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1.
J Eur Acad Dermatol Venereol ; 36 Suppl 1: 41-44, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34855243

RESUMO

Cutaneous squamous cell carcinoma (cSCC) numbers among the most common types of skin cancer and is known as one of the cancer entities with the highest mutational burden among all solid tumours. Due to the positive correlation between mutational burden and response rate to inhibitors of the programmed cell death 1 (PD-1), those inhibitors are considered promising candidates for the systemic therapy of cSCC. Recently, the PD-1 inhibitors pembrolizumab, nivolumab and cemiplimab demonstrated efficacy in the systemic treatment of locally advanced or metastatic cSCC leading to the approval of cemiplimab by the FDA (U.S. Food and Drug Administration) in 2018 and the EMA (European Medicines Agency) in 2019. Patients with haematological malignancies tend to develop skin cancers of high aggressiveness, enhanced cumulative recurrence rate and higher rates of metastases with subsequent death. Chronic lymphocytic leukaemia (CLL) is the most frequent type of leukaemia in the United States and Europe with the majority of patients older than 50 years of age. This neoplasm predominantly originates from B -cells leading to an impaired immune system of the patient. Although CLL is a B-cell malignancy, studies have also described the involvement of T cells in the pathogenesis and progression of the disease with contradictory findings on the effects of PD-1 inhibitors in CLL. Due to their underlying hematologic malignancy, these patients have commonly no access to PD-1 inhibitor trials for treatment of advanced cSCC. We report on two patients with locally advanced or metastatic cSCC. Both patients had been suffering from a CLL for many years without indication for treatment. Despite a potential immunosuppressive state of the patients due to their CLL, both were treated with the PD-1 inhibitor pembrolizumab resulting in different therapy outcomes.


Assuntos
Carcinoma de Células Escamosas , Leucemia Linfocítica Crônica de Células B , Neoplasias Cutâneas , Carcinoma de Células Escamosas/tratamento farmacológico , Humanos , Inibidores de Checkpoint Imunológico , Imunoterapia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Masculino , Neoplasias Cutâneas/tratamento farmacológico , Estados Unidos
2.
Mol Imaging Biol ; 22(3): 788-796, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31482413

RESUMO

PURPOSE: The aim of this study was to evaluate the detection rate of [68Ga]prostate-specific membrane antigen ([68Ga]PSMA-11) positron emission tomography (PET)/magnetic resonance imaging (MRI) and to compare it with [68Ga]PSMA-11 PET/X-ray computed tomography (CT) in patients with recurrent prostate cancer (PC) after radical prostatectomy. PROCEDURES: A total of 93 patients with biochemically recurrent prostate cancer underwent [68Ga]PSMA-11 PET/CT and subsequently a whole-body integrated PET/MRI examination. Board certified nuclear medicine physicians and radiologists evaluated PET/CT and PET/MRI datasets regarding identification of tumor lesions ((i) lymph nodes, (ii) bone lesions, (iii) local recurrence, and (iv) parenchymal lesions) based on maximum [68Ga]PSMA-11 uptake as well as morphological changes. Quality of PET images for both PET/CT and PET/MRI were rated using a 5-point scoring system by evaluating lesion homogeneity, contrast, contour, and delineation. Wilcoxon signed-rank tests were used to determine statistical differences. RESULTS: PC relapse was detected in 62/93 patients. PET/MRI detected 148 out of 150 lesions described in PET/CT. In addition, PET/MRI detected 11 lesions not detected in PET/CT (5 lymph nodes, 6 local recurrences). The exact McNemar statistical test (one-sided) showed significant difference between PET/CT and PET/MRI for diagnosis of local recurrence (p value = 0.031). Diagnostic confidence for (iii) was higher in PET/MRI compared with PET/CT (PET/CT = 1.1; PET/MRI = 4.9). Diagnostic confidence for (i) (PET/CT = 4.9; PET/MRI = 4.6), (ii) (PET/CT = 4.9; PET/MRI = 4.6), and (iv) (PET/CT = 4.6; PET/MRI = 4.8) was equivalent between PET/MRI and PET/CT. CONCLUSIONS: Integrated [68Ga]PSMA-11 PET/MRI provides a similarly high diagnostic performance for localization of recurrent PC as PET/CT. For the detection of local recurrences [68Ga]PSMA-11 PET/MRI is superior compared with [68Ga]PSMA-11 PET/CT.


