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1.
Skeletal Radiol ; 51(2): 375-380, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33851252

RESUMEN

OBJECTIVE: During the COVID-19 pandemic, the number of patients presenting in hospitals because of emergency conditions decreased. Radiology is thus confronted with the effects of the pandemic. The aim of this study was to use natural language processing (NLP) to automatically analyze the number and distribution of fractures during the pandemic and in the 5 years before the pandemic. MATERIALS AND METHODS: We used a pre-trained commercially available NLP engine to automatically categorize 5397 radiological reports of radiographs (hand/wrist, elbow, shoulder, ankle, knee, pelvis/hip) within a 6-week period from March to April in 2015-2020 into "fracture affirmed" or "fracture not affirmed." The NLP engine achieved an F1 score of 0.81 compared to human annotators. RESULTS: In 2020, we found a significant decrease of fractures in general (p < 0.001); the average number of fractures in 2015-2019 was 295, whereas it was 233 in 2020. In children and adolescents (p < 0.001), and in adults up to 65 years (p = 0.006), significantly fewer fractures were reported in 2020. The number of fractures in the elderly did not change (p = 0.15). The number of hand/wrist fractures (p < 0.001) and fractures of the elbow (p < 0.001) was significantly lower in 2020 compared with the average in the years 2015-2019. CONCLUSION: NLP can be used to identify relevant changes in the number of pathologies as shown here for the use case fracture detection. This may trigger root cause analysis and enable automated real-time monitoring in radiology.


Asunto(s)
COVID-19 , Radiología , Adolescente , Distribución por Edad , Anciano , Niño , Humanos , Incidencia , Procesamiento de Lenguaje Natural , Pandemias , SARS-CoV-2
2.
Clin Radiol ; 75(1): 78.e1-78.e7, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31587801

RESUMEN

AIM: To develop a robust open-source method for fully automated extraction of total lung capacity (TLC) from computed tomography (CT) images and to demonstrate its integration into the clinical workflow. MATERIALS AND METHODS: Using only open-source software, an algorithm was developed based on a region-growing method that does not require manual interaction. Lung volumes calculated from reconstructions with different kernels (TLCCT) were assessed. To validate the algorithm calculations, the results were correlated to TLC measured by pulmonary function testing (TLCPFT) in a subgroup of patients for which this information was available within 3 days of the CT examination. RESULTS: A total of 288 patients were analysed retrospectively. Manual review revealed poor segmentation results in 13 (4.5%) patients. In the validation subgroup, the correlation between TLCCT and TLCPFT was r=0.87 (p<0.001). Measurements showed excellent agreement between the two reconstruction kernels with an intraclass correlation coefficient (ICC) of 0.99. Calculation of the volumes took an average of 5 seconds (standard deviation: 3.72 seconds). Integration of the algorithm into the departments of the PACS environment was successful. A DICOM-encapsulated PDF document with measurements and an overlay of the segmentation results was sent to the PACS to allow the radiologists to detect false measurements. CONCLUSIONS: The algorithm developed allows fast and fully automated calculation of lung volume without any additional input from the radiologist. The algorithm delivers excellent segmentation in >95% of cases with significant positive correlations between lung volume on CT and TLC on PFT.


Asunto(s)
Algoritmos , Mediciones del Volumen Pulmonar/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía Torácica/métodos , Tomografía Computarizada por Rayos X/métodos , Femenino , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Pruebas de Función Respiratoria , Estudios Retrospectivos , Programas Informáticos
3.
J Digit Imaging ; 33(4): 1026-1033, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32318897

