A deep learning approach for virtual contrast enhancement in Contrast Enhanced Spectral Mammography.

Contrast Enhanced Spectral Mammography (CESM) is a dual-energy mammographic imaging technique that first requires intravenously administering an iodinated contrast medium. Then, it collects both a low-energy image, comparable to standard mammography, and a high-energy image. The two scans are combined to get a recombined image showing contrast enhancement. Despite CESM diagnostic advantages for breast cancer diagnosis, the use of contrast medium can cause side effects, and CESM also beams patients with a higher radiation dose compared to standard mammography. To address these limitations, this work proposes using deep generative models for virtual contrast enhancement on CESM, aiming to make CESM contrast-free and reduce the radiation dose. Our deep networks, consisting of an autoencoder and two Generative Adversarial Networks, the Pix2Pix, and the CycleGAN, generate synthetic recombined images solely from low-energy images. We perform an extensive quantitative and qualitative analysis of the model's performance, also exploiting radiologists' assessments, on a novel CESM dataset that includes 1138 images. As a further contribution to this work, we make the dataset publicly available. The results show that CycleGAN is the most promising deep network to generate synthetic recombined images, highlighting the potential of artificial intelligence techniques for virtual contrast enhancement in this field.

The Correlation between Morpho-Dynamic Contrast-Enhanced Mammography (CEM) Features and Prognostic Factors in Breast Cancer: A Single-Center Retrospective Analysis.

Breast cancer, a major contributor to female mortality globally, presents challenges in detection, prompting exploration beyond digital mammography. Contrast-Enhanced Mammography (CEM), integrating morphological and functional information, emerges as a promising alternative, offering advantages in cost-effectiveness and reduced anxiety compared to MRI. This study investigates CEM's correlation with breast cancer prognostic factors, encompassing histology, grade, and molecular markers. In a retrospective analysis involving 114 women, CEM revealed diverse lesion characteristics. Statistical analyses identified correlations between specific CEM features, such as spiculated margins and irregular shape, and prognostic factors like tumor grade and molecular markers. Notably, spiculated margins predicted lower grade and HER2 status, while irregular shape correlated with PgR and Ki-67 status. The study emphasizes CEM's potential in predicting breast cancer prognosis, shedding light on tumor behavior. Despite the limitations, including sample size and single-observer analysis, the findings advocate for CEM's role in stratifying breast cancers based on biological characteristics. CEM features, particularly spiculated margins, irregular shape, and enhancement dynamics, may serve as valuable indicators for personalized treatment decisions. Further research is crucial to validate these correlations and enhance CEM's clinical utility in breast cancer assessment.

Contrast-Enhanced Mammography-Guided Biopsy: Preliminary Results of a Single-Center Retrospective Experience.

Background: CEM-guided breast biopsy is an advanced diagnostic procedure that takes advantage of the ability of CEM to enhance suspicious breast lesions. The aim pf this paper is to describe a single-center retrospective experience on CEM-guided breast biopsy in terms of procedural features and histological outcomes. Methods: 69 patients underwent the procedure. Patient age, breast density, presentation, dimensions, and lesion target enhancement were recorded. All the biopsy procedures were performed using a 7- or 10-gauge (G) vacuum-assisted biopsy needle. The procedural approach (horizontal or vertical) and the decubitus of the patient (lateral or in a sitting position) were noted. Results: A total of 69 patients underwent a CEM-guided biopsy. Suspicious lesions presented as mass enhancement in 35% of cases and non-mass enhancement in 65% of cases. The median size of the target lesions was 20 mm. The median procedural time for each biopsy was 10 ± 4 min. The patients were placed in a lateral decubitus position in 52% of cases and seated in 48% of cases. The most common approach was horizontal (57%). The mean AGD was 14.8 mGy. At histology, cancer detection rate was 28% (20/71). Conclusions: CEM-guided biopsy was feasible, with high procedure success rates and high tolerance by the patients.

Fat Matters: Exploring Cancer Risk through the Lens of Computed Tomography and Visceral Adiposity.

Obesity is an established risk factor for cancer. However, conventional measures like body mass index lack precision in assessing specific tissue quantities, particularly of the two primary abdominal fat compartments, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Computed tomography (CT) stands as the gold standard for precisely quantifying diverse tissue types. VAT, distinguished by heightened hormonal and metabolic activity, plays a pivotal role in obesity-related tumor development. Excessive VAT is linked to aberrant secretion of adipokines, proinflammatory cytokines, and growth factors, fostering the carcinogenesis of obesity-related tumors. Accurate quantification of abdominal fat compartments is crucial for understanding VAT as an oncological risk factor. The purpose of the present research is to elucidate the role of CT, performed for staging purposes, in assessing VAT (quantity and distribution) as a critical factor in the oncogenesis of obesity-related tumors. In the field of precision medicine, this work takes on considerable importance, as quantifying VAT in oncological patients becomes fundamental in understanding the influence of VAT on cancer development-the potential "phenotypic expression" of excessive VAT accumulation. Previous studies analyzed in this research showed that VAT is a risk factor for clear cell renal cell carcinoma, non-clear cell renal cell carcinoma, prostate cancer, and hepatocarcinoma recurrence. Further studies will need to quantify VAT in other oncological diseases with specific mutations or gene expressions, in order to investigate the relationship of VAT with tumor genomics.

Visceral adiposity in patients with lipomatous hypertrophy of the interatrial septum.

