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OBJECTIVE: To evaluate effectiveness and safety of computed tomography (CT)-guided cyst rupture with intraarticular contrast-enhanced injection of steroid and local anesthetic as first choice therapy in patients with facet joint cyst-induced radicular pain. DESIGN: Retrospective data set analysis. SETTING: University hospital. SUBJECTS: One hundred and twenty-one patients suffering from radicular pain attributable to facet joint cysts were included. METHODS: The rate of patients without following surgery was assessed and defined as surrogate to measure effectiveness. Patients' characteristics, procedure-associated complications, technical aspects, and imaging findings on magnetic resonance imaging (MRI) were analyzed. A subgroup of 65 patients (54%) underwent telephone interview to assess pain relief and clinical outcome measured by Numeric Rating Scale and Oswestry Disability Index. Analyses between the groups with and without surgery were performed by Fisher exact test and two-sample unpaired t-test, respectively. RESULTS: The effectiveness of CT-guided cyst rupture was found to be 66.1%. Procedure-induced pain yielded in premature abort in two cases (1.7%). The detection of epidural contrast agent was statistically significantly associated with no need for surgery (P = .010). The cyst level was associated with the status of following surgery (P = .026), that is, cysts at lower lumbar spine were easier to rupture than cysts at other locations (cervical, thoracic, or upper lumbar spine). No further significant association was found. CONCLUSIONS: CT-guided cyst rupture as the first-choice therapy in patients with cyst-induced radicular pain was safe and effective. Successful cyst rupture was associated with no need for surgery. Cysts at lower lumbar spine revealed the highest success rate.
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Quistes , Dolor de la Región Lumbar , Quiste Sinovial , Articulación Cigapofisaria , Humanos , Quiste Sinovial/complicaciones , Quiste Sinovial/diagnóstico por imagen , Quiste Sinovial/cirugía , Articulación Cigapofisaria/diagnóstico por imagen , Articulación Cigapofisaria/cirugía , Estudios Retrospectivos , Dolor de la Región Lumbar/terapia , Quistes/patología , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Tomografía Computarizada por Rayos X/métodos , Artralgia/complicaciones , Resultado del TratamientoRESUMEN
To evaluate the educational benefits of teaching ultrasound in an elective radiological course for medical students. We conducted a single-center retrospective analysis of a one-week elective ultrasound course in which 39 medical students (25 female; median age 25.8 ± 2.8 years, range 21-35, 4th and 5th years of undergraduate medical education) participated as part of their radiological training. The students completed a pre- and post-course questionnaire using a five-point Likert scale for self-assessment of technical knowledge, confidence in the procedure regarding different organs, motivation for performing ultrasound, and the importance of ultrasound in medical education. The students also assessed the value of ultrasound teaching in the context of their general medical degree. Pre-test and post-test scores showed significantly improved radiology knowledge (p ≤ 0.001) concerning all abdominal organs (liver, spleen, gallbladder, kidney, urinary bladder, aorta and retroperitoneum). A significant improvement was registered in performing ultrasound of peripheral arteries and venous structures (each p = 0.001), and also of the thyroid gland (p = 0.006). General surveys at the end of the elective were overwhelmingly positive, with constructive criticism and complimentary comments. Systematic training in ultrasound markedly improved the students' skills. This was especially pronounced for solid organ structures, while students requested more education regarding the retroperitoneum and vascular structures. Teaching ultrasound in an elective hands-on training course improves anatomical understanding and practical skills associated with increased motivation. The results affirm the necessity and clinical relevance of the course during the radiological training of medical students.
