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25 result(s) for "Falkowski, Anna L."
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Comparison of image quality and radiation dose between split-filter dual-energy images and single-energy images in single-source abdominal CT
ObjectivesTo compare image quality and radiation dose of abdominal split-filter dual-energy CT (SF-DECT) combined with monoenergetic imaging to single-energy CT (SECT) with automatic tube voltage selection (ATVS).MethodsTwo-hundred single-source abdominal CT scans were performed as SECT with ATVS (n = 100) and SF-DECT (n = 100). SF-DECT scans were reconstructed and subdivided into composed images (SF-CI) and monoenergetic images at 55 keV (SF-MI). Objective and subjective image quality were compared among single-energy images (SEI), SF-CI and SF-MI. CNR and FOM were separately calculated for the liver (e.g. CNRliv) and the portal vein (CNRpv). Radiation dose was compared using size-specific dose estimate (SSDE). Results of the three groups were compared using non-parametric tests.ResultsImage noise of SF-CI was 18% lower compared to SEI and 48% lower compared to SF-MI (p < 0.001). Composed images yielded higher CNRliv over single-energy images (23.4 vs. 20.9; p < 0.001), whereas CNRpv was significantly lower (3.5 vs. 5.2; p < 0.001). Monoenergetic images overcame this inferiority in CNRpv and achieved similar results compared to single-energy images (5.1 vs. 5.2; p > 0.628). Subjective sharpness was equal between single-energy and monoenergetic images and diagnostic confidence was equal between single-energy and composed images. FOMliv was highest for SF-CI. FOMpv was equal for SEI and SF-MI (p = 0.78). SSDE was significant lower for SF-DECT compared to SECT (p < 0.022).ConclusionsThe combined use of split-filter dual-energy CT images provides comparable objective and subjective image quality at lower radiation dose compared to single-energy CT with ATVS.Key points• Split-filter dual-energy results in 18% lower noise compared to single-energy with ATVS.• Split-filter dual-energy results in 11% lower SSDE compared to single-energy with ATVS.• Spectral shaping of split-filter dual-energy leads to an increased dose-efficiency.
Cartilage icing and chondrocalcinosis on knee radiographs in the differentiation between gout and calcium pyrophosphate deposition
To determine if findings of \"cartilage icing\" and chondrocalcinosis on knee radiography can differentiate between gout and calcium pyrophosphate deposition (CPPD). IRB-approval was obtained and informed consent was waived for this retrospective study. Electronic medical records from over 2.3 million patients were searched for keywords to identify subjects with knee aspiration-proven cases of gout or CPPD. Radiographs were reviewed by two fellowship-trained musculoskeletal radiologists in randomized order, blinded to the patients' diagnoses. Images were evaluated regarding the presence or absence of cartilage icing, chondrocalcinosis, tophi, gastrocnemius tendon calcification, and joint effusion. Descriptive statistics, sensitivity, specificity, positive and negative predictive values, and accuracy were calculated. From 49 knee radiographic studies in 46 subjects (31 males and 15 females; mean age 66±13 years), 39% (19/49) showed gout and 61% (30/49) CPPD on aspiration. On knee radiographs, cartilage icing showed a higher sensitivity for CPPD than gout (53-67% and 26%, respectively). Chondrocalcinosis also showed a higher sensitivity for CPPD than gout (50-57% versus 5%), with 95% specificity and 94% positive predictive value for diagnosis of CPPD versus gout. Soft tissue tophus-like opacities were present in gout at the patellar tendon (5%, 1/19) and at the popliteus groove in CPPD (15%, 4/27). Gastrocnemius tendon calcification was present in 30% (8/27) of subjects with CPPD, and 5% (1/19) of gout. In subjects with joint aspiration-proven crystal disease of the knee, the radiographic finding of cartilage icing was seen in both gout and CPPD. Chondrocalcinosis (overall and hyaline cartilage) as well as gastrocnemius tendon calcification positively correlated with the diagnosis of CPPD over gout.
