Diagnostic value of LGE and T1 mapping in multiple myeloma patients'heart.

BACKGROUND: Unidentified heart failure occurs in patients with multiple myeloma when their heart was involved. CMR with late gadolinium enhancement (LGE) and T1 mapping can identify myocardial amyloid infiltrations. PURPOSE: To explore the role of CMR with late gadolinium enhancement (LGE) and T1 mapping for detection of multiple myeloma patients'heart. MATERIAL AND METHODS: A total of 16 MM patients with above underwent CMR (3.0-T) with T1 mapping (pre-contrast and post-contrast) and LGE imaging. In addition, 26 patients with non-obstructive hypertrophic cardiomyopathy and 26 healthy volunteers were compared to age- and sex-matched healthy controls without a history of cardiac disease, diabetes mellitus, or normal in CMR. All statistical analyses were performed using the statistical software GraphPad Prism. The measurement data were represented by median (X) and single sample T test was adopted. Enumeration data were represented by examples and Chi-tested was adopted. All tests were two-sided, and P values < 0.05 were considered statistically significant. RESULTS: In MM group, LVEF was lower than healthy controls and higher than that of non-obstructive hypertrophic cardiomyopathy group, but without statistically significant difference (%: 49.1 ± 17.5 vs. 55.6 ± 10.3, 40.4 ± 15.6, all P > 0.05). Pre-contrast T1 values of MM group were obviously higher than those of healthy controls and non-obstructive hypertrophic cardiomyopathy group (ms:1462.0 ± 71.3vs. 1269.3 ± 42.3, 1324.0 ± 45.1, all P < 0.05). 16 cases (100%) in MM group all had LGE. CONCLUSION: LGE joint T1 mapping wider clinical use techniques and follow-up the patients'disease severity.

Diffusion probabilistic versus generative adversarial models to reduce contrast agent dose in breast MRI.

BACKGROUND: To compare denoising diffusion probabilistic models (DDPM) and generative adversarial networks (GAN) for recovering contrast-enhanced breast magnetic resonance imaging (MRI) subtraction images from virtual low-dose subtraction images. METHODS: Retrospective, ethically approved study. DDPM- and GAN-reconstructed single-slice subtraction images of 50 breasts with enhancing lesions were compared to original ones at three dose levels (25%, 10%, 5%) using quantitative measures and radiologic evaluations. Two radiologists stated their preference based on the reconstruction quality and scored the lesion conspicuity as compared to the original, blinded to the model. Fifty lesion-free maximum intensity projections were evaluated for the presence of false-positives. Results were compared between models and dose levels, using generalized linear mixed models. RESULTS: At 5% dose, both radiologists preferred the GAN-generated images, whereas at 25% dose, both radiologists preferred the DDPM-generated images. Median lesion conspicuity scores did not differ between GAN and DDPM at 25% dose (5 versus 5, p = 1.000) and 10% dose (4 versus 4, p = 1.000). At 5% dose, both readers assigned higher conspicuity to the GAN than to the DDPM (3 versus 2, p = 0.007). In the lesion-free examinations, DDPM and GAN showed no differences in the false-positive rate at 5% (15% versus 22%), 10% (10% versus 6%), and 25% (6% versus 4%) (p = 1.000). CONCLUSIONS: Both GAN and DDPM yielded promising results in low-dose image reconstruction. However, neither of them showed superior results over the other model for all dose levels and evaluation metrics. Further development is needed to counteract false-positives. RELEVANCE STATEMENT: For MRI-based breast cancer screening, reducing the contrast agent dose is desirable. Diffusion probabilistic models and generative adversarial networks were capable of retrospectively enhancing the signal of low-dose images. Hence, they may supplement imaging with reduced doses in the future. KEY POINTS: • Deep learning may help recover signal in low-dose contrast-enhanced breast MRI. • Two models (DDPM and GAN) were trained at different dose levels. • Radiologists preferred DDPM at 25%, and GAN images at 5% dose. • Lesion conspicuity between DDPM and GAN was similar, except at 5% dose. • GAN and DDPM yield promising results in low-dose image reconstruction.

Intraprocedural continuous saline infusion lines significantly reduce the incidence of acute kidney injury during endovascular procedures for stroke and myocardial infarction: evidence from a systematic review and meta-regression.