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Educación de Pregrado en Medicina , Estudiantes de Medicina , Adulto , Competencia Clínica , Curriculum , Educación de Pregrado en Medicina/métodos , Evaluación Educacional , Femenino , Humanos , Estudios Retrospectivos , Ultrasonografía , Adulto JovenRESUMEN
INTRODUCTION: Cranial nonenhanced CT (NECT) imaging in hyperacute ischemic stroke is rarely used for assessing arterial obstruction of middle cerebral artery by identifying hyperdense artery sign (HAS). Considering, however, its growing importance due to its impact on the decision-making process of thrombolysis with or without mechanical thrombectomy improved sensitivity to HAS is necessary, particularly in the group of less experienced clinicians being frequently the first one assessing the presence of HAS on NECT. OBJECTIVE: The present study aimed to investigate the effect of different NECT image reconstructions on the correct detection of hyperdense middle cerebral artery sign in a cohort of observers with lower experience level on NECT. Particularly, MIP image reconstructions were expected to be useful for less experienced observers due to both strengthening of the hyperdensity of HAS and streamlining to less image slices. METHODS: Twenty-five of 100 patients' NECT image data presented with HAS. Sixteen observers with lower practice level on NECT (10 radiologists and 6 neurologists) evaluated independently the 3 image reconstructions of each data set with thin slice 1.5 mm, thick slab 5 mm, and 6-mm maximum intensity projection (MIP) and rated the presence of HAS in middle cerebral artery. A GEE model with random observer effect was used to examine the influence of the 3 image reconstructions on sensitivity to HAS. A linear mixed effects regression model was used to investigate the ranking of detectability of HAS. Interrater reliability was determined by Fleiss' kappa coefficient (κ). RESULTS: Recognition of HAS and sensitivity to HAS significantly differed between the 3 image reconstructions (p = 0.0106). MIP and thin slice reconstructions yielded each on average the highest sensitivities with 73% compared to thick slab reconstruction with 45% sensitivity. The interobserver reliability was fair (κ, 0.3-0.4). Detectability of HAS was significantly easier and better visible ranked on MIP and thin slice reconstructions compared to thick slab (p < 0.05). CONCLUSION: MIP and thin slice reconstructions increased the sensitivity to HAS (73%), whereas thick slab reconstructions seemed to be less appropriate (45%).
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Angiografía Cerebral/métodos , Angiografía por Tomografía Computarizada , Interpretación de Imagen Asistida por Computador , Infarto de la Arteria Cerebral Media/diagnóstico por imagen , Arteria Cerebral Media/diagnóstico por imagen , Tomografía Computarizada Multidetector , Humanos , Infarto de la Arteria Cerebral Media/terapia , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Pronóstico , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Pulmonary involvement is common in several infectious and non-infectious diagnostic settings. Imaging findings consistently overlap and are therefore difficult to differentiate by chest-CT. The aim of this study was to evaluate the role of CT-textural features(CTTA) for discrimination between atypical viral (respiratory-syncitial-virus(RSV) and herpes-simplex-1-virus (HSV1)), fungal (pneumocystis-jirovecii-pneumonia(PJP)) interstitial pneumonias and alveolar hemorrhage. METHODS: By retrospective single-centre analysis we identified 46 consecutive patients (29 m) with RSV(n = 5), HSV1(n = 6), PJP(n = 21) and lung hemorrhage(n = 14) who underwent unenhanced chest CTs in early stages of the disease between 01/2016 and 02/2017. All cases were confirmed by microbiologic direct analysis of bronchial lavage. On chest-CT-scans, the presence of imaging features like ground-glass opacity(GGO), crazy-paving, air-space consolidation, reticulation, bronchial wall thickening and centrilobular nodules were described. A representative large area was chosen in both lungs and used for CTTA-parameters (included heterogeneity, intensity, average, deviation, skewness). RESULTS: Discriminatory CTTA-features were found between alveolar hemorrhage and PJP consisting of differences in mean heterogeneity(p < 0.015) and uniformity of skewness(p < 0.006). There was no difference between CT-textural features of diffuse alveolar hemorrhage and viral pneumonia or PJP and viral pneumonia. Visual HRCT-assessment yielded great overlap of imaging findings with predominance of GGO for PJP and airspace consolidation for pneumonia/alveolar hemorrhage. Significant correlations between HRCT-based imaging findings and CT-textural features were found for all three disease groups. CONCLUSION: CT-textural features showed significant differences in mean heterogeneity and uniformity of skewness. HRCT-based imaging findings correlated with certain CT-textural features showing that the latter have the potential to characterize structural properties of lung parenchyma and related abnormalities.
