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BACKGROUND: The purpose of this work is to describe the objectives and design of cardiovascular magnetic resonance (CMR) imaging in the single center, prospective, population-based Hamburg City Health study (HCHS). The HCHS aims at improving risk stratification for coronary artery disease (CAD), atrial fibrillation (AF) and heart failure (HF). METHODS: The HCHS will finally include 45,000 inhabitants of the city of Hamburg (Germany) between 45 and 74 years who undergo an extensive cardiovascular evaluation and collection of biomaterials. Risk-scores for CAD, AF and HF are used to create enriched subpopulations who are invited for CMR. A total number of approximately 12,362 subjects will undergo CMR and incident CAD, AF and HF will be assessed after 6 years follow-up. The standard CMR protocol includes cine-CMR, T1 and T2 mapping, aortic/mitral valve flow measurements, Late gadolinium enhancement, angiographies and measurements of aortic distensibility. A stress-perfusion scan is added in individuals at risk for CAD. The workflow of CMR data acquisition and analyses was evaluated in a pilot cohort of 200 unselected subjects. RESULTS: The obtained CMR findings in the pilot cohort agree with current reference values and demonstrate the ability of the established workflow to accomplish the objectives of HCHS. CONCLUSIONS: CMR in HCHS promises novel insights into major cardiovascular diseases, their subclinical precursors and the prognostic value of novel imaging biomarkers. The HCHS database will facilitate combined analyses of imaging, clinical and molecular data ("Radiomics").
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Fibrilación Atrial/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Insuficiencia Cardíaca/diagnóstico por imagen , Imagen por Resonancia Cinemagnética , Proyectos de Investigación , Anciano , Fibrilación Atrial/epidemiología , Fibrilación Atrial/fisiopatología , Medios de Contraste/administración & dosificación , Enfermedad de la Arteria Coronaria/epidemiología , Enfermedad de la Arteria Coronaria/fisiopatología , Femenino , Estudios de Seguimiento , Alemania/epidemiología , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/fisiopatología , Humanos , Incidencia , Masculino , Meglumina/administración & dosificación , Persona de Mediana Edad , Compuestos Organometálicos/administración & dosificación , Proyectos Piloto , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Reproducibilidad de los Resultados , Factores de Tiempo , Flujo de TrabajoRESUMEN
To determine the diagnostic yield of cone beam computed tomography (CBCT) compared with 3 T magnetic resonance imaging (MRI) for the evaluation of subchondral insufficiency fractures of the knee. Consecutive patients with subchondral insufficiency fractures of the knee examined by 3 T MRI and CBCT of the femoral condyles were reviewed. Two experienced raters graded the lesion severity on 3 T MRI and CBCT images: grade 1: no signs of a subchondral bone lesion; grade 2: subchondral trabecular fracture or cystic changes, but without infraction of the subchondral bone plate; grade 3: collapse of the subchondral bone plate. Ratings were repeated after six weeks to determine reliability. In addition, the bone lesion size was measured as elliptical area (mm2) and compared between CBCT and T1-weighted MRI sequences. Among 30 patients included (43.3% women; mean age: 60.9 ± 12.8 years; body mass index (BMI) 29.0 ± 12.8 kg/m2), the medial femoral condyle was affected in 21/30 patients (70%). The grading of subchondral lesions between MRI and CBCT did not match in 12 cases (40%). Based on MRI images, an underestimation (i.e., undergrading) compared with CBCT was observed in nine cases (30%), whereas overgrading occurred in three cases (10%). Compared to CBCT, routine T1-weighted 3 T sequences significantly overestimated osseus defect zones in sagittal (84.7 ± 68.9 mm2 vs. 35.9 ± 38.2 mm2, p < 0.01, Cohen's d = 1.14) and coronal orientation (53.1 ± 24.0 mm2 vs. 22.0 ± 15.2 mm2, p < 0.01, Cohen's d = 1.23). The reproducibility of the grading determined by intra- and inter-rater agreement was very high in MRI (intra-class correlation coefficient (ICC) 0.78 and 0.90, respectively) and CBCT (ICC 0.96 and 0.96, respectively). In patients with subchondral insufficiency fractures of the knee, the use of CBCT revealed discrepancies in lesion grading compared with MRI. These findings are clinically relevant, as precise determination of subchondral bone plate integrity may influence the decision about conservative or surgical treatment. CBCT represents our imaging modality of choice for grading the lesion and assessing subchondral bone plate integrity. MRI remains the gold standard modality to detect especially early stages.