BACKGROUND: Contrast media used in mechanical therapies for stroke and myocardial infarction represent a significant cause of acute kidney injury (AKI) in acute medical scenarios. Although the continuous saline infusion line (CSIL) is a standard procedure to prevent thrombus formation within the catheter during neurovascular interventions of mechanical thrombectomy (MT), it is not utilized in percutaneous coronary interventions (PCI). METHODS: A systematic review of the incidence of AKI after MT for stroke treatment was performed. These data were compared with those reported in the literature regarding the incidence of AKI after PCI for acute myocardial infarction. A random-effect model meta-regression was performed to explore the effects of CSIL on AKI incidence, using clinical details as covariates. RESULTS: A total of 18 and 33 studies on MT and PCI were included, respectively, with 69,464 patients (30,138 [43.4%] for MT and 39,326 [56.6%] for PCI). The mean age was 63.6 years±5.8 with male 66.6%±12.8. Chronic kidney disease ranged 2.0-50.3%. Diabetes prevalence spanned 11.1% to 53.0%. Smoking status had a prevalence of 7.5-72.0%. Incidence of AKI proved highly variable (I2=98%, Cochrane's Q 2985), and appeared significantly lower in the MT subgroup than in the PCI subgroups (respectively 8.3% [95% confidence interval: 4.7-11.9%] vs. 14.7 [12.6-16.8%], P<0.05). Meta-regression showed that CSIL was significantly associated with a decreased incidence of AKI (OR=0.93 [1.001-1.16]; P=0.03). CONCLUSIONS: Implementation of CSIL during endovascular procedures in acute settings was associated with a significant decrease in the risk of AKI, and its safety should be routinely considered in such interventions.

Contrast-enhanced Ultrasound Using Intradermal Microbubble Sulfur Hexafluoride in Non-invasive Axillary Staging in Breast Cancer: Are we Missing a Chance?

BACKGROUND/AIM: In the context of surgical de-escalation in early breast cancer (EBC), this study aimed to evaluate the contrast enhancement ultrasound (CEUS) sentinel lymph node (SLN) procedure as a non-invasive axillary staging procedure in EBC in comparison with standard SLN biopsy (SLNB). PATIENTS AND METHODS: A subanalysis of the AX-CES study, a prospective single-arm, monocentric phase 3 study was performed (EudraCT: 2020-000393-20). The study included patients with EBC undergoing upfront surgery and SLN resection, with no prior history of locoregional treatment, and weighing between 40-85 kg. All patients underwent the CEUS SLN procedure as a non-invasive axillary staging procedure, with CEUS SLN accumulation marked using blue dye. After the CEUS SLN procedure, all patients underwent the standard mapping procedure. Data on success rate, systemic reactions, mean procedure time, mean surgical procedure, mean procedure without axillary staging, CEUS SLN appearance (normal/pathological), SLN number, and concordance with standard mapping procedure were collected. RESULTS: After the CEUS SLN procedure, 29 LNs among 16 patients were identified and marked. In all cases, CEUS SLN revealed at least one LN enhancement. Six (37.50%) LNs were defined as pathological after the CEUS SLN procedure. Definitive staining of CEUS SLN pathology revealed metastatic involvement in four (66.67%) of the cases. Two SLNs were identified during the CEUS SLN procedure; however, owing to the low disease burden, no change in the surgical plan was reported. CONCLUSION: The CEUS SLN procedure shows promise as a technique for non-invasive assessment of the axilla, potentially enabling safe axillary de-escalation in EBC by estimating the axillary disease burden.

[A case of neurosarcoidosis initially diagnosed as cervical spondylotic myelopathy, leading to diagnosis by gadolinium contrast-enhanced MRI].

A 70-year-old female presented with bilateral numbness in her upper limbs. She was diagnosed with cervical spondylotic myelopathy and underwent cervical laminoplasty. However, there was no significant improvement in sensory disturbance, and at 6 months after surgery, she developed subacute motor and gait disturbance in four extremities. Spinal MRI revealed a long lesion of the spinal cord with edema, and a part of the lesion showed gadolinium contrast enhancement. Bronchoscopy revealed an elevated CD4/8 ratio, and gallium scintigraphy demonstrated an accumulation in the hilar lymph nodes, leading to a diagnosis of neurosarcoidosis. In case of rapid deterioration during the course of cervical spondylotic myelopathy, neurosarcoidosis should be considered as a differential diagnosis, which can be assessed by contrast-enhanced MRI.

Clinical implementation of a fully automated quantitative perfusion cardiovascular magnetic resonance imaging workflow with a simplified dual-bolus contrast administration scheme.

This study clinically implemented a ready-to-use quantitative perfusion (QP) cardiovascular magnetic resonance (QP CMR) workflow, encompassing a simplified dual-bolus gadolinium-based contrast agent (GBCA) administration scheme and fully automated QP image post-processing. Twenty-five patients with suspected obstructive coronary artery disease (CAD) underwent both adenosine stress perfusion CMR and an invasive coronary angiography or coronary computed tomography angiography. The dual-bolus protocol consisted of a pre-bolus (0.0075 mmol/kg GBCA at 0.5 mmol/ml concentration + 20 ml saline) and a main bolus (0.075 mmol/kg GBCA at 0.5 mmol/ml concentration + 20 ml saline) at an infusion rate of 3 ml/s. The arterial input function curves showed excellent quality. Stress MBF ≤ 1.84 ml/g/min accurately detected obstructive CAD (area under the curve 0.79; 95% Confidence Interval: 0.66 to 0.89). Combined visual assessment of color pixel QP maps and conventional perfusion images yielded a diagnostic accuracy of 84%, sensitivity of 70% and specificity of 93%. The proposed easy-to-use dual-bolus QP CMR workflow provides good image quality and holds promise for high accuracy in diagnosis of obstructive CAD. Implementation of this approach has the potential to serve as an alternative to current methods thus increasing the accessibility to offer high-quality QP CMR imaging by a wide range of CMR laboratories.

Association of breast cancer with quantitative mammographic density measures for women receiving contrast-enhanced mammography.

Women with high mammographic density have an increased risk of breast cancer. They may be offered contrast-enhanced mammography to improve breast cancer screening performance. Using a cohort of women receiving contrast-enhanced mammography, we evaluated whether conventional and modified mammographic density measures were associated with breast cancer. Sixty-six patients with newly diagnosed unilateral breast cancer were frequency matched on the basis of age to 133 cancer-free control individuals. On low-energy craniocaudal contrast-enhanced mammograms (equivalent to standard mammograms), we measured quantitative mammographic density using CUMULUS software at the conventional intensity threshold ("Cumulus") and higher-than-conventional thresholds ("Altocumulus," "Cirrocumulus"). The measures were standardized to enable estimation of odds ratio per adjusted standard deviation (OPERA). In multivariable logistic regression of case-control status, only the highest-intensity measure (Cirrocumulus) was statistically significantly associated with breast cancer (OPERA = 1.40, 95% confidence interval = 1.04 to 1.89). Conventional Cumulus did not contribute to model fit. For women receiving contrast-enhanced mammography, Cirrocumulus mammographic density may better predict breast cancer than conventional quantitative mammographic density.

The effect of CTCA guided selective invasive graft assessment on coronary angiographic parameters and outcomes: Insights from the BYPASS-CTCA trial.

BACKGROUND: Computed tomography cardiac angiography (CTCA) is recommended for the evaluation of patients with prior coronary artery bypass graft (CABG) surgery. The BYPASS-CTCA study demonstrated that CTCA prior to invasive coronary angiography (ICA) in CABG patients leads to significant reductions in procedure time and contrast-induced nephropathy (CIN), alongside improved patient satisfaction. However, whether CTCA information was used to facilitate selective graft cannulation at ICA was not protocol mandated. In this post-hoc analysis we investigated the influence of CTCA facilitated selective graft assessment on angiographic parameters and study endpoints. METHODS: BYPASS-CTCA was a randomized controlled trial in which patients with previous CABG referred for ICA were randomized to undergo CTCA prior to ICA, or ICA alone. In this post-hoc analysis we assessed the impact of selective ICA (grafts not invasively cannulated based on the CTCA result) following CTCA versus non-selective ICA (imaging all grafts irrespective of CTCA findings). The primary endpoints were ICA procedural duration, incidence of CIN, and patient satisfaction post-ICA. Secondary endpoints included the incidence of procedural complications and 1-year major adverse cardiac events. RESULTS: In the CTCA cohort (n â€‹= â€‹343), 214 (62.4%) patients had selective coronary angiography performed, whereas 129 (37.6%) patients had non-selective ICA. Procedure times were significantly reduced in the selective CTCA â€‹+ â€‹ICA group compared to the non-selective CTCA â€‹+ â€‹ICA group (-5.82min, 95% CI -7.99 to -3.65, p â€‹< â€‹0.001) along with reduction of CIN (1.5% vs 5.8%, OR 0.26, 95% CI 0.10 to 0.98). No difference was seen in patient satisfaction with the ICA, however procedural complications (0.9% vs 4.7%, OR 0.21, 95% CI 0.09-0.87) and 1-year major adverse cardiac events (13.1% vs 20.9%, HR 0.55, 95% CI 0.32-0.96) were significantly lower in the selective group. CONCLUSIONS: In patients with prior CABG, CTCA guided selective angiographic assessment of bypass grafts is associated with improved procedural parameters, lower complication rates and better 12-month outcomes. Taken in addition to the main findings of the BYPASS-CTCA trial, these results suggest a synergistic approach between CTCA and ICA should be considered in this patient group. REGISTRATION: ClinicalTrials.gov, NCT03736018.

Anatomical variations in the superficial venous system of the neck: an image-based study using contrast-enhanced computed tomography.

PURPOSE: The superficial venous system (SVS) of the neck receives blood from the face and oral cavity. The SVS comprises the anterior jugular vein (AJV), external jugular vein (EJV), and facial vein (FV). Comprehensive knowledge of the normal anatomy and potential variations in the venous system is valuable in surgical and radiological procedures. This study aimed to update the anatomic knowledge of the SVS using a radiographic approach, which is a beneficial data source in clinical practice. METHODS: Contrast-enhanced computed tomography images of the neck of patients with head and neck cancer treated between 2017 and 2020 were retrospectively evaluated. Each side of the neck was counted separately. A total of 302 necks of 151 patients were enrolled in this study. RESULTS: The medial AJV was absent in 49.7% (75/151) of the patients on the left side, which was significantly greater than the 19.2% (29/151) on the right (p < 0.001). The left AJV drained into the right venous system in 6.6% (10/151) of the necks. In 48.3% (146/302) of the necks, the FV did not flow into the internal jugular vein but rather into the EJV or AJV; these findings were significantly more frequent than those reported in previous studies. The diameters of the veins were significantly larger when they received blood from the FV than when they were not connected to the FV. CONCLUSION: These findings indicate that the AJV has a rightward preference during its course. The course of the FV is diverse and affects the diameter of connected veins.

Patient Experience of Women With Dense Breasts Undergoing Screening Contrast-Enhanced Mammography.

OBJECTIVE: We investigated patient experience with screening contrast-enhanced mammography (CEM) to determine whether a general population of women with dense breasts would accept CEM in a screening setting. METHODS: In this institutional review board-approved prospective study, patients with heterogeneous and extremely dense breasts on their mammogram were invited to undergo screening CEM and complete pre-CEM and post-CEM surveys. On the pre-CEM survey, patients were asked about their attitudes regarding supplemental screening in general. On the post-CEM survey, patients were asked about their experience undergoing screening CEM, including causes and severity of any discomfort and whether they would consider undergoing screening CEM again in the future or recommend it to a friend. RESULTS: One hundred sixty-three women were surveyed before and after screening CEM. Most patients, 97.5% (159/163), reported minimal or no unpleasantness associated with undergoing screening CEM. In addition, 91.4% (149/163) said they would probably or very likely undergo screening CEM in the future if it cost the same as a traditional screening mammogram, and 95.1% (155/163) said they would probably or very likely recommend screening CEM to a friend. Patients in this study, who were all willing to undergo CEM, more frequently reported a family history of breast cancer than a comparison cohort of women with dense breasts (58.2% vs 47.1%, P = .027). CONCLUSION: Patients from a general population of women with dense breasts reported a positive experience undergoing screening CEM, suggesting screening CEM might be well received by this patient population, particularly if the cost was comparable with traditional screening mammography.

Contrast-free left atrial appendage occlusion in patients using the LAMBRE™ device.

BACKGROUND: Advances in imaging have led to procedural optimization of left atrial appendage closure (LAAC). Contrast-free approaches, guided merely by echocardiography, have been established, however data on this topic remains scarce. In this analysis, we assessed contrast-free procedural results with the LAMBRE LAAC device. METHODS: The multicenter retrospective BoBoMa (Bonn/Bordeaux/Mainz)-Registry included a total of 118 patients that underwent LAAC with LAMBRE devices omitting contrast-dye. Baseline and echocardiographic characteristics as well as intra- and postprocedural complications and outcomes were assessed. RESULTS: Patients were at a mean age of 77.5 ± 7.5 years with high thromboembolic and bleeding risk (CHADS-VASc-score 4.6 ± 1.4, HAS-BLED-score 3.7 ± 1.0, respectively). Renal function was impaired with a mean glomerular filtration rate (GFR) of 50 ± 22 ml/min. Mean procedural time was 47.2 ± 37.5  minutes with a mean radiation dose of 4.75 ± 5.25 Gy*cm2. Device success, defined as proper deployment in a correct position, was achieved in 97.5% (115/118) of cases with repositioning of the occluder in 7.6% (9/118) and resizing in 3.4% (4/118) of cases. No relevant peri-device leakage (>3 mm) was observed with 42% of occluders being implanted in an ostial position. Periprocedural complications occurred in 6.8% (8/118) of cases, including two cases of device embolization and one case of clinically-relevant pericardial effusion requiring surgical intervention. Other complications included pericardial effusion (2.5%, 3/118) and vascular access site complications (1.7%, 2/118). CONCLUSION: Echocardiography-guided contrast-free LAAC using the LAMBRE device is safe and feasible. Further prospective studies including the direct comparison of devices as well as imaging techniques are warranted in contrast-free LAAC.

Halved contrast medium dose coronary dual-layer CT-angiography - phantom study of tube current and patient characteristics.

Virtual mono-energetic images (VMI) using dual-layer computed tomography (DLCT) enable substantial contrast medium (CM) reductions. However, the combined impact of patient size, tube voltage, and heart rate (HR) on VMI of coronary CT angiography (CCTA) remains unknown. This phantom study aimed to assess VMI levels achieving comparable contrast-to-noise ratio (CNR) in CCTA at 50% CM dose across varying tube voltages, patient sizes, and HR, compared to the reference protocol (100% CM dose, conventional at 120 kVp). A 5 mm artificial coronary artery with 100% (400 HU) and 50% (200 HU) iodine CM-dose was positioned centrally in an anthropomorphic thorax phantom. Horizontal coronary movement was matched to HR (at 0, < 60, 60-75, > 75 bpm), with varying patient sizes simulated using phantom extension rings. Raw data was acquired using a clinical CCTA protocol at 120 and 140 kVp (five repetitions). VMI images (40-70 keV, 5 keV steps) were then reconstructed; non-overlapping 95% CNR confidence intervals indicated significant differences from the reference. Higher CM-dose, reduced VMI, slower HR, higher tube voltage, and smaller patient sizes demonstrated a trend of higher CNR. Regardless of HR, patient size, and tube voltage, no significant CNR differences were found compared to the reference, with 100% CM dose at 60 keV, or 50% CM dose at 40 keV. DLCT reconstructions at 40 keV from 120 to 140 kVp acquisitions facilitate 50% CM dose reduction for various patient sizes and HR with equivalent CNR to conventional CCTA at 100% CM dose, although clinical validation is needed.

Risk Factors for Contrast Media Extravasation in Intravenous Contrast-Enhanced Computed Tomography: An Observational Cohort Study.

RATIONALE AND OBJECTIVES: To identify the risk factors for contrast media (CM) extravasation and provide effective guidance for reducing its incidence. MATERIALS AND METHODS: We observed adult inpatients (n = 38 281) who underwent intravenous contrast-enhanced computed tomography between January 1, 2018, and December 31, 2022. Risk factors for CM extravasation were evaluated using univariate and multivariate logistic regression. RESULTS: Among the 38 281 inpatients who underwent enhanced computed tomography angiography, 3885 received peripherally inserted central venous catheters (PICCs) and 34 396 received peripheral short catheters. In 3885 cases of PICCs, no CM extravasation occurred, but in five cases, ordinary PICCs that are unable to withstand high pressure were mistakenly used; three of those patients experienced catheter rupture, and eventually, all five patients underwent unplanned extubation. Among 34 396 cases of peripheral short catheters, 224 (0.65%) had CM extravasation. Female sex (odds ratio [OR]=1.541, 95% confidence interval [CI]: 1.111-2.137), diabetes (OR=2.265, 95% CI: 1.549-3.314), venous thrombosis (OR=2.157, 95% CI: 1.039-4.478), multi-site angiography (OR=9.757, CI: 6.803-13.994), and injection rate ≥ 3 mL/s (OR=6.073, 95% CI: 4.349-8.481) were independent risk factors for CM extravasation. Due to peripheral vascular protection measures in patients with malignant tumor, there was a low incidence of CM extravasation (OR=0.394, 95% CI: 0.272-0.570). CONCLUSION: Main risk factors for CM extravasation are female, diabetes, venous thrombosis, multi-site angiography, and injection rate ≥ 3 mL/s. However, patients with malignant tumor have a low incidence of CM extravasation. CLINICAL IMPACT: Analysis of these risk factors can help reduce the incidence of CM extravasation.

Early detection of nasopharyngeal carcinoma: performance of a short contrast-free screening magnetic resonance imaging.

BACKGROUND: Although contrast-enhanced magnetic resonance imaging (MRI) detects early-stage nasopharyngeal carcinoma (NPC) not detected by endoscopic-guided biopsy (EGB), a short contrast-free screening MRI would be desirable for NPC screening programs. This study evaluated a screening MRI in a plasma Epstein-Barr virus (EBV)-DNA NPC screening program. METHODS: EBV-DNA-screen-positive patients underwent endoscopy, and endoscopy-positive patients underwent EGB. EGB was negative if the biopsy was negative or was not performed. Patients also underwent a screening MRI. Diagnostic performance was based on histologic confirmation of NPC in the initial study or during a follow-up period of at least 2 years. RESULTS: The study prospectively recruited 354 patients for MRI and endoscopy; 40/354 (11.3%) endoscopy-positive patients underwent EGB. Eighteen had NPC (5.1%), and 336 without NPC (94.9%) were followed up for a median of 44.8 months. MRI detected additional NPCs in 3/18 (16.7%) endoscopy-negative and 2/18 (11.1%) EGB-negative patients (stage I/II, n = 4; stage III, n = 1). None of the 24 EGB-negative patients who were MRI-negative had NPC. MRI missed NPC in 2/18 (11.1%), one of which was also endoscopy-negative. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MRI, endoscopy, and EGB were 88.9%, 91.1%, 34.8%, 99.4%, and 91.0%; 77.8%, 92.3%, 35.0%, 98.7%, and 91.5%; and 66.7%, 92.3%, 31.6%, 98.1%, and 91.0%, respectively. CONCLUSION: A quick contrast-free screening MRI complements endoscopy in NPC screening programs. In EBV-screen-positive patients, MRI enables early detection of NPC that is endoscopically occult or negative on EGB and increases confidence that NPC has not been missed.

Virtual non-contrast series of photon-counting detector computed tomography angiography for aortic valve calcium scoring.

The aim of our study was to evaluate two different virtual non-contrast (VNC) algorithms applied to photon counting detector (PCD)-CT data in terms of noise, effectiveness of contrast media subtraction and aortic valve calcium (AVC) scoring compared to reference true non-contrast (TNC)-based results. Consecutive patients underwent TAVR planning examination comprising a TNC scan, followed by a CTA of the heart. VNC series were reconstructed using a conventional (VNCconv) and a calcium-preserving (VNCpc) algorithm. Noise was analyzed by means of the standard deviation of CT-values within the left ventricle. To assess the effectiveness of contrast media removal, heart volumes were segmented and the proportion of their histograms > 130HU was taken. AVC was measured by Agatston and volume score. 41 patients were included. Comparable noise levels to TNC were achieved with all VNC reconstructions. Contrast media was effectively virtually removed (proportions > 130HU from 81% to < 1%). Median calcium scores derived from VNCconv underestimated TNC-based scores (up to 74%). Results with smallest absolute difference to TNC were obtained with VNCpc reconstructions (0.4 mm, Br36, QIR 4), but with persistent significant underestimation (median 29%). Both VNC algorithms showed near-perfect (r²>0.9) correlation with TNC. Thin-slice VNC reconstructions provide equivalent noise levels to standard thick-slice TNC series and effective virtual removal of iodinated contrast. AVC scoring was feasible on both VNC series, showing near-perfect correlation, but with significant underestimation. VNCpc with 0.4 mm slices and Br36 kernel at QIR 4 gave the most comparable results and, with further advances, could be a promising replacement for additional TNC.

Current and Advanced Applications of Gadoxetic Acid-enhanced MRI in Hepatobiliary Disorders.

Gadoxetic acid is an MRI contrast agent that has specific applications in the study of hepatobiliary disease. After being distributed in the vascular and extravascular spaces during the dynamic phase, gadoxetic acid is progressively taken up by hepatocytes and excreted to the bile ducts during the hepatobiliary phase. The information derived from the enhancement characteristics during dynamic and hepatobiliary phases is particularly relevant in the detection and characterization of focal liver lesions and in the evaluation of the structure and function of the liver and biliary system. The use of new MRI sequences and advanced imaging techniques (eg, relaxometry, multiparametric imaging, and analysis of heterogeneity), the introduction of artificial intelligence, and the development of biomarkers and radiomic and radiogenomic tools based on gadoxetic acid-enhanced MRI findings will play an important role in the future in assessing liver function, chronic liver disease, and focal liver lesions; in studying biliary pathologic conditions; and in predicting treatment responses and prognosis. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Holographically Activatable Nanoprobe via Glutathione/Albumin-Mediated Exponential Signal Amplification for High-Contrast Tumor Imaging.

Glutathione (GSH)-activatable probes hold great promise for in vivo cancer imaging, but are restricted by their dependence on non-selective intracellular GSH enrichment and uncontrollable background noise. Here, a holographically activatable nanoprobe caging manganese tetraoxide is shown for tumor-selective contrast enhancement in magnetic resonance imaging (MRI) through cooperative GSH/albumin-mediated cascade signal amplification in tumors and rapid elimination in normal tissues. Once targeting tumors, the endocytosed nanoprobe effectively senses the lysosomal microenvironment to undergo instantaneous decomposition into Mn2+ with threshold GSH concentration of ≈ 0.12 mm for brightening MRI signals, thus achieving high contrast tumor imaging and flexible monitoring of GSH-relevant cisplatin resistance during chemotherapy. Upon efficient up-regulation of extracellular GSH in tumor via exogenous injection, the relaxivity-silent interstitial nanoprobe remarkably evolves into Mn2+ that are further captured/retained and re-activated into ultrahigh-relaxivity-capable complex by stromal albumin in the tumor, and simultaneously allows the renal clearance of off-targeted nanoprobe in the form of Mn2+ via lymphatic vessels for suppressing background noise to distinguish tiny liver metastasis. These findings demonstrate the concept of holographic tumor activation via both tumor GSH/albumin-mediated cascade signal amplification and simultaneous background suppression for precise tumor malignancy detection, surveillance, and surgical guidance.

Intravenous contrast medium extravasation: systematic review and updated ESUR Contrast Media Safety Committee Guidelines.

NEED FOR A REVIEW: Guidelines for management and prevention of contrast media extravasation have not been updated recently. In view of emerging research and changing working practices, this review aims to inform update on the current guidelines. AREAS COVERED: In this paper, we review the literature pertaining to the pathophysiology, diagnosis, risk factors and treatments of contrast media extravasation. A suggested protocol and guidelines are recommended based upon the available literature. KEY POINTS: • Risk of extravasation is dependent on scanning technique and patient risk factors. • Diagnosis is mostly clinical, and outcomes are mostly favourable. • Referral to surgery should be based on clinical severity rather than extravasated volume.

Ultrasmall MnSe Nanoparticles as T1-MRI Contrast Agents for In Vivo Tumor Imaging.

Magnetic resonance imaging (MRI) has excellent potential in the clinical monitoring of tumors because it can provide high-resolution soft tissue imaging. However, commercial contrast agents (CAs) used in MRI still have some problems such as potential toxicity to the human body, low relaxivity, and a short MRI acquisition window. In this study, ultrasmall MnSe nanoparticles are synthesized by living Staphylococcus aureus cells. The as-prepared MnSe nanoparticles are monodispersed with a uniform particle size (3.50 ± 0.52 nm). Due to the ultrasmall particle size and good water solubility, the MnSe nanoparticles exhibit in vitro high longitudinal relaxivity properties (14.12 ± 1.85 mM-1·s-1). The CCK-8 colorimetric assay, histological analysis, and body weight results show that the MnSe nanoparticles do not have appreciable toxicity on cells and organisms. Besides, the MnSe nanoparticles as T1-MRI CAs offer a long MRI acquisition window to tumor imaging (∼7 h). This work provides a promising T1-MRI CA for clinical tumor imaging and a good reference for the application of functional MnSe nanoparticles in the biomedicine field.