RESUMEN

Structured reporting is a favorable and sustainable form of reporting in radiology. Among its advantages are better presentation, clearer nomenclature, and higher quality. By using MRRT-compliant templates, the content of the categorized items (e.g., select fields) can be automatically stored in a database, which allows further research and quality analytics based on established ontologies like RadLex® linked to the items. Additionally, it is relevant to provide free-text input for descriptions of findings and impressions in complex imaging studies or for the information included with the clinical referral. So far, however, this unstructured content cannot be categorized. We developed a solution to analyze and code these free-text parts of the templates in our MRRT-compliant reporting platform, using natural language processing (NLP) with RadLex® terms in addition to the already categorized items. The established hybrid reporting concept is working successfully. The NLP tool provides RadLex® codes with modifiers (affirmed, speculated, negated). Radiologists can confirm or reject codes provided by NLP before finalizing the structured report. Furthermore, users can suggest RadLex® codes from free text that is not correctly coded with NLP or can suggest to change the modifier. Analyzing free-text fields took 1.23 s on average. Hybrid reporting enables coding of free-text information in our MRRT-compliant templates and thus increases the amount of categorized data that can be stored in the database. This enhances the possibilities for further analyses, such as correlating clinical information with radiological findings or storing high-quality structured information for machine-learning approaches.


Asunto(s)
Sistemas de Información Radiológica , Radiología , Diagnóstico por Imagen , Humanos , Procesamiento de Lenguaje Natural , Radiografía
4.
Blood Cells Mol Dis ; 57: 35-41, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26852653

RESUMEN

OBJECTIVE: This was a retrospective data analysis to evaluate the treatment response to enzyme replacement therapy (ERT) with Velaglucerase alfa using whole-body magnetic resonance imaging (MRI). MATERIALS AND METHODS: A baseline and follow-up MRI were performed on 18 Gaucher Type 1 patients at an interval of 11.6 months. The MRI score systems determined the Bone-Marrow-Burden (BMB) score, the Düsseldorf-Gaucher score (DGS), and the Vertebra-Disc-Ratio (VDR). The Severity Score Index Type 1 (GD-DS3) was also assessed. RESULTS: The baseline MRI medians were: BMB, 7.00; DGS, 3.00; and VDR: 1.70; while, the follow-up MRI medians were: BMB, 7.00; DGS, 3.00; and VDR: 1.73. The baseline GD-DS3 median was 2.40 (BMB excl.: 0.50) and the follow-up median was 2.00 (BMB excl.: 0.50). There was weak statistical significance with the Wilcoxon signed-rank test for the DGS (p=0.034) and GD-DS3 (p=0.047) between both MRIs. CONCLUSION: Velaglucerase alfa therapy is a effective long-term treatment for Gaucher Type 1 patients who are newly diagnosed or switching therapies. Measurements with whole-body MRI and an objective scoring system were reliable tools for detecting early stage bone marrow activity. Further research is needed to evaluate the "Booster-Effect" of Velaglucerase alfa therapy in Gaucher skeletal disease.


Asunto(s)
Terapia de Reemplazo Enzimático/métodos , Enfermedad de Gaucher/diagnóstico , Enfermedad de Gaucher/tratamiento farmacológico , Glucosilceramidasa/uso terapéutico , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Médula Ósea/efectos de los fármacos , Médula Ósea/patología , Femenino , Estudios de Seguimiento , Enfermedad de Gaucher/patología , Humanos , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Proteínas Recombinantes/uso terapéutico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Imagen de Cuerpo Entero/métodos
5.
Magn Reson Med ; 74(3): 884-93, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25213218

RESUMEN

PURPOSE: MRI of lung airspaces using gases with MR-active nuclei ((3) He, (129) Xe, and (19) F) is an important area of research in pulmonary imaging. The volume-controlled administration of gas mixtures is important for obtaining quantitative information from MR images. State-of-the-art gas administration using plastic bags (PBs) does not allow for a precise determination of both the volume and timing of a (3) He bolus. METHODS: A novel application unit (AU) was built according to the requirements of the German medical devices law. Integrated spirometers enable the monitoring of the inhaled gas flow. The device is particularly suited for hyperpolarized (HP) gases (e.g., storage and administration with minimal HP losses). The setup was tested in a clinical trial (n = 10 healthy volunteers) according to the German medicinal products law using static and dynamic ventilation HP-(3) He MRI. RESULTS: The required specifications for the AU were successfully realized. Compared to PB-administration, better reproducibility of gas intrapulmonary distribution was observed when using the AU for both static and dynamic ventilation imaging. CONCLUSION: The new AU meets the special requirements for HP gases, which are storage and administration with minimal losses. Our data suggest that gas AU-administration is superior to manual modes for determining the key parameters of dynamic ventilation measurements.