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Tomografía Computarizada de Haz Cónico , Imagen por Resonancia Magnética , Humanos , Tomografía Computarizada de Haz Cónico/métodos , Femenino , Masculino , Imagen por Resonancia Magnética/métodos , Persona de Mediana Edad , Anciano , Fracturas por Estrés/diagnóstico por imagen , Articulación de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/patología , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: The pathogenesis of primary nephrotic kidney diseases is not completely understood. As T-cell involvement is suspected, cytotoxic T-lymphocyte antigen 4 (CTLA-4) expressed on activated T cells could play a role in the immune response. Single-nucleotide polymorphisms (SNPs) in the CTLA-4 gene are associated with several autoimmune-related diseases. METHODS: Our goal was to study the occurrence of the SNPs -318C/T, +49A/G and CT60 on the CTLA-4 gene in healthy blood donors (N = 156) compared with nephrotic patients with biopsy-proven minimal-change disease (MCD, N = 160), focal segmental glomerulosclerosis (FSGS, N = 159) and membranous nephropathy (MN, N = 185). Odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to estimate the strength of the association. RESULTS: The +49GG genotype was significantly (P < 0.001) associated with the risk for MCD, FSGS and MN (AA versus GG: OR = 3.403, 95% CI = 1.748-6.622, OR = 3.846, 95% CI = 1.945-7.604 and OR = 2.381, 95% CI = 1.257-4.511, respectively). No further significant associations, neither with the heterozygous genotype of +49A/G nor for the -318C/T or CT60 SNP, were detected. CONCLUSIONS: The +49GG genotype of the +49A/G SNP in the CTLA-4 gene is associated with the risk for MCD, FSGS and MN, suggesting a possible role for CTLA-4 in a proposed common final pathway in the pathogenesis of primary nephrotic kidney diseases.
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Antígeno CTLA-4/genética , Predisposición Genética a la Enfermedad , Glomerulonefritis Membranosa/genética , Glomeruloesclerosis Focal y Segmentaria/genética , Nefrosis Lipoidea/genética , Polimorfismo de Nucleótido Simple/genética , Adulto , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , PronósticoRESUMEN
BACKGROUND: Nephrometry scores aid in clinical decision-making, yet evidence is scarce regarding their impact on cumulative morbidity following partial nephrectomy (PN). PATIENTS AND METHODS: Retrospective, monocentric study of 122 patients with suspicious renal masses undergoing open or robot-assisted PN between January 2019 and August 2020. Morbidity assessment followed European Association of Urology guidelines on complication reporting. 30-d complications were extracted using a PN-specific catalog, were graded by the Clavien-Dindo classification (CDC), and Comprehensive Complication Index (CCI®) values were calculated. The impact of nephrometry on cumulative morbidity was evaluated by (1) comparing morbidity estimates between Preoperative Aspects and Dimensions Used for an Anatomical (PADUA)/R.E.N.A.L. complexity groups, (2) by Pearson's correlation between nephrometry scores and CCI®, and (3) by multivariable regression models using any 30-d complication and 30-d CCI® as endpoints. RESULTS: Of 122 patients, 101 (83%) underwent open and 21 (17%) robot-assisted PN. Median PADUA and R.E.N.A.L. scores were 9 (interquartile range, IQR 8-10) and 8 (IQR 6-9), respectively. Of 218 complications in 92 patients (75%), the majority was classified as minor (CDC grade ≤IIIa). Median 30-d CCI® was 8.7 (IQR 0.50-15). There was a small positive correlation between PADUA or R.E.N.A.L. score with CCI® (all P ≤ 0.026), explaining 4.7% and 4.1% of the variation in CCI®, respectively. After adjustment, nephrometry scores were associated with any 30-d complication and the CCI® (all P ≤ 0.011). PADUA and R.E.N.A.L. high complexity tumors were positively associated with both morbidity endpoints compared to low complexity tumors (all P ≤ 0.041). CONCLUSIONS: At a referral center, PN may be safely performed, even if morbidity assessment follows a strict protocol. Nephrometry risk classification does only marginally translate into clinical relevant differences regarding short-term complications. Thus, nephron-sparing surgery should not be withheld from patients with high complexity renal masses.
