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Introduction: Photon-counting detector computed tomography (PCD-CT) represents the next generation of CT technology, offering enhanced capabilities for detecting the orientation of directional leads in deep brain stimulation (DBS). This study aims to refine PCD-CT-based lead orientation determination using an automated method applicable to devices from various manufacturers, addressing current methodological limitations and improving neurosurgical precision., Methods: An automated method was developed to ascertain the orientation of directional DBS leads using PCD-CT data and grayscale model fitting for devices from Boston Scientific, Medtronic, and Abbott. A phantom study was conducted to evaluate the precision and accuracy of this method, comparing it with the stripe artifact method across different lead alignments relative to the CT gantry axis., Results: Except for the Medtronic Sensight™ lead, where detection was occasionally unfeasible if aligned normal to the z-axis of the CT gantry, a clinically very unlikely alignment, the lead orientation could be automatically determined regardless of its position. The accuracy and precision of this automated method was comparable to those of the stripe artifact method., Conclusion: PCD-CT enables the automatic determination of lead orientation from leading manufacturers with an accuracy comparable to the stripe artifact method, and it offers the added benefit of being independent of the clinically occurring orientation of the head and, consequently, the lead relative to the CT gantry axis., (© 2024 S. Karger AG, Basel.)

Introduction: With recent advancements in deep brain stimulation (DBS), directional leads featuring segmented contacts have been introduced, allowing for targeted stimulation of specific brain regions. Given that manufacturers employ diverse markers for lead orientation, our investigation focuses on the adaptability of the 2017 techniques proposed by the Cologne research group for lead orientation determination., Methods: We tailored the two separate 2D and 3D X-ray-based techniques published in 2017 and originally developed for C-shaped markers, to the dual-marker of the Medtronic SenSight™ lead. In a retrospective patient study, we evaluated their feasibility and consistency by comparing the degree of agreement between the two methods., Results: The Bland-Altman plot showed favorable concordance without any noticeable systematic errors. The mean difference was 0.79°, with limits of agreement spanning from 21.4° to -19.8°. The algorithms demonstrated high reliability, evidenced by an intraclass correlation coefficient of 0.99 (p < 0.001)., Conclusion: The 2D and 3D algorithms, initially formulated for discerning the circular orientation of a C-shaped marker, were adapted to the marker of the Medtronic SenSight™ lead. Statistical analyses revealed a significant level of agreement between the two methods. Our findings highlight the adaptability of these algorithms to different markers, achievable through both low-dose intraoperative 2D X-ray imaging and standard CT imaging., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Polymethylmethacrylate (PMMA) removal during septic total joint arthroplasty revision is associated with a high fracture and perforation risk. Ultrasonic cement removal is considered a bone-preserving technique. Currently, there is still a lack of sound data on efficacy as it is difficult to detect smaller residues with reasonable technical effort. However, incomplete removal is associated with the risk of biofilm coverage of the residue. Therefore, the study aimed to investigate the efficiency of ultrasonic-based PMMA removal in a human cadaver model. The femoral components of a total hip and a total knee prosthesis were implanted in two cadaver femoral canals by 3rd generation cement fixation technique. Implants were then removed. Cement mantle extraction was performed with the OSCAR-3-System ultrasonic system (Orthofix®). Quantitative analysis of cement residues was carried out with dual-energy and microcomputer tomography. With a 20 µm resolution, in vitro microcomputer tomography visualized tiniest PMMA residues. For clinical use, dual-energy computer tomography tissue decomposition with 0.75 mm resolution is suitable. With ultrasound, more than 99% of PMMA was removed. Seven hundred thirty-four residues with a mean volume of 0.40 ± 4.95 mm 3 were identified with only 4 exceeding 1 cm in length in at least one axis. Ultrasonic cement removal of PMMA was almost complete and can therefore be considered a highly effective technique. For the first time, PMMA residues in the sub-millimetre range were detected by computer tomography. Clinical implications of the small remaining PMMA fraction on the eradication rate of periprosthetic joint infection warrants further investigations., (© 2022 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.)