Asunto(s)
Medios de Contraste/administración & dosificación , Helio/administración & dosificación , Isótopos/administración & dosificación , Pulmón/fisiología , Imagen por Resonancia Magnética/métodos , Ventilación Pulmonar/fisiología , Adulto , Medios de Contraste/química , Medios de Contraste/uso terapéutico , Diseño de Equipo , Helio/química , Helio/uso terapéutico , Humanos , Isótopos/química , Isótopos/uso terapéutico , Imagen por Resonancia Magnética/instrumentación , Masculino
6.
Eur Radiol ; 25(3): 785-91, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25316056

RESUMEN

OBJECTIVE: To assess whether MRI is a suitable modality for the preoperative assessment and quantification of pectus excavatum. METHODS: A total of 69 patients (57 male, 12 female; median age 15 years, range 5-35 years) with pectus excavatum were evaluated preoperatively using standardized MRI sequences on 1.5- and 3-Tesla systems (T2-HASTE/inspiration and expiration, T1-VIBE, T2-TRUFI free-breathing, T2-BLADE). The MR sequences were analysed for quality semiquantitatively. The Haller index, correction index, sternal rotation angle and asymmetry index were assessed; correlations between these indices and changes in inspiration and expiration were evaluated. RESULTS: T2-HASTE was the best sequence to assess pectus excavatum morphology, with a higher quality at 3 T than at 1.5 T. All indices could be assessed in every patient. A total of 37 patients had a symmetric deformity, 32 patients an asymmetric deformity. The Haller index correlated significantly (p < 0.001) with the correction index, both becoming higher in expiration. The asymmetry index correlated with the sternal rotation angle (p < 0.001) and did not change significantly in expiration (p = 0.28). CONCLUSIONS: Thoracic MRI is suitable for the preoperative evaluation of patients with pectus excavatum. An exact morphologic assessment is possible without radiation exposure as well as the determination of several indices to quantify the deformities.


Asunto(s)
Tórax en Embudo/patología , Imagen por Resonancia Magnética/normas , Adolescente , Adulto , Niño , Preescolar , Femenino , Tórax en Embudo/fisiopatología , Tórax en Embudo/cirugía , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Cuidados Preoperatorios/métodos , Respiración , Estudios Retrospectivos , Rotación , Sensibilidad y Especificidad , Esternón/fisiología , Adulto Joven
7.
Radiologe ; 54(5): 487-90, 2014 May.
Artículo en Alemán | MEDLINE | ID: mdl-24733696

RESUMEN

Due to economic considerations and thanks to technological advances there is a growing interest in the integration of teleradiological applications into the regular radiological workflow. The legal and technical hurdles which are still to be overcome are being discussed in politics as well as by national and international radiological societies. The European Commission as well as the German Federal Ministry of Health placed a focus on telemedicine with their recent eHealth initiatives. The European Society of Radiology (ESR) recently published a white paper on teleradiology. In Germany §3 section 4 of the Röntgenverordnung (RöV, X-ray regulations) and DIN 6868-159 set a framework in which teleradiology can also be used for primary reads. These possibilities are already being used by various networks and some commercial providers across Germany. With regards to cross-border teleradiology, which currently stands in contrast to the RöV, many issues remain unsolved.


Asunto(s)
Guías de Práctica Clínica como Asunto , Radiología/legislación & jurisprudencia , Radiología/normas , Telerradiología/legislación & jurisprudencia , Telerradiología/normas , Alemania , Internacionalidad
8.
Radiologe ; 54(1): 40-4, 2014 Jan.
Artículo en Alemán | MEDLINE | ID: mdl-24366353

RESUMEN

Radiology plays an important role in introduction and use of information technology (IT) systems in the daily clinical routine. The radiology information system (RIS) and picture archiving and communication system (PACS) are the main systems used in a digital radiology department. In this article the basic principles and functions of these systems and trends in development are described.