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Neoplasias Renales , Humanos , Neoplasias Renales/cirugía , Neoplasias Renales/patología , Estudios Retrospectivos , Riñón/patología , Nefrectomía/efectos adversos , Nefrectomía/métodos , MorbilidadRESUMEN
Persisting patellar maltracking following surgical realignment often remains unseen. The aim of this study was to analyze the effects of realignment procedures on patellofemoral kinematics in patients with patellofemoral instability (PFI) and patellofemoral maltracking (PM) by using dynamic magnetic resonance imaging (MRI). Patients planned for surgical patellar realignment due to PFI and a clinically and radiologically apparent PM between December 2019 and May 2022 were included. Patients without PM, limited range of motion, joint effusion, or concomitant injuries were excluded. Dynamic mediolateral translation (dMPT) and patella tilt (dPT) were measured preoperatively and three months postoperatively. In 24 patients (7 men, 17 women; mean age 23.0 years), 10 tibial tubercle transfers, 5 soft tissue patella tendon transfers, 6 trochleoplasties, 3 lateral lengthenings, 1 varizating distal femoral osteotomy (DFO), and 1 torsional DFO were performed. At final follow-up, dMPT (from 10.95 ± 5.93 mm to 4.89 ± 0.40 mm, p < 0.001) and dPT (from 14.50° ± 10.33° to 8.44° ± 7.46°, p = 0.026) were significantly improved. All static radiological parameters were corrected to physiological values. Surgical patellar realignment contributed to the significant improvement of patellofemoral kinematics, with an approximation to normal values. The postoperative application of dynamic MRI allowed for a quantification of the performed correction, allowing for a postoperative control of success.
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PURPOSE: Adrenal vein sampling (AVS) is the reference standard for evaluation of lateralized hormone production in primary aldosteronism. We aimed to investigate the impact of pre-interventional right renal vein (RRV) to right adrenal vein (RAV) distance measurement on fluoroscopy time, contrast agent exposure and radiation dose during AVS. MATERIALS AND METHODS: Forty-five patients with primary aldosteronism undergoing AVS were enrolled in our retrospective study and divided into three groups. In the group "ruler" (n = 14), RRV-RAV-distances were determined pre-interventionally by cross-sectional imaging (CT/MRI) and AVS was performed by one interventional radiologist with limited experience in AVS. CT/MRI-derived and fluoroscopy-derived RRV-RAV-distances were correlated for aimed cannulation of the RAV. Patients in group "no ruler" (n = 24, three interventional radiologists with limited experience in AVS) and in group "expert", (n = 7, one expert interventional radiologist) underwent AVS without pre-interventional estimation of RRV-RAV-distances. Procedure parameters (fluoroscopy time, contrast agent volume, radiation dose) of group "ruler" were compared to both other groups by Kruskal-Wallis rank-sum test. RESULTS: Correlation of CT/MRI-derived and fluoroscopy-derived RRV-RAV-distances was good (r = 0.74;p = 0.003). The median RRV-RAV-distance was 4.5cm at CT/MRI (95%-CI:4.2-5.0cm) and 4.0cm at fluoroscopy (95%-CI:3.8-4.5cm). Fluoroscopy time (p<0.0001), contrast agent exposure (p = 0.0003) and radiation dose (air kerma and dose area product both p = 0.038) were significantly lower in group "ruler" compared to group "no ruler" (all p<0.05), and similar to group "expert" (all p>0.05). CONCLUSIONS: CT/MRI-derived pre-interventional renal-adrenal vein distance measurements correlate well with angiographic distance measurements. Pre-interventional estimation of the RRV-RAV-distance allows for aimed cannulation of the RAV with potential reduction of fluoroscopy time, contrast agent exposure and radiation-dose during AVS.