Purpose: The benefits of antiviral treatment with remdesivir in hospitalized patients with COVID-19 remain controversial. Clinical analyses are needed to demonstrate which patient populations are most likely to benefit., Methods: In a retrospective monocentric analysis, patients with COVID-19 treated between July 1, 2020 and June 30, 2021 at Hospital St. Georg, Leipzig, Germany were evaluated. The primary endpoint was time to clinical improvement, and the secondary endpoint was 28-day mortality. Propensity score matching was used for the endpoint analysis., Results: A total of 839 patients were fully evaluated, 68% of whom received specific COVID-19 drug therapy. Remdesivir was used in 31.3% of the patients, corticosteroids in 61.7%, and monoclonal antibodies in 2.3%. While dexamethasone administration was the most common therapeutic approach during the second pandemic wave, combination therapy with remdesivir and corticosteroids predominated during the third wave. Cox regression analysis revealed that combination therapy was not associated with faster clinical improvement (median: 13 days in both matched groups, HR 0.97 [95% CI 0.77-1.21], P = 0.762). By contrast, 28-day mortality was significantly lower in the corticosteroid-remdesivir group (14.8% versus 22.2% in the corticosteroid group, HR 0.60 [95% CI 0.39-0.95], P = 0.03) in the low-care setting. This effect was also demonstrated in a subgroup analysis of patients with remdesivir monotherapy (n = 44) versus standard of care (SOC)., Conclusion: In COVID-19 patients with only mild disease (low-flow oxygen therapy and treatment in a normal ward) who received corticosteroids and/or remdesivir in addition to SOC, early administration of remdesivir was associated with a measurable survival benefit., (© 2022. The Author(s).)

Background: In critically ill ICU patients, initial results showed that opposite enhancement of the adrenal glands (↑) and spleen (↓) on portal venous CT scans was associated with increased mortality over the next days to a month, with short-term mortality being best predicted. The study aimed to validate the adrenal-to-spleen ratio determined in a pilot study concerning mortality prediction., Method: 371 portal venous CT scans of 203 ICU patients (127 men, age: 68.1 ± 14.4 years) were included in the retrospective analysis. Region-of-interest (ROI)-based Hounsfield units of the adrenal glands and the spleen and their density ratio were evaluated. The Matthews correlation coefficient (MCC) and ROC analysis were used to establish a threshold for the adrenal-to-spleen ratio regarding mortality within 72 hours of imaging. The quality of the classification of survivors and deceased patients in the current collective based on the threshold determined in a pilot study and on the current threshold was determined. The precision-recall curve (PRC) was used to test the influence of the addition of patients with low vital risk on the ROC., Results: The current threshold of 1.37 for the adrenal-to-spleen ratio provides good discriminatory power between those who died and those who survived (MCC: 0.87; sensitivity: 83.7 %; specificity: 99.1 %; PPV: 93.2 %; NPV: 97.6 %) and differs only slightly from the threshold of 1.41 determined in the pilot study, which consequently has comparable discriminatory power., Conclusion: As a reproducible image-based prognostic marker, the portal venous adrenal-to-spleen ratio has a high predictive power for short-term death in ICU patients. It is, therefore, suitable as an indicator of high risk of death within 72 hours after imaging., Key Points: · In cases of shock, CT perfusion changes of the abdominal organs can be observed.. · These changes are summarized under the term CT hypoperfusion complex.. · Organ enhancement ratios allow conclusions about the patient's short-term survival.. · The portal venous adrenal-to-spleen ratio is a sufficient prognostic mortality parameter.., Citation Format: · Winzer R, Hoffmann R, Fedders D. The Portal-Venous Enhancement Ratio of the Adrenal Glands and Spleen as a Short-Term Predictor of Mortality in Intensive Care Patients. Fortschr Röntgenstr 2022; 194: 1250 - 1257., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Background: Systemic inflammation can occur after transcatheter aortic valve replacement (TAVR) and correlates with adverse outcome. The impact of remote ischemic preconditioning (RIPC) on TAVR associated systemic inflammation is unknown and was focus of this study., Methods: We performed a prospective controlled trial at a single center and included 66 patients treated with remote ischemic preconditioning (RIPC) prior to TAVR, who were matched to a control group by propensity score. RIPC was applied to the upper extremity using a conventional tourniquet. Definition of systemic inflammation was based on leucocyte count, C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6), assessed in the first 5 days following the TAVR procedure. Mortality was determined within 6 months after TAVR. RIPC group and matched control group showed comparable baseline characteristics., Results: Systemic inflammation occurred in 66% of all patients after TAVR. Overall, survival after 6 months was significantly reduced in patients with systemic inflammation. RIPC, in comparison to control, did not significantly alter the plasma levels of leucocyte count, CRP, PCT or IL-6 within the first 5 days after TAVR. Furthermore, inflammation associated survival after 6 months was not improved by RIPC. Of all peri-interventional variables assessed, only the amount of the applied contrast agent was connected to the occurrence of systemic inflammation., Conclusions: Systemic inflammation frequently occurs after TAVR and leads to increased mortality after 6 months. RIPC neither reduces the incidence of systemic inflammation nor improves inflammation associated patient survival within 6 months., Competing Interests: TFR received honoraria as speaker, proctor, and/or preceptor from Abbott Laboratories and Edwards Lifesciences. All other authors declare no conflicts of interest., (© 2022 The Author(s). Published by IMR Press.)