Asunto(s)
Atención a la Salud/organización & administración , Informática Médica/métodos , Modelos Organizacionales , Sistemas de Información Radiológica/organización & administración , Tecnología Radiológica/organización & administración , Interfaz Usuario-Computador , Alemania
9.
Radiologe ; 53(3): 257-60, 2013 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-23456043

RESUMEN

Due to increasing amounts of data in radiology methods for image compression appear both economically and technically interesting. Irreversible image compression allows markedly higher reduction of data volume in comparison with reversible compression algorithms but is, however, accompanied by a certain amount of mathematical and visual loss of information. Various national and international radiological societies have published recommendations for the use of irreversible image compression. The degree of acceptable compression varies across modalities and regions of interest.The DICOM standard supports JPEG, which achieves compression through tiling, DCT/DWT and quantization. Although mathematical loss due to rounding up errors and reduction of high frequency information occurs this results in relatively low visual degradation.It is still unclear where to implement irreversible compression in the radiological workflow as only few studies analyzed the impact of irreversible compression on specialized image postprocessing. As long as this is within the limits recommended by the German Radiological Society irreversible image compression could be implemented directly at the imaging modality as it would comply with § 28 of the roentgen act (RöV).


Asunto(s)
Compresión de Datos/métodos , Compresión de Datos/tendencias , Intensificación de Imagen Radiográfica/métodos , Intensificación de Imagen Radiográfica/tendencias , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía/métodos , Radiografía/tendencias , Algoritmos , Humanos
10.
Radiologe ; 53(6): 535-8, 2013 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-23519445

RESUMEN

Strategies for reducing radiation exposure are an important part of optimizing medical imaging and therefore a relevant quality factor in radiology. Regarding the medical radiation exposure, computed tomography has a special relevance. The use of the integrating the healthcare enterprise (IHE) radiation exposure monitoring (REM) profile is the upcoming standard for organizing and collecting exposure data in radiology. Currently most installed base devices do not support this profile generating the required digital imaging and communication in medicine (DICOM) dose structured reporting (SR). For this reason different solutions had been developed to register dose exposure measurements without having the dose SR object.Registration and analysis of dose-related parameters is required for constantly optimizing examination protocols, especially computed tomography (CT) examinations based on the latest research results in order to minimize the individual radiation dose exposure from medical imaging according to the principle as low as reasonably achievable (ALARA).


Asunto(s)
Carga Corporal (Radioterapia) , Documentación/métodos , Dosis de Radiación , Protección Radiológica/métodos , Radiometría/métodos , Tomografía Computarizada por Rayos X/métodos , Humanos
11.
Acad Radiol ; 30 Suppl 1: S143-S154, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37095047

RESUMEN

RATIONALE AND OBJECTIVES: Hepatocellular carcinoma (HCC) is the only tumor entity that allows non-invasive diagnosis based on imaging without further histological proof. Therefore, excellent image quality is of utmost importance for HCC diagnosis. Novel photon-counting detector (PCD) CT improves image quality via noise reduction and higher spatial resolution, inherently providing spectral information. The aim of this study was to investigate these improvements for HCC imaging with triple-phase liver PCD-CT in a phantom and patient population study focusing on identification of the optimal reconstruction kernel. MATERIALS AND METHODS: Phantom experiments were performed to analyze objective quality characteristics of the regular body and quantitative reconstruction kernels, each with four sharpness levels (36-40-44-48). For 24 patients with viable HCC lesions on PCD-CT, virtual monoenergetic images at 50 keV were reconstructed using these kernels. Quantitative image analysis included contrast-to-noise ratio (CNR) and edge sharpness. Three raters performed qualitative analyses evaluating noise, contrast, lesion conspicuity, and overall image quality. RESULTS: In all contrast phases, the CNR was highest using the kernels with a sharpness level of 36 (all p < 0.05), with no significant influence on lesion sharpness. Softer reconstruction kernels were also rated better regarding noise and image quality (all p < 0.05). No significant differences were found in image contrast and lesion conspicuity. Comparing body and quantitative kernels with equal sharpness levels, there was no difference in image quality criteria, neither regarding in vitro nor in vivo analysis. CONCLUSION: Soft reconstruction kernels yield the best overall quality for the evaluation of HCC in PCD-CT. As the image quality of quantitative kernels with potential for spectral post-processing is not restricted compared to regular body kernels, they should be preferred.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagen , Neoplasias Hepáticas/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Fantasmas de Imagen
13.
Eur J Radiol ; 156: 110514, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36108479