Assuntos
Antígenos de Superfície/metabolismo , Ácido Edético/análogos & derivados , Glutamato Carboxipeptidase II/metabolismo , Imageamento por Ressonância Magnética/métodos , Oligopeptídeos/farmacocinética , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Próstata/patologia , Imagem Corporal Total/métodos , Idoso , Idoso de 80 Anos ou mais , Ácido Edético/química , Ácido Edético/farmacocinética , Isótopos de Gálio , Radioisótopos de Gálio , Humanos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Oligopeptídeos/química , Prostatectomia/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/cirurgia , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/farmacocinética , Padrões de Referência , Distribuição Tecidual
3.
Eur Radiol ; 26(11): 4072-4079, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26943131

RESUMO

OBJECTIVES: To assess the impact of the scout view orientation on radiation exposure and image quality in thoracoabdominal CT, when automated tube voltage selection (ATVS) and automated tube current modulation (ATCM) are used in combination with scan planning on a single scout view. METHODS: Fifty patients underwent two thoracoabdominal CT examinations, one planned on an anteroposterior scout view, one planned on a lateral scout view. Both examinations included contrast-enhanced imaging of chest (CH) and abdomen (AB) and non-contrast-enhanced imaging of the liver (LI). For all examinations the same imaging protocol was used on the same dual-source CT scanner. The radiation exposure was recorded and objective as well as visual image quality was assessed for all examinations. RESULTS: The median dose-length product was significantly lower in scans planned on a lateral scout view (CH: 179 vs. 218 mGy*cm, LI: 148 vs. 178 mGy*cm, AB: 324 vs. 370 mGy*cm, p < 0.0001). Objective image quality was marginal lower in scans planned on a lateral scout view, whereas the visual image quality was rated as equal. CONCLUSION: At the tested radiation doses, the orientation of the scout view has a significant impact on the radiation exposure but no clinically relevant impact on the image quality. KEY POINTS: • The scout view orientation has a significant impact on the radiation exposure. • The scout view orientation has no clinically relevant impact on image quality. • A lateral scout view should be preferred with regard to radiation exposure.


Assuntos
Doses de Radiação , Exposição à Radiação/estatística & dados numéricos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Radiografia Abdominal/métodos , Radiografia Torácica/métodos , Tomografia Computadorizada por Raios X/métodos , Abdome/diagnóstico por imagem , Feminino , Humanos , Fígado , Masculino , Pessoa de Meia-Idade , Radiografia Abdominal/normas , Radiografia Torácica/normas , Reprodutibilidade dos Testes , Tórax/diagnóstico por imagem , Tomografia Computadorizada por Raios X/normas
5.
Urologe A ; 55(3): 350-5, 2016 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-26893136

RESUMO

More than other medical discipline, radiology is marked by technical innovation and continuous development, as well as the optimization of the underlying physical principles. In this respect, several trends that will crucially change and develop radiology over the next decade can be observed. Through the use of ever faster computer tomography, which also shows an ever-decreasing radiation exposure, the "workhorse" of radiology will have an even greater place and displace conventional X­ray techniques further. In addition, hybrid imaging, which is based on a combination of nuclear medicine and radiological techniques (keywords: PET/CT, PET/MRI) will become much more established and, in particular, will improve oncological imaging further, allowing increasingly individualized imaging for specific tracers and techniques of functional magnetic resonance imaging for a particular tumour. Future radiology will be strongly characterized by innovations in the software and Internet industry, which will enable new image viewing and processing methods and open up new possibilities in the context of the organization of radiological work.


