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.

Multiparametric cardiac magnetic resonance in patients with thalassemia intermedia: new insights from the E-MIOT network.

PURPOSE: In a relatively large cohort of thalassemia intermedia (TI) patients, we systematically investigated myocardial iron overload (MIO), function, and replacement fibrosis using cardiac magnetic resonance (CMR), we assessed the clinical determinants of global heart T2* values, and we explored the association between multiparametric CMR findings and cardiac complications. MATERIALS AND METHODS: We considered 254 beta-TI patients (43.14 ± 13.69 years, 138 females) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia project. MIO was quantified by T2* technique and biventricular function and atrial areas by cine images. Macroscopic myocardial fibrosis was detected by late gadolinium enhancement technique. RESULTS: Compared to never/sporadically transfused patients, regularly transfused (RT)-TI patients exhibited significantly lower global heart T2* values, biventricular end-diastolic volume indexes, left ventricular mass index, and cardiac index. In RT-TI patients, age and serum ferritin levels were the strongest predictors of global heart T2* values. Independently from the transfusional state, cardiac T2* values were not associated with biventricular function. Of the 103 (40.6%) patients in whom the contrast medium was administrated, 27 (26.2%) had replacement myocardial fibrosis. Age, sex distribution, cardiac iron, and biventricular function parameters were comparable between patients without and without replacement myocardial fibrosis. Twenty-five (9.8%) patients had a history of cardiac complications (heart failure and arrhythmias). Increased age and replacement myocardial fibrosis emerged as significant risk markers for cardiac complications. CONCLUSIONS: In TI, regular transfusions are associated with less pronounced cardiac remodeling but increase the risk of MIO. Replacement myocardial fibrosis is a frequent finding associated with cardiac complications.

Pancreatic iron in pediatric transfusion-dependent beta-thalassemia patients: A longitudinal MRI study.

BACKGROUND: In pediatric transfusion-dependent thalassemia (TDT) patients, we evaluated the prevalence, pattern, and clinical associations of pancreatic siderosis and the changes in pancreatic iron levels and their association with baseline and changes in total body iron balance. PROCEDURE: We considered 86 pediatric TDT patients consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network. Iron overload (IO) was quantified by R2* magnetic resonance imaging (MRI). RESULTS: Sixty-three (73%) patients had pancreatic IO (R2* > 38 Hz). Global pancreas R2* values were significantly correlated with mean serum ferritin levels, MRI liver iron concentration (LIC) values, and global heart R2* values. Global pancreas R2* values were significantly higher in patients with altered versus normal glucose metabolism. Thirty-one patients also performed the follow-up MRI at 18 ± 3 months. Higher pancreatic R2* values were detected at the follow-up, but the difference versus the baseline MRI was not significant. The 20% of patients with baseline pancreatic IO showed no pancreatic IO at the follow-up. The 46% of patients without baseline pancreatic IO developed pancreatic siderosis. The changes in global pancreas R2* between the two MRIs were not correlated with baseline serum ferritin levels, baseline, final, and changes in MRI LIC values, or baseline pancreatic iron levels. CONCLUSIONS: In children with TDT, pancreatic siderosis is a frequent finding associated with hepatic siderosis and represents a risk factor for myocardial siderosis and alterations of glucose metabolism. Iron removal from the pancreas is exceptionally challenging and independent from hepatic iron status.

Abdominal Emergencies in Cancer Patients.

Abdominal emergencies in cancer patients encompass a wide spectrum of oncologic conditions caused directly by malignancies, paraneoplastic syndromes, reactions to the chemotherapy or often represent the first clinical manifestation of an unknown malignancy. Not rarely, clinical symptoms are the tip of an iceberg. In this scenario, the radiologist is asked to exclude the cause responsible for the patient's symptoms, to suggest the best way to manage and to rule out the underlying malignancy. In this article, we discuss some of the most common abdominal oncological emergencies that may be encountered in an emergency department.

Point-of-Care Lung Ultrasound in the Intensive Care Unit-The Dark Side of Radiology: Where Do We Stand?

Patients in intensive care units (ICUs) are critically ill and require constant monitoring of clinical conditions. Due to the severity of the underlying disease and the need to monitor devices, imaging plays a crucial role in critically ill patients' care. Given the clinical complexity of these patients, who typically need respiratory assistance as well as continuous monitoring of vital functions and equipment, computed tomography (CT) can be regarded as the diagnostic gold standard, although it is not a bedside diagnostic technique. Despite its limitations, portable chest X-ray (CXR) is still today an essential diagnostic tool used in the ICU. Being a widely accessible imaging technique, which can be performed at the patient's bedside and at a low healthcare cost, it provides additional diagnostic support to the patient's clinical management. In recent years, the use of point-of-care lung ultrasound (LUS) in ICUs for procedure guidance, diagnosis, and screening has proliferated, and it is usually performed at the patient's bedside. This review illustrates the role of point-of-care LUS in ICUs from a purely radiological point of view as an advanced method in ICU CXR reports to improve the interpretation and monitoring of lung CXR findings.