RESUMEN

PURPOSE: Photon-counting detector (PCD)-CT is expected to have a substantial impact on oncologic abdominal imaging. We compared subjective and objective image quality between PCD-CT and conventional energy-integrating detector (EID-)CT arterial phase abdominal scans. METHODS: This study included 84 patients undergoing both types of abdominal CT. EID-CT scans were acquired with a tube voltage of 100 kVp. With PCD-CT, acquired with 120-kVp, we reconstructed polychromatic T3D images and virtual monoenergetic images (VMIs) in 10-keV intervals from 40 to 90 keV. Quantitative image analysis included noise and contrast-to-noise ratio (CNR) of hepatic vessels, kidney cortex, and hypervascular liver lesions to liver parenchyma. Three raters used a 5-point Likert scale for qualitative image analysis of image noise and contrast, lesion conspicuity, and overall image quality. Radiation dose exposure (CT dose index) was compared between the two CT types. RESULTS: Mean CT dose index and effective dose were respectively 18 % and 26 % lower with PCD-CT versus EID-CT. Compared with EID-CT, CNRs of kidney cortex and vessel to liver parenchyma were significantly higher in PCD-CT VMIs at energies ≤ 60 keV and in polychromatic T3D images (p < 0.004). Overall image quality of PCD-CT VMIs at 50 and 60 keV was rated as significantly better (p < 0.01) than the EID-CT images (inter-reader agreement alpha = 0.80). Lesion conspicuity was significantly better in low-keV VMIs (p < 0.03) and worse in > 70-keV VMIs. CONCLUSIONS: With low-keV VMI, PCD-CT yields significantly improved objective and subjective quality of arterial phase oncological imaging compared with EID-CT. This advantage may translate into higher diagnostic confidence and lower radiation dose protocols.

14.
Eur Radiol ; 21(11): 2354-61, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21739349

RESUMEN

OBJECTIVES: To analyze the clinical results and complications of fluoroscopy guided internal-external Pull-type percutaneous radiological gastrostomy (Pull-type-PRG) and conventional external-internal percutaneous radiological gastrostomy (Push-type-PRG). METHODS: A total of 253 patients underwent radiological gastrostomy between January 2002 and January 2010. Data were collected retrospectively from radiology reports, Chart review of clinical notes, procedure reports, discharge summaries and subsequent hospital visits. Statistical analysis was performed to compare the two methods for gastrostomy with respect to peri-interventional aspects and clinical results. RESULTS: 128 patients received the Pull-type-PRG whereas the other 125 patients were served with the Push-type-PRG. Indications for gastrostomy were similar in these two groups. The most frequent indications for the both methods were stenotic oesophageal tumors or head/neck tumors (54.7% in Pull-type-PRG, 68% in Push-type-PRG). Gastrostomy procedures were successful in 98.3% in Pull-type-PRG compared to 92% in Push-type-PRG. There was no procedure-related mortality. Compared to Push-type-PRG, the peri-interventional complication rate was significantly reduced in Pull-type-PRG (14.8% versus 34.4%, P = 0.002). CONCLUSIONS: Compared to the external-internal Push-type-PRG, the internal-external Pull-type-PRG showed a high primary success rate and a decreased incidence of peri-interventional complications.


Asunto(s)
Fluoroscopía/métodos , Gastrostomía/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Diagnóstico por Imagen/métodos , Femenino , Neoplasias Gastrointestinales/cirugía , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Enfermedades del Sistema Nervioso/cirugía , Radiología/métodos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos
15.
Z Gastroenterol ; 49(4): 436-42, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21476179