Assuntos
Diagnóstico por Imagem/tendências , Previsões , Radiologia/tendências , Neoplasias Urológicas/diagnóstico por imagem , Neoplasias Urológicas/patologia , Alemanha , Humanos , Estadiamento de Neoplasias
7.
Neuroradiol J ; 26(1): 84-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23859173

RESUMO

We describe a case of combined mechanical thrombectomy of the right middle cerebral artery and stent angioplasty of the right internal carotid artery in a severe stroke caused by arterio-arterial embolism due to a traumatic dissection of the internal carotid artery. The patient was admitted with an NIHSS score of 19 and was discharged from hospital with a score of 2. Three months later neurological examination disclosed no pathological findings. The case demonstrates the crucial role of interventional procedures in the treatment of severe stroke where intravenous thrombolysis has little prospect of success.


Assuntos
Dissecação da Artéria Carótida Interna/terapia , Infarto da Artéria Cerebral Média/terapia , Stents , Trombectomia/métodos , Artéria Carótida Interna/patologia , Dissecação da Artéria Carótida Interna/complicações , Angiografia Cerebral , Angiografia Coronária , Humanos , Infarto da Artéria Cerebral Média/complicações , Masculino , Pessoa de Meia-Idade
8.
Clin Neuroradiol ; 22(4): 327-33, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22941252

RESUMO

PURPOSE: The aim of this study was to show the different origins and courses of the extracranial VA on CTA with special emphasis on embryological considerations. The duplicated VA is an anomaly that has been assumed to predispose for dissection and to be associated with aneurysms. We report its frequency and clinical significance. METHODS: We retrospectively reviewed CTA of 539 patients by using a contrast-enhanced CTA protocol of the VA on CT. RESULTS: Ninety-four-point-two percent of left VA originated from left subclavian artery and entered the transverse foramen at C6 in nearly all cases. Six-point-three-percent of left VA (m = 4 %, f = 10 %) originated from the aortic arch and entered the transverse foramen either at C4, C5 or C7 but never at C6. One case of an aberrant retroesophageal right VA originated from the aortic arch distal to the left subclavian artery and entered at C7 (0.19 %). All other right VA originated from the right subclavian artery (99.8 %) and entered between C4 and C6. We diagnosed four cases of duplicated VA (0.74 %) with a female predominance (1.9 %) without any signs of dissection on CTA. Two cases with VA duplication had intracranial arterial aneurysms. CONCLUSIONS: The VA is a longitudinal anastomosis of segmental metameric arteries. The level of entrance into the transverse foramen indicates which metameric artery or arteries persist. Duplication corresponds to persistence of two segmental arteries and is a rare phenomenon. VA duplication might be associated with vascular lesions.


Assuntos
Angiografia Cerebral , Tomografia Computadorizada Multidetectores , Artéria Vertebral/diagnóstico por imagem , Artéria Vertebral/embriologia , Adulto , Idoso de 80 Anos ou mais , Aneurisma/diagnóstico por imagem , Aneurisma/embriologia , Aorta Torácica/anormalidades , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/embriologia , Meios de Contraste , Feminino , Humanos , Iohexol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Hemorragia Subaracnóidea/diagnóstico por imagem , Hemorragia Subaracnóidea/embriologia , Artéria Subclávia/anormalidades , Artéria Subclávia/diagnóstico por imagem , Artéria Subclávia/embriologia , Artéria Vertebral/anormalidades , Insuficiência Vertebrobasilar/diagnóstico por imagem , Insuficiência Vertebrobasilar/embriologia
10.
Opt Express ; 20(3): 3296-301, 2012 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-22330567

RESUMO

We have demonstrated a monolithic cladding-pumped ytterbium-doped single all-fiber laser oscillator generating 1 kW of CW signal power at 1080 nm with 71% slope efficiency and near diffraction-limited beam quality. Fiber components were highly integrated on "spliceless" passive fibers to promote laser efficiency and alleviate non-linear effects. The laser was pumped through a 7:1 pump combiner with seven 200-W 91x nm fiber-pigtailed wavelength-beam-combined diode-stack modules. The signal power of such a single all-fiber laser oscillator showed no evidence of roll-over, and the highest output was limited only by available pump power.