Primary angiitis of the central nervous system: predictors of stroke during immunosuppressant treatment
Objective To evaluate predictors of ischemic stroke in patients with primary angiitis of the central nervous system after initiation of immunosuppressive therapy. Materials and methods This retrospective study included 204 MRI examinations of 23 patients with primary angiitis of the central nervous system, treated with immunosuppressive therapy between 2015 and 2020 at the University Hospital Bern and the Cantonal Hospital St. Gallen, Switzerland. Two senior neuroradiologists evaluated the MRI exams with regard to the occurrence and location of ischemic stroke and hemorrhage, as well as the following characteristics of inflamed vessels on 3D time-of-flight angiography and T1 dark-blood post contrast: signal intensity of vessel walls, length of enhancement, circular extent of enhancement, and stenosis. After matching ischemic strokes to their corresponding vessel, the temporal relationship of vessel alterations in accordance with therapy initiation and stroke onset was calculated. Results The majority (77.6%) of observed strokes were in the vascular territory of an inflamed vessel. A significant, non-linear temporal relationship between the timing of MRI and the initiation of immunosuppression was found. The highest predicted probability of ischemic stroke was observed between 10 and 20 days after the initiation of immunosuppressant therapy, reaching approximately 12%. Out of all evaluated vessel characteristics, a higher degree of stenosis (Estimate: 0.93, p  = 0.006) and a higher circularity of enhancement (Estimate: 0.76, p  = 0.01) were significantly associated with a higher likelihood of stroke. Conclusions A better understanding of unfavorable constellations (critical timeframe, characteristic vessel wall changes) in patients treated for primary angiitis of the central nervous system may help to prevent secondary ischemic strokes. Critical relevance statement A better understanding of ischemic stroke predictors in patients treated for primary angiitis of the central nervous system may prompt closer monitoring or therapy adjustment. Key Points To evaluate risk factors for ischemic stroke in patients treated for primary angiitis of the central nervous system. Higher degree of stenosis and circular enhancement are associated with a higher likelihood of ischemic strokes, which typically occur between 10 and 20 days after therapy onset. Data obtained from this may prompt closer monitoring or therapy adjustment. Graphical Abstract
The biomechanical consequence of posterior interventions at the thoracolumbar spine on the passively stabilized flexed posture
In the flexed end-of-range position (e.g., during slumped sitting), the trunk is passively stabilized. Little is known about the biomechanical consequence of posterior approaches on passive stabilization. The aim of this study is to investigate the effect of posterior surgical interventions on local and distant spinal regions. While being fixed at the pelvis, five human torsos were passively flexed. The change in spinal angulation at Th4, Th12, L4 and S1 was measured after level-wise longitudinal incisions of the thoracolumbar fascia, the paraspinal muscles, horizontal incisions of the inter- & supraspinous ligaments (ISL/SSL) and horizontal incision of the thoracolumbar fascia and the paraspinal muscles. Lumbar angulation (Th12-S1) was increased by 0.3° for fascia, 0.5° for muscle and 0.8° for ISL/SSL-incisions per lumbar level. The effect of level-wise incisions at the lumbar spine was 1.4, 3.5 and 2.6 times greater compared to thoracic interventions for fascia, muscle and ISL/SSL respectively. The combined midline interventions at the lumbar spine were associated with 2.2° extension of the thoracic spine. Horizontal incision of the fascia increased spinal angulation by 0.3°, while horizontal muscle incision resulted in a collapse of 4/5 specimens. The thoracolumbar fascia, the paraspinal muscle and the ISL/SSL are important passive stabilizers for the trunk in the flexed end-of-range position. Lumbar interventions needed for approaches to the spine have a larger effect on spinal posture than thoracic interventions and the increase of spinal angulation at the level of the intervention is partially compensated at the neighboring spinal regions.