RESUMEN

BACKGROUND: Surgery represents the only potentially curative treatment of hilar cholangiocarcinoma (hilCC). It may be suggested that meticulous preoperative work-up in Asian countries leads to higher resection rates. METHOD: One hundred and eighty-two patients treated in our department between 1998 and 2008 were included in an analysis based on our prospectively recorded database. Among them, 75 % had a percutaneous transhepatic cholangiography as part of their diagnostic work-up. A total of 160 patients underwent explorative surgery and 123 patients were resected (77 % of patients undergoing exploration, 68 % of all patients). RESULTS: Ninety-one percent of the patients were diagnosed to have Bismuth III and IV tumours. En-bloc resection of the tumour and the adjacent liver including segment 1 was the standard procedure in 109 of these patients, while hilar resection was performed in 14 patients. Upon tumour resection, hospital mortality was 5.7 %. Five-year survival in patients without surgery or with mere exploration was 0 %, after resection it reached 26 %. Patients with R 1 resection experienced longer survival than patients without resection (p < 0.001). Right and left hemihepatectomies were performed with identical frequency resulting in identical survival. Lymph node involvement proved to be the only significant predictor of prognosis (p = 0.006). CONCLUSION: Resection should be performed whenever possible since even after palliative resection survival is substantially increased compared to patients without resection. Meticulous preoperative work-up may contribute to a high resection rate in patients with hilCC by providing additional information allowing the surgeon to perform more aggressive approaches.


Asunto(s)
Neoplasias de los Conductos Biliares/mortalidad , Neoplasias de los Conductos Biliares/cirugía , Conducto Hepático Común/cirugía , Tumor de Klatskin/mortalidad , Tumor de Klatskin/cirugía , Cuidados Preoperatorios/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de los Conductos Biliares/diagnóstico por imagen , Colangiografía/estadística & datos numéricos , Femenino , Alemania/epidemiología , Conducto Hepático Común/diagnóstico por imagen , Humanos , Tumor de Klatskin/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Cuidados Preoperatorios/mortalidad , Medición de Riesgo , Factores de Riesgo , Análisis de Supervivencia , Tasa de Supervivencia , Resultado del Tratamiento
16.
Eur Surg Res ; 43(1): 13-23, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19365131

RESUMEN

BACKGROUND/AIMS: Clinical differentiation between infarcted and viable myocardium in the ischemic area at risk is controversial. We investigated the potential of contrast-enhanced cardiac magnetic resonance imaging (ceCMRI) in determining the area at risk 24 h after ischemia. METHODS: Myocardial ischemia was induced by percutaneous coronary intervention of the left anterior descending coronary artery in pigs. Coronary occlusion time was 30 min in group A, which caused little myocardial infarction and 45 min in group B, which led to irreversible damage. 24 h after reperfusion ceCMRI was performed at 2 and 15 min after administration of gadolinium-diethylenetriamine pentaacetic acid. The area at risk was determined by intravenous injection of Evans blue and myocardial viability by triphenyltetrazolium-chloride staining. RESULTS: The signal-intense areas at 2 and 15 min after contrast administration matched the area at risk in groups A and B. Nonviable myocardium in group A was overestimated (14-15%) while good agreement was present in group B. CONCLUSION: The area at risk of reperfused ischemic myocardium can be determined by ceCMRI 24 h after coronary recanalization. This type of information might have relevant clinical implications in the treatment and stratification of patients with acute coronary syndrome in particular after surgical interventions.


Asunto(s)
Imagen por Resonancia Magnética , Daño por Reperfusión Miocárdica/patología , Miocardio/patología , Animales , Supervivencia Celular , Angiografía Coronaria , Femenino , Gadolinio DTPA , Masculino , Necrosis , Porcinos , Supervivencia Tisular
17.
IEEE Trans Med Imaging ; 27(1): 64-74, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18270063

RESUMEN

The technology of multislice X-ray computed tomography (MSCT) provides volume data sets with approximately isotropic resolution, which permits a noninvasive 3-D measurement and quantification of airway geometry. In different diseases, like emphysema, chronic obstructive pulmonary disease (COPD), or cystic fribrosis, changes in lung parenchyma are associated with an increase in airway wall thickness. In this paper, we describe an objective measuring method of the airway geometry in the 3-D space. The limited spatial resolution of clinical CT scanners in comparison to thin structures like airway walls causes difficulties in the measurement of the density and the thickness of these structures. Initially, these difficulties will be addressed and then a new method is introduced to circumvent the problems. Therefore the wall thickness is approximated by an integral based closed-form solution, based on the volume conservation property of convolution. We evaluated the method with a phantom containing 10 silicone tubes and proved the repeatability in datasets of eight pigs scanned twice. Furthermore, a comparison of CT datasets of 16 smokers and 15 nonsmokers was done. Further medical studies are ongoing.