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Medios de Contraste , Hiperaldosteronismo , Humanos , Estudios Retrospectivos , Glándulas Suprarrenales/diagnóstico por imagen , Dosis de Radiación , AldosteronaRESUMEN
To compare the patient radiation doses during angiographic selective adrenal vein sampling (AVS) before and after an imaging technology upgrade. In this retrospective single-center-study, cumulative air kerma (AK), cumulative dose area product (DAP), fluoroscopy time and contrast agent dosage were recorded from 70 patients during AVS. 35 procedures were performed before and 35 after an imaging processing technology upgrade. Mean values were calculated and compared using an unpaired student's t-test. DSA image quality was assessed independently by two blinded readers using a four-point Likert scale (1 = poor; 4 = excellent) and compared using Wilcoxon signed-rank test. After the technology upgrade we observed a significant reduction of 35% in AK (1.7 ± 0.7 vs. 1.1 ± 0.7 Gy, p = 0.01) and a significant reduction of 28% in DAP (235.1 ± 113 vs. 170.1 ± 94 Gy*cm2, p = 0.01) in comparison to procedures before the upgrade. There were no significant differences between the number of exposure frames (143 ± 86 vs. 132 ± 61 frames, p = 0.53), fluoroscopy time (42 ± 23 vs. 36 ± 18 min, p = 0.22), or the amount of contrast medium used (179.5 ± 84 vs. 198.1 ± 109 ml, p = 0.41). There was also no significant difference regarding image quality (3 (2-4) vs. 3 (2-4), p = 0.67). The angiographic imaging technology upgrade significantly decreases the radiation dose during adrenal vein sampling without increasing time of fluoroscopy or contrast volume and without compromising image quality.
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Reducción Gradual de Medicamentos , Exposición a la Radiación , Fluoroscopía/métodos , Humanos , Dosis de Radiación , Estudios Retrospectivos , TecnologíaRESUMEN
OBJECTIVES: Papillary muscle repositioning in functional mitral regurgitation (FMR) alleviates mitral valve (MV) tenting by reducing the distance between papillary muscle tips and MV annular plane, i.e. apical left ventricular (LV) displacement. We aimed to quantify the effect of papillary muscle repositioning on papillary muscle geometry and to evaluate whether improved papillary muscle geometry after papillary muscle repositioning translates into the global LV reverse remodelling in FMR type IIIb. METHODS: Patients with severe FMR type IIIb were prospectively enrolled and underwent pre- and postoperative 1.5-T cardiac magnetic resonance imaging. A new variable was defined, the papillary muscle to mitral annulus distance, which quantifies the distance between papillary muscle tips and MV annular plane. All parameters were measured by 2 independent investigators. RESULTS: A total of 63 patients were enrolled. In all patients, papillary muscle to mitral annulus distance correlated significantly with established markers of LV remodelling and MV tenting severity. In patients who underwent subannular papillary muscle repositioning procedure (surgical cohort, n = 23), preoperative median papillary muscle to mitral annulus distance was 30 mm [interquartile range (IQR): 27-34 mm] and was significantly reduced postoperatively to 25 mm (IQR: 21-27 mm) (P = 0.001). LV end-diastolic diameter was reduced from 66 mm (IQR: 60-71) preoperatively to 58 mm (IQR: 53-67) after the surgery (P = 0.001). CONCLUSIONS: MV repair with papillary muscle repositioning results in a papillary muscle to mitral annulus distance reduction and significantly improved MV tenting parameters. Improved papillary muscle geometry after papillary muscle repositioning is associated with a global LV reverse remodelling and may, thereby, improve the prognosis of FMR patients.