Ultra-high resolution 3D MRI for chondrocalcinosis detection in the knee—a prospective diagnostic accuracy study comparing 7-tesla and 3-tesla MRI with CT
Objectives To test the diagnostic accuracy of a 3D dual-echo steady-state (DESS) sequence at 7-T MRI regarding the detection of chondral calcific deposits of the knee in comparison to 3-T MRI, using CT as cross-sectional imaging reference standard. Methods CT and 7-T MRI (DESS) of knee joints in 42 patients with radiographically known chondrocalcinosis (13 of 42 bilateral) were prospectively acquired for all included patients (n = 55 knee joints). Additionally, 3-T MRI (DESS) was performed for 20 of these 55 knee joints. Two fellowship-trained musculoskeletal radiologists scored eight cartilage regions of each knee joint separately regarding presence of cartilage calcification, diagnostic confidence level, and sharpness of calcific deposits. In an explorative subanalysis, micro-CT of the menisci was evaluated after knee arthroplasty in one patient. Diagnostic performance metrics and nonparametric tests were used to compare between modalities. p values < 0.05 were considered to represent statistical significance. Results Sensitivity for chondrocalcinosis detection was significantly higher for 7-T MRI (100%) compared to 3-T MRI (reader 1: 95.9%, p = 0.03; reader 2: 93.2%, p = 0.002). The diagnostic confidence was significantly higher for both readers at 7 T compared to both 3-T MRI ( p < 0.001) and to CT ( p = 0.03). The delineation of chondral calcifications was significantly sharper for 7-T compared to both 3-T MRI and CT ( p < 0.001, both readers). Micro-CT in one patient suggested that 7-T MRI may potentially outperform standard CT in diagnosing chondral calcifications. Conclusion 3D-DESS imaging at 7-T MRI offers a significantly higher sensitivity in detection of chondral calcific deposits compared to 3-T MRI. Key Points • 3D dual-echo steady-state (DESS) MRI at 7 T has a higher sensitivity in detection of chondral calcific deposits compared to 3-T MRI (p ≤ 0.03). • 3D DESS MRI at 7 T yields no false-negative cases regarding presence of chondral calcific deposits. • 3D DESS MRI at 7 T offers better delineation and higher diagnostic confidence in detection of chondral calcific deposits compared to 3-T MRI (p < 0.001).
MR imaging of the quadriceps femoris tendon: distal tear characterization and clinical significance of rupture types
Objective To characterize quadriceps femoris tendon tears on magnetic resonance (MR) imaging regarding tear extent, location, and presence of bony avulsion. Materials and methods IRB approval was obtained and informed consent was waived for this retrospective case series. Electronic medical records from all patients in our hospital system were searched for keywords: knee MR imaging, and quadriceps tendon rupture or tear. MRI studies were randomized and independently evaluated by two fellowship-trained musculoskeletal radiologists. MR imaging was used to characterize each individual quadriceps tendon as having tendinosis, tear (location, partial versus complete, size, and retraction distance), and bony avulsion. Knee radiographs were reviewed for presence or absence of bony avulsion. Descriptive statistics and inter-reader reliability (Cohen’s Kappa and Wilcoxon-signed-rank test) were calculated. Results Fifty-two patients with 53 quadriceps tears were evaluated (45 males, 7 females; mean age: 51 ± 13 years). The vastus intermedius (VI) tendon more often incurred a partial rather than a complete tear (39.6% vs. 37.7%), while the rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) incurred complete tears more commonly (64.2–66%). Subjects with bony avulsion on radiographs had higher-grade tears of the RF, VM, and VL tears ( p = 0.020–0.043) but not the VI. Most tendons tore at or immediately proximal to the patella (84.8–93.6%). Gaps in retracted torn tendons measured between 2.3 and 2.7 cm. Inter-reader reliability was substantial to almost perfect (κ = 0.624–0.953). Conclusion Quadriceps femoris tendon tears most commonly involve the RF or VL/VM layers usually in proximity to the patella. A bony avulsion correlates with a more extensive tear. Key Points • Quadriceps femoris tendon tears most commonly involve the rectus femoris or vastus lateralis/vastus medialis layers. • A rupture of the quadriceps femoris tendon usually occurs in proximity to the patella. • A bony avulsion of the patella correlates with a more extensive tear of the superficial and middle layers of the quadriceps tendon.