Asunto(s)
Algoritmos , Broncografía/métodos , Imagenología Tridimensional/métodos , Pulmón/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Animales , Fantasmas de Imagen , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Porcinos , Tomografía Computarizada por Rayos X/instrumentación
18.
Rofo ; 179(3): 289-99, 2007 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-17325996

RESUMEN

PURPOSE: To analyze the course of disease of patients treated with sequential TACE and to evaluate the dependent and independent prognostic factors for patient survival using the Cox Proportional Hazard Model. MATERIALS AND METHODS: 94 patients palliatively treated with TACE. Patients were selected if they had been treated at least 3 times. The TACE procedure was carried out at 8-week intervals using a suspension consisting of a fixed dosage of Mitomycin C (10 mg) and 10 ml Lipiodol. Follow-up investigations included contrast-enhanced multislice CT before and after TACE and assessment of the laboratory test results (i. e., blood count, liver enzymes, and coagulation). RESULTS: In 66.7 % of the patients, multifocal tumors were found. In 16.0 % of the patients, the tumor load represented more then 50 % of the liver volume. In 23.4 % of the cases, a portal vein thrombosis was found in the initial CT scan. The mean survival for the total cohort was 24.1 months (95 %-CI 20.1 - 28.2). During the investigation period, 72/94 of the patients died. The cumulative 1-year, 2-year, and 3-year survival rates are 71.6 %, 33.9 %, und 17.2 %, respectively. A median of 6.0 +/- 3.1 (range 14, n total = 612 TACE) was performed in each patient. A total of 62.5 % patients died because of tumor progression whereas 18.1 % died due to progressive liver failure. Patients in whom the tumor responded to the TACE treatment and who did not develop ascites or those with Okuda stage I or unifocal tumor growth showed a survival benefit whereas the presence of portal vein thrombosis was associated with a significantly poor outcome (p < 0.05). The Child-Pugh stage was not statistically significant for the disease course; the occurrence of new tumor lesions had no influence with regard to 1-year and 2-year survival but had a significant influence on long-term survival (p < 0.05). Independent prognostic factors are (multivariate analysis; p < 0.05): number of TACE performed, tumor type (i. e., unifocal vs. multifocal), response to TACE (response vs. progression), and Okuda stage. CONCLUSION: Our results emphasize the value of TACE in the palliative treatment of HCC. Under sequential TACE therapy the course of disease in patients suffering from portal vein thrombosis was not significantly worse. Crucial prognostic factors for the course of the HCC are tumor type and extension, response to TACE, and liver function at the beginning of TACE.


Asunto(s)
Carcinoma Hepatocelular/terapia , Quimioembolización Terapéutica/métodos , Neoplasias Hepáticas/terapia , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Hepatocelular/diagnóstico por imagen , Quimioembolización Terapéutica/efectos adversos , Femenino , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Cuidados Paliativos , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
19.
Rofo ; 178(8): 801-9, 2006 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-16862507

RESUMEN

PURPOSE: To evaluate the value of MDCT in the monitoring of vertebral body architecture after balloon kyphoplasty and observe morphological changes of the vertebral body. MATERIAL AND METHODS: During a period of 26 months, 66 osteoporotic fractures of the vertebral bodies were treated with percutanous balloon kyphoplasty. The height of the vertebral body, width of spinal space, sagittal indices, kyphosis und COBB angle, and cement leakage were evaluated by computed tomography before and after treatment and in a long-term follow up. Statistical analysis was performed by calculating quantitative constant parameters of descriptive key data. In addition, parametric and distribution-free procedures were performed for all questions. RESULTS: After kyphoplasty, the treated vertebral bodies showed a significant gain in the height of the leading edge (0.15 cm; p < 0.0001) and in the central part of the vertebral body (0.17 cm; p < 0.0001). The height of the trailing edge did not change significantly. A corresponding gain in the sagittal index was found. The index remained stable during follow-up. Treated vertebral bodies as well as untreated references showed a comparable loss of height over the period of one year. The shape of the vertebral bodies remained stable. In comparison to these findings, treated vertebral bodies showed a reduced loss of height. A significant change in kyphosis und the COBB angle was noted. In total, pallacos leakage was detected in 71 % of cases. CONCLUSION: MDCT is an accurate method for evaluating vertebral body architecture after treatment with balloon kyphoplasty. Morphological changes in the vertebral bodies, and complications such as pallacos leakage and progression of osteoprosis can be accurately documented. The significant increase in the vertebral body height after treatment is closely correlated with a gain in the sagittal index and reduced kyphosis and COBB angle.