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Hemorragia/diagnóstico por imagen , Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Neumonía por Pneumocystis/diagnóstico por imagen , Neumonía Viral/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Diagnóstico Diferencial , Femenino , Humanos , Pulmón/diagnóstico por imagen , Pulmón/microbiología , Masculino , Persona de Mediana Edad , Pneumocystis carinii/aislamiento & purificación , Interpretación de Imagen Radiográfica Asistida por Computador , Estudios Retrospectivos , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos XRESUMEN
OBJECTIVE: The aim of this study was the elaboration of clinical symptoms and image findings in injuries of the wrist and ulnar-sided pain with accompanying damage to the articular disc and the triangular fibrocartilage complex (TFCC). MATERIAL AND METHODS: This article reports about a 26-year-old male patient who presented to the department of surgery of this hospital after repeated falls onto the right wrist. Following the latest fall there was persistent wrist pain and limited movement, especially in supination. The physical examination showed pressure pain above the ulnocarpal complex; however, under forced pronation and supination no pain in the ulnocarpal complex could be triggered. RESULTS: Due to the symptoms damage to the TFCC was suspected and a magnetic resonance imaging (MRI) examination of the wrist was carried out. A TFCC damage reaching as far as the dorsal radioulnar ligament involving the dorsal suspension was demarcated with dislocation and displacement of the disc. For further differentiation of the damaged structures arthrography was performed and contrast medium containing gadolinium was injected into the joint gap. The imaging showed avulsion of the dorsal triangular disc from the dorsal suspension with volar dislocation. Treatment was continued with an arthrotomy by the formation of an ulnar pedicled capsular flap, the luxated TFCC was repositioned, central frayed and torn parts were resected and smoothed. Finally, the TFCC was refixed with two 3/0 PDS Usutures. CONCLUSION: Ulnar-sided wrist pain can be caused by a variety of clinical pathologies, so that often no diagnosis can be made based on clinical symptoms alone and an imaging method is required; however, for a clear assessment of the ligament or joint injuries an MRI is necessary. Particularly for the evaluation of the TFCC injuries MRI is a sensitive diagnostic method. In the decision making, especially when atypical injury patterns are present, an arthrography should be performed in addition to MRI to obtain the best possible information on the anatomical circumstances. KEY POINTS: In cases of injuries of the wrist and ulnar-sided pain collateral damage to the articular disc and the TFCC should always be considered and excluded when appropriate. A dislocation of the disc at the wrist is a rare consequence of trauma but should be considered in the differential diagnosis. In cases of unclear MRI results and complex injuries of the wrist or unclear symptoms, MR arthrography can be helpful.
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Luxaciones Articulares/diagnóstico , Fibrocartílago Triangular , Traumatismos de la Muñeca/diagnóstico , Adulto , Artrografía , Humanos , Imagen por Resonancia Magnética , Masculino , Muñeca , Articulación de la MuñecaRESUMEN
PURPOSE: To compare qualitative and quantitative computed tomography (CT) and magnetic resonance imaging (MRI) parameters for longitudinal disease monitoring of multiple myeloma (MM) of the axial skeleton. MATERIALS AND METHODS: We included 31 consecutive patients (17 m; mean age 59.20 ± 8.08 years) with MM, who underwent all baseline (n = 31) and at least one or more (n = 47) follow-up examinations consisting of multi-parametric non-enhanced whole-body MRI (WBMRI) and non-enhanced whole-body reduced-dose thin-section MDCT (NEWBMDCT) between 06/2013 and 09/2016. We classified response according to qualitative CT criteria into progression (PD), stable(SD), partial/very good partial (PR/VGPR) and complete response(CR), grouping the latter three together for statistical analysis because CT cannot reliably assess PR and CR. Qualitative MR-response criteria were defined and grouped similarly to CT using longitudinal quantification of signal-intensity changes on T1w/STIR/ T2*w and calculating ADC-values. Standard of reference was the hematological laboratory (M-gradient). RESULTS: Hematological response categories were CR (14/47, 29.7%), PR (2/47, 4.2%), SD (16/47, 34.0%) and PD (15/47, 29.9%). Qualitative-CT-evaluation showed PD in 12/47 (25.5%) and SD/PR/VGPR/CR in 35/47 (74.5%) cases. These results were confirmed by quantitative-CT in all focal lytic lesions (p < 0.001). Quantitative-CT at sites with diffuse bone involvement showed significant increase of maximum bone attenuation (p < 0.001*) and significant decrease of minimal bone (p < 0.002*) in the SD/PR/VGPR/CR group. Qualitative MRI showed PD in 14/47 (29.7%) and SD/PR/VGPR/CR in 33/47 (70.3%). Quantitative MRI diagnosis showed a statistically significant decrease in signal intensity on short tau inversion recovery sequences (STIR) in bone marrow in patients with diffuse bone marrow involvement achieving SD/PR/VGPR/CR (p < 0.001*). CONCLUSION: Imaging response monitoring using MRI is superior to CT only if qualitative parameters are used, whereas there was no definite benefit from using quantitative parameters with either CT or MRI.