Background: The analysis aimed to compare the radiotracers [ 68 Ga]-Ga-PSMA-11 and [ 18 F]-F-PSMA-1007 intraindividually in terms of malignant lesions, mi(molecular-imaging)TNM staging and presumable unspecific lesions retrospectively as used in routine clinical practice., Methods: A retrospective analysis of 46 prostate cancer patients (median age: 71 years) who underwent consecutive [ 68 Ga]-Ga-PSMA-11- and [ 18 F]-F-PSMA-1007-PET/CT or PET/MRI within a mean of 12 ± 8.0 days was performed. MiTNM staging was performed in both studies by two nuclear medicine physicians who were blinded to the results of the other tracer. After intradisciplinary and interdisciplinary consensus with two radiologists was reached, differences in both malignant and presumable nonspecific tracer accumulation were analyzed., Results: Differences in terms of miTNM stages in both studies occurred in nine of the 46 patients (19.6%). The miT stages differed in five patients (10.9%), the miN stages differed in three patients (6.5%), and different miM stages occurred only in one patient who was upstaged in [ 18 F]-F-PSMA-1007 PET. Concordant miTNM stages were obtained in 37 patients (80.4%). There was no significant difference between [ 18 F]-F-PSMA-1007 and [ 68 Ga]-Ga-PSMA-11 in the SUV max locally (31.5 vs. 32.7; p = 0.658), in lymph node metastases (28.9 vs. 24.9; p = 0.30) or in bone metastases (22.9 vs. 27.6; p = 0.286). In [ 18 F]-F-PSMA-1007 PET, more patients featured presumable unspecific uptake in the lymph nodes (52.2% vs. 28.3%; p: < 0.001), bones (71.7% vs. 23.9%; p < 0.001) and ganglia (71.7% vs. 43.5%; p < 0.001). Probable unspecific, exclusively [ 18 F]-F-PSMA-1007-positive lesions mainly occurred in the ribs (58.7%), axillary lymph nodes (39.1%) and cervical ganglia (28.3%)., Conclusion: In terms of miTNM staging, both tracers appeared widely exchangeable, as no tracer relevantly outperformed the other. The differences between the two tracers were far more common in presumable unspecific lesions than in malignant spots. A routinely performed two-tracer study could not be shown to be superior. Since it seems at least challenging for most nuclear medicine departments to provide both [ 18 F]-F-PSMA-1007 and [ 68 Ga]-Ga-PSMA-11, it appears reasonable to choose the PSMA radiotracer depending on local availability with attention to the greater occurrence of nonspecific bone findings with [ 18 F]-F-PSMA-1007., (© 2021. The Author(s).)

