Safe and Informed Use of Gadolinium-Based Contrast Agent in Body Magnetic Resonance Imaging: Where We Were and Where We Are.

Gadolinium-based contrast agents (GBCAs) have helped to improve the role of magnetic resonance imaging (MRI) for the diagnosis and treatment of diseases. There are currently nine different commercially available gadolinium-based contrast agents (GBCAs) that can be used for body MRI cases, and which are classifiable according to their structures (cyclic or linear) or biodistribution (extracellular-space agents, target/specific-agents, and blood-pool agents). The aim of this review is to illustrate the commercially available MRI contrast agents, their effect on imaging, and adverse reaction on the body, with the goal to lead to their proper selection in different clinical contexts. When we have to choose between the different GBCAs, we have to consider several factors: (1) safety and clinical impact; (2) biodistribution and diagnostic application; (3) higher relaxivity and better lesion detection; (4) higher stability and lower tissue deposit; (5) gadolinium dose/concentration and lower volume injection; (6) pulse sequences and protocol optimization; (7) higher contrast-to-noise ratio at 3.0 T than at 1.5 T. Knowing the patient's clinical information, the relevant GBCAs properties and their effect on body MRI sequences are the key features to perform efficient and high-quality MRI examination.

Barbed sutures and skin adhesives improve wound closure in hip and knee arthroplasty.

PURPOSE: This study aimed to formulate evidence-based recommendations for optimising wound management in hip and knee arthroplasty by exploring alternative methods such as barbed sutures and skin adhesives. METHODS: A Delphi panel, comprising seven orthopaedic surgeons, one musculoskeletal infectious disease specialist, and one health economics expert, was convened to evaluate the use of barbed sutures and skin adhesives for wound closure in hip and knee arthroplasty. Two systematic reviews informed the development of questionnaires, with panelists ranking their agreement on statements using a 5-point Likert scale. Consensus was achieved if ≥75% agreement. Unresolved statements were revisited in a second round. RESULTS: Consensus was reached on 11 statements, providing evidence-based recommendations. The expert panel advocates for a multilayer watertight technique using barbed sutures to prevent surgical site infections (SSI), reduce complications, shorten surgical times, optimise resources and improve cosmetic appearance. For skin closure, the panel recommends topical adhesives to decrease wound dehiscence, enhance cosmetic appearance, promote patient compliance, prevent SSIs, and optimise resources. CONCLUSION: The Delphi consensus by Italian total joint arthroplasty experts underscores the pivotal role of barbed sutures and skin adhesives in optimising outcomes. While guiding clinical decision-making, these recommendations are not prescriptive and should be adapted to local practices. The study encourages further research to enhance current evidence. LEVEL OF EVIDENCE: Level III.

Hepatobiliary-specific magnetic resonance contrast agents: role in biliary trauma.

Non-iatrogenic traumatic bile duct injuries (NI-TBIs) are a rare complication after abdominal trauma, with an estimated prevalence of 2.8-7.4% in patients underwent blunt liver injuries. They may be overlooked in patients with extensive multi-organ trauma, particularly hepatic, splenic and duodenal injuries, which have a prevalence of 91%, 54% and 54%, respectively. Whole body contrast-enhanced computed tomography (CE-CT) represents the examination of choice in polytraumatized hemodynamically stable patients, as it allows a comprehensive evaluation of vascular, parenchymal, bone and soft tissues injuries, but the diagnosis of any biliary leaks is limited to the evaluation of nonspecific imaging findings and on findings evolution in the follow-up, such as the progressive growth of fluid collections. Furthermore, biliary complications, such as the occurrence of biloma or biliary peritonitis, may become manifest several days after the initial trauma, often with unspecific progressive signs and symptoms. Although CT and ultrasonography can suggest bile leaks based on several nonspecific imaging findings (e.g., fluid collections), magnetic resonance imaging (MRI) using hepatobiliary contrast agents helps to identify the site and entity of post-traumatic biliary disruption. Indeed, MRI allows to obtain cholangiographic sequences that may show post-traumatic active bile leakage and cysto-biliary communications by direct visualisation of contrast material extravasation into fluid collections, increasing the preoperative accuracy of NI-TBIs. Few data are available about MRI use in the follow-up of trauma with NI-TBI management. So, in the present mini review, its role is reviewed and our preliminary experience in this field is reported.

Prediction of placenta accreta spectrum in patients with placenta previa using a clinical, US and MRI combined model: A retrospective study with external validation.

PURPOSE: To build and validate a predictive model of placental accreta spectrum (PAS) in patients with placenta previa (PP) combining clinical risk factors (CRF) with US and MRI signs. METHOD: Our retrospective study included patients with PP from two institutions. All patients underwent US and MRI examinations for suspicion of PAS. CRF consisting of maternal age, cesarean section number, smoking and hypertension were retrieved. US and MRI signs suggestive of PAS were evaluated. Logistic regression analysis was performed to identify CRF and/or US and MRI signs associated with PAS considering histology as the reference standard. A nomogram was created using significant CRF and imaging signs at multivariate analysis, and its diagnostic accuracy was measured using the area under the binomial ROC curve (AUC), and the cut-off point was determined by Youden's J statistic. RESULTS: A total of 171 patients were enrolled from two institutions. Independent predictors of PAS included in the nomogram were: 1) smoking and number of previous CS among CRF; 2) loss of the retroplacental clear space at US; 3) intraplacental dark bands, focal interruption of the myometrial border and placental bulging at MRI. A PAS-prediction nomogram was built including these parameters and an optimal cut-off of 14.5 points was identified, showing the highest sensitivity (91%) and specificity (88%) with an AUC value of 0.95 (AUC of 0.80 in the external validation cohort). CONCLUSION: A nomogram-based model combining CRF with US and MRI signs might help to predict PAS in PP patients, with MRI contributing more than US as imaging evaluation.

Abdominal compartment syndrome: what radiologist needs to know.

The intra-abdominal hypertension (IAH) and the abdominal compartment syndrome (ACS) are life-threatening conditions with a significant rate of mortality; therefore, early detection is paramount in their optimal management. IAH is diagnosed when the intra-abdominal pressure (IAP) is more than 12 mmHg. It can occur when the intra-abdominal volume increases (ileus, ascites, trauma, pancreatitis, etc.) and/or the abdominal wall compliance decreases. IAH can cause decreased venous flow, low cardiac output, renal impairment, and decreased respiratory compliance. Consequently, these complications can lead to multiple organ failure and induce the abdominal compartment syndrome (ACS) when IAP rises above 20 mmHg. The diagnosis is usually made with intravesical pressure measurement. However, this measurement was not always possible to obtain; therefore, alternative diagnostic techniques should be considered. In this setting, computed tomography (CT) may play a crucial role, allowing the detection and characterization of pathological conditions that may lead to IAH. This review is focused on the pathogenesis, clinical features, and radiological findings of ACS, because their presence allows radiologists to raise the suspicion of IAH/ACS in critically ill patients, guiding the most appropriate treatment.

Segmentation methods applied to MRI-derived radiomic analysis for the prediction of placenta accreta spectrum in patients with placenta previa.

PURPOSE: To retrospectively evaluate the performance of different manual segmentation methods of placenta MR images for predicting Placenta Accreta Spectrum (PAS) disorders in patients with placenta previa (PP) using a Machine Learning (ML) Radiomics analysis. METHODS: 64 patients (n=41 with PAS and n= 23 without PAS) with PP who underwent MRI examination for suspicion of PAS were retrospectively selected. All MRI examinations were acquired on a 1.5 T using T2-weighted (T2w) sequences on axial, sagittal and coronal planes. Ten different manual segmentation methods were performed on sagittal placental T2-weighted images obtaining five sets of 2D regions of interest (ROIs) and five sets of 3D volumes of interest (VOIs) from each patient. In detail, ROIs and VOIs were positioned on the following areas: placental tissue, retroplacental myometrium, cervix, placenta with underneath myometrium, placenta with underneath myometrium and cervix. For feature stability testing, the same process was repeated on 30 randomly selected placental MRI examinations by two additional radiologists, working independently and blinded to the original segmentation. Radiomic features were extracted from all available ROIs and VOIs. 100 iterations of 5-fold cross-validation with nested feature selection, based on recursive feature elimination, were subsequently run on each ROI/VOI to identify the best-performing method to classify instances correctly. RESULTS: Among the segmentation methods, the best performance in predicting PAS was obtained by the VOIs covering the retroplacental myometrium (Mean validation score: 0.761, standard deviation: 0.116). CONCLUSION: Our preliminary results show that the VOI including the retroplacental myometrium using T2w images seems to be the best method when segmenting images for the development of ML radiomics predictive models to identify PAS in patients with PP.

Non-Operative Management of Polytraumatized Patients: Body Imaging beyond CT.

In the transition from the operative to the conservative approach for the polytraumatized patients who undergo blunt trauma, diagnostic imaging has assumed a pivotal role, currently offering various opportunities, particularly in the follow-up of these patients. The choice of the most suitable imaging method in this setting mainly depends on the injury complications we are looking for, the patient conditions (mobilization, cooperation, medications, allergies and age), the biological invasiveness, and the availability of each imaging method. Computed Tomography (CT) represents the "standard" imaging technique in the polytraumatized patient due to the high diagnostic performance when a correct imaging protocol is adopted, despite suffering from invasiveness due to radiation dose and intravenous contrast agent administration. Ultrasound (US) is a readily available technology, cheap, bedside performable and integrable with intravenous contrast agent (Contrast enhanced US-CEUS) to enhance the diagnostic performance, but it may suffer particularly from limited panoramicity and operator dependance. Magnetic Resonance (MR), until now, has been adopted in specific contexts, such as biliopancreatic injuries, but in recent experiences, it showed a great potential in the follow-up of polytraumatized patients; however, its availability may be limited in some context, and there are specific contraindications, such as as claustrophobia and the presence non-MR compatible devices. In this article, the role of each imaging method in the body-imaging follow-up of adult polytraumatized patients will be reviewed, enhancing the value of integrated imaging, as shown in several cases from our experience.

An update on pyelonephritis: role of contrast enhancement ultrasound (CEUS).

Acute pyelonephritis (APN) is a bacterial infection causing inflammation of the kidneys. Diagnosis is usually based on clinical and laboratory findings. Imaging is required if a complication is suspected in acute pyelonephritis to assess the nature and extent of the lesions and to detect underlying causes. CT represents the current imaging modality of choice in clinical practice. CEUS is an alternative that has been proven to be equally accurate in the detection of acute pyelonephritis renal lesions. CEUS allows us to distinguish small simple nephritic involvement from abscess complications and to follow their evolution over time during antibiotic therapy. The absence of ionizing radiation and the lack of nephrotoxicity make CEUS an ideal tool in the study of pyelonephritis.

Multimodality ultrasound assessment of the spleen: Normal appearances and emergency abnormalities.

This paper summarizes the main splenic emergencies and their ultrasonographic findings to orient appropriate patient management. US requires minimal preparation time and allows to examine the parenchyma and to detect intraperitoneal fluid collections, which may be indirect evidence of solid organ injuries. In this paper, we analyze the role of B-mode, Doppler and Contrast-Enhanced Ultrasound in the diagnosis of splenic emergencies, with a particular focus on splenic infarction, infection, traumatic injuries and vascular splenic anomalies.

Balancing in Unicompartmental Knee Arthroplasty: Balancing in Flexion or in Extension?

Unicompartmental knee arthroplasty (UKA) is an established procedure for the treatment of predominant single compartmental femorotibial osteoarthritis (OA) or osteonecrosis [...].

Oncologic Imaging and Radiomics: A Walkthrough Review of Methodological Challenges.

Imaging plays a crucial role in the management of oncologic patients, from the initial diagnosis to staging and treatment response monitoring. Recently, it has been suggested that its importance could be further increased by accessing a new layer of previously hidden quantitative data at the pixel level. Using a multi-step process, radiomics extracts potential biomarkers from medical images that could power decision support tools. Despite the growing interest and rising number of research articles being published, radiomics is still far from fulfilling its promise of guiding oncologic imaging toward personalized medicine. This is, at least partly, due to the heterogeneous methodological quality in radiomic research, caused by the complexity of the analysis pipelines. In this review, we aim to disentangle this complexity with a stepwise approach. Specifically, we focus on challenges to face during image preprocessing and segmentation, how to handle imbalanced classes and avoid information leaks, as well as strategies for the proper validation of findings.

Placenta Accreta Spectrum Disorders and Radiomics: Systematic review and quality appraisal.

PURPOSE: Ultrasound and magnetic resonance imaging are the imaging modalities of choice for placenta accrete spectrum (PAS) disorders assessment. Radiomics could further increase the value of medical images and allow to overcome the limitations linked to their visual assessment. Aim of this systematic review was to identify and appraise the methodological quality of radiomics studies focused PAS disorders applications. METHOD: Three online databases (PubMed, Scopus and Web of Science) were searched to identify original research articles on human subjects published in English. For the qualitative synthesis of results, data regarding study design (e.g., retrospective or prospective), purpose, patient population (e.g., sample size), imaging modalities and radiomics pipelines (e.g., segmentation and feature extraction strategy) were collected. The appraisal of methodological quality was performed using the Radiomics Quality Score (RQS). RESULTS: 10 articles were finally included and analyzed. All were retrospective and MRI-powered. The majority included more than 100 patients (6/10). Four were prognostic (focused on either the prediction of bleeding volume or the prediction of needed management) while six diagnostic (PAS vs not PAS classification) studies. The median RQS was 8, with maximum and minimum respectively equal to 17/36 and - 6/36. Major methodological concerns were the lack of feature stability to multiple segmentation testing and poor data openness. CONCLUSIONS: Radiomics studies focused on PAS disorders showed a heterogeneous methodological quality, overall lower than desirable. Furthermore, many relevant research questions remain unexplored. More robust investigations are needed to foster advancements in the field and possibly clinical translation.

Hybrid Cementation Technique Using the New Modular System for Aseptic Knee Arthroplasty Revision Surgery.

Background: To evaluate the clinical and radiological outcomes of aseptic revision of total knee arthroplasty (TKA) using the Vanguard 360 Revision Knee System with the hybrid cementation technique. Methods: Between January 2014 and October 2016, nineteen aseptic revision TKAs were carried out with the Vanguard 360 Revision Knee System (Zimmer-Biomet, Warsaw, IN, USA) performed by two different surgeons. The patients were evaluated clinically and radiographically at one, six, and twelve months after surgery and yearly thereafter. Functional outcomes were assessed according to the range of motion (ROM), knee society knee score (KSKS) and knee society function score (KSFS). Radiological evaluations were performed using the hip-knee-ankle angle (HKA), weight-bearing anteroposterior view, latero-lateral view, Rosenberg x-rays of the knee and skyline patellar x-rays. A triple-phase technetium bone scan was performed on all the patients complaining of knee pain after one year from surgery. Results: Clinical and radiological results including KSKS, KSFS, ROM and HKA angle improved after revision of TKA with a statistically significant difference (p <0.05). There were seven revisions of the CCK prosthesis due to persistent pain. Conclusion: Patients who underwent revision of TKA using the Vanguard 360 with the hybrid cementation technique had a failure rate of 36.8% at a mean time of 29 months due to aseptic loosening. Further studies are required to analyse the role of cementation in detail to prevent this complication.

Pelvic Pain in Reproductive Age: US Findings.

Pelvic pain in reproductive age often represents a diagnostic challenge due to the variety of potential causes characterized by overlapping clinical symptoms, including gynecological and other disorders (e.g., entero-colic or urological). It is also necessary to determine if there is a possibility of pregnancy to rule out any related complications, such as ectopic pregnancy. Although ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) are strongly integrated, the choice of which is the ideal diagnostic tool should be guided both by clinical suspicion (gynecological vs. non-gynecological cause) and by the risk ratio-benefit (ionizing radiation and instrumental costs), too. The didactic objective proposed by this review consists in the diagnosis of the cause and differential of pelvic pain in reproductive age by describing and critically analyzing the US diagnostic clues of the most frequent adnexal, uterine, and vascular causes.

Radiomics in Cross-Sectional Adrenal Imaging: A Systematic Review and Quality Assessment Study.

In this study, we aimed to systematically review the current literature on radiomics applied to cross-sectional adrenal imaging and assess its methodological quality. Scopus, PubMed and Web of Science were searched to identify original research articles investigating radiomics applications on cross-sectional adrenal imaging (search end date February 2021). For qualitative synthesis, details regarding study design, aim, sample size and imaging modality were recorded as well as those regarding the radiomics pipeline (e.g., segmentation and feature extraction strategy). The methodological quality of each study was evaluated using the radiomics quality score (RQS). After duplicate removal and selection criteria application, 25 full-text articles were included and evaluated. All were retrospective studies, mostly based on CT images (17/25, 68%), with manual (19/25, 76%) and two-dimensional segmentation (13/25, 52%) being preferred. Machine learning was paired to radiomics in about half of the studies (12/25, 48%). The median total and percentage RQS scores were 2 (interquartile range, IQR = -5-8) and 6% (IQR = 0-22%), respectively. The highest and lowest scores registered were 12/36 (33%) and -5/36 (0%). The most critical issues were the absence of proper feature selection, the lack of appropriate model validation and poor data openness. The methodological quality of radiomics studies on adrenal cross-sectional imaging is heterogeneous and lower than desirable. Efforts toward building higher quality evidence are essential to facilitate the future translation into clinical practice.

Common and Uncommon Errors in Emergency Ultrasound.

Errors in emergency ultrasound (US) have been representing an increasing problem in recent years thanks to several unique features related to both the inherent characteristics of the discipline and to the latest developments, which every medical operator should be aware of. Because of the subjective nature of the interpretation of emergency US findings, it is more prone to errors than other diagnostic imaging modalities. The misinterpretation of US images should therefore be considered as a serious risk in diagnosis. The etiology of error is multi-factorial: it depends on environmental factors, patients and the technical skills of the operator; it is influenced by intrinsic US artifacts, poor clinical correlation, US-setting errors and anatomical variants; and it is conditioned by the lack of a methodologically correct clinical approach and excessive diagnostic confidence too. In this review, we evaluate the common and uncommon sources of diagnostic errors in emergency US during clinical practice, showing how to recognize and avoid them.

Role of Ultrasound in the Assessment and Differential Diagnosis of Pelvic Pain in Pregnancy.

Pelvic pain (PP) is common in pregnant women and can be caused by several diseases, including obstetrics, gynaecological, gastrointestinal, genitourinary, and vascular disorders. Timely and accurate diagnosis as well as prompt treatment are crucial for the well-being of the mother and foetus. However, these are very challenging. It should be considered that the physiological changes occurring during pregnancy may confuse the diagnosis. In this setting, ultrasound (US) represents the first-line imaging technique since it is readily and widely available and does not use ionizing radiations. In some cases, US may be conclusive for the diagnosis (e.g., if it detects no foetal cardiac activity in suspected spontaneous abortion; if it shows an extrauterine gestational sac in suspected ectopic pregnancy; or if it reveals a dilated, aperistaltic, and blind-ending tubular structure arising from the cecum in suspicious of acute appendicitis). Magnetic resonance imaging (MRI), overcoming some limits of US, represents the second-line imaging technique when an US is negative or inconclusive, to detect the cause of bowel obstruction, or to characterize adnexal masses.

The Technique and Advantages of Contrast-Enhanced Ultrasound in the Diagnosis and Follow-Up of Traumatic Abdomen Solid Organ Injuries.

Trauma is one of the most common causes of death or permanent disability in young people, so a timely diagnostic approach is crucial. In polytrauma patients, CEUS (contrast enhanced ultrasound) has been shown to be more sensitive than US (ultrasound) for the detection of solid organ injuries, improving the identification and grading of traumatic abdominal lesions with levels of sensitivity and specificity similar to those seen with MDCT (multidetector tomography). CEUS is recommended for the diagnostic evaluation of hemodynamically stable patients with isolated blunt moderate-energy abdominal traumas and the diagnostic follow-up of conservatively managed abdominal traumas. In this pictorial review, we illustrate the advantages and disadvantages of CEUS and the procedure details with tips and tricks during the investigation of blunt moderate-energy abdominal trauma as well as during follow-up in non-operative management.