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Imagen por Resonancia Magnética/métodos , Mieloma Múltiple/diagnóstico por imagen , Neoplasias de la Columna Vertebral/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mieloma Múltiple/terapia , Estudios Retrospectivos , Neoplasias de la Columna Vertebral/terapia , Imagen de Cuerpo EnteroRESUMEN
PURPOSE: To evaluate the diagnostic performance of a novel CT post-processing software that generates subtraction maps of baseline and follow-up CT examinations in the course of myeloma bone lesions. MATERIALS AND METHODS: This study included 61 consecutive myeloma patients who underwent repeated whole-body reduced-dose MDCT at our institution between November 2013 and June 2015. CT subtraction maps classified a progressive disease (PD) vs. stable disease (SD)/remission. Bone subtraction maps (BSMs) only and in combination with 1-mm (BSM+) source images were compared with 5-mm axial/MPR scans. RESULTS: Haematological response categories at follow-up were: complete remission (n = 9), very good partial remission (n = 2), partial remission (n = 17) and SDh (n = 19) vs. PDh (n = 14). Five-millimetre CT scan yielded PD (n = 14) and SD/remission (n = 47) whereas bone subtraction + 1-mm axial scans (BSM+) reading resulted in PD (n = 18) and SD/remission (n = 43). Sensitivity/ specificity/accuracy for 5-mm/1-mm/BSM(alone)/BSM + in "lesion-by-lesion" reading was 89.4 %/98.9 %/98.3 %/ 99.5 %; 69.1 %/96.9 %/72 %/92.1 % and 83.8 %/98.4 %/92.1 %/98.3 %, respectively. The use of BSM+ resulted in a change of response classification in 9.8 % patients (n = 6) from SD to PD. CONCLUSION: BSM reading is more accurate for monitoring myeloma compared to axial scans whereas BSM+ yields similar results with 1-mm reading (gold standard) but by significantly reduced reading time. KEY POINTS: ⢠CT evaluation of myeloma bone disease using a longitudinal bone subtraction post-processing algorithm. ⢠Bone subtraction post-processing algorithm is more accurate for assessment of therapy. ⢠Bone subtraction allowed improved and more efficient detection of myeloma bone lesions. ⢠Post-processing tool demonstrating a change in response classification in 9.8 % patients (all showing PD). ⢠Reading time could be substantially shortened as compared to regular CT assessment.
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Algoritmos , Interpretación de Imagen Asistida por Computador/métodos , Tomografía Computarizada Multidetector/métodos , Mieloma Múltiple/diagnóstico , Estadificación de Neoplasias/métodos , Huesos Pélvicos/diagnóstico por imagen , Imagen de Cuerpo Entero , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Reproducibilidad de los Resultados , Estudios Retrospectivos , Programas Informáticos , Técnica de SustracciónRESUMEN
OBJECTIVES: The aim of this study was to evaluate the course of SSc-related pulmonary abnormalities following high-dose chemotherapy with autologous stem cell transplantation (SCT) by quantitative chest CT analysis and compare the results with those of pulmonary function tests and the response of cutaneous involvement. METHODS: Chest CT quantification was performed before, directly after [0.49 years (sd 0.20)] and at a mean of 2.2 years (sd 2.1) following autologous SCT in 26 consecutive patients with SSc between March 2001 and March 2015. Quantitative CT used fully automated software to calculate inspiratory total lung volume, mean lung density, high attenuation value and their pulmonary distribution (core vs peel). All patients underwent pulmonary function tests. We additionally analysed parallels in the response of associated skin changes by using the modified Rodnan skin score (mRSS). RESULTS: The forced vital capacity (FVC) course at 6 months was used to classify patients into responders [n = 20 (76.9%)] and non-responders [n = 6 (23.1%)]. FVC, forced expiratory volume in 1 s, vital capacity (VC) as well as single-breath diffusion capacity for carbon monoxide significantly improved (P = 0.03, 0.001, 0.001 and 0.013, respectively) in responders. At quantitative CT, total lung volume increased (P = 0.018), whereas mean lung density (P = 0.026) and high attenuation value decreased (P = 0.020) after autologous SCT in responders. Correspondingly, mRSS improved from 27.35 (sd 9.25) before to 10.81 (sd 8.64) after autologous SCT (P = 0.003) in responders. Changes in mRSS before autologous SCT and thereafter correlated significantly with those 24 months after autologous SCT (r = 0.575; P = 0.031). CONCLUSIONS: CT quantification of lung volume and parenchymal attenuation in SSc patients presenting with alveolitis and fibrosis that undergo autologous SCT yields parameters that match well with those of pulmonary function and even clinical tests. It might therefore be used as a substitute marker in patients who are unable to adequately perform lung function tests.