From Network Governance to Real-World-Time Learning: A High-Reliability Operating Model for Rare Cancers
Background: Rare cancers combine low incidence with high biological heterogeneity and multi-institutional care trajectories. These features make single-center learning structurally incomplete and render pathway fragmentation a dominant driver of preventable harm, variability, and waste. In this context, care quality is best understood as a property of pathway integrity across routing, diagnostics (imaging/biopsy planning), multidisciplinary intent-setting, definitive treatment, and surveillance—rather than as a department-level attribute. Objective: To define a pragmatic, transferable operating blueprint for a rare-cancer Learning Health System (LHS) that turns routine care into continuous, auditable learning under explicit governance, while maintaining claims discipline and protecting measurement validity. Approach: We synthesize an implementation-oriented operating model using the Swiss Sarcoma Network (SSN) as an exemplar. The blueprint couples clinical governance (Integrated Practice Unit logic, hub-and-spoke routing, auditable multidisciplinary team decision systems) with an interoperable real-world-time data backbone designed for benchmarking, pathway mapping, and feedback. The operating logic is expressed as a closed-loop control cycle: capture → harmonize → benchmark → learn → implement → re-measure, with explicit owners, minimum requirements, and failure modes. Results/Blueprint: (i) The model specifies a minimal set of data primitives—time-stamped and traceable decision points covering baseline and tumor characteristics, pathway timing, treatment exposure, outcomes and complications, and feasible longitudinal PROMs and PREMs; (ii) a VBHC-ready, multi-domain measurement backbone spanning outcomes, harms, timeliness, function, process fidelity, and resource stewardship; and (iii) two non-negotiable validity guardrails: explicit applicability (“N/A”) rules and mandatory case-mix/complexity stratification. Implementation is treated as a governed step with defined workflow levers, fidelity criteria, balancing measures, and escalation thresholds to prevent “dashboard medicine” and surrogate-driven optimization. Conclusions: This perspective contributes an operating model—not a platform or single intervention—that enables credible improvement science and establishes prerequisites for downstream causal learning and minimum viable digital twins. By distinguishing enabling infrastructure from the governed clinical system as the primary intervention, the blueprint supports scalable, learnable excellence in rare-cancer care while protecting against gaming, inequity, and inference drift. Distinct from generic LHS or VBHC frameworks, this blueprint specifies validity gates required for rare-cancer benchmarking—explicit applicability (“N/A”) rules, denominator integrity/capture completeness disclosure, anti-gaming safeguards, and escalation governance. These elements are critical in rare cancers because small denominators, high heterogeneity, and multi-institutional pathways otherwise make benchmarking prone to artifacts and unsafe inferences.
In vivo 3D tomography of the lumbar spine using a twin robotic X-ray system: quantitative and qualitative evaluation of the lumbar neural foramina in supine and upright position
Objectives Supine lumbar spine examinations underestimate body weight effects on neuroforaminal size. Therefore, our purpose was to evaluate size changes of the lumbar neuroforamina using supine and upright 3D tomography and to initially assess image quality compared with computed tomography (CT). Methods The lumbar spines were prospectively scanned in 48 patients in upright (3D tomographic twin robotic X-ray) and supine (30 with 3D tomography, 18 with CT) position. Cross-sectional area (CSA), cranio-caudal (CC), and ventro-dorsal (VD) diameters of foramina were measured by two readers and additionally graded in relation to the intervertebral disc height. Visibility of bone/soft tissue structures and image quality were assessed independently on a 5-point Likert scale for the 18 patients scanned with both modalities. Descriptive statistics, Wilcoxon’s signed-rank test ( p < 0.05), and interreader reliability were calculated. Results Neuroforaminal size significantly decreased at all levels for both readers from the supine (normal intervertebral disc height; CSA 1.25 ± 0.32 cm 2 ; CC 1.84 ± 0.24 cm 2 ; VD 0.88 ± 0.16 cm 2 ) to upright position (CSA 1.12 ± 0.34 cm 2 ; CC 1.78 ± 0.24 cm 2 ; VD 0.83 ± 0.16 cm 2 ; each p < 0.001). Decrease in intervertebral disc height correlated with decrease in foraminal size (supine: CSA 0.88 ± 0.34 cm 2 ; CC 1.39 ± 0.33 cm 2 ; VD 0.87 ± 0.26 cm 2 ; upright: CSA 0.83 ± 0.37 cm 2 , p = 0.010; CC 1.32 ± 0.33 cm 2 , p = 0.015; VD 0.80 ± 0.21 cm 2 , p = 0.021). Interreader reliability for area was fair to excellent (0.51–0.89) with a wide range for cranio-caudal (0.32–0.74) and ventro-dorsal (0.03–0.70) distances. Image quality was superior for CT compared with that for 3D tomography ( p < 0.001; κ , CT = 0.66–0.92/3D tomography = 0.51–1.00). Conclusions The size of the lumbar foramina is smaller in the upright weight-bearing position compared with that in the supine position. Image quality, especially nerve root delineation, is inferior using 3D tomography compared to CT. Key Points • Weight-bearing examination demonstrates a decrease of the neuroforaminal size. • Patients with higher decrease in intervertebral disc showed a narrower foraminal size. • Image quality is superior with CT compared to 3D tomographic twin robotic X-ray at the lumbar spine.