Assuntos
Amplificadores Eletrônicos , Lasers Semicondutores , Oscilometria/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento
11.
Unfallchirurg ; 114(1): 41-6, 2011 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-21153393

RESUMO

BACKGROUND: The aim of the study was to ascertain the state of the art in x-ray assessment in an emergency surgical department. METHODS: From August 2008 to February 2009 a total of 1,588 plain x-rays of 658 patients from the emergency department were included in this study. The images were assessed by 3 experienced orthopedic surgeons and 1 experienced radiologist. The incidence of missed traumatic lesions and suspected lesions and the treatment of these patients were noted. RESULTS: A total of 136 pathological cases with 238 pathological x-ray findings were found. The mean rate of missed lesions was 13% of the assessed cases. Despite the fact that the rate of missed lesions varied from 9-25% depending on the level of experience, all patients were treated adequately. The quality of x-ray assessment improved with the level of training of the individual doctors. CONCLUSION: The present situation is in need of improvement but it is not critical. Junior medical staff should undergo a special training in x-ray assessment.


Assuntos
Erros de Diagnóstico/estatística & dados numéricos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Competência Profissional/estatística & dados numéricos , Centros de Traumatologia/estatística & dados numéricos , Traumatologia/estatística & dados numéricos , Ferimentos e Lesões/diagnóstico por imagem , Ferimentos e Lesões/epidemiologia , Erros de Diagnóstico/prevenção & controle , Reações Falso-Negativas , Alemanha/epidemiologia , Humanos , Incidência , Radiografia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Eur J Med Res ; 11(8): 336-42, 2006 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-17052969

RESUMO

OBJECTIVE: For staging, follow-up and even screening (www.screening.info) an "all-in-one" imaging examination is desirable. In the concept of whole body MRI, lung imaging prevails as the weakest link. The purpose of our study was to determine the optimal MRI sequences for the detection of malignant lung nodules. PATIENTS AND METHODS: On the basis of 6 lung cancer, 46 metastases and one tuberculoma in 13 patients eight MRI sequences--HASTE, IR-HASTE, fat saturated TrueFISP, STIR, VIBEipat = 2, and contrast-enhanced (CE) VIBE (with ipat = 2, 0, 4) performed with parallel imaging and 12 matrix coil elements--were compared in terms of contrast-to-noise ratio (CNR) and quality in the visualization of the lung nodules using multidetector CT as standard of reference. The parameters of the sequences were pragmatically selected to minimize the imaging time to allow for imaging the entire lung within one breathold interval. RESULTS: The STIR sequence was found to be the best for detecting malignant lung nodules (p<0.01) followed by the FS TrueFISP, CE VIBE subsetipat = 0, CE VIBE subsetipat = 2, IR-HASTE, HASTE, CE VIBE subsetipat = 4, and VIBE. The STIR sequence visualized malignant nodules down to 2 mm in size and did not display the 19 mm tuberculoma. CONCLUSION: The STIR sequence should be included in future studies investigating if MRI can compete with CT in the early identification (detection and classification) of malignant lung nodules.


Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/patologia , Imageamento por Ressonância Magnética/métodos , Idoso , Carcinoma/diagnóstico , Carcinoma/diagnóstico por imagem , Carcinoma/patologia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/secundário , Neoplasias do Colo/patologia , Neoplasias do Colo/secundário , Feminino , Humanos , Masculino , Melanoma/patologia , Melanoma/secundário , Pessoa de Meia-Idade , Metástase Neoplásica/diagnóstico , Metástase Neoplásica/diagnóstico por imagem , Metástase Neoplásica/patologia , Estadiamento de Neoplasias , Neoplasias Parotídeas/patologia , Neoplasias Parotídeas/secundário , Projetos Piloto , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/secundário , Tomografia Computadorizada por Raios X/métodos , Tuberculoma/patologia
13.
Radiologe ; 46(6): 513-9, 2006 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-16786388

RESUMO

Back pain associated with a herniated disk has become an important and increasing general health problem in Germany and other industrialized countries. After all methods of conservative treatment have been exhausted, nucleolysis may be a minimally invasive alternative to surgery. In nucleolysis, chondrolytic substances or other substances, which reduce the pressure within the disk by other means, are injected into the nucleus pulposus under CT guidance. Among various substances, which have been employed for nucleolysis, an ozone-oxygen mixture appears to be very promising. The water-binding capacity of ozone results in a reduction of pain for several months. Moreover, it has an anti-inflammatory effect and results in an increase of perfusion. Ozone is converted into pure oxygen in the body and has a low allergic potential. Recent minimally invasive therapeutic methods such as percutaneous nucleotomy or laser treatment do not result in superior results compared with nucleolysis.


Assuntos
Dor nas Costas/etiologia , Dor nas Costas/prevenção & controle , Quimiólise do Disco Intervertebral/métodos , Deslocamento do Disco Intervertebral/complicações , Deslocamento do Disco Intervertebral/terapia , Ozônio/uso terapêutico , Humanos , Guias de Prática Clínica como Assunto , Padrões de Prática Médica , Resultado do Tratamento
14.
Rofo ; 178(4): 385-90, 2006 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-16607587

RESUMO

PURPOSE: To evaluate the predictive value of MR imaging criteria, the biopsy Gleason score, and preoperative PSA levels for differentiating between T2 and T3 prostate carcinomas. MATERIALS AND METHODS: Endorectal MR images of 81 patients (median age: 65 years, range: 48 to 81 years) who had biopsy-proven prostate cancer and underwent a radical prostatectomy were analyzed retrospectively. The existence of different imaging features were recorded for each patient. A radiological analysis comprising all used imaging criteria was also performed for every patient. Optimal cut-off levels for the biopsy Gleason score and preoperative PSA levels were obtained using ROC analyses. Subsequently, a logistic regression analysis was performed to identify features which make a significant contribution to the prediction of the tumor stage. RESULTS: Histological examination showed that 24 patients (29.6 %) had a T3 tumor and 57 patients (70.4 %) had a T2 tumor. The mean preoperative PSA level was 9.4 ng/ml (+/- 7 ng/ml), and the median Gleason score was 6 with a range of 4 to 8. The radiological judgment comprising all imaging criteria led to a sensitivity of 54.2 % and specificity of 79 % for the detection of a T3 tumor. The obliteration of the rectoprostatic angle (regression coefficient B = 2.30; standard error (se) = 0.80; p = 0.002) and the biopsy Gleason score (B = 1.16; se = 0.3; p = 0.001) were the parameters with the highest independent predictive value for the diagnosis of an extracapsular tumor spread. The other radiological criteria and the preoperative PSA level were not statistically significant. A combination of the parameters "obliteration of the rectoprostatic angle" and "biopsy Gleason score" led to a sensitivity and specificity of 75 % and 79 %, respectively (existence of one parameter sufficient). The optimal cut-off value was a Gleason score of 7 for the differentiation between T2 and T3 prostate carcinomas. CONCLUSION: In our study, only the criteria "obliteration of the rectoprostatic angle" and "biopsy Gleason score" were of predictive value for the diagnosis of a T3 prostate carcinoma. The other MR imaging criteria and the preoperative PSA levels had no additional benefit.