Introduction: To investigate the value of contrast-enhanced CT findings - splenic and aortic radiodensities and their ratios (spleno-aortic ratio) - in predicting the prognosis of critical care unit patients (CCU)., Methods: One hundred thirteen continuous CCU patients with an acute deterioration (Group A: 37 women, age: 67.2 ± 14.0 years) were included in the retrospective study. Radiodensities of the spleen and aorta were evaluated by two radiologists separately. The spleno-aortic ratio was calculated. Matthews correlation coefficient (MCC) was used in conjunction with receiver operating characteristic analysis (ROC) to assess if and which parameter was most suitable for short-term mortality prediction. The intra-class correlation coefficient assessed consensus across readers. To validate the results for the best predictor, a second cohort was evaluated (Group B: 354 CT scans)., Results: The portal venous spleno-aortic ratio was best suited to predict 72-hour mortality (AUC = 0.91). A threshold ratio ≤0.53 predicted short-term mortality with a high sensitivity (80.95%) and specificity (96.74%, MCC = 0.79). The post-test probability was 85%, assuming a pre-test probability of 18.6% (72-hour mortality rate). ICCs of HU measurements in the aorta, spleen, and its ratios showed high interrater agreement (ICC: 0.92-0.99). In a control cohort, a threshold ratio ≤0.53 predicted CCU patientś outcome satisfactorily (SENS = 83.93%, SPEC = 97.65%, PPV = 87.00%, NPV = 97.00%)., Conclusions: The portal venous spleno-aortic ratio serves as a distinctive imaging feature to predict short-term mortality. For CCU patients with a cut-off portal venous spleno-aortic ratio ≤0.53, the risk of dying within three days after CT scan is approximately twenty times higher., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Purpose: To investigate whether adrenal gland radiodensities alone or set in relation to either the inferior vena cava (IVC) or the spleen can predict hospital mortality in intensive care unit patients., Methods: One hundred thirty-three intensive care patients (90 males, age: 66.3 ± 14.5 years) with an acute clinical deterioration were included in this retrospective analysis. CT attenuation (Hounsfield units) of adrenal glands, IVC, and spleen was evaluated by 2 radiologists separately. Adrenal-to-IVC and adrenal-to-spleen ratios were calculated. Receiver operating characteristic (ROC) analysis, combined with the Matthews correlation coefficient (MCC) as a classifier, was used to assess which parameter is the most suitable for short-term, intermediate-term, and overall mortality prediction. Interrater agreement was assessed using intraclass correlation coefficient (ICC)., Results: The highest discriminative power to distinguish between deceased and survivors was found for the adrenal gland-to-spleen ratio for the 72-h mortality. A threshold of > 1.4 predicted 72-h mortality with a sensitivity of 79.31% and a specificity of 98.08% (area und the curve (AUC) = 0.94; p < 0.0001; MCCs = 0.81). The positive likelihood ratio was 41; the positive predictive value was 92.20%. Adrenal gland-to-spleen ratio was also best suited to predict the 24-h and overall mortality. ICCs of HU measurements in adrenal gland, IVC, and spleen indicated a high interrater agreement (ICC 0.95-0.99)., Conclusions: To conclude, the adrenal-to-spleen ratio in CT in portal venous phase may serve as an imaged-based predictor for short, intermediate, and overall mortality and as reproducible prognostic marker for patient outcome.

Purpose: To investigate whether adrenal gland radiodensities alone or compared to the inferior vena cava (IVC) can correctly predict hospital mortality in patients in intensive care., Methods: One hundred thirteen intensive care patients (76 males, age: 67.2 ± 14.0 years) with an acute clinical deterioration were included in this retrospective analysis. For the venous and the arterial phase CT attenuation (Hounsfield units) of adrenal glands and IVC was ROI-based evaluated by two radiologists separately. ROC analysis, combined with the Matthews Correlation Coefficient (MCC) as a classifier, was used to assess whether one of the parameters is suitable for predicting short and medium-term mortality and, if so, which parameter is most appropriate. Interrater agreement was assessed using the intraclass correlation coefficient., Results: Twenty-one patients (18.6%) died within three days in the ICU. Measurements of the adrenal glands in the portal venous phase yielded the highest discriminative power (=AUC) to distinguish between deceased and survivors. A threshold ratio of >95.5 predicted 72-hour mortality with a sensitivity of 76.19% and a specificity of 92.39% (AUC = 0.84; p < 0.0001). The positive likelihood ratio was 10.1; the positive predictive value was 69%. The predictive power for 24-hour mortality was slightly lower. Venous adrenal-to-IVC ratios and arterial measurements as a whole were substantially less suitable. All intraclass correlation coefficients indicated a high interrater agreement., Conclusions: In the portal venous phase, hyperattenuating of the adrenal glands on contrast-enhanced CT can predict short and intermediate ICU mortality quite well and may serve as a reproducible prognostic marker for individual patient outcomes., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: To assess the type and frequency of vascular changes in the superior mesenteric artery (SMA) associated with the hypovolemic shock complex (HSC)., Methods: Twenty-six patients (14 males, 70.6 ± 11.2 years) meeting the criteria for hypovolemic shock complex in computed tomography were examined for the presence of angiographic signs of non-occlusive mesenteric ischemia (NOMI) in the SMA: the string of sausages sign and spasms of the arcades of mesenteric arteries on coronal maximum intensity projection images (MIP). Interrater agreement was assessed using weighted kappa (κ)., Results: Vascular changes of the SMA were visible in almost all of the patients with HSC with a frequency of 88.5 %-96.2 %. Intraclass correlation coefficients indicated a substantial to almost perfect interrater agreement., Conclusions: Using computed tomography, it is possible to reliably and reproducibly detect vascular changes in SMA known from angiography in the context of hypoperfusion. The pathological vascular changes also occur more frequently than other classic signs of a CT hypoperfusion complex. Since the qualitative assessment of the SMA requires only a small amount of time, it is suitable as a further criterion for the presence of the CT hypoperfusion complex., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: The study aimed to evaluate the effect of androgen deprivation therapy (ADT) on PSMA imaging and its correlation to the PSA concentration by comparing qualitative and quantitative parameters: SUV max , SUV mean , PSMA-derived tumor volume (PSMA-TV), total lesion PSMA (TL-PSMA) and molecular imaging (mi)PSMA score., Methods: Retrospective analysis of 21 therapy-naïve patients with oligometastatic prostate cancer (median age 70 years) who underwent either [ 68 Ga]Ga-PSMA-11-PET/CT or -PET/MRI before initiation of (T1) as well as during ADT (T2). The median duration of ADT was 155 days (range 61-289 days). All lesions were analyzed using several qualitative and quantitative PET parameters., Results: A total of 109 PSMA-positive lesions (24 intraprostatic, 56 lymphonodal and 29 osseous) were visually detected at any of the examinations, while at T2, two new bone lesions were detected in one patient. During ADT, all patients experienced a decrease in their PSA level (median: 29.1 before vs. 0.71 after; p < 0.001). During long-term ADT, a relevant decrease in lesion count occurred, especially in patients with a T2 PSA value < 1 ng/ml (median: 4 vs. 0.9; p = 0.007) and PSMA expression, which resulted in miN- and/or miM-downstaging in 11 patients (52.7%). All analyzed PET parameters correlated strongly with each other. The PSA level at T2 correlated modestly with the decrease in PSMA expression and its derived volumes., Conclusion: Post-ADT scans detected, especially in patients with a residual PSA < 1 ng/ml, fewer PSMA-positive lesions with overall lower PSMA expression, regardless of primary tumor site or metastatic sites. None of the PET parameters has proven to be superior, as they all correlated modestly with the PSA value at T2. Thus, the simply acquirable miPSMA score seems to be the most suitable for evaluating the effect of ADT on PSMA expression.

Purpose: To investigate the outcome of local intra-arterial papaverine infusion therapy in patients with non-occlusive mesenteric ischemia (NOMI), and factors influencing survival, in comparison with a conservative approach., Methods: From 2013 to 2019, patients with NOMI confirmed by imaging were included in a retrospective two-center study. According to different in-house standard procedures, patients were treated in each center either conservatively or interventionally by a standardized local infusion of intra-arterial papaverine into the splanchnic arteries. Thirty-day mortality and factors influencing the outcome, such as different demographics and laboratories, were compared between groups using Kaplan-Meier survival analysis and Cox regression, respectively., Results: A total of 66 patients with NOMI were included, with n = 35 treated interventionally (21 males, mean age 67.7 ± 12.3 years) and n = 31 treated conservatively (18 females, mean age 71.6 ± 9.6 years). There was a significant difference in 30-day mortality between the interventional (65.7%; 12/35 survived) and the conservative group (96.8%; 1/31 survived) (hazard ratio 2.44; P = 0.005). Thresholds associated with a worse outcome of interventional therapy are > 7.68 mmol/l for lactate, < 7.31 for pH and <  - 4.55 for base excess., Conclusion: Local intra-arterial papaverine infusion therapy in patients with NOMI significantly increases survival rate in comparison with conservative treatment. High lactate levels, low pH and high base excess, and high demand for catecholamines are associated with a poor outcome., Level of Evidence: Level III.