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Insuficiencia de la Válvula Mitral , Humanos , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/cirugía , Válvula Mitral/diagnóstico por imagen , Válvula Mitral/cirugía , Músculos Papilares/diagnóstico por imagen , Músculos Papilares/cirugía , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/cirugía , Remodelación Ventricular/fisiologíaRESUMEN
INTRODUCTION: Detection of symptomatic foreign bodies (FB) after penetrating hand injuries can be challenging. Multiplanar radiography is most frequently used for FB detection and may be complemented by multislice computed tomography (MSCT) if suspected FBs cannot be identified and clinical symptoms are persisting. Cone beam computed tomography (CBCT) is a promising imaging modality for traumatology aside from fracture detection. The aim of this study was to evaluate the diagnostic yield of CBCT for different small FBs in the hand in comparison with radiography, MSCT and magnetic resonance imaging (MRI). METHODS: In ten cadaveric hands of voluntary body donors, 20 different FBs (metal, glass, stone, wood, thorn) in predefined sizes (0.5, 1 and 2mm) were randomly placed in the central hand and the basal phalanges. All hands were imaged using radiography, 256-slice CT, CBCT, and 3T MRI. A total of 200 subcutaneous and intramuscular particles were analyzed for their visibility by two observers at two time points. The Cohens Kappa coefficient was calculated as a measure of interobserver agreement and intraobserver reliability. The particle detection rate between different imaging modalities was compared using McNemar Chi2-tests. RESULTS: CBCT and MSCT provided a higher detection rate (94.6% and 86.3%) for detecting metal, glass and stone particles compared to standard radiography (70.0%; each p<0.001). MRI did not provide a diagnostic benefit. Wood particles and thorns were not reliably recognizable by any imaging technique. The interobserver agreement (K=0.768; p<0.001) and the intraobserver reliability for both observers (K1=0.914 and K2=0.907; p<0.001) were good. The dose length product (DLP) was 2-fold lower in CBCT than in MSCT (39.2 ± 2.1 vs. 81.4 ± 2.9 mGy*cm; p<0.001). CONCLUSIONS: In this ex vivo study, CBCT provided a high detection rate for small metal, glass, and stone particles while the radiation exposure was significantly lower compared to MSCT. These results suggest that CBCT instead of MSCT seems a reasonable option in supplementary diagnostics to exclude of FBs. The primary use of CBCT instead of radiography may be considered for symptomatic patients with expected small radiopaque particles <1mm. Organic FBs can be visualized indirectly in MRI and CBCT/MSCT by entrapped surrounding air. LEVEL OF EVIDENCE: Level I, diagnostic study.
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Cuerpos Extraños , Tomografía Computarizada Multidetector , Tomografía Computarizada de Haz Cónico , Cuerpos Extraños/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Radiografía , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVES: This study aimed to assess the clinical outcome of the bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary obstruction (BASILICA) technique in a single-center patient cohort considered at high or prohibitive risk of transcatheter aortic valve implantation (TAVI)-induced coronary obstruction. METHODS: Between October 2019 and January 2021, a total of 15 consecutive patients (age 81.0 [78.1, 84.4] years; 53.3% female; EuroSCORE II 10.6 [6.3, 14.8] %) underwent BASILICA procedure prior to TAVI at our institution. Indications for TAVI were degeneration of stented (n = 12, 80.0%) or stentless (n = 1, 6.7%) bioprosthetic aortic valves, or calcific stenosis of native aortic valves (n = 2, 13.3%), respectively. Individual risk of TAVI-induced coronary obstruction was assessed by pre-procedural computed tomography analysis. Procedural and 30-day outcomes were documented in accordance with Valve Academic Research Consortium (VARC)-2 criteria. RESULTS: BASILICA was attempted for single left coronary cusp in 12 patients (80.0%), for single right coronary cusp in 2 patients (13.3%), and for both cusps in 1 patient (6.7%), respectively. The procedure was feasible in 13 patients (86.7%) resulting in effective prevention of coronary obstruction, whilst TAVI was performed without prior successful bioprosthetic leaflet laceration in two patients (13.3%). In one of these patients (6.7%), additional chimney stenting immediately after TAVI was performed. No all-cause deaths or strokes were documented after 30 days. CONCLUSION: The BASILICA technique appears to be a feasible, safe and effective concept to avoid iatrogenic coronary artery obstruction during TAVI in both native and bioprosthetic valves of patients at high or prohibitive risk. ClinicalTrials.gov Identifier: NCT04227002 (Hamburg AoRtic Valve cOhoRt).