Assuntos
Biomarcadores Tumorais/sangue , Biópsia , Imageamento por Ressonância Magnética/métodos , Proctoscopia/métodos , Antígeno Prostático Específico/sangue , Próstata/patologia , Neoplasias da Próstata/patologia , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/cirurgia , Sensibilidade e Especificidade
15.
Rofo ; 178(3): 278-86, 2006 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-16508834

RESUMO

PURPOSE: To evaluate the diagnostic quality and minimum required dose to obtain acceptable images for diagnostic purposes in the field of musculoskeletal radiology. MATERIALS AND METHODS: A critical comparison of the image quality produced by a novel flat panel detector and the conventional screen/film system using a contrast-detail phantom was performed in phase I. Images from both systems were obtained with the same dose and displayed with similar contrast and density. In phase II images of significant anatomical structures in cadaver extremities obtained using the digital detector system and the standard film/screen system were critically evaluated. After a successive reduction in the X-ray dose for 84 patients in phase III, eight independent radiologists compared the image quality of the screen/film system to that of the novel flat panel detector. RESULTS: Phases I and II revealed a difference in the image quality achieved by the standard screen/film system and the digital detector system to the advantage of the digital detector system. In 77 of 84 patients (91.7 %), phase III showed equal image quality after a 50 % reduction in the X-ray dose. In 3 cases (3.6 %) the image quality and the level of contrast were better. No unified statement could be made for 4 patients (4.7 %). CONCLUSION: Digital imaging of skeletal disorders using the novel flat panel detector makes it possible to reduce the X-ray dose by 50 % with equal or even better image quality.


Assuntos
Doenças Ósseas/diagnóstico por imagem , Sistema Musculoesquelético/diagnóstico por imagem , Doses de Radiação , Intensificação de Imagem Radiográfica , Adulto , Pré-Escolar , Feminino , Fraturas Ósseas/diagnóstico por imagem , Humanos , Masculino , Imagens de Fantasmas , Valores de Referência , Selênio
16.
Rofo ; 178(1): 71-7, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16392060

RESUMO

PURPOSE: To evaluate the accuracy of software for computer-aided detection (CAD) of lung nodules using different reconstruction slice thickness protocols in multidetector CT. MATERIALS AND METHODS: Raw image data sets for 15 patients who had undergone 16-row multidetector CT (MDCT) for known pulmonary nodules were reconstructed at a reconstruction thickness of 5.0, 2.0 and 1.0 mm with a reconstruction increment of 1.5, 1.0 and 0.5 mm, respectively. The "Nodule Enhanced Viewing" (NEV) tool of LungCare for computer-aided detection of lung nodules was applied to the reconstructed images. The reconstructed images were also blinded and then evaluated by 2 radiologists (A and B). Data from the evaluating radiologists and CAD was then compared to an independent reference standard established using the consensus of 2 independent experienced chest radiologists. The eligible nodules were grouped according to their size (diameter > 10, 5 - 10, < 5 mm) for assessment. Statistical analysis was performed using the receiver operating characteristic (ROC) curve analysis, t-test and two-rater Cohen's Kappa co-efficient. RESULTS: A total of 103 nodules were included in the reference standard by the consensus panel. The performance of CAD was marginally lower than that of readers at a 5.0-mm reconstruction thickness (AUC = 0.522, 0.517 and 0.497 for A, B and CAD, respectively). In the case of 2.0-mm reconstruction slices, the performance of CAD was better than that of the readers (AUC = 0.524, 0.524 and 0.614 for A, B and CAD, respectively). CAD was found to be significantly superior to radiologists in the case of 1.0-mm reconstruction slices (AUC = 0.537, 0.531 and 0.675 for A, B and CAD, respectively). The sensitivity at a reconstruction thickness of 1.0 mm was determined to be 66.99 %, 68.93 % and 80.58 % for A, B and CAD, respectively. The time required for detection was shortest for CAD at reconstruction slices of 1.0 mm (mean t = 4 min). The performance of radiologists was greatly enhanced when using CAD: sensitivity 91.26 % and 94.17 % for CAD+A and CAD+B, respectively (AUC = 0.889 and 0.917). CAD was most advantageous in the detection of nodules < 10 mm. CONCLUSION: At a 1.0-mm reconstruction thickness, CAD's ability to detect nodules < 10 mm is superior to that of radiologists and its relatively short evaluation time makes it a viable second reader.


Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Diagnóstico por Computador/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Software
17.
Eur Radiol ; 16(9): 2044-50, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16344961

RESUMO

The purpose of this study was to examine the feasibility and safety of MR-guided biopsies with a newly designed cordless coil in an open low-field magnetic resonance (MR) system. Eleven patients were biopsied using a low-field system (0.2 T, Magnetom Concerto, Siemens) by using the new cordless coil (Siemens). The biopsies were performed in different organ systems [liver (n = 7), abdomen (n = 1), shoulder (n = 1), pelvis (n = 1) and hip (n = 1)]. The procedures were guided using T1-weighted FLASH (fast low-angle shot) sequences. The lesions were biopsied using the coaxial technique through a 15-gauge puncture needle with a 16-gauge biopsy handy. Coil handling, image quality and complications were evaluated. Imaging quality and visualization of the lesions were optimal up to a penetration depth of 9 cm. In all cases the biopsy procedures were successfully performed with MR guidance without any complications. Pathological findings revealed seven cases of malignant tissue and four cases of non-malignant tissue. The use of the cordless coil allows improved patient access during the biopsy and an improved handling of the coil system. MR-guided biopsy using the novel cordless coil system can be performed safely and precisely with easy handling of the coil. This coil concept, however, is restricted to special indications.


Assuntos
Biópsia por Agulha , Imageamento por Ressonância Magnética , Neoplasias/diagnóstico , Idoso , Biópsia por Agulha/métodos , Osso e Ossos/patologia , Estudos de Viabilidade , Humanos , Fígado/patologia , Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Imagens de Fantasmas , Imagem Corporal Total
18.
Eur Radiol ; 16(2): 307-12, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16059677

RESUMO

The purpose of this study was to evaluate the safety and precision of MRI-guided biopsies of retroperitoneal space-occupying tumors in an open low-field system. In 30 patients with indistinct retroperitoneal tumors [paraaortic lesion (n=20), kidney (n=2), suprarenal gland (n=3) and pancreas (n=5)] MR-guided biopsies were performed using a low-field system (0.2 T, Magnetom Concerto, Siemens, Germany). For the monitoring of the biopsies T1-weighted FLASH sequences (TR/TE=160/5 ms; 90 degrees ) were used in all patients and modified FLASH sequences (TR/TE=160/13 ms; 90 degrees ) in ten patients. After positioning of the needle in the tumors 114 biopsy specimens were acquired in coaxial technique with 16-gauge cutting needles (Somatex, Germany). The biopsies were successfully performed in all patients without vascular or organ injuries. The visualization of the aortic blood flow with MRI facilitated the biopsy procedures of paraaortic lesions. The size of the lesions ranged from 1.6 to 7.5 cm. The median distance of the biopsy access path was 10.4 cm. Adequate specimens were obtained in 28 cases (93.3%) resulting in a correct histological classification of 27 lesions (90%). In conclusion, MR-guided biopsies of retroperitoneal lesions using an open low-field system can be performed safely and accurately and is an alternative to CT-guided biopsies.


Assuntos
Biópsia por Agulha , Aumento da Imagem , Neoplasias Retroperitoneais/patologia , Cirurgia Assistida por Computador , Adulto , Idoso , Idoso de 80 Anos ou mais , Artefatos , Diagnóstico Diferencial , Feminino , Humanos , Neoplasias Renais/patologia , Linfoma/patologia , Masculino , Pessoa de Meia-Idade , Neurofibroma/patologia , Pâncreas/patologia , Neoplasias Pancreáticas/patologia , Fibrose Retroperitoneal/patologia , Neoplasias Retroperitoneais/secundário , Espaço Retroperitoneal/patologia , Sensibilidade e Especificidade , Avaliação da Tecnologia Biomédica
19.
Eur Radiol ; 15(1): 174-82, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15351902