Lipomatous hypertrophy of the interatrial septum (LHIS) is a benign cardiac mass determined by abnormal deposition of adipose tissue in the interatrial septum. The quantitative relationship between LHIS and visceral adiposity has not been explored to date.In this retrospective study, three groups of consecutive patients undergoing CT imaging were enrolled: L + with LHIS, L- without LHIS, and LO- without both LHIS and history of malignancies. Areas of total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and LHIS areas were calculated on CT images. The relationship between LHIS and abdominal fat distribution was investigated with linear regression models. Bonferroni correction was applied to account for multiple testing. Statistical significance was set at 5%. In this study we enrolled a total of 175 subjects: 58 (33.14%) with LHIS (L +), 51(29.14%) without LHIS (L-) and 66 (37.71%) without both LHIS and medical history of malignancies (LO-). VAT (coeff: 105.82; 95% CI 59.37-152.27), SAT (coeff: 74.59; 95% CI 31.63-117.54), and TAT (coeff: 190.37; 95% CI 115.02-265.72), were significantly higher in L + patients. Moreover, VAT (coeff: 24.95; 95% CI 6.94-42.96) and TAT (coeff: 36.58; 95% CI 8.75-64.41) were statistically significant linear predictors for LHIS area. Here, we report a novel association between LHIS and visceral adiposity using a quantitative CT-based imaging approach. The results are of great importance also because they might drive early identification of subjects with LHIS at risk for visceral obesity, and trigger lifestyle interventions aimed at weight loss.

Can Machine Learning Models Detect and Predict Lymph Node Involvement in Prostate Cancer? A Comprehensive Systematic Review.

(1) Background: Recently, Artificial Intelligence (AI)-based models have been investigated for lymph node involvement (LNI) detection and prediction in Prostate cancer (PCa) patients, in order to reduce surgical risks and improve patient outcomes. This review aims to gather and analyze the few studies available in the literature to examine their initial findings. (2) Methods: Two reviewers conducted independently a search of MEDLINE databases, identifying articles exploring AI's role in PCa LNI. Sixteen studies were selected, and their methodological quality was appraised using the Radiomics Quality Score. (3) Results: AI models in Magnetic Resonance Imaging (MRI)-based studies exhibited comparable LNI prediction accuracy to standard nomograms. Computed Tomography (CT)-based and Positron Emission Tomography (PET)-CT models demonstrated high diagnostic and prognostic results. (4) Conclusions: AI models showed promising results in LN metastasis prediction and detection in PCa patients. Limitations of the reviewed studies encompass retrospective design, non-standardization, manual segmentation, and limited studies and participants. Further research is crucial to enhance AI tools' effectiveness in this area.

Imaging of knee osteoarthritis: a review of multimodal diagnostic approach.

Knee osteoarthritis (KOA) is a common chronic condition among the elderly population that significantly affects the quality of life. Imaging is crucial in the diagnosis, evaluation, and management of KOA. This manuscript reviews the various imaging modalities available until now, with a little focus on the recent developments with Artificial Intelligence. Currently, radiography is the first-line imaging modality recommended for the diagnosis of KOA, owing to its wide availability, affordability, and ability to provide a clear view of bony components of the knee. Although radiography is useful in assessing joint space narrowing (JSN), osteophytes and subchondral sclerosis, it has limited effectiveness in detecting early cartilage damage, soft tissue abnormalities and synovial inflammation. Ultrasound is a safe and affordable imaging technique that can provide information on cartilage thickness, synovial fluid, JSN and osteophytes, though its ability to evaluate deep structures such as subchondral bone is limited. Magnetic resonance imaging (MRI) represents the optimal imaging modality to assess soft tissue structures. New MRI techniques are able to detect early cartilage damage measuring the T1ρ and T2 relaxation time of knee cartilage. Delayed gadolinium-enhanced MRI of cartilage, by injecting a contrast agent to enhance the visibility of the cartilage on MRI scans, can provide information about its integrity. Despite these techniques can provide valuable information about the biochemical composition of knee cartilage and can help detect early signs of osteoarthritis (OA), they may not be widely available. Computed tomography (CT) has restricted utility in evaluating OA; nonetheless, weight-bearing CT imaging, using the joint space mapping technique, exhibits potential in quantifying knee joint space width and detecting structural joint ailments. PET-MRI is a hybrid imaging technique able to combine morphological information on bone and soft tissue alterations with the biochemical changes, but more research is needed to justify its high cost and time involved. The new tools of artificial intelligence, including machine learning models, can assist in detecting patterns and correlations in KOA that may be useful in the diagnosis, grading, predicting the need for arthroplasty, and improving surgical accuracy.

The role of Lung Ultrasound in the diagnosis of SARS-COV-2 disease in pregnant women.

AIM: To evaluate the role of lung ultrasound (LUS) in recognizing lung abnormalities in pregnant women affected by COVID-19 pneumonia. MATERIALS AND METHODS: An observational study analyzing LUS patterns in 60 consecutively enrolled pregnant women affected by COVID-19 infection was performed. LUS was performed by using a standardized protocol by Soldati et al. The scoring system of LUS findings ranged from 0 to 3 in increasing alteration severity. The highest score obtained from each landmark was reported and the sum of the 12 zones examined was calculated. RESULTS: Patients were divided into two groups: 26 (43.3%) patients with respiratory symptoms and 32 (53.3%) patients without respiratory symptoms; 2 patients were asymptomatic (3.3%). Among the patients with respiratory symptoms 3 (12.5%) had dyspnea that required a mild Oxygen therapy. A significant correlation was found between respiratory symptoms and LUS score (p < 0.001) and between gestational weeks and respiratory symptoms (p = 0.023). Regression analysis showed that age and respiratory symptoms were risk factors for highest LUS score (p < 0.005). DISCUSSION: LUS can affect the clinical decision course and can help in stratifying patients according to its findings. The lack of ionizing radiation and its repeatability makes it a reliable diagnostic tool in the management of pregnant women.

Extended-FAST plus MDCT in pneumothorax diagnