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.

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.

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.

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.

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.

Accuracy of MDCT in the preoperative definition of Peritoneal Cancer Index (PCI) in patients with advanced ovarian cancer who underwent peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC).

PURPOSE: To evaluate the accuracy of MDCT in the preoperative definition of Peritoneal Cancer Index (PCI) in patients with advanced ovarian cancer who underwent a peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC) after neoadjuvant chemotherapy to obtain a pre-surgery prognostic evaluation and a prediction of optimal cytoreduction surgery. MATERIALS AND METHODS: Pre-HIPEC CT examinations of 43 patients with advanced ovarian cancer after neoadjuvant chemotherapy were analyzed by two radiologists. The PCI was scored according to the Sugarbaker classification, based on lesion size and distribution. The results were compared with macroscopic and histologic data after peritonectomy and HIPEC. To evaluate the accuracy of MDCT to detect and localize peritoneal carcinomatosis, both patient-level and regional-level analyses were conducted. A correlation between PCI CT and histologic values for each patient was searched according to the PCI grading. RESULTS: Considering the patient-level analysis, CT shows a sensitivity, specificity, PPV, NPV, and an accuracy in detecting the peritoneal carcinomatosis of 100 %, 40 %, 93 % 100 %, and 93 %, respectively. Considering the regional level analysis, a sensitivity, specificity, PPV, NPV, and diagnostic accuracy of 72 %, 80 %, 66 %, 84 %, and 77 %, respectively were obtained for the correlation between CT and histology. CONCLUSION: Our results encourage the use of MDCT as the only technique sufficient to select patients with peritoneal carcinomatosis for cytoreductive surgery and HIPEC on the condition that a CT examination will be performed using a dedicated protocol optimized to detect minimal peritoneal disease and CT images will be analyzed by an experienced reader.

Differences in perfusion CT parameter values with commercial software upgrades: a preliminary report about algorithm consistency and stability.

BACKGROUND: Computed tomographic perfusion (CTp) imaging is a promising technique that allows functional imaging, as an adjunct to a morphologic CT examination, that can be used as an aid to carefully evaluate the response to therapy in oncologic patients. Considering this statement, it could be desirable that the measurements obtained with the CT perfusion software, and their upgrades, are consistent and reproducible. PURPOSE: To determine how commercial software upgrades impact on algorithm consistency and stability among the three version upgrades of the same platform in a preliminary study. MATERIAL AND METHODS: Blood volume (BV), blood flow (BF), mean transit time (MTT), and permeability surface area product (PS) were calculated with repeated measurements (n = 1119) while truncating the time density curve at different time values in six CT perfusion studies using CT perfusion software version 4D (CT Perfusion 4D), then repeated with the previous version (CT Perfusion 3.0 and CT Perfusion 4.0), using a fixed ROI both for arterial input and target lesion. The software upgrades were compared in pairs by applying a Kolmogorov-Smirnov test to all the parameters measured. Stability and reliability of the three versions were verified through the variation of the truncated parameters. RESULTS: The three software versions provided different parent distributions for approximately 80% of the 72 parameters measured. A complete agreement was found only for one patient in version 3.0 vs. 4.0 and 3.0 vs. 4D. Perfusion 4.0 vs. 4D: a complete agreement was found only in two cases. Parameters obtained with Perfusion 4D always showed the lowest standard deviation in all temporal intervals and also for all individual parameters. CONCLUSION: The three versions of the same platform tested yield different perfusion measurements. Thus, our preliminary results show that Perfusion 4D version uses a stable deconvolution algorithm to provide more reliable measurements.

[Quantitative CT perfusion measurements in characterization of solitary pulmonary nodules: new insights and limitations]. / La perfusione con TC nella caratterizzazione del nodulo polmonare solitario: possibilità e limiti in uno studio preliminare.

Although computed tomography (CT) scans remain the basis of morphologic evaluation in the characterization of solitary pulmonary nodules (SPNs), perfusion CT can represent an additional feasible technique offering reproducible measurements, at least in SPNs with a diameter >10 mm. In particular, CT perfusion could reduce the number of SPNs, diagnosed as undetermined at morphologic CT, avoiding long term follow-up CT, FDG-PET studies, biopsy or unnecessary surgery with a significant reduction in healthcare costs. In order to reduce the radiation dose, an optimization of the CT perfusion protocol could be obtained using axial mode acquisition, using shorter acquisition time and adaptative statistical iterative reconstruction algorithm.

Computed tomographic evaluation of mesentery: diagnostic value in acute mesenteric ischemia.

OBJECTIVE: To evaluate the computed tomographic appearances of mesentery in acute mesenteric ischemia (AMI) to recognize characteristic features and their prognostic values. METHODS: Computed tomographic examinations of 34 patients with a confirmed diagnosis of AMI were retrospectively reviewed to evaluate the number of mesenteric vessels, diameter of the superior mesenteric artery and superior mesenteric vein, mesenteric fat stranding, mesenteric vessel pneumatosis and ascites. RESULTS: Overall, at least one of these mesenteric signs was present in all but 1 patient. In all AMI of arterial occlusive type and in 68% of nonocclusive mesenteric ischemia, the number of arterial vessels was reduced (P = 0.067). Mesenteric vessel pneumatosis and reduced number of venous vessels were significantly associated with higher mortality (P = 0.027 and P = 0.042, respectively). Reperfusion signs were associated with a reduced mortality (28.7% vs 65.5%). CONCLUSION: Considering its characteristic features and its possible prognostic value, the evaluation of mesentery will supply additional information in the interpretation of computed tomography in AMI.

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.

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.

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.

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.

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.

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.

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.

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.

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.