MRI Appearance of Focal Lesions in Liver Iron Overload

Liver iron overload is defined as an accumulation of the chemical element Fe in the hepatic parenchyma that exceeds the normal storage. When iron accumulates, it can be toxic for the liver by producing inflammation and cell damage. This can potentially lead to cirrhosis and hepatocellular carcinoma, as well as to other liver lesions depending on the underlying condition associated to liver iron overload. The correct assessment of liver iron storage is pivotal to drive the best treatment and prevent complication. Nowadays, magnetic resonance imaging (MRI) is the best non-invasive modality to detect and quantify liver iron overload. However, due to its superparamagnetic properties, iron provides a natural source of contrast enhancement that can make challenging the differential diagnosis between different focal liver lesions (FLLs). To date, a fully comprehensive description of MRI features of liver lesions commonly found in iron-overloaded liver is lacking in the literature. Through an extensive review of the published literature, we aim to summarize the MRI signal intensity and enhancement pattern of the most common FLLs that can occur in liver iron overload

Reduction of Metal Artifacts Caused by Titanium Peduncular Screws in the Spine by Means of Monoenergetic Images and the Metal Artifact Reduction Software in Dual-Energy Computed Tomography

Objectives: To evaluate the reduction of metal artifacts in patients with titanium peduncular screws in the spine using (1) conventional images (CI), (2) virtual monoenergetic reconstructions (VMRs), and (3) VMR + Metal Artifact Reduction Software (VMR + MARS), with dual-energy computed tomography (DECT). Materials and Methods: Twenty-four patients with titanium peduncular screws in the spine were studied using a 64-channel DECT. During the postprocessing phase, the CI, the VMRs from 100 to 140 keV, and the VMR at 140 keV + MARS were synthesized. All the images were considered, and a quantitative evaluation was performed measuring the attenuation values (in terms of Hounsfield Units) with region of interest, in correspondence with the most hyperdense and hypodense artifacts. All the values were then compared. A qualitative evaluation, in terms of image quality and extent of artifacts, was also performed by two radiologists. Results: In quantitative terms, the 140 keV + MARS reconstruction was able to significantly reduce both bright and dark metal artifacts, compared to CI and to VMRs. The VMR was capable of significantly reducing both dark and bright artifacts, compared to CI. In qualitative terms, the VMR at 140 keV proved to be the best, compared to CI and VMR + MARS images. Conclusions: The VMR + MARS image reduces metal artifacts from titanium peduncular screws more than VMRs alone and CI. Furthermore, the VMR can decrease metal artifacts from a quantitative and a qualitative point of view. Combining information from VMRs and VMR + MARS images could be the best way to solve the issue of metal artifacts on computed tomography images

Pseudoaneurysm of the splenic artery mimicking a solid lesion

A 64-year-old man presented to the hospital because of hematemesis; on admission, he had weakness and pale skin, tachycardia and hypotension. Laboratory tests revealed severe anemia (hemoglobin 7.8 g/dL); liver, renal and pancreatic function tests were normal. An upper digestive endoscopy revealed a gastric ulcer of the cardia, treated with metallic clips and adrenalin injection. The patient was treated with fluids and was transfused with three units of red blood cells. In the previous two months, due to the presence of bloating and diarrhea, associated with abdominal distension, a colon-computed tomography (CT) revealed a large retroperitoneal hypodense mass, 53x37 mm in size, without contrast enhancement localized between the body and the tail of the pancreas and the stomach, near the splenic artery and without signs of infiltration. To better define the mass, endoscopic ultrasound and biopsy were performed; however histopathology of multiple biopsies was not diagnostic, because of the presence of necrotic tissue and inflammatory cells. Since hematemesis recurred, the patient underwent a second upper digestive endoscopic examination, but no source of bleeding was found. Then a new contrast enhanced CT was performed that showed a size reduction of the mass, the presence of blood in the stomach and a small pseudoaneurysm of the splenic artery. Because of these findings an angiograpghic study was carried out; angiography confirmed a splenic artery pseudoaneurysm that was successfully embolized with metal microcoils

An asymptomatic detachment of the appendix evolved to giant abscess and complete colliquative necrosis: pivotal role of computed tomography in patient management

Acute appendicitis (AA) is one of the most common causes of acute abdominal pain and it generally affects young males in the second or third decade of their life. Due to its often insidious presentations, the diagnosis is challenging and, if delayed, can lead to life-threatening complications. This report describes a rare case of an almost asymptomatic complicated appendicitis caused by an appendicolith followed by spontaneous detachment of the vermiform appendix and its complete colliquative necrosis with abscess formation. Thus far this is the first case of spontaneous appendix avulsion in an adult where the appendix is entirely colliquated into an abscess

Clinical Application of Diffusion Tensor Imaging for a Brachial Plexus Injury

Brachial plexus injuries are commonly diagnosed clinically, as conventional imaging has a low sensitivity. In recent years, diffusion tensor imaging has established a clinical role in the study of the central nervous system and, while still presenting some limitations due to the technical complexity of the acquisition method, is showing promising results when applied to peripheral nerves. Moreover, deterministic fiber tracking with the Euler's method and multishell acquisition are two novel advances in the field which contribute to enhancing the reliability of the technique reducing the respiratory and inhomogeneity artifacts in this "magnetically complex" region, and better isolating the fibers in a heterogeneous territory. Here, we report a case of brachial plexus traumatic injury, a healthy reference subject, and details on the acquisition protocol of the reconstruction algorithm

The role of MRI in the detection of local recurrence: Added value of multiparametric approach and Signal Intensity/Time Curve analysis

Objective: The aim of the study was to evaluate the accuracy of multiparametric Magnetic Resonance Imaging (mpMRI) in the detection of local recurrence of prostate cancer (PCa) with the evaluation of the added value of signal Intensity/Time (UT) curves.Materials and methods: A retrospective analysis of 22 patients undergoing mpMRI from 2015 to 2020 was carried out, with the following inclusion criteria: performing trans rectal ultrasound guided biopsy within 3 months in the case of positive or doubtful findings and undergoing biopsy and/or clinical follow-up for 24 months in the case of negative results. The images were reviewed, and the lesions were catalogued according to morphological, diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) features.Results: The presence of local recurrence was detected in 11/22 patients (50%). Greater diameter, hyperintensity on DWI, positive contrast enhancement and type 2/3 signal UT curves were more frequently observed in patients with local recurrence (all p < 0.05). Of all the sequences, DCE was the most accurate; however, the combination of DCE and DWI showed the best results, with a sensitivity of 100%, a specificity of 82%, a negative predictive value of 100% and a positive predictive value of 85%.Conclusions: The utility of MRI in the detection of local recurrence is tied to the multiparametric approach, with all sequences providing useful information. A combination of DCE and DWI is particularly effective. Moreover, specificity could be additionally improved using analysis of the signal UT curves

Initiative on Superselective Conventional Transarterial Chemoembolization Results (INSPIRE)

Several publications show that superselective conventional TransArterial ChemoEmbolization (cTACE), meaning cTACE performed selectively with a microcatheter positioned as close as possible to the tumor, improves outcomes, maximizing the anti-tumoral effect and minimizing the collateral damages of the surrounding liver parenchyma. Recent recommendations coming from the European Association for the Study of the Liver (EASL) and European Society of Medical Oncology (ESMO) highlighted that TACE must be used in Hepatocellular Carcinoma (HCC) "selectively targetable" and "accessible to supraselective catheterization." The goal of the manuscript is to better define such population and to standardize superselective cTACE (ss-cTACE) technique. An expert panel with extensive clinical-procedural experience in TACE, have come together in a virtual meeting to generate recommendations and express their consensus. Experts recommend that anytime cTACE is proposed, it should be ss-cTACE, preferably with a 1.5-2.0 Fr microcatheter. Ideally, ss-cTACE should be proposed to patients with less than five lesions and a maximum number of two segments involved, with largest tumor smaller than 5 cm. Angio Cone-Beam Computed Tomography (CBCT) should be used to detect enhancing tumors, tumor feeders and guide tumor targeting. Whole tumor volume should be covered to obtain the best response. Adding peritumoral margins is encouraged but not mandatory. The treatment should involve a water-in-oil emulsion, whose quality is assessable with the "drop test." Additional particulate embolization should be systematically performed, as per definition of cTACE procedure. Non-contrast CBCT or Multi-Detector Computed Tomography (MDCT) combined with angiography has been considered the gold standard for imaging during TACE, and should be used to assess tumor coverage during the procedure. Experts convene that superselectivity decreases incidence of adverse effects and improves tolerance. Experts recommend contrast-enhanced Computed Tomography (CT) as initial imaging on first follow-up after ss-cTACE, and Magnetic Resonance Imaging (MRI) if remaining tumor viability cannot be confidently assessed on CT. If no response is obtained after two ss-cTACE sessions within six months, patient must be considered unsuitable for TACE and proposed for alternative therapy. Patients are best served by multidisciplinary decision-making, and Interventional Radiologists should take an active role in patient selection, treatment allocation, and post-procedural care