Diagnostic Role of Multi-Detector Computed Tomography in Acute Mesenteric Ischemia.

Mesenteric ischemia diagnosis is challenging, with an overall mortality of up to 50% of cases despite advances in treatment. The main problem that affects the outcome is delayed diagnosis because of non-specific clinical presentation. Multi-Detector CT Angiography (MDCTA) is the first-line investigation for the suspected diagnosis of vascular abdominal pathologies and the diagnostic test of choice in suspected mesenteric bowel ischemia. MDCTA can accurately detect the presence of arterial and venous thrombosis, determine the extent and the gastrointestinal tract involved, and provide detailed information determining the subtype and the stage progression of the diseases, helping clinicians and surgeons with appropriate management. CT (Computed Tomography) can differentiate forms that are still susceptible to pharmacological or interventional treatment (NOM = non-operative management) from advanced disease with transmural necrosis in which a surgical approach is required. Knowledge of CT imaging patterns and corresponding vascular pathways is mandatory in emergency settings to reach a prompt and accurate diagnosis. The aims of this paper are 1. to provide technical information about the optimal CTA (CT Angiography) protocol; 2. to explain the CTA arterial and venous supply to the gastrointestinal tract and the relevant ischemic pattern; and 3. to describe vascular, bowel, and extraintestinal CT findings for the diagnosis of acute mesenteric ischemia.

Management of Giant Pulmonary Artery Aneurysm with Quadricuspid Valve Stenosis.

The pulmonary artery aneurysm (PAA) is a rare disease with no well-defined guidelines about the diagnostic criteria and its management. In fact, the indications for surgical treatment and the type of surgical approach are not clear. However, in case of giant PAAs with hypertension and pulmonary valve abnormalities, surgery should be considered as an effective and safe approach to prevent dissections or ruptures. In this report, we describe a successful case of surgical repair, using a Bioconduit with a pericardial patch to recreate the pulmonary artery bifurcation in a 72-year-old male with aneurysm of the pulmonary artery (max diameter: 72 mm), associated with quadricuspid pulmonary valve stenosis and pulmonary hypertension. The procedure was uncomplicated and the follow-up computed tomography scan at 4 months showed correct positioning of the graft with no sign of contrast leakage.

Mission analysis, dynamics and robust control of an indoor blimp in a CERN detector magnetic environment.

At the European Organization for Nuclear Research (CERN), a Research and Development (R&D) program studies robotic systems for inspection and maintenance of the next-generation of particle detectors. The design and operation of these systems are affected by the detector's cavern harsh environment consisting of high magnetic fields and radiations. This work presents a feasibility study for aerial inspection and mapping around a CERN particle detector using a robotic Lighter-than-Air (LtA) Unmanned Aerial Vehicle (UAV), specifically a blimp. Firstly, mission scenarios and the detector environment are introduced; in this context a new empirical model is proposed for the estimation of magnetic disturbances resulting from the interaction of electromagnetic motors with the external magnetic field. Subsequently, the design of a reference blimp and the control system is presented, comparing different control techniques, namely, Computed Torque Control (CTC), Sliding Mode Control (SMC) and Nonsingular Terminal Sliding Mode Control (NTSMC). Finally, the results of trajectory tracking simulations are reported, considering both the uncertainties of the dynamic parameters and the estimated magnetic disturbances. This work demonstrates that the blimp successfully follows desired trajectory, navigating complex environments while maintaining stability and accuracy. Despite the challenges posed by high magnetic fields, indoor blimps can effectively offer safer and more efficient approaches to facility surveillance and maintenance, reducing radiation exposure for human personnel and minimizing detector downtime.

Pleuroparenchymal Fibroelastosis-like Lesions in Clinical Practice: A Rare Entity? Review of a Radiological Database.

Background: Pleuroparenchymal Fibroelastosis (PPFE) is a rare disease that consists of elastofibrosis that involves the pleura and subpleural lung parenchyma; it is an unusual pulmonary disease with unique clinical, radiological and pathological characteristics. According to recent studies, PPFE may not be a definite disease but a form of chronic lung injury. The aim of this retrospective study is to determine the incidence and to evaluate the distribution, severity and progression of this radiological entity on high-resolution CT (HRCT) exams of the chest, performed in routine clinical practice. In total, 1514 HRCT exams performed in the period January 2016-June 2018 were analyzed. For each exam, the presence of PPFE was evaluated and a quantitative score was assigned (from 0 to 7 points, based on the maximum depth of fibrotic involvement of the parenchyma). When available, two exams with a time interval of at least 6 months were compared for each patient in order to evaluate progression (defined as the increase in the disease score). Patients were divided into different groups according to exposure and their associated diseases. Statistical analysis was performed by using the Wilcoxon test and Kruskal-Wallis test. Results: PPFE was detected in 174 out of 1514 patients (11.6%), with a mean score of 6.1 ± 3.9 (range 1-14). In 106 out of 174 patients (60.9%), a previous CT scan was available and an evolution of PPFE was detected in 19 of these (11.5%). Among these 19 patients with worsening PPFE, 4 had isolated PPFE that was associated with chronic exposure or connective tissue disorders, and the other 15 had an associated lung disease and/or a chronic exposure. In this group, it was found that the ventral segments of the upper lobes, fissures and apical segments of the lower lobes had a greater statistically significant involvement in the progression of the disease compared to the non-progressive group. In 16 of 174 patients (9.2%, 7 of which belonged to the radiological progression group) a biopsy through video-assisted thoracoscopic surgery or apicoectomy confirmed PPFE. Conclusion: PPFE-like lesions are not uncommon on HRCT exams in routine clinical practice, and are frequently found in patients with different forms of chronic lung injury. Further studies are necessary to explain why the disease progresses in some cases, while in most, it remains stationary over time.

Non-occlusive mesenteric ischemia (NOMI) and prognostic signs at CT: reperfusion or not reperfusion that is the question!

PURPOSE: Non-occlusive mesenteric ischemia (NOMI) is a misdiagnosed and dangerous condition. To our knowledge, a comprehensive evaluation of CT parameters that can predict the outcome of patients suffering from NOMI is still missing. MATERIALS AND METHODS: Contrast-enhanced CT examination of 84 patients with a confirmed diagnosis of NOMI (37 with clinical and laboratory confirmation and 47 biopsy or surgery proven) was retrospectively reviewed by assessing vessels, mesentery, bowel, and peritoneal cavity CT quantitative and dichotomous parameters, and data were analyzed with Fisher's test. Diameter of superior mesenteric artery (SMA), celiac trunk (CT), inferior vena cava (IVC), superior mesenteric vein (SMV), and differences in CT HU (Delta HU) of the bowel wall before and after intravenous contrast media (ICM) administration were correlated to the patients' outcome using ANOVA test. Receiver operating characteristic (ROC) curves were elaborated after a binary logistic regression was performed. RESULTS: Increased number and diameter of vessels, bowel wall thickening, and hypervascularity were more frequent in patients with good prognosis. Conversely, pale mesentery, paper thin, hypovascularity, and aeroportia were more frequent in patients with bad prognosis. A significant correlation between diameters of SMA, CT, IVC, IMA, and SMV and outcome was found at univariate analysis. Also Delta HU resulted to be correlated with the outcome. At multivariate analysis only IVC and Delta HU were significant (p = 0.038 and 0.01) and the combined AUC resulted in 0.806 (CI 0.708-0.903). CONCLUSION: Dichotomous signs of reperfusion and quantitative CT parameters can predict the outcome of patients with NOMI. In particular the combination of IVC diameter and Delta HU of bowel wall allows to predict the prognosis with the highest accuracy.

Comparison of indocyanine green fluorescence lymphangiography and magnetic resonance lymphangiography to investigate lymphedema of the extremities.

PURPOSE: The aim of this study is to compare two dynamic imaging modalities employed to study peripheral lymphatic system, Magnetic Resonance Lymphangiography (MRL) and Indocyanine Green Lymphangiography (ICGL), evaluating their role for planning lymphaticovenular anastomosis (LVA) or other surgical-nonsurgical treatments in patients with lymphedema of the extremities. MATERIALS AND METHODS: We conducted a retrospective study of 32 patients (26 women) with a mean age of 38 years (range 18-73) enrolled from January 2014 to December 2018; 20 out of 32 were affected by lower limb lymphedema with 6 cases of primary lymphedema; all of them had stage II disease. All the patient underwent ICGL and MRL within a month of one another, by injecting different contrast medium into interdigital web spaces. In each patient we rated the number of lymphatic vessels visualized, considering the wrist for the upper limb and the ankle for the lower limb. Student's t-test was applied. RESULTS: All patients completed both the diagnostic examinations without any significant complications. A statistically significant difference (p < 0.05) was found between the number of lymphatic vessels identified on the wrist/ankle (34 on ICGL vs 70 on MRL and 82 on ICGL vs 26 on MRL, considering affected and healthy limbs respectively). In particular, dermal backflow in advanced lymphedema seems to hinder lymphatic vessels detection on ICGL. Conversely, on healthy limbs, MRL hardly identifies lymphatics, because of their fast lymphatic flow and almost virtual lumen. CONCLUSIONS: Both MRL and ICGL are dynamic diagnostic modalities that permit an effective evaluation of lymphatic vessels anatomical and functional status in extremities lymphedema these diagnostic procedures may be considered complementary because they show different aspects of lymphatic system. KEY WORDS: Indocyanine green, MR lymphangiography.

Advancement in Diagnostic Imaging of Thymic Tumors.

Thymic tumors are rare neoplasms even if they are the most common primary neoplasm of the anterior mediastinum. In the era of advanced imaging modalities, such as functional MRI, dual-energy CT, perfusion CT and radiomics, it is possible to improve characterization of thymic epithelial tumors and other mediastinal tumors, assessment of tumor invasion into adjacent structures and detection of secondary lymph nodes and metastases. This review aims to illustrate the actual state of the art in diagnostic imaging of thymic lesions, describing imaging findings of thymoma and differential diagnosis.

Magnetic resonance lymphangiography: with or without contrast?

Lymphedema is an important medical issue around the world, caused by an anomalous collection of fluid in soft tissue due to congenital malformations or stenosis or obstruction of lymphatic vessels. Magnetic resonance lymphangiography (MRL) is an emerging technique focused on noninvasive or minimally invasive imaging of lymphatics with the goal to diagnose and treat lymphedema. This review will briefly discuss lymphatic imaging starting with lymphography and radionuclide lymphoscintigraphy up to the newest methods, focusing on MRL, a rising technique, and highlighting the technical aspects fundamental for achieving high-resolution MRL.

Feasibility, Image Quality and Clinical Evaluation of Contrast-Enhanced Breast MRI Performed in a Supine Position Compared to the Standard Prone Position.

BACKGROUND: To assess the feasibility, image quality and diagnostic value of contrast-enhanced breast magnetic resonance imaging (MRI) performed in a supine compared to a prone position. METHODS: One hundred and fifty-one patients who had undergone a breast MRI in both the standard prone and supine position were evaluated retrospectively. Two 1.5 T MR scanners were used with the same image resolution, sequences and contrast medium in all examinations. The image quality and the number and dimensions of lesions were assessed by two expert radiologists in an independent and randomized fashion. Two different classification systems were used. Histopathology was the standard of reference. RESULTS: Two hundred and forty MRIs from 120 patients were compared. The analysis revealed 134 MRIs with monofocal (U), 68 with multifocal (M) and 38 with multicentric (C) lesions. There was no difference between the image quality and number of lesions in the prone and supine examinations. A significant difference in the lesion extension was observed between the prone and supine position. No significant differences emerged in the classification of the lesions detected in the prone compared to the supine position. CONCLUSIONS: It is possible to perform breast MRI in a supine position with the same image quality, resolution and diagnostic value as in a prone position. In the prone position, the lesion dimensions are overestimated with a higher wash-in peak than in the supine position.

MRL as one-shot examination for patients suffering from lymphedema.

MR lymphangiography (MRL) is an emerging technique focalized on a noninvasive or minimally invasive imaging of lymphatics with the goal to treat and plan lymphedema. Doctor Cellina M. and colleagues clearly underlined the possible role of MRL with volume calculation as an objective mark also in evaluating response to treatment. In this Letter to the Editor, we would like to highlight the rising role of MRL, pointing out the advantages of both the non-contrast and contrast-enhanced approach, in lymphatic vessels study.

Non-occlusive Mesenteric Ischemia as a Fatal Complication in Acute Pancreatitis: A Brief Radiological Comment.

Non-occlusive mesenteric ischemia (NOMI) is the result of the reduction of mesenteric blood supply, due to mesenteric arterial vasoconstriction secondary to hypotension in cases of shock, septicemia, dehydration, heart surgery, or major abdominal surgery. NOMI represents a complex and often misdiagnosed syndrome. Imaging, and in particular CT, has a remarkable importance in NOMI, and despite its complexity, it could allow an early diagnosis and an improved management resulting in life-threatening therapeutic approaches, much better than in the past, provided it is correctly performed and interpreted by experienced radiologists.

Dual energy CT in gland tumors: a comprehensive narrative review and differential diagnosis.

Dual energy CT (DECT)with image acquisition at two different photon X-ray levels allows the characterization of a specific tissue or material/elements, the extrapolation of virtual unenhanced and monoenergetic images, and the quantification of iodine uptake; such special capabilities make the DECT the perfect technique to support oncological imaging for tumor detection and characterization and treatment monitoring, while concurrently reducing the dose of radiation and iodine and improving the metal artifact reduction. Even though its potential in the field of oncology has not been fully explored yet, DECT is already widely used today thanks to the availability of different CT technologies, such as dual-source, single-source rapid-switching, single-source sequential, single-source twin-beam and dual-layer technologies. Moreover DECT technology represents the future of the imaging innovation and it is subject to ongoing development that increase according its clinical potentiality, in particular in the field of oncology. This review points out recent state-of-the-art in DECT applications in gland tumors, with special focus on its potential uses in the field of oncological imaging of endocrine and exocrine glands.

Update in diagnostic imaging of the thymus and anterior mediastinal masses.

Anterior mediastinal masses include a wide spectrum of malignant and benign pathologies with a large percentage represented by thymic lesions. Distinguishing these masses on diagnostic imaging is fundamental to guide the proper management for each patient. This review illustrates possibilities and limits of different imaging modalities to diagnose a lesion of the anterior mediastinum with particular attention to thymic disease.

Magnetic resonance imaging of the sacroiliac joints in SpA: with or without intravenous contrast media? A preliminary report.

OBJECT: Active sacroiliitis based on magnetic resonance imaging (MRI) without intravenous (I.V.) contrast material injection is considered sufficient for the diagnosis of spondyloarthritis (SpA), according to the Assessment of SpondyloArthritis International Society (ASAS) criteria. This work shows the added value of administering I.V. contrast material when evaluating the response to tumor necrosis factor (TNF) antagonists therapy, on the extension of bone marrow oedema (BMO) and pathological enhancement (osteitis/synovitis) in the sacroiliac joints (SIJs) on MRI. MATERIALS AND METHODS: Forty-three patients (25 females and 18 males, mean age of 54 ± 16.60 years, range 22-75 years) with a clinical diagnosis of SpA and active sacroiliitis at MRI with I.V. contrast material, were considered for a follow-up MRI after 6 months of TNF antagonists therapy. Disease activity was monitored by a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) questionnaire. Descriptive statistics, Student's t test and Cohen's kappa were used. P < 0.05 was considered statistically significant. RESULTS: Thirty-eight patients were finally included in the study; 36 of them showed an improvement on clinical assessment after therapy. Score's difference (improvement) after treatment was calculated in the MRI sequences both with and without contrast agent (respectively, mean value and range 3.18, 0-12 with contrast and 1.63, 0-7 without contrast). This improvement was statistically significant in each group (P value of 7.097e-08 with contrast and 6.741e-06 without contrast), and there was a significant difference between the two group too (P-value of 8.598e-07). Cohen's kappa for dichotomous variables showed a better agreement between the post-contrast MRI findings and BASDAI (K = 0.53, agreement = 92.11%, P = 0.0001) than MRI without contrast and BASDAI (K = 0.11, agreement = 57.89%, P = 0.06). CONCLUSIONS: The evaluation of enhancement is a reliable tool for the assessment of the response to therapy in SIJs involvement in SpA, better than BMO; hence, it should be advised in the MRI of these patients.

Occupational Lung Diseases: Underreported Diagnosis in Radiological Practice.

Underreporting of occupational lung diseases is a widespread problem in clinical practice. In Europe there is not a common regulation even for the recognition of occupational cancers. Furthermore epidemiologic data on occupational interstitial lung diseases, in general, is limited by no standardized diagnostic criteria, varied physician awareness and training, limitations inherent to the various data sources, and the long latency period. Therefore, to optimize the management of the patient with occupational pathology, the collaboration and skills of the multidisciplinary at the service of the patient, play a fundamental role. In particular, radiologists should give substance to a clinical suspicion on an anamnestic basis and at the same time should recognize patterns of illness that can lead to the emergence of stories of misunderstood exposures. This article aims to provide an overview of the main occupational lung diseases with attention to diagnostic possibilities of the different imaging techniques. The issue of the radiological error is investigated, providing tools to minimize it in the daily practice.

Efficacy of Second-Look Ultrasound with MR Coregistration for Evaluating Additional Enhancing Lesions of the Breast: Review of the Literature.

Contrast enhanced magnetic resonance imaging (CE-MRI) has acquired a central role in the field of diagnosis and evaluation of breast cancer due to its high sensitivity; on the other hand, MRI has shown a variable specificity because of the wide overlap between the imaging features of benign and malignant lesions. Therefore, when an additional breast lesion is identified at CE-MRI, a second look with targeted US is generally performed because it provides additional information to further characterise the target lesion and makes it possible to perform US-guided biopsies which are costless and more comfortable for patients compared with MRI-guided ones. Nevertheless, there is not always a correspondence between CE-MR findings and targeted US due to several factors including different operator's experience and position of patients. A new technique has recently been developed in order to overcome these limitations: US with MR coregistration, which can synchronise a sonography image and the MR image with multiplanar reconstruction (MPR) of the same section in real time. The aim of our study is to review the literature concerning the second look performed with this emerging and promising technique, showing both advantages and limitations in comparison with conventional targeted US.

Gastric Cancer Maximum Tumour Diameter Reduction Rate at CT Examination as a Radiological Index for Predicting Histopathological Regression after Neoadjuvant Treatment: A Multicentre GIRCG Study.

AIM: To investigate the role of maximum tumour diameter (D-max) reduction rate at CT examination in predicting histopathological tumour regression grade (TRG according to the Becker grade), after neoadjuvant chemotherapy (NAC), in patients with resectable advanced gastric cancer (AGC). MATERIALS AND METHODS: Eighty-six patients (53 M, mean age 62.1 years) with resectable AGC (≥T3 or N+), treated with NAC and radical surgery, were enrolled from 5 centres of the Italian Research Group for Gastric Cancer (GIRCG). Staging and restaging CT and histological results were retrospectively reviewed. CT examinations were contrast enhanced, and the stomach was previously distended. The D-max was measured using 2D software and compared with Becker TRG. Statistical data were obtained using "R" software. RESULTS: The interobserver agreement was good/very good. Becker TRG was predicted by CT with a sensitivity and specificity, respectively, of 97.3% and 90.9% for Becker 1 (D-max reduction rate > 65.1%), 76.4% and 80% for Becker 3 (D-max reduction rate < 29.9%), and 70.8% and 83.9% for Becker 2. Correlation between radiological and histological D-max measurements was strongly confirmed by the correlation index (c.i.= 0.829). CONCLUSIONS: D-max reduction rate in AGC patients may be helpful as a simple and reproducible radiological index in predicting TRG after NAC.

Imaging of the thymus in myotonic dystrophy type 1.

The occurrence of thymoma in myotonic dystrophy type 1 (DM1) has been occasionally reported, and an increased risk of tumors has been observed. We performed imaging of the thymus in 22 patients carrying DMPK expansion. Clinical examination and routine instrumental exams were performed at the same time. We observed no thymic abnormalities in 13 subjects, thymic hyperplasia in eight patients, and an invasive thymoma in one case. Subjects with thymic abnormalities did not show peculiarities as regards clinical and electrophysiological features. We observed thymoma in one patient with an expansion in the higher range. Abnormalities of the thymus including hyperplasia and thymoma can be present in DM1, but do not seem to play a major role in DM1 pathogenesis. Further studies are needed to understand if some RNA splicing factors involved in DM1 and influenced by CTG expansion size could have a role in thymocytes proliferation.

High-resolution MR lymphangiography for planning lymphaticovenous anastomosis treatment: a single-centre experience.

PURPOSE: This article illustrates the feasibility of MR lymphangiography (MRL) for imaging lymphatic vessels in patients with lymphedema, its accuracy in distinguishing lymphatic vessels from veins, and its utility for planning Lymphaticovenous anastomosis (LVA) treatment. MATERIALS AND METHODS: We prospectively enrolled 30 patients (24 women, range 18-70, 17 cases of lower limb lymphedema, 6 cases of primary lymphedema). All the patients underwent MRL, using a 1.5T MR unit (Signa Twin Speed Hdxt; GE), after the subcutaneous injection of gadobenate dimeglumine (Gd-BOPTA) with a little dose of lidocaine into the interdigital webs of the dorsal foot or hand. Lymphatic vessels identified for the LVA at MRL were histologically confirmed after surgery. Enhancement of lymphatic vessels and veins at different times after injection of contrast medium and their diameters were measured. RESULTS: A total of 79 lymphatic vessels were clearly identified in 29 patients at MRL; their morphology was tortuous in 22 patients and rectilinear in 7, whereas, the adjacent veins were straight with focal bulging only at the level of venous valve; the enhancement kinetic of the two different structures were different (p < 0.05) but the mean diameter of affected lymphatic vessels was similar to the adjacent veins (p > 0.05). Thirty-four out of 38 specimens of presumed lymphatic vessels at MRL, collected during surgery, resulted positive at the immunoistochemical marker d2-40, with a significant association (Chi-square = 40.421, DF = 1, p < 0.05, contingency coefficent 0.644). One patient had an early complication 1 month after treatment. CONCLUSIONS: MRL is easy and safe to use and combines extensive information on the anatomy and functionality of lymphatic vessels and veins in a single process; therefore, it could be useful in LVA treatment planning and evaluating possible super-microsurgical treatment complications in patients with lymphedema.