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Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Fibrosis Pulmonar/diagnóstico por imagen , Esclerodermia Sistémica/diagnóstico por imagen , Trasplante de Células Madre/métodos , Adolescente , Adulto , Niño , Terapia Combinada , Femenino , Volumen Espiratorio Forzado/fisiología , Humanos , Inmunosupresores/uso terapéutico , Enfermedades Pulmonares Intersticiales/terapia , Mediciones del Volumen Pulmonar , Persona de Mediana Edad , Embarazo , Fibrosis Pulmonar/terapia , Estudios Retrospectivos , Esclerodermia Sistémica/terapia , Tomografía Computarizada por Rayos X , Trasplante Homólogo , Capacidad Vital/fisiología , Adulto JovenRESUMEN
OBJECTIVE: The purpose of this study is to evaluate the benefit of using novel CT postprocessing software that generates unfolded rib images for more-accurate evaluation of multiple myeloma (MM) at follow-up, response monitoring, and visualization of treatment-related bone changes. MATERIALS AND METHODS: Between January 2012 and February 2015, 40 consecutive patients with MM underwent repeated whole-body reduced-dose CT at our institution. The results were retrospectively evaluated and compared with established hematologic markers. Unfolded rib reformatted images were compared with 5- and 1-mm-thick slices with regard to bone changes, bone marrow attenuation, and bone sclerosis. RESULTS: Hematologic response categories at follow-up were complete response (CR; n = 2), very good partial response (VGPR; n = 1), partial response (PR; n = 9), stable disease (n = 9), and progressive disease (PD; n = 19). The number of lesions increased in 11 patients (all with PD), decreased in two patients (both with CR), and stayed unchanged in 27 patients. The size of the lesions increased in 14 patients (all with PD), decreased in five patients (two with CR, two with PR, and one with stable disease), and remained unchanged in 21 patients. There was a mean (± SD) difference of 27.99 ± 19.71 HU in bone marrow attenuation for patients with PD (p < 0.0001) and -31.24 ± 13.57 HU in the responders group (p = 0.002), whereas patients with stable disease showed stable bone marrow attenuation at follow-up (mean, -3.37 ± 10.55 HU). Increased bone sclerosis was detected in 12 patients (all of whom were receiving therapy). The sensitivity and specificity of unfolded rib images, 5-mm slices, and 1-mm slices were, respectively, 78.9% and 100%, 52.6% and 100%, and 63.2% and 100% for accurate bone response assessment; 100% and 95.2%, 94.74% and 42.9%, and 89.47% and 47.62% for bone marrow attenuation; and 100% and 100%, 58.3% and 100%, and 91.67% and 100% for sclerosis. CONCLUSION: For therapy response assessment, unfolded rib reading is more accurate than transverse CT slices.
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Mieloma Múltiple/diagnóstico por imagen , Interpretación de Imagen Radiográfica Asistida por Computador , Costillas/diagnóstico por imagen , Programas Informáticos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Mieloma Múltiple/patología , Estadificación de Neoplasias , Mejoramiento de la Calidad , Estudios Retrospectivos , Costillas/patología , Sensibilidad y Especificidad , Imagen de Cuerpo EnteroRESUMEN
OBJECTIVE: To observe the distribution and potential distribution patterns of osteolytic and sclerotic vertebral involvement in a representative collective of multiple myeloma patients. MATERIALS AND METHODS: A total of 66 consecutive patients with a diagnosis of multiple myeloma at initial diagnosis or during follow-up were examined by multidetector reduced-dose computed tomography to evaluate the distribution of bone lesions along the spine with focus on size, location, and lesion character. Confirmation of diagnosis was performed by comparison to follow-up computed tomography or magnetic resonance tomography. If >50% of all detected malignant lesions occurred in one spinal segment, the distribution pattern was called cervical, thoracic, lumbar, or sacral, otherwise a "mixed" pattern was classified. RESULTS: Of a total number of 933 osseous spine lesions, 632 (67.7%) were classified as malignant (98.9% of them osteolytic) and 293 (31.5%) as benign. The distribution pattern analysis yielded two patients (3.8%) with a cervical, 26 (50%) with a thoracic, 4 (7.7%) with a lumbar, one (1.9%) with a sacral pattern, and 19 cases (36.6%) showed a mixed distribution pattern. Segment-wise, the mean lesion size was 6.52 ± 2.76 mm (cervical), 8.97 ± 5.43 mm (thoracic), 11.97 ± 7.11 mm (lumbar), and 17.5 ± 16.465 (sacral), whilst, related to the vertebra size, the lesion/vertebra size ratio is decreasing through the whole spine beginning from the top. CONCLUSIONS: Multiple myeloma bone lesions occur preferably and are larger in the thoracic and lumbar spine. Moreover, a specific distribution pattern is present in about 60%.
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Tomografía Computarizada Multidetector/métodos , Mieloma Múltiple/diagnóstico por imagen , Exposición a la Radiación/prevención & control , Protección Radiológica/métodos , Neoplasias de la Columna Vertebral/diagnóstico por imagen , Imagen de Cuerpo Entero/métodos , Anciano , Femenino , Humanos , Masculino , Dosis de Radiación , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
The successful integration of neural networks in a clinical setting is still uncommon despite major successes achieved by artificial intelligence in other domains. This is mainly due to the black box characteristic of most optimized models and the undetermined generalization ability of the trained architectures. The current work tackles both issues in the radiology domain by focusing on developing an effective and interpretable cardiomegaly detection architecture based on segmentation models. The architecture consists of two distinct neural networks performing the segmentation of both cardiac and thoracic areas of a radiograph. The respective segmentation outputs are subsequently used to estimate the cardiothoracic ratio, and the corresponding radiograph is classified as a case of cardiomegaly based on a given threshold. Due to the scarcity of pixel-level labeled chest radiographs, both segmentation models are optimized in a semi-supervised manner. This results in a significant reduction in the costs of manual annotation. The resulting segmentation outputs significantly improve the interpretability of the architecture's final classification results. The generalization ability of the architecture is assessed in a cross-domain setting. The assessment shows the effectiveness of the semi-supervised optimization of the segmentation models and the robustness of the ensuing classification architecture.
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Inteligencia Artificial , Cardiomegalia , Humanos , Cardiomegalia/diagnóstico por imagen , Generalización Psicológica , Corazón , Procesamiento de Imagen Asistido por Computador , Redes Neurales de la ComputaciónRESUMEN
PURPOSE: Technical feasibility of CT-based calculation of fractional flow reserve (cFFR) using a 128-row computed tomography scanner in an everyday routine setting. Post-processing and everyday practicability should be analyzed on the scanner on-site in connection with clinical parameters. MATERIALS AND METHODS: This single-center retrospective analysis included 230 patients (74 female; mean age 63.8 years) with CCTA within 21 months between 01/2018 and 09/2019 without non-pathological examinations. cFFR values were obtained using a deep learning-based non-commercial research prototype (cFFR Version3.5.0; Siemens Healthineers GmbH, Erlangen). cFFR values were evaluated at two points: at the maximum point of the stenosis and 1.0âcm distal to the stenosis. Comparison with invasive coronary angiography in 57/230 patients (24.7â%) was performed. CT parameters and quality were evaluated. Further subgroup classification concerning criteria of technical postprocessing was performed: no changes necessary, minor corrections necessary, major corrections necessary, and no evaluation was possible. The required time from starting the software to the final result was evaluated. RESULTS: A total of 116/448 (25.9â%) mild, 223/448 (49.8â%) moderate, and 109/448 (24.3â%) obstructive stenoses was found. The mean cFFR at the maximum point of the stenosis was 0.92â±â0.09 and significantly higher than the cFRR value of 0.89â±â0.13 distal to the stenosis (pâ<â0.001*). The mean degree of stenosis was 44.02â±â26.99â% (range: 1-99â%) with an area of 5.39â±â3.30âmm2. In a total of 45 patients (19.1â%), a relevant reduction in cFFR below 0.80 was determined. Overall, in 57/230 patients (24.8â%), catheter angiography was performed. No significant difference in the degree of maximal stenosis (CAD-RADS 0-2/3/4) was detected between the classification of CCTA and ICA (pâ=â0.171). The mean post-processing time varied significantly with 8.34â±â4.66âmin. in single-vessel CADâvs. 12.91â±â3.92âmin. in two-vessel CADâvs. 21.80â± 5.94âmin. in three-vessel CADâ(each pâ<â0.001). CONCLUSION: Noninvasive onsite quantification of cFFR is feasible with minimal observer interaction in a routine real-world setting on a 128-row scanner. Deep learning-based algorithms allow a robust and semi-automatic on-site determination of cFFR based on data from standard CT scanners. KEY POINTS: · Non-invasive on-site quantification of cFFR is feasible with minimal observer interaction.. · Deep-learning based algorithms allow robust and semi-automatic on-site determination of cFFR.. · The mean follow-up time varied significantly with the extent of vascular CAD..
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Enfermedad de la Arteria Coronaria , Estenosis Coronaria , Reserva del Flujo Fraccional Miocárdico , Humanos , Femenino , Persona de Mediana Edad , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Estudios Retrospectivos , Estenosis Coronaria/diagnóstico por imagen , Constricción Patológica , Estudios de Factibilidad , Angiografía por Tomografía Computarizada/métodos , Valor Predictivo de las Pruebas , Angiografía Coronaria/métodosRESUMEN
Background: Before surgical or transcatheter aortic valve implantation (TAVI), coronary status evaluation is required. The role of combined computed coronary tomography angiography (cCTA) and TAVI planning CT in this context is not yet well elucidated. This study assessed whether relevant proximal coronary disease requiring coronary revascularization can be safely detected by combined cCTA and TAVI planning CT, including CT-derived fractional flow reserve (FFR) calculation in patients with severe aortic stenosis. Methods: This study analyzed patients with successful cCTA combined with TAVI planning CT using a 128-slice dual-source scanner. The detection via cCTA of relevant left main stem stenosis (>50%) or proximal coronary artery stenosis (>70%) was compared to invasive coronary angiography (ICA). Results: This study comprised 101 consecutive TAVI patients with a median age of 83 [77-86] years, a median STS score of 3.7 [2.4-6.1] and 54% of whom had known coronary artery disease. Of 15 patients with relevant coronary stenoses, 14 (93.3%) were detected with cCTA, while false positive results were found in 25 patients. Only in patients with previous percutaneous coronary stent implantation (PCI) were false positive rates (11/29) increased. In the subgroup without previous PCI, an improved classification performance of 87.5%, being mainly due to 11.1% false positive classifications, led to a negative predictive value of 98.5%. Conclusions: Combined cCTA and CT-FFR with TAVI planning CT via state-of-the-art scanners and protocols as a one-stop shop can replace routine ICA in patients prior to TAVI due to its safe detection of relevant coronary artery stenosis, although diagnostic performance of cCTA is only reduced in patients with coronary stents.
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BACKGROUND: Arterial spin labeling (ASL) is a magnetic resonance imaging (MRI)-based technique using labeled blood-water of the brain-feeding arteries as an endogenous tracer to derive information about brain perfusion. It enables the assessment of cerebral blood flow (CBF). METHOD: This review aims to provide a methodological and technical overview of ASL techniques, and to give examples of clinical use cases for various diseases affecting the central nervous system (CNS). There is a special focus on recent developments including super-selective ASL (ssASL) and time-resolved ASL-based magnetic resonance angiography (MRA) and on diseases commonly not leading to characteristic alterations on conventional structural MRI (e.âg., concussion or migraine). RESULTS: ASL-derived CBF may represent a clinically relevant parameter in various pathologies such as cerebrovascular diseases, neoplasms, or neurodegenerative diseases. Furthermore, ASL has also been used to investigate CBF in mild traumatic brain injury or migraine, potentially leading to the establishment of imaging-based biomarkers. Recent advances made possible the acquisition of ssASL by selective labeling of single brain-feeding arteries, enabling spatial perfusion territory mapping dependent on blood flow of a specific preselected artery. Furthermore, ASL-based MRA has been introduced, providing time-resolved delineation of single intracranial vessels. CONCLUSION: Perfusion imaging by ASL has shown promise in various diseases of the CNS.âGiven that ASL does not require intravenous administration of a gadolinium-based contrast agent, it may be of particular interest for investigations in pediatric cohorts, patients with impaired kidney function, patients with relevant allergies, or patients that undergo serial MRI for clinical indications such as disease monitoring. KEY POINTS: · ASL is an MRI technique that uses labeled blood-water as an endogenous tracer for brain perfusion imaging.. · It allows the assessment of CBF without the need for administration of a gadolinium-based contrast agent.. · CBF quantification by ASL has been used in several pathologies including brain tumors or neurodegenerative diseases.. · Vessel-selective ASL methods can provide brain perfusion territory mapping in cerebrovascular diseases.. · ASL may be of particular interest in patient cohorts with caveats concerning gadolinium administration..
Asunto(s)
Trastornos Cerebrovasculares , Trastornos Migrañosos , Enfermedades Neurodegenerativas , Humanos , Niño , Medios de Contraste , Marcadores de Spin , Gadolinio , Imagen por Resonancia Magnética/métodos , Arterias , Angiografía por Resonancia Magnética/métodos , Trastornos Cerebrovasculares/diagnóstico por imagen , AguaRESUMEN
CT protocols that diagnose COVID-19 vary in regard to the associated radiation exposure and the desired image quality (IQ). This study aims to evaluate CT protocols of hospitals participating in the RACOON (Radiological Cooperative Network) project, consolidating CT protocols to provide recommendations and strategies for future pandemics. In this retrospective study, CT acquisitions of COVID-19 patients scanned between March 2020 and October 2020 (RACOON phase 1) were included, and all non-contrast protocols were evaluated. For this purpose, CT protocol parameters, IQ ratings, radiation exposure (CTDIvol), and central patient diameters were sampled. Eventually, the data from 14 sites and 534 CT acquisitions were analyzed. IQ was rated good for 81% of the evaluated examinations. Motion, beam-hardening artefacts, or image noise were reasons for a suboptimal IQ. The tube potential ranged between 80 and 140 kVp, with the majority between 100 and 120 kVp. CTDIvol was 3.7 ± 3.4 mGy. Most healthcare facilities included did not have a specific non-contrast CT protocol. Furthermore, CT protocols for chest imaging varied in their settings and radiation exposure. In future, it will be necessary to make recommendations regarding the required IQ and protocol parameters for the majority of CT scanners to enable comparable IQ as well as radiation exposure for different sites but identical diagnostic questions.
RESUMEN
In recent years, several deep learning approaches have been successfully applied in the field of medical image analysis. More specifically, different deep neural network architectures have been proposed and assessed for the detection of various pathologies based on chest X-ray images. While the performed assessments have shown very promising results, most of them consist in training and evaluating the performance of the proposed approaches on a single data set. However, the generalization of such models is quite limited in a cross-domain setting, since a significant performance degradation can be observed when these models are evaluated on data sets stemming from different medical centers or recorded under different protocols. The performance degradation is mostly caused by the domain shift between the training set and the evaluation set. To alleviate this problem, different unsupervised domain adaptation approaches are proposed and evaluated in the current work, for the detection of cardiomegaly based on chest X-ray images, in a cross-domain setting. The proposed approaches generate domain invariant feature representations by adapting the parameters of a model optimized on a large set of labeled samples, to a set of unlabeled images stemming from a different data set. The performed evaluation points to the effectiveness of the proposed approaches, since the adapted models outperform optimized models which are directly applied to the evaluation sets without any form of domain adaptation.
RESUMEN
Imaging of the temporal bone and middle ear is challenging for radiologists due to the abundance of distinct anatomical structures and the plethora of possible pathologies. The basis for a precise diagnosis is knowledge of the underlying anatomy as well as the clinical presentation and the individual patient's otological status. In this article, we aimed to summarize the most common inflammatory lesions of the temporal bone and middle ear, describe their specific imaging characteristics, and highlight their differential diagnoses. First, we introduce anatomical and imaging fundamentals. Additionally, a point-to-point comparison of the radiological and histological features of the wide spectrum of inflammatory diseases of the temporal bone and middle ear in context with a review of the current literature and current trends is given.