Asunto(s)
Cateterismo/métodos , Descompresión Quirúrgica/métodos , Laminectomía/métodos , Osteoporosis/diagnóstico por imagen , Fracturas de la Columna Vertebral/diagnóstico por imagen , Columna Vertebral/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Fracturas Espontáneas/diagnóstico por imagen , Fracturas Espontáneas/etiología , Humanos , Masculino , Persona de Mediana Edad , Osteoporosis/complicaciones , Pronóstico , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Fracturas de la Columna Vertebral/etiología , Tomografía Computarizada por Rayos X/instrumentación , Resultado del Tratamiento
20.
Rofo ; 178(3): 330-6, 2006 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-16508842

RESUMEN

PURPOSE: To assess the effect of a second diagnostic reading of breast imaging at a university department of radiology. MATERIAL AND METHODS: The diagnostic reports of first readers from different private radiology practices and the reports of second readers from the university department of radiology were compared with the histological results (n = 214) and outcome of follow-ups for 4 years (n = 74) in 236 patients (mean age 55 years). BI-RADS categories were used for this purpose. The initial examinations had been performed because of symptoms (n = 117), early detection outside an organized screening program (n = 102), evaluations following breast cancer therapy (n = 13) and unknown primary tumors (n = 4). In addition, the number of complementary examinations and the influence of a second reading on patient management were evaluated. RESULTS: A total of 140 lesions were malignant and 148 were benign. Of the 288 lesions, 49 % were classified identically in the second reading; 36 % (79/217) of the lesions initially classified as BI-RADS 4 and 5 were downgraded to benign; and 41 % (29/71) of the lesions classified as BI-RADS 1 to 3 were upgraded as suspected of being malignant. The kappa value between the first and second readers was 0.34 with respect to each BI-RADS category separately and 0.18 with respect to categories 1 to 3 (benign) versus 4 and 5 (malignant). A second reading increased the sensitivity from 81 % (114/140) to 96 % (135/140) and the specificity from 30 % (45/148) to 78 % (116/148). Second readers detected 23 additional malignant lesions, changed two lesions correctly classified as malignant to benign categories and caused 6 additional false-positive findings. In all, 38 surgical biopsies could be prevented, one biopsy was erroneously delayed and three unnecessary excisional biopsies were initiated. In the study group, 49 MRI examinations revealed 5 additional malignant lesions and positively influenced surgical planning in 28 patients. In addition to these MRI examinations, 221 patients were examined using ultrasonography, 62 patients using complementary mammography, and 7 using galactography. CONCLUSION: The benefit of a second reading outweighs the expenditure.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Carcinoma Ductal de Mama/diagnóstico , Carcinoma Intraductal no Infiltrante/diagnóstico , Carcinoma Lobular/diagnóstico , Fibroadenoma/diagnóstico , Imagen por Resonancia Magnética , Mamografía , Papiloma/diagnóstico , Servicio de Radiología en Hospital , Ultrasonografía Mamaria , Biopsia , Mama/patología , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/economía , Neoplasias de la Mama/patología , Neoplasias de la Mama/cirugía , Carcinoma Ductal de Mama/patología , Carcinoma Intraductal no Infiltrante/patología , Carcinoma Lobular/patología , Análisis Costo-Beneficio , Diagnóstico Diferencial , Femenino , Fibroadenoma/patología , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Papiloma/patología , Factores de Tiempo
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