Hand-Held Portable Versus Conventional Cart-Based Ultrasound in Musculoskeletal Imaging
Background: Portable ultrasound machines are now common, used for point-of-care applications and needle guidance for percutaneous procedures; however, the effectiveness of portable ultrasound in evaluation of the musculoskeletal system has not been fully assessed. Purpose: To prospectively evaluate the use of portable hand-held ultrasound in comparison with conventional cart-based ultrasound in evaluation of the musculoskeletal system. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: In this institutional review board–approved, prospective study, 100 consecutive patients with informed consent were imaged through use of both portable and cart-based ultrasound equipment using 12-5 MHz linear transducers. Agreement in ultrasound diagnosis was documented along with expected clinical changes in management if there was disagreement (definitely no, probably no, uncertain, probably yes, definitely yes). Imaging details of disagreement cases were recorded, and descriptive statistics were calculated. Results: There were 42 male and 58 female patients (mean ± SD age, 53 ± 13 years) imaged over a time period of 20 months. Anatomic areas scanned were the shoulder (n = 30), elbow (n = 11), hand and wrist (n = 15), hip (n = 10), knee (n = 11), foot and ankle (n = 12), and others (n = 11). Scanning with conventional ultrasound revealed abnormality in 92% of patients. Agreement in diagnosis made between portable versus cart-based ultrasound was found in 65% of patients. In the 35% of patients with discordant results, the change in diagnosis resulted in no change in clinical management in 46%, probably no change in 29%, uncertain change in 14%, probable change in 11%, and definite change in 0%. The diagnoses changing management (4%; 4/100) included nondetection of a satellite nodule (n = 1), ganglion cyst (n = 1), hernia (n = 1), and underestimated tendon tear (n = 1). Conclusion: When compared with conventional cart-based ultrasound, a musculoskeletal diagnosis using portable hand-held ultrasound was concordant or was discordant without clinical relevance in 96% (96/100) of patients. Knowledge of benefits and limitations of portable hand-held ultrasound will help determine areas where specific types of ultrasound equipment can be used.
Enhancing Patient Experience in Sarcoma Core Biopsies: The Role of Communication, Anxiety Management, and Pain Control
Background/Objectives: This study evaluates the effectiveness of communication strategies and pain management protocols to enhance patients’ experiences during sarcoma core biopsies. Recognizing the complexity and anxiety associated with sarcoma diagnoses, this research aims to assess the utility of the Invasive Procedure Assessment (IPA) tool, focusing on its ability to identify areas for improvement through Patient-Reported Outcome Measures (PROMs) and Patient-Reported Experience Measures (PREMs). Methods: Conducted at two Integrated Practice Units (IPUs) within the Swiss Sarcoma Network, this study involved 282 consecutive patients who underwent core biopsies. One week post-procedure, patients completed the IPA questionnaire, which included PROMs and PREMs. Statistical analyses explored correlations between physician communication, patient understanding, anxiety, pain, and overall satisfaction. Results: The IPA tool effectively captured patient perspectives on sarcoma core biopsies. A significant positive correlation (rho = 0.619, p < 0.0001) was found between effective physician communication and patient understanding, which was associated with reduced anxiety and pain. Higher anxiety levels strongly correlated with increased pain perception (rho = 0.653, p < 0.0001), emphasizing the need for anxiety management. Patients with malignant tumors reported lower overall satisfaction compared to those with benign tumors (p = 0.0003), highlighting the need for tailored communication and pain management strategies. The data also suggested that clear communication might mitigate overly negative subjective impressions, such as concerns about wound complications. Conclusions: Effective communication and anxiety management are essential for improving patient satisfaction during sarcoma core biopsies. The study emphasizes the need for personalized care strategies tailored to tumor characteristics and patient demographics. Future research should validate these findings in diverse healthcare settings and explore the broader application of the IPA tool across different cultural and demographic contexts.