RESUMO

The purpose of this study was to examine the feasibility and safety of MR-guided biopsies with a transgluteal approach in patients with uncertain or suspicious prostate lesions. Twenty-five patients with uncertain or suspicious focal prostate lesions detected by high-field MR imaging of the prostate gland using endorectal coil imaging were biopsied with a transgluteal approach in a low-field MRI system (0.2 T, Concerto, Siemens). The procedures were guided using T1-weighted FLASH sequences. The prostate gland was biopsied repeatedly with a coaxial technique through a 15-gauge pencil tip with a 16-gauge biopsy handy (median 3.8 samples per patient). Complications and biopsy findings were documented retrospectively. Using T1-weighted sequences biopsy procedures were performed successfully with MR guidance in all cases without any side effects or complications. The median intervention time was 11.3 min. Pathological findings revealed ten cases of hyperplasia or atrophy, three cases of prostatitis, ten cases of carcinoma and two cases of normal tissue. The clinical follow-up showed that in two patients prostate cancer was missed at MR-guided biopsy. Transgluteal MR-guided biopsy of the prostate gland is a safe and promising approach for histological clarification of uncertain or suspicious lesions.


Assuntos
Biópsia por Agulha/métodos , Nádegas , Imageamento por Ressonância Magnética , Neoplasias da Próstata/patologia , Idoso , Estudos de Viabilidade , Humanos , Masculino , Pessoa de Meia-Idade , Segurança
20.
Eur Radiol ; 14(12): 2228-35, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15449012

RESUMO

A computed tomography (CT) cut-off for differentiating neoplastic lesions (polyps/carcinoma) from normal colon in contrast-enhanced CT colonography (CTC) relating to the contrast phase and lesion size is determined. CT values of 64 colonic lesions (27 polyps <10 mm, 13 polyps > or =10 mm, 24 carcinomas) were determined by region-of-interest (ROI) measurements in 38 patients who underwent contrast-enhanced CTC. In addition, the height (H) of the colonic lesions was measured in CT. CT values were also measured in the aorta (A), superior mesenteric vein (V) and colonic wall. The contrast phase was defined by xA + (1-x)V using x as a weighting factor for describing the different contrast phases ranging from the pure arterial phase (x=1) over the intermediate phases (x=0.9-0.1) to the pure venous phase (x=0). The CT values of the lesions were correlated with their height (H), the different phases (xA+(1-x)V) and the ratio [xA+(I-x)V]/H. The CT cut-off was linearly adjusted to the imaged contrast phase and height of the lesion by the line y=m[xA+(1-x)V]H+y(0). The slope m was determined by linear regression in the correlation (lesion approximately [xA+(i-x)V]/H) and the Y-intercept y(0) by the minimal shift of the line needed to maximize the accuracy of separating the colonic wall from the lesions. The CT value of the lesions correlated best with the intermediate phase: 0.4A + 0.6V (r=0.8 for polyps > or =10 mm, r=0.6 for carcinomas, r=0.4 for polyps <10 mm). The accuracy in the differentiation between lesions and normal colonic wall increased with the height implemented as divisor, reached 91% and was obtained by the dynamic cut-off described by the formula: cut-off (A,V,H)=1.1 [0.4A+0.6V]/H+69.8. The CT value of colonic polyps or carcinomas can be increased extrinsically by scanning in the phase in which 0.4A + 0.6V reaches its maximum. Differentiating lesions from normal colon based on CT values is possible in contrast-enhanced CTC and improves when the cut-off is adjusted (normalized) to the contrast phase and lesion size.


Assuntos
Carcinoma/diagnóstico por imagem , Colo/diagnóstico por imagem , Neoplasias do Colo/diagnóstico por imagem , Pólipos do Colo/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Colonografia Tomográfica Computadorizada , Meios de Contraste , Diagnóstico por Computador , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
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