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Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Bioprótesis/efectos adversos , Oclusión Coronaria/prevención & control , Prótesis Valvulares Cardíacas/efectos adversos , Enfermedad Iatrogénica/prevención & control , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Anciano , Anciano de 80 o más Años , Válvula Aórtica/diagnóstico por imagen , Angiografía Coronaria , Oclusión Coronaria/diagnóstico , Vasos Coronarios/diagnóstico por imagen , Ecocardiografía , Femenino , Fluoroscopía , Estudios de Seguimiento , Humanos , Masculino , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/prevención & control , Diseño de Prótesis , Estudios Retrospectivos , Tomografía Computarizada por Rayos XAsunto(s)
Antígeno CTLA-4/genética , Regulación de la Expresión Génica/fisiología , Nefrosis Lipoidea/genética , Adolescente , Antígeno CTLA-4/inmunología , Antígeno CTLA-4/metabolismo , Estudios de Casos y Controles , Niño , Femenino , Frecuencia de los Genes , Humanos , Masculino , Mortalidad , Nefrosis Lipoidea/inmunología , Nefrosis Lipoidea/metabolismo , Podocitos/efectos de los fármacos , Polimorfismo de Nucleótido SimpleRESUMEN
BACKGROUND & AIMS: Refractory ascites is the main reason for the implantation of a transjugular intrahepatic portosystemic shunt (TIPS) in liver cirrhosis, but ascites control by TIPS fails in a relevant proportion of cases. Here, we investigated whether routine parameters pre-TIPS can predict persistent ascites after TIPS implantation and whether persistent ascites predicts long-term clinical outcome. METHODS: A detailed retrospective analysis of 128 patients receiving expanded polytetrafluoroethylene-covered stents for the treatment of refractory ascites was performed. Persistent ascites post-TIPS was defined as the prolonged need for paracentesis >3 months after TIPS. The influence of demographics, laboratory results, pre-TIPS heart and liver ultrasound results, and invasive hemodynamic parameters on persistent ascites was evaluated by univariable and multivariable logistic regression. Predictors of the composite endpoint liver transplantation/death were analyzed using a multivariable Cox regression. RESULTS: Ascites control post-TIPS was achieved in 95/128 patients (74%), whereas ascites remained persistent in 33/128 cases (26%). On multivariable analysis, a lower paracentesis frequency pre-TIPS (odds ratio 1.672; 95% CI 1.253-2.355) and lower baseline creatinine levels (odds ratio 2.640; CI 1.201-6.607) were associated with ascites control. Patients with persistent ascites post-TIPS had and impaired transplant-free survival (median 10.0 vs. 25.8 months), for which persistent ascites was the only independent predictor (hazard ratio 5.654; CI 3.019-10.59). CONCLUSION: TIPS-placement in patients with lower paracentesis frequency and creatinine levels is associated with superior ascites control. Thus, TIPS implantation should be considered in moderate decompensation and not as a last resort. Persistent ascites post-TIPS seems to be the only predictor of liver transplantation and death. LAY SUMMARY: The insertion of a transjugular intrahepatic portosystemic shunt (TIPS) in patients with refractory ascites should be considered in patients with moderate decompensation and not as a last resort, as lower paracentesis frequency and creatinine levels pre-TIPS are associated with superior ascites control. In turn, failure to control ascites seems to be the only predictor of liver transplantation and death.
