourteen of the 24 patients in the butylscopolamine group underwent repeat imaging after a mean of 29 min. Quantitative analysis of the ghosting artifacts was done by measuring signal intensities in regions of interest placed in air anterior to the patient. In addition, image quality was assessed qualitatively by two radiologists by consensus. RESULTS: Spasmolytic medication with butylscopolamine reduced ghosting artifacts and significantly improved image quality of the respiratory-triggered T2w TSE sequence. The most pronounced effect of butylscopolamine administration on image quality was found for the pancreas and the left hepatic lobe. The rate of examinations with excellent or good depiction of the pancreas and the left hepatic lobe in the group without premedication and in the butylscopolamine group was 55% vs. 96% (pancreatic head), 35% vs. 88% (pancreatic body), 43% vs. 96% (pancreatic tail), and 45% vs. 83% (left hepatic lobe), respectively. Regarding the duration of the effect of intramuscular butylscopolamine, repeat imaging after a mean of 29 min did not result in a significant deterioration of image quality. CONCLUSION: Intramuscular butylscopolamine administration significantly improves image quality of respiratory-triggered T2-weighted abdominal MR imaging by persistent reduction of peristaltic artifacts. MR imaging of the liver and pancreas in particular benefits from the suppression of gastrointestinal peristalsis by butylscopolamine.


Assuntos
Brometo de Butilescopolamônio/administração & dosagem , Doenças do Sistema Digestório/diagnóstico , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Parassimpatolíticos/administração & dosagem , Distribuição de Qui-Quadrado , Meios de Contraste , Dextranos , Feminino , Óxido Ferroso-Férrico , Humanos , Interpretação de Imagem Assistida por Computador , Injeções Intramusculares , Ferro , Nanopartículas de Magnetita , Masculino , Pessoa de Meia-Idade , Óxidos , Respiração , Estudos Retrospectivos , Estatísticas não Paramétricas
19.
Rofo ; 179(10): 1061-7, 2007 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-17786895

RESUMO

PURPOSE: Many patients dislike oral contrast media due to their bad taste. The aim of the present study was to identify a solution that tastes better while providing the same opacification in order to offer oncological patients an alternative to the routinely used bad tasting oral contrast media. MATERIALS AND METHODS: In a single blinded, prospective clinical study, the orally administered intravenous contrast media iohexol (Omnipaque), iopromide (Ultravist), and iotrolan (Isovist) as well as the oral contrast media sodium amidotrizoate (Gastrografin) and ioxithalamate (Telebrix) were each compared to the oral contrast medium lysine amidotrizoate as the reference standard at a constant dilution. The density values of all contrast media with the same dilutions were first measured in a phantom study. The patient study included 160 patients who had undergone a prior abdominal CT scan with lysine amidotrizoate within 6 months. The patients rated their subjective taste impression on a scale of 0 (very bad) to 10 (excellent). In addition, adverse events and opacification were recorded and prices were compared. RESULTS: The phantom study revealed identical density values. Patients assigned much higher taste impression scores of 8 and 7 to iohexol and iotrolan, respectively, as compared to a score of 3 for the conventional lysine amidotrizoate (p< 0.05). Iopromide and sodium amidotrizoate did not differ significantly from lysine amidotrizoate. The opacification of all contrast media and experienced adverse events did not differ significantly. Iotrolan (ca. 120 euro/100 ml), Iohexol and Iopromide (ca. 70 euro/100 ml) are more expensive than the conventional oral contrast media (ca. 10 - 20 euro/100 ml). CONCLUSION: Orally administered solutions of non-ionic contrast media improve patient comfort due to the better taste and provide the same opacification in comparison to conventional oral contrast media. At present, their use should be limited to individual cases due to the higher costs.


Assuntos
Meios de Contraste/administração & dosagem , Meios de Contraste/economia , Iohexol/administração & dosagem , Iohexol/economia , Radiografia Abdominal , Paladar , Tomografia Computadorizada por Raios X , Ácidos Tri-Iodobenzoicos/administração & dosagem , Ácidos Tri-Iodobenzoicos/economia , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Interpretação Estatística de Dados , Diatrizoato de Meglumina/administração & dosagem , Diatrizoato de Meglumina/economia , Feminino , Humanos , Injeções Intravenosas , Intestino Delgado/diagnóstico por imagem , Iohexol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde , Imagens de Fantasmas , Estudos Prospectivos , Padrões de Referência
20.
Acta Radiol ; 47(9): 899-906, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17077038

RESUMO

PURPOSE: To evaluate several substances regarding small bowel distension and contrast on balanced steady-state free precession (bSSFP) cine magnetic resonance (MR) images. MATERIAL AND METHODS: Luminal contrast was evaluated in 24 volunteers after oral application of two different contrast agent groups leading to either bright lumen (pineapple, blueberry juice) or dark lumen (tap water, orange juice) on T1-weighted images. Bowel distension was evaluated in 30 patients ingesting either methylcellulose or mannitol solution for limiting intestinal absorption. Fifteen patients with duodeno-jejunal intubation served as the control. Quantitative evaluation included measurement of luminal signal intensities and diameters of four bowel segments, qualitative evaluation assessed luminal contrast and distension on a five-point scale. RESULTS: Quantitative and qualitative evaluation of the four contrast agents revealed no significant differences regarding luminal contrast on bSSFP images. Quantitative evaluation revealed significantly lower (P<0.05) small bowel distension for three out of four segments (qualitative evaluation: two out of four segments) for methylcellulose in comparison to the control. Mannitol was found to be equal to the control. CONCLUSION: Oral ingestion of tap water or orange juice in combination with mannitol is recommended for cine MR imaging of the small bowel regarding luminal contrast and small bowel distension on bSSFP sequences.


Assuntos
Meios de Contraste/administração & dosagem , Intestino Delgado/patologia , Imagem Cinética por Ressonância Magnética , Administração Oral , Adolescente , Adulto , Idoso , Feminino , Humanos , Imagem Cinética por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA