Application Of Contrast Media Research Articles

The Impact of Insulin Resistance on the Development of Post-PCI Contrast-Induced Nephropathy in Non-Diabetic STEMI.

Contrast-induced nephropathy (CIN) is a condition characterized by rapidly decreasing renal funciton following by the application of contrast material. Precutaneous coronary intervention (PCI) is a life-saving treatment method that should be applied under emergent conditions. Unfortunately, the incidence of CIN after PCI is common. Patients with insulin resistance or diabetes have a greater risk of developing CIN than most of the population. Therefore, studies on the predictive effects of insulin resistance indicators on CIN are gaining momentum. One of the most popular indicators is triglyceride/glucose-body mass index (TyG-BMI). In this study we aimed to evaluate the effect of TyG-BMI index on CIN. A total of 960 patinets who underwent emergency PCI due to ST elevation myocardial infarction (STEMI) between 2020 and 2023 were included in the study. Laboratory and demographic parameters were compared between the patients who did and did not develop CIN. While CIN developed in 120 of the 980 patients included in the study, it did not develop in 860 patients. There were significant differences between the groups in terms of age (p < 0.001), gender (p = 0.005), presence of hypertension (p = 0.021), heart rate (p = 0.049), amount of contrast material (p < 0.001), left ventricular ejection fraction (p < 0.001), stent length (p = 0.022), SYNTAX score (p < 0.001), fasting plasma glucose (p < 0.001), baseline creatinine (p < 0.001), glomerular filtration rate (p < 0.001), uric acid (p < 0.001), C reactive protein (CRP) (p < 0.001), baseline creatin kinase myocard band (CKMB) (p = 0.019), CKMB peak (p = 0.030), triglyceride (p = 0.017), and TyG-BMI (p < 0.001). CRP, creatinine, uric asid, amount of contrast material, and TyG-BMI were independent predictors for the development of CIN. TyG-BMI was a predictor of CIN in STEMI patient who underwent PCI under emergency conditions. In addition, the predicitive power of TyG-BMI was stronger than triglyceride-glucose index.

Editorial Comment: Are Children Just Small Adults? Exploring the Unique Concepts and Application of Contrast Media in Pediatrics.

Editorial Comment: Are Children Just Small Adults? Exploring the Unique Concepts and Application of Contrast Media in Pediatrics.

Evaluation of pathways involved in the protective effect of trans sodium crocetinate against contrast-induced nephropathy in rats.

Contrast-induced nephropathy (CIN) is the most important side effect following contrast media application. The purpose of this study was to investigate the nephroprotective effects of trans sodium crocetinate (TSC) against sodium amidotrizoate/meglumine amidotrizoate (SAMA).Wistar rats were classified into eight groups (n = 6, male, 220-250g) including (1) sham, injection of solvents (intraperitoneally; i.p.), (2) premedication-control, N(ω)-nitro-L-arginine methyl ester (L-NAME, 10mg/kg, i.p.) + indomethacin (IND, 10mg/kg, i.p.), (3) model (L-NAME + IND + SAMA (12.5ml/kg, i.p.)), (4-6) TSC 10, 20, and 40mg/kg/day, 7 days, i.p., and L-NAME + IND + SAMA, (7) N-acetylcysteine (NAC, 125mg/kg/day, 7 days, i.p.) and L-NAME + IND + SAMA, (8) TSC alone (40mg/kg/day, 7 days, i.p.). Rats were injected with L-NAME, IND, and SAMA 40h after water deprivation.SAMA caused the enhancement of histopathological damage in kidney tissue, biochemical factors (serum blood urea nitrogen and creatinine), and oxidative stress. Moreover, SAMA increased inflammation (TNF-α), apoptosis proteins(Caspase 3-cleaved and Bax/Bcl-2 ratio), and autophagy markers (Beclin-1 and LC3 II/I ratio). TSC declined biochemical factors and oxidative stress. Also, TSC 40mg/kg decreased histopathological damage, inflammation, apoptosis, and autophagy markers.This study demonstrated that TSC has nephroprotective effects through anti-oxidant, anti-inflammatory, and anti-apoptotic properties, as well as regulating autophagy.

Radiographic anatomy of the nasal conchal bullae and conchal sinuses in mature horses.

The dorsal and ventral nasal conchal bullae and conchal sinuses are part of the complex equine paranasal sinus system and are commonly affected by secondary sinusitis. However, the radiographic anatomy of the conchal sinuses is poorly reported in the literature. The present study aimed to describe the radiographic anatomical characteristics of the nasal conchal bullae and conchal sinuses in mature horses. Six equine cadaveric heads without sinus or dental disorders were studied. A maxillary sinusotomy was performed to identify the dorsal and ventral nasal conchal bullae and conchal sinuses, allowing the application of radiopaque contrast medium in these structures. Afterward, the same projections were repeated. Laterolateral views allowed an adequate visualization of nasal conchal bullae and conchal sinuses; however, they overlapped the same contralateral structure. In the latero30°dorsal- lateroventral obliqueview, the same structures were easily recognizable, but in an oblique view, the structures were projected dorsally in relation to the contralateral one. The dorsoventral view allowed partial visualization of the dorsal conchal bullae and dorsal sinuses, but it was not possible to identify the ventral conchal sinus and ventral conchal bullae. The offset dorsoventral view helped in the identification of the dorsal conchal bullae and dorsal conchal sinus, also achieving visualization of the medial region of the ventral conchal sinus and ventral conchal bullae. The use of contrast medium, added to the anatomical dissection, allowed a better radiographic identification of the sinuses and conchal bullae. The combination of different radiographic views is recommended for the evaluation of these structures.

Prevention and management of allergic-like reactions to iodine contrast media: a best practice implementation project.

With the wide application of iodine contrast media (ICM), the occurrence of allergic-like reactions to iodine contrast media (ALR-ICM) has increased. Strategies for the prevention and management of ALR-ICM need to be identified to provide quality care to patients undergoing enhanced computed tomography. The overarching aim of this project was to improve the prevention and management of ALR-ICM at a medical imaging center of a nearly 5,000-bed tertiary hospital in China. This project was guided by the JBI Evidence Implementation Framework, which is grounded in an audit, feedback, and re-audit strategy. A baseline audit was conducted to measure current practices against recommended best practices. Feedback from the audit was used to identify barriers and design strategies to improve practice. A follow-up audit was conducted to measure changes in compliance with best practices. The results revealed a positive change in compliance with best practices. More than 60% compliance with the four audit criteria was observed. The overall ALR-ICM rate decreased from 0.56% to 0.19%, while emergency equipment management dramatically increased from 37.50% to 100%. The smallest improvement was observed for pre-procedure prophylactic treatment of high-risk patients (27.66%). Most audit criteria showed moderate improvements in compliance with best practices. Further testing of this program in more hospitals is needed. http://links.lww.com/IJEBH/A269.

Illustrated cross-sectional computed tomography of the cetacean abdomino-pelvic organs

Computed tomography (CT) is a non-invasive diagnostic imaging modality which can be used to study the anatomy and morphology of live or deceased animals in-situ. In cetaceans, existing CT anatomy studies mostly focused on the head and thoracic regions. Using postmortem CT (PMCT) scans of Indo-Pacific finless porpoises (Neophocaena phocaenoides), this study describes the cross-sectional imaging anatomy of the cetacean abdomino-pelvic organs for the first time. PMCT scans of finless porpoises stranded in Hong Kong waters were reviewed, of which two freshly dead cases, one male and one female, were selected for illustration. In addition, a contrast-enhanced PMCT scan was performed on the female subject as a trial for a PMCT-angiography study (PMCTA) in cetaceans. A total of 18 axial PMCT images were acquired at selected vertebral levels in the abdomen and supplemented with a series of corresponding labeled anatomical diagrams. By applying different image rendering techniques, most osseous and soft tissue structures in the finless porpoise abdomen were successfully depicted and annotated on PMCT, including the male and female reproductive organs in the pelvic region. The application of contrast medium in PMCT created artificial radiodensity differences which improved the ability to visualize and differentiate soft organs and vasculature. The merits and limitations of CT compared to other imaging modalities, as well as the future directions of PMCT in stranding investigation, were discussed. The findings from this study significantly enhance the applications of CT in cetaceans by assisting researchers and veterinarians in the interpretation of cetacean abdomino-pelvic CT for morphological and pathological assessment during clinical or postmortem examination.

The influence of contrast media on calcium-based imaging of the spine in dual-layer CT

This study aimed to evaluate the impact of contrast media application on CT attenuation of the bone using a novel calcium-only imaging technique (VCa) from dual-layer spectral detector CT (DLCT), which enables CT-based bone mineral density measurement unimpeded by soft tissue components. For this, true non-contrast (TNC) and venous phase images (VP) of n = 97 patients were acquired. CT attenuation of the first lumbar vertebra (L1) was measured in TNC-VCa, VP-VCa, and in virtual non-contrast images (VNC). CT attenuation was significantly higher in VP-VCa than in TNC-VCa (p < 0.001), although regression analyses revealed a strong linear association between these measures (R2 = 0.84). A statistical model for the prediction of TNC-VCa CT attenuation was established (TNC-VCa[HU] = − 6.81 + 0.87 × VP-VCa[HU]-0.55 × body weight[kg]) and yielded good agreement between observed and predicted values. Furthermore, a L1 CT attenuation threshold of 293 HU in VP-VCa showed a sensitivity of 90% and a specificity of 96% for detecting osteoporosis. The application of contrast media leads to an overestimation of L1 CT attenuation in VCa. However, CT attenuation values from VP-VCa can be used within CT-based opportunistic osteoporosis screening eighter by applying a separate threshold of 293 HU or by converting measured data to TNC-VCa CT attenuation with the given regression equation.

Imaging of congenital heart defects with a focus on magnetic resonance imaging and computed tomography

Due to advances in diagnostics and therapy, the survival rate of patients with congenital heart defects is continuously increasing. The aim of this review is to compare various imaging modalities that are used in the diagnosis of congenital heart defects. Transthoracic echocardiography is the imaging method of choice in the presence of acongenital heart defect because of its wide availability and non-invasiveness. It can be complemented by transesophageal echocardiography, cardiac catheterization, computed tomography (CT), and magnetic resonance imaging (MRI) of the heart and vessels close to the heart. The radiation exposure of CT examinations of the heart is continuously decreasing because of improved technologies. MRI is also being continuously optimized, e.g., by the acquisition of MR angiographies without contrast medium application or athin three-dimensional (3D) visualization of the entire heart with the possibility of reconstruction in all spatial planes (whole-heart technique) as well as 2D to 4D flow. Due to the complexity of congenital heart defects and the variety of possible pathologies, the choice of imaging modality and its exact performance has to be coordinated in an interdisciplinary context and individually adapted.

Cardiac Magnetic Resonance Imaging as a Risk Stratification Tool in COVID-19 Myocarditis.

The aim of this retrospective study was to identify myocardial injury after COVID-19 inflammation and explore whether myocardial damage could be a possible cause of the persistent symptoms following COVID-19 infection in previously healthy individuals. This study included 139 patients who were enrolled between January and June 2021, with a mean age of 46.7 ± 15.2 years, of whom 68 were men and 71 were women without known cardiac or pulmonary diseases. All patients underwent clinical work-up, laboratory analysis, cardiac ultrasound, and CMR on a 1.5 T scanner using a recommended protocol for morphological and functional assessment before and after contrast media application with multi-parametric sequences. In 39% of patients, late gadolinium enhancement (LGE) was found as a sign of myocarditis. Fibrinogen was statistically significantly higher in patients with LGE than in those without LGE (4.3 ± 0.23 vs. 3.2 ± 0.14 g/L, p < 0.05, respectively), as well as D-dimer (1.8 ± 0.3 vs. 0.8 ± 0.1 mg/L FEU). Also, troponin was statistically significantly higher in patients with myocardial LGE (13.1 ± 0.4 ng/L) compared to those with normal myocardium (4.9 ± 0.3 ng/L, p < 0.001). We demonstrated chest pain, fatigue, and elevated troponin to be independent predictors for LGE. Septal LGE was shown to be a predictor for arrhythmias. The use of CMR is a potential risk stratification tool in evaluating outcomes following COVID-19 myocarditis.

Variation of rectal temperature in dogs undergoing 3T-MRI in general anesthesia.

Managing body temperature during MRI scanning under general anesthesia poses challenges for both human and veterinary patients, as many temperature monitoring devices and patient warming systems are unsuitable for the use inside an MRI scanner. MRI has the potential to cause tissue and body warming, but this effect may be counteracted by the hypothermia induced by general anesthesia and the low ambient temperature usually encountered in scanner rooms. This study aimed to observe temperature variations in dogs undergoing MRI under general anesthesia. In this prospective observational study, client-owned dogs scheduled for 3-Tesla MRI under anesthesia between February and October 2020 at a veterinary teaching hospital were eligible for enrollment. Recorded data included breed, body mass, body condition score, age, fur quality, pre- and post-MRI rectal temperatures, time in the MRI room, scan area and coil used, application of contrast medium, choice of anesthetic agents, use of blankets, and infusion therapy. Group comparisons were conducted using the Mann-Whitney U-test or Kruskal-Wallis test, with p < 0.05 considered significant. In total 171 dogs met the inclusion criteria. The median body temperature at admission was 38.4°C (IQR 38.1-38.7°C). The median body temperature before MRI was 38.2°C (IQR 37.8-38.6°C), and the median temperature after the MRI scan was 37.7°C (IQR 37.238.2°C) resulting in a median temperature difference (∆T) before and after MRI of - 0.6°C (IQR -0.8--0.1°C). The median duration of MRI scans was 49 min (IQR 38-63 min). A temperature loss of more than 0.1°C was observed in 121 (70.8%) dogs, 29 (16.9%) dogs maintained their temperature within 0.1°C, and 21 (12.3%) dogs experienced a temperature increase of more than 0.1°C. Factors associated with a higher post-MRI temperature included greater body mass, medium or long fur, and the application of α2- receptor-agonists. Dogs undergoing MRI under general anesthesia are likely to experience temperature loss in the given circumstances. However, in larger dogs and those with much fur, an increase in body temperature is possible and more common than generally anticipated, although clinically insignificant in most cases.

Juvenile idiopathic arthritis of the knee: is contrast needed to score disease activity when using an augmented MRI protocol comprising PD-weighted sequences?

ObjectiveTo compare unenhanced versus enhanced knee joint magnetic resonance imaging (MRI) to assess disease activity of juvenile idiopathic arthritis (JIA).MethodsFifty-three knee joint MRI examinations were performed on a 3-Tesla system in 27 patients (age: 11.40 ± 3.61 years; 21 females, 6 males). MRI protocols comprised PD-weighted sequences in addition to the widely used standard protocol. JIA subgroups comprised oligoarticular arthritis (n = 16), extended oligoarthritis (n = 6), rheumatoid factor-negative polyarticular arthritis (n = 3), enthesitis-related arthritis (n = 1), and psoriatic arthritis (n = 1). MR images were retrospectively analyzed by 3 experienced radiologists in two readings, using JAMRIS (juvenile arthritis MRI scoring) system and a modified IPSG (international prophylaxis study group) classification. In the first reading session, only unenhanced MR images were evaluated. In a second reading session, all images before and after contrast medium application were included. In order to avoid bias, an interval of at least 2 weeks was set between the two readings. The clinical JADAS10 (juvenile arthritis disease activity score) was calculated including clinical assessment and laboratory workup and correlated with MRI scores. Statistical analysis comprised Pearson’s correlation for correlating two scoring results of unenhanced and the enhanced MRI, intra-class correlation coefficient (ICC) for inter- and intra-reader agreement. Diagnostic accuracy was calculated using ROC (receiver operating characteristics) curve analysis.ResultsInter-reader agreement determined by ICC for unenhanced and enhanced MRI scores for IPSG was moderate (0.65, 95% CI 0.51–0.76, and 0.62, 95% CI 0.48–0.75) and high for JAMRIS (0.83, 95% CI 0.75–0.89, and 0.82, 95% CI 0.74–0.89). Intra-reader agreement was good to very good for JAMRIS (0.85 95% CI 0.81–0.88, 0.87 95% CI 0.83–0.89 and 0.96 95% CI 0.92–0.98) and IPSG (0.76 95% CI 0.62–0.86, 0.86 95% CI 0.77–0.92 and 0.92 95% CI 0.86–0.96). Scores of unenhanced MRI correlated with contrast-enhanced MRI: JAMRIS (r = 0.97, R2 = 0.93, p < 0.01), modified IPSG (r = 0.95, R2 = 0.91, p < 0.01). When using JADAS10 as a reference standard, moderate accuracy for both unenhanced and enhanced MRI scores was noted: JAMRIS (AUC = 0.68, 95% CI 0.51–0.85, and AUC = 0.66, 95% 0.49–0.82), IPSG score (AUC = 0.68, 95% 0.50–0.86, and AUC = 0.61, 95% 0.41–0.81).ConclusionsOur results suggest that contrast agent application could be omitted in JIA patients with an augmented knee MRI protocol comprising PD-weighted sequence.Key Points• Unenhanced MRI can detect disease activity of the knee joint in patients with JIA with equally high accuracy compared to contrast-enhanced MRI.• The intra- and inter-reader agreement was high for unenhanced and enhanced MRI JAMRIS scores, which indicate relatively good applicability of the scoring system, even for less experienced readers.• When using the clinical JADAS10 as a reference standard for the detection of disease activity, moderate accuracy for both unenhanced and enhanced MRI scores, both JAMRIS and IPSG, was noted, which might be caused by the fact that the majority of patients had either no or minimal clinical disease activity.

Application of CT contrast medium is not associated with an increased risk for acute kidney injury in patients with decompensated cirrhosis.

Acute kidney injury (AKI) is a frequent complication in patients with decompensated cirrhosis. Studies reported conflicting results regarding the nephrotoxic potential of iodinated contrast medium (CM) for computer tomography (CT). To investigate the impact of diagnostic CM application on kidney function in patients with decompensated cirrhosis. First, we evaluated the impact of diagnostic CM-CT on AKI incidence in a cross-sectional approach. Second, we analysed 28-day AKI incidence post-CM-CT in patients with impaired kidney function (i.e., creatinine >133 μmoL/L). Third, we excluded all patients with relevant interventions besides CM-CT. All remaining patients were matched via propensity score matching (PPSM) and further analysed. Last, we validated the results in an independent dataset of prospectively collected registry data of 118 patients with decompensated cirrhosis. Here, plasma samples were analysed regarding neutrophil-gelatinase-associated-lipocalin (NGAL). Of the 611 included patients, 98 (16%) received CM-CT. CM-CT was not associated with AKI in the cross-sectional approach (CM-CT:8% vs. no CM-CT:15%; p= 0.08). Furthermore, CM-CT was not associated with higher 28-day AKI incidence among patients with impaired kidney function (HR:0.79; 95% CI 0.45-1.38; p= 0.40). The PPSM cohort revealed no association between CM-CT and AKI or severe AKI (HR:1.28, p= 0.45 and HR:1.62; p= 0.43). Moreover, CM-CT did not result in worsening of kidney function after CM application. In the validation cohort, CM-CT was also not linked to AKI (p= 0.85) and NGAL levels were not increased in those with CM-CT (CM-CT:309 ng/ml vs. No CM-CT:266 ng/ml, p= 0.35). Decompensated cirrhosis per se should not preclude diagnostic CM-CT.

Synthetic Post-Contrast Imaging through Artificial Intelligence: Clinical Applications of Virtual and Augmented Contrast Media.

Contrast media are widely diffused in biomedical imaging, due to their relevance in the diagnosis of numerous disorders. However, the risk of adverse reactions, the concern of potential damage to sensitive organs, and the recently described brain deposition of gadolinium salts, limit the use of contrast media in clinical practice. In recent years, the application of artificial intelligence (AI) techniques to biomedical imaging has led to the development of 'virtual' and 'augmented' contrasts. The idea behind these applications is to generate synthetic post-contrast images through AI computational modeling starting from the information available on other images acquired during the same scan. In these AI models, non-contrast images (virtual contrast) or low-dose post-contrast images (augmented contrast) are used as input data to generate synthetic post-contrast images, which are often undistinguishable from the native ones. In this review, we discuss the most recent advances of AI applications to biomedical imaging relative to synthetic contrast media.

Individualized Contrast Media Application Based on Body Weight and Contrast Enhancement in Computed Tomography of Livers without Steatosis.

This study analyzes the homogeneity in liver attenuation of a body-weight-based protocol compared to a semi-fixed protocol. Patients undergoing abdominal multiphase computed tomography received 0.500 g of iodine (gI) per kilogram of body weight. Liver attenuation and enhancement were determined using regions of interest on scans in the pre-contrast and portal venous phases. The outcomes were analyzed for interpatient uniformity in weight groups. The subjective image quality was scored using a four-point Likert scale (excellent, good, moderate, and nondiagnostic). A total of 80 patients were included (56.3% male, 64 years, 78.0 kg) and were compared to 80 propensity-score-matched patients (62.5% male, 63 years, 81.7 kg). The liver attenuation values for different weight groups of the TBW-based protocol were not significantly different (p = 0.331): 109.1 ± 13.8 HU (≤70 kg), 104.6 ± 9.70 HU (70–90 kg), and 105.1 ± 11.6 HU (≥90 kg). For the semi-fixed protocol, there was a significant difference between the weight groups (p < 0.001): 121.1 ± 12.1 HU (≤70 kg), 108.9 ± 11.0 HU (70–90 kg), and 105.0 ± 9.8 HU (≥90 kg). For the TBW-based protocol, the enhancement was not significantly different between the weight groups (p = 0.064): 46.2 ± 15.1 HU (≤70 kg), 59.3 ± 6.8 HU (70–90 kg), and 52.1 ± 11.7 HU (≥90 kg). Additionally, for the semi-fixed protocol, the enhancement was not significantly different between the weight groups (p = 0.069): 59.4 ± 11.0 HU (≤70 kg), 53.0 ± 10.3 HU (70–90 kg), and 52.4 ± 7.5 HU (≥90 kg). The mean administered amount of iodine per kilogram was less for the TBW-based protocol compared to the semi-fixed protocol: 0.499 ± 0.012 and 0.528 ± 0.079, respectively (p = 0.002). Of the TBW-based protocol, 17.5% of the scans scored excellent enhancement quality, 76.3% good, and 6.3% moderate. Of the semi-fixed protocol, 70.0% scored excellent quality, 21.3% scored good, and 8.8% scored moderate. In conclusion, the TBW-based protocol increased the interpatient uniformity of liver attenuation but not the enhancement in the portal venous phase compared to the semi-fixed protocol, using an overall lower amount of contrast media and maintaining good subjective image quality.

Risk of acute kidney injury after contrast-enhanced computerized tomography: a systematic review and meta-analysis of 21 propensity score–matched cohort studies

ObjectivesIntravenous application of contrast media is part of a wide spectrum of diagnostic procedures for better imaging quality. Clinical avoidance of contrast-enhanced imaging is an ever-present quandary in patients with impaired kidney function. The objective of this study was to estimate the risk for acute kidney injury (AKI), dialysis and mortality among patients undergoing contrast-enhanced CT compared to propensity score–matched controls (i.e. contrast-unenhanced CT). Selected cohort studies featured high-risk patients with advanced kidney disease and critical illness.MethodsThis review was designed to conform to the Preferred Reporting Items in Systematic Reviews and Meta-Analysis (PRISMA) guidelines. PubMed was searched from August 2021 to November 2021 for all-language articles without date restriction. A random-effects model (DerSimonian and Laird method) was used for meta-analysis.ResultsTwenty-one articles were included, comprising data of 169,455 patients. The overall risk of AKI was similar in the contrast-enhanced and unenhanced groups (OR: 0.97 [95% CI: 0.85; 1.11], p = 0.64), regardless of baseline renal function and underlying disease. Substantial heterogeneity was detected (I2 = 90%, p ≤ 0.0001). Multivariable logistic regression identified hypertension (p = 0.03) and estimated glomerular filtration rate (eGFR) ≤ 30 mL/min/1.73 m2 (p = 0.0001) as factors associated with greater risk of post-contrast AKI.ConclusionsBased on propensity score–matched pairs obtained from 21 cohort studies, we found no evidence for increased risk for AKI, dialysis or mortality after contrast-enhanced CT among patients with eGFR ≥ 45 mL/min/1.73 m2. In congruence with the emerging evidence in the literature, caution should be exercised in patients with hypertension and eGFR ≤ 30 mL/min/1.73 m2.Key Points• The application of contrast media for medical imaging is not associated with higher odds for AKI, induction of renal replacement therapy, or mortality. Many comorbidities traditionally associated with greater risk for acute kidney injury do not appear to predispose for renal decline after contrast media exposure.• Underlying hypertension and eGFR less than or equal to 30 mL/min/1.73 m2seem to predispose for post-contrast acute kidney injury.• Propensity score matching cannot account for unmeasured influences on AKI incidence, which needs to be addressed in the interpretation of results.

Prognostic Role of the Pectoralis Musculature in Patients with COVID-19. A Multicenter Study

Rationale and ObjectivesTo evaluate the impact of low skeletal muscle mass in patients with COVID-19 on relevant outcomes like 30-day mortality, need for intubation and need for intensive care unit admission.Materials and MethodsFor this study, data from six centers were acquired. The acquired sample comprises 1138 patients. There were 547 women (48.1%) and 591 men (51.9%) with a mean age of 54.5 ± 18.8 years; median age, 55 years; range, 18–84 years). In every case, thoracic CT without intravenous application of contrast medium was performed. The following parameters of the pectoralis muscles were estimated: muscle area as a sum of the bilateral areas of the pectoralis major and minor muscles, muscle density, muscle index (PMI) (pectoralis muscle area divided by the patient's body height square) as a ratio pectoralis major and minor muscles divided by the patient's body height2, and muscle gauge as PMI x muscle density.ResultsOverall, 220 patients (19.33%) were admitted to the intensive care unit. In 171 patients (15.03%), mechanical lung ventilation was performed. Finally, 154 patients (13.53%) died within the observation time of 30-day. All investigated parameters of pectoralis muscle were lower in the patients with unfavorable courses of Covid-19. All pectoralis muscle parameters were associated with 30-day mortality in multivariate analyses adjusted for age and sex: pectoralis muscle area, HR = 0.93 CI 95% (0.91–0.95) p < 0.001; pectoralis muscle density, HR = 0.94 CI 95% (0.93–0.96) p < 0.001; pectoralis muscle index, HR = 0.79 CI 95% (0.75–0.85) p < 0.001, pectoralis muscle gauge, HR = 0.995 CI 95% (0.99–0.996) p < 0.001.Conclusionin COVID-19, survivors have larger areas and higher index, gauge and density of the pectoralis muscles in comparison to nonsurvivors. However, the analyzed muscle parameters cannot be used for prediction of disease courses.

Can magnetic resonance imaging replace conventional computerized tomography for follow-up of patients with testicular cancer? A systematic review

PurposeFollow-up protocols for patients with testicular cancer (TC) have significantly reduced the number of cross-sectional imaging studies to reduce radiation exposure. At present, it is unclear whether magnetic resonance imaging (MRI) could replace conventional computerized tomography (CT) imaging. The objective of this study is to summarize the scientific evidence on this topic and to review guideline recommendations with regard to the use of MRI.MethodsA systematic literature review was performed searching Medline and Cochrane databases for prospective studies on patients with TC in the follow-up care (last search in February 2021). Additionally, guideline recommendations for TC were screened. Data extraction and quality assessment of included studies were performed and used for a descriptive presentation of results.ResultsA total of four studies including two ongoing trials were identified. Overall, the scientific evidence of prospective comparative studies is based on 102 patients. Data suggest that abdominal imaging with MRI can replace conventional CT for detection of lymph node metastasis of the retroperitoneum to spare radiation exposure and contrast media application. However, experienced radiologists are needed. Clinical guidelines are aware of the risk of diagnosis-induced secondary malignancy due to CT imaging and some have adapted their recommendations accordingly. Results of the two ongoing trials on 738 patients are expected soon to provide more reliable results on this topic.ConclusionsThere is growing evidence that abdominopelvic MRI imaging can replace CT imaging during follow-up of patients with TC in order to reduce radiation exposure and diagnosis-induced secondary malignancy.

The influence of contrast enhancement and experience of observers on the assessment of mediastinal lymph nodes in sarcoidosis patients.

PurposeThe aim of this study was to assess the influence of contrast enhancement (CE) and experience of observers on the assessment of chest lymph nodes in patients with sarcoidosis.Material and methodsA retrospective analysis of chest lymph nodes on computed tomography (CT) examinations, including CE and non-contrast-enhanced (non-CE) phase, was performed on 40 patients with proven diagnosis of sarcoidosis. Phases were separated, anonymized, and randomized. The assessment was performed by 5 observers: 2 general radiologists, 2 residents, and a senior chest CT expert.ResultsThere were no significant differences between radiologists and residents, apart from the determination of the 4R node short diameter on CE images. Agreement between the reference observer and both residents and specialists was equally high, without any significant difference in the assessment all chest nodes and hilar nodes, and between non-CE and CE images. There was a significant difference between all observers in the determination of the largest 4R node short diameter on non-CE images, but not on CE images. The number of affected node levels was found to be significantly higher when evaluated on CE images than on non-CE images. Compared to CE images, non-CE computed tomography has sensitivity of 0.94-1.00 and specificity of 0.98-1.00, depending on the observer.ConclusionsThe application of contrast medium has a limited impact on the quality of assessment of the chest lymph nodes in patients with sarcoidosis, regardless of the experience of the observer.

Post-Contrast Acute Kidney Injury after Acute Stroke-Insights from a German Tertiary Care Center.

Background: Our aim was to investigate the relationship between additional iodinated contrast medium (CM) application for acute stroke imaging and Post-Contrast Acute Kidney Injury (PC-AKI). Methods: We performed a retrospective analysis of consecutive patients with acute stroke who received a CT angiogram (CTA) with or without additional CT perfusion (CTP) at admission between 2017 and 2020. The primary endpoint was the incidence of PC-AKI. Potential causes of renal function impairment were recorded and logistic regression was performed to determine predictors of PC-AKI. Results: Of 3134 cases screened, n = 989 met the predefined inclusion criteria. PC-AKI occurred in 22 (5.4%) patients who received CTA only and 18 (3.1%) patients who received CTA and additional CTP (unadjusted OR, CI; 0.59, 0.29–1.05). In 31/40 (77.5%) patients who suffered PC-AKI, a non-CM-related cause of renal function impairment was identified. Stroke etiology (hemorrhagic vs. ischemic) and indicators of prior kidney disease were independent predictors of PC-AKI. Conclusions: Additional administration of CM for perfusion imaging in acute stroke did not show a relevant influence on the occurrence of PC-AKI. Patients with intracranial hemorrhage and/or prior kidney disease are at particular risk of developing AKI.

Quantitative assessment of contrast-enhancement patterns of the healthy dental pulp by magnetic resonance imaging: A prospective in vivo study.

This prospective in vivo study aimed to optimize the assessment of pulpal contrast-enhancement (PCE) on dental magnetic resonance imaging (dMRI) and investigate physiological PCE patterns. In 70 study participants, 1585 healthy teeth were examined using 3-Tesla dMRI before and after contrast agent administration. For all teeth, the quotient of post- and pre-contrast pulp signal intensity (Q-PSI) was calculated to quantify PCE. First, pulp chambers were analysed in 10 participants to compare the coefficient of variation of mean versus maximum Q-PSI values (Q-PSImean versus Q-PSImax ). Second, dynamic PCE was evaluated in 10 subjects to optimize the time interval between contrast agent application and image acquisition. Finally, 50 participants (age groups: 20-29, 30-39, 40-49, 50-59 and 60-69years) were examined to analyse age, gender, tooth types and maxilla versus mandible as independent factors of PCE. Statistical analysis was performed using Wilcoxon signed rank test and linear mixed models. PCE assessment based on Q-PSImax was associated with a significantly smaller coefficient of variation compared with Q-PSImean , with median values of 0.17 versus 0.21 (p=.002). Analysis of dynamic PCE revealed an optimal timing interval for image acquisition 4min after contrast media application. No significant differences in PCE were observed by comparing age groups, female versus male participants and maxillary versus mandibular teeth (p>.05). Differences between tooth types were small (median Q-PSImax values of 2.52/2.32/2.30/2.20 for molars/premolars/canines/incisors) but significant (p<.05), except for the comparison of canines versus premolars (p=.80). PCE in dMRI was a stable intra-individual marker with only minor differences between different tooth types, thus forming an important basis for intra-individual controls when assessing teeth with suspected endodontic pathosis. Furthermore, it was demonstrated that PCE is independent of age, gender and jaw type. These findings indicate that dMRI-based PCE analysis could be a valuable diagnostic tool for the identification of various pulp diseases in future patient studies.