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PURPOSE: The purpose of the study was to assess the impact of iterative model reconstruction (IMR) on reader confidence with respect to stone detection and image quality in comparison to filtered back-projection (FBP) and iDose level 4 (iDose4) in abdominal MDCT with radiation doses below 2âmSv. MATERIALS AND METHODS: For 32 consecutive patients with suspected ureteral stone disease, the raw data of unenhanced 256 slice MDCT (120âkV, 40 reference mAs, mean CTDIvol: 2.7â±â0.8âmGy, mean DLP: 126â±â38âmGyâ×âcm) were reconstructed using a prototype version of IMR (levels 1â-â3), iDose4 (level 4) and FBP at a 3âmm slice thickness. Image analysis was independently performed by two radiologists in a blinded fashion. The reader confidence level with respect to stone detection was recorded based on a 5-point scale (1 - certain exclusion; 5 - concrement definitely present) as well as for the evaluation of image quality regarding the depiction of anatomical details (1 - poor; 5 - excellent). A clinical reference standard for stone detection was not established. Statistical evaluation included weighted kappa analysis and Wilcoxon test. RESULTS: 17 pelvic and ureteral stones were found. 11 further concrements were located within the ostium of the urinary bladder or the bladder itself. Applying IMR, a distinct improvement in image quality was observed at every level (mean value for FBP, 2.0; iDose4, 2.9; IMR L1, 4.2; IMR L2, 4.0; IMR L3, 3.9; all pâ<â0.001). Applying the higher IMR levels L2 and L3, a certain level of so-called "blotchiness" of anatomical contours was observed. Reader confidence was significantly improved and was independent of IMR level (certain stone detection FBP, 69â%; iDose4, 81â%; IMR L1 to L3, 95â%; all pâ>â0.001). With increasing IMR levels, the reduction in streak artifacts was quantified by a decrease in image noise. A loss of anatomical information was not observed. The sensitivity rates for stone detection were equivalent for all MDCTs reconstructed with FBP, iDose4 and IMR. A mean effective dose of 1.9â±â0.6âmSv was calculated. CONCLUSION: In comparison to FBP and iDose4, a significant increase in mean image quality, reduction in image noise and improvement in subjective reader confidence can be achieved by applying IMR even at significantly reduced dose settings below 2âmSv. Results indicate that a further dose reduction might be possible with IMR. KEY POINTS: · Urinary tract. · urolithiasis. · iterative reconstruction. CITATION FORMAT: · Schmidt-Holtz J, Laqmani A, Butscheidt S etâal. Iterative Model Reconstruction (IMR) in MDCT Below 2mSv for the Detection of Urinary Calculi: Diagnostic Accuracy and Image Quality in Comparison to Filtered Back-Projection and 4th Generation Iterative Reconstruction (iDose4). Fortschr Röntgenstr 2018; 190: 630â-â636.
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Interpretación de Imagen Asistida por Computador/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Tomografía Computarizada Multidetector/métodos , Intensificación de Imagen Radiográfica/métodos , Cálculos Urinarios/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Artefactos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Sensibilidad y Especificidad , Adulto JovenRESUMEN
OBJECTIVES: As the number of transvenous lead extractions continues to increase, preprocedural protocols for this procedure must be assessed. The objective of this study was to determine whether an electrocardiogram (ECG)-triggered computed tomography (Et-CT) with three-dimensional (3D) reconstructions could aid lead extractors in choosing the optimal tools to improve procedural success and avoid complications. METHODS: In this study, 31 patients scheduled for transvenous lead extraction underwent a preprocedural Et-CT between January 2016 and May 2017. Both 3D-reconstructions and the two-dimensional files were reviewed for possible lead adhesions, calcifications, migrations or perforations. RESULTS: Mean age was 46.7 ± 14.0 years. Seventy-one percent of patients were men, and 29.0% had undergone prior cardiac surgery. Indications for extraction included infection (n = 18, 58.1%), lead dysfunction (n = 8, 25.8%), upgrade (n = 3, 9.7%), severe tricuspid regurgitation (n = 1, 3.2%) and superior vena cava occlusion (n = 1, 3.2%). Eighteen patients had an implantable cardioverter defibrillator (58.1%). Sixty-eight of 70 targeted leads were extracted with a mean of 2.2 leads per patient and an average lead age of 109.3 ± 58.7 months. Et-CT files supported transvenous lead extraction by revealing possible adhesions in 16 patients, 5 perforations and 2 venous occlusions. Lead extraction was performed using the excimer laser, mechanical tools and femoral snares. Complete procedural success was achieved in 93.5% (n = 29) of cases. Clinical success was 100%, and intraoperative mortality was 0%. CONCLUSIONS: A preprocedural Et-CT with 3D reconstructions can help to visualize lead alignment and identify abnormalities that may foreshadow procedural difficulties. A preprocedural Et-CT may therefore aid lead extractors in choosing the optimal extraction tool and strategy.