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.

Pattern and clinical correlates of renal iron deposition in adult beta-thalassemia major patients.

We evaluated pattern and clinical correlates of renal T2* measurements in adult ß-thalassemia major (ß-TM) patients. Ninety ß-TM patients (48 females, 38.15 ± 7.94 years), consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia network, underwent T2* magnetic resonance imaging (MRI) for quantification of iron overload (IO) in kidneys, liver, pancreas, and heart. Ten (11.1%) patients showed renal IO (T2* < 31 ms). Global kidney T2* values did not show a correlation with gender, age, splenectomy, regular transfusions or chelation starting age, pre-transfusion hemoglobin, and serum ferritin levels. Global kidney T2* values showed an inverse correlation with MRI liver iron concentration (LIC) values (R = - 0.349; p = 0.001) and a positive correlation with global pancreas T2* values (R = 0.212; p = 0.045). Frequency of renal IO was significantly higher in patients with cardiac IO than in patients without cardiac IO (50.0% vs. 6.3%; p = 0.001). A significant inverse association was detected between global kidneys T2* values and lactate dehydrogenase (LDH) (R = - 0.529; p < 0.0001). In multivariate regression analysis, MRI LIC and LDH were the strongest predictors of global kidney T2* values. A MRI LIC > 4.83 mg/g dw predicted the presence of renal IO (sensitivity = 90.0%; specificity = 61.2%). Global kidney T2* values were inversely correlated with uric acid (R = - 0.269; p = 0.025). In conclusion, in adult ß-TM patients, renal iron deposition is not common and is linked to both hemolysis and total body iron overload.

The Role of CT-Angiography in the Acute Gastrointestinal Bleeding: A Pictorial Essay of Active and Obscure Findings.

Gastrointestinal bleeding is a potentially life-threatening abdominal emergency that remains a common cause of hospitalisation. Although 80-85% of cases of gastrointestinal bleeding resolve spontaneously, it can result in massive haemorrhage and death. The presentation of gastrointestinal bleeding can range from asymptomatic or mildly ill patients requiring only conservative treatments to severely ill patients requiring immediate intervention. Identifying the source of the bleeding can be difficult due to the wide range of potential causes, the length of the gastrointestinal tract and the intermittent nature of the bleeding. The diagnostic and therapeutic approach is fully dependent on the nature of the bleeding and the patient's haemodynamic status. Radiologists should be aware of the appropriate uses of computed tomography angiography and other imaging modalities in patients with acute gastrointestinal bleeding, as well as the semiotics of bleeding and diagnostic pitfalls in order to appropriately diagnose and manage these patients. The learning objective of this review is to illustrate the computed tomography angiography technique, including the potential role of dual-energy computed tomography angiography, also highlighting the tips and tricks to identify the most common and uncommon features of acute gastrointestinal bleeding and its obscure form.

Frequency, pattern, and associations of renal iron accumulation in sickle/ß-thalassemia patients.

We evaluated frequency, pattern, and associations of renal iron accumulation in sickle/ß-thalassemia. Thirty-three sickle/ß-thalassemia patients (36.5 ± 14.7 years; 13 females), 14 homozygous sickle cell disease (SCD) patients, and 71 thalassemia major (TM) patients, enrolled in the E-MIOT Network, underwent magnetic resonance imaging. Iron overload (IO) was quantified by the T2* technique. Sickle/ß-thalassemia patients had a significantly lower frequency of renal IO (T2* < 31 ms) than homozygous SCD patients (9.1% vs. 57.1%; P = 0.001), besides having similar hepatic, cardiac and pancreatic IO. Kidney T2* values were comparable between regularly transfused sickle/ß-thalassemia and TM patients but were significantly lower in regularly transfused homozygous SCD patients than in the other two groups. In sickle/ß-thalassemia patients, global renal T2* values were not associated with age, gender, splenectomy, and presence of regular transfusions or chelation. No correlation was detected between renal T2* values and serum ferritin levels or iron load in the other organs. Global renal T2* values were not associated with serum creatinine levels but showed a significant inverse correlation with serum lactate dehydrogenase (R = - 0.709; P < 0.0001) and indirect bilirubin (R = - 0.462; P = 0.012). Renal IO is not common in sickle/ß-thalassemia patients, with a prevalence significantly lower compared to that of homozygous SCD patients, but with a similar underlying mechanism due to the chronic hemolysis.

Qualitative evaluation of MR images for assessing placenta accreta spectrum disorders in patients with placenta previa: A pilot validation study.

PURPOSE: To validate a qualitative imaging method using magnetic resonance (MR) for predicting placental accreta spectrum (PAS) in patients with placenta previa (PP). METHOD: Two MR imaging methods built in our previous experience was tested in an external comparable group of sixty-five patients with PP; these methods consisted of presence of at least one (Method 1) or two (Method 2) of the following abnormal MR imaging signs: intraplacental dark bands, focal interruption of myometrial border and abnormal placental vascularity. Three groups of radiologists with different level of expertise evaluated MR images: at least 5 years of experience in body imaging (Group 1); at least 10 (Group 2) or 20 (Group 3) years of experience in genito-urinary MR. While radiologists of Group 1 routinely evaluated MR images, those of Groups 2 and 3 used both Methods 1 and 2. RESULTS: A significant (p < 0.005) difference was found between the diagnostic accuracy values of imaging evaluation performed by Group 3 using Method 1 (63%) and Method 2 (89%); of note, the accuracy of Method 2 by Group 3 was also significantly (p < 0.005) higher compared to that of both Methods 1 (46%) and 2 (63%) by Group 2 as well as to that of the routine evaluation by Group 1 (60%). CONCLUSIONS: The qualitative identification of at least two abnormal MR signs (Method 2) represents an accurate method for predicting PAS in patients with PP particularly when this method was used by more experienced radiologists; thus, imaging expertise and methodology is required for this purpose.

Computed tomography imaging of septic shock. Beyond the cause: the "CT hypoperfusion complex". A pictorial essay.

Septic shock is a medical emergency that represents one of the most important underlying causes for presentation to the Emergency Department. Sepsis is defined as organ dysfunction, life-threatening event caused by a deregulated inflammatory host response to infection, with a mortality risk ranging from 10 to 40%. Early sepsis identification is the cornerstone of management and diagnostic imaging can play a pivotal role in this clinical context. The choice of imaging modality depends on several factors, associated with the clinical condition and the presence or absence of localising signs and symptoms. The diagnostic accuracy of contrast-enhanced total-body CT has been well established during septic shock, allowing for a rapid, panoramic, and detailed study of multiple body areas, simultaneously. The aim of this article is to illustrate the controversial CT hypoperfusion complex in patients with septic shock, characterised by the following imaging features: decreased enhancement of the viscera; increased mucosal enhancement; luminal dilation of the small bowel; mural thickening and fluid-filled loops of the small bowel; the halo sign and flattening of the inferior vena cava; reduced aortic diameter; peripancreatic oedema; abnormal parenchymal perfusion; and other controversial findings that are variably associated with each other and reversible during the early stages. Increasing physicians' awareness of the significance of these findings could prompt alternative approaches to the early assessment and management of septic shock. In this perspective, CT imaging represents a useful tool for a complete, rapid and detailed diagnosis of clinically suspected septic shock, which can be used to improve patient outcomes.

Insight into Dunbar syndrome: color-Doppler ultrasound findings and literature review.

Dunbar syndrome, also known as median arcuate ligament syndrome, is a rare clinical condition due to the external compression of the celiac trunk by the median arcuate ligament causing abdominal angina. We report a case of Dunbar syndrome and its borderline imaging findings focused on the crucial diagnostic role of color-Doppler ultrasound. We also reviewed the current literature, delineating the clinical manifestations and the diagnostic workup of the Dunbar syndrome with the objective to increase the knowledge of this clinical entity as a cause of postprandial abdominal pain and to underline the pivotal role of color-Doppler ultrasound to avoid incorrect or delayed diagnosis.

High-flow post-traumatic priapism: diagnostic and therapeutic workup.

Priapism is a prolonged penile tumescence or erection unrelated to sexual stimulation that lasts more than 6 h. High-flow priapism is a rare condition usually due to a perineal trauma with the formation of an arterio-cavernosal fistula between a cavernosal artery and the lacunar spaces of the penis. High-flow priapism is usually diagnosed by clinical examination and color Doppler ultrasound, and the gold standard therapeutic management is represented by digital subtraction angiography. We report a case of a young patient with high-flow priapism after a motorcycle blunt perineal trauma, examining in detail the specific color Doppler ultrasound findings, the diagnostic workup and the therapeutic management.

Ultrasound of scrotal and penile emergency: how, why and when.

High-resolution ultrasound is the most common imaging technique used to supplement the physical examination of scrotum and penis with great accuracy in assisting the diagnosis of the various pathologies of male genital system, with the highest diagnostic potential in emergency conditions. Technical advancements in real-time high-resolution, color flow Doppler sonography and contrast enhanced ultrasonography (CEUS) have led to an increase in the clinical applications of scrotal and penile sonography. In this pictorial review we focus on common and uncommon male genitalia emergency with special emphasis on the role of ultrasound assessment and its specific findings to improve diagnostic accuracy.

Acute Aortic Syndromes: Diagnostic and Therapeutic Pathways.

Acute aortic syndromes are life-threatening medical conditions that include classic acute aortic dissection (AAD), aortic intramural hematoma, penetrating aortic ulcer, and even aortic pseudoaneurysm and traumatic aortic injury. The European Society of Cardiology has designed a multiparametric diagnostic algorithm to provide stepwise diagnosis. All patients with AAD should receive aggressive medical therapy to control blood pressure and heart rate. Urgent surgical repair is recommended for type A AAD. Uncomplicated type B AAD requires aggressive medical therapy. In contrast thoracic endovascular repair is recommended for complicated type B. AAD should be considered a lifelong disease that affects the entire aorta.

Secondary Neurolymphomatosis of the Radial Nerve: A Diagnostic Challenge.

BACKGROUND Secondary neurolymphomatosis is a rare clinical condition that may be observed in patients with hematologic malignancies. Clinical findings can overlap with other conditions. Diagnosis can be obtained by magnetic resonance imaging (MRI) and imaging with positron emission tomography (PET) and confirmed by biopsy. CASE REPORT A 55-year-old male patient with known previous history of periocular non-Hodgkin's lymphoma mucosa-associated lymphoid tissue (MALT) type presented reporting he had a focal soft-tissue swelling mass on the external side of the right arm, suspected for lipoma. US, MRI, and FDG PET/CT were performed, revealing malignant imaging characteristics of the lesion, suspected to be a neurolymphoma. A biopsy confirmed the nature of the lesion. No further sites of malignancy were detected on whole-body PET/CT. CONCLUSIONS Lymphomatous involvement of peripheral nerves may clinically overlap with other, more common, benign conditions; therefore, although it is rarer, this diagnosis has to be considered in patients with a clinical history of hematologic malignancies.

Ultrasonographic and multimodal imaging of pediatric genital female diseases.

Ultrasonography is the first-line imaging modality in the evaluation of the female pelvis in childhood and adolescence, because it is easy to perform, non-invasive and it does not require sedation. The transabdominal approach is preferred in children and adolescents, after filling the bladder to move away the bowel loops from the pelvis. The probe frequency must be adapted to age, thickness of tissues and depth of the structures under examination. High-frequency (4-12 MHz) linear or convex probes are used in newborns; high-frequency linear probes (4-12 MHz) in toddler, convex 5-7.5 MHz probes in girls and convex 3.5-5 MHz probes in teenagers. In this article, the main pathological conditions of the genital female tract in pediatric age are examined, such as congenital anomalies, disorders of sex development, ovarian cysts, ovarian tumors, adnexal torsion, primary amenorrhea, precocious puberty and pelvic inflammatory disease.

Pediatric musculoskeletal ultrasound: a pictorial essay.

Ultrasound (US) is the main imaging modality for the evaluation of pediatric patients with musculoskeletal diseases; particularly, it is an appropriate and reliable tool for diagnosis, follow-up and treatment of several musculoskeletal pathologies affecting the pediatric age. High-frequency (10-15 MHz) and high-resolution probes provide very lofty quality images, allowing a detailed study of the pediatric musculoskeletal system. Among the well-known advantages of this technique-such as the absence of ionizing radiations, its low cost and wide availability-US can as well rely on some intrinsic characteristics of the pediatric musculoskeletal system that can improve its diagnostic capability. The unossified portions of the pediatric skeleton and the absence of a thickened adipose tissue allow US to be highly effective and reliable in the study of muscles, tendons and cartilage. Lower-frequency sectoral transducers can be required in the study of some joints such as the shoulder or the hip, as well as in the examination of deep soft-tissue lesions. Furthermore, both color and spectral Doppler play an important role in the examination of soft-tissue lesions and synovial phlogosis. In this pictorial essay the main pathological conditions of pediatric musculoskeletal system will be examined, such as painful hip, evolutionary hip dysplasia, osteochondrosis, trauma-related pathologies and juvenile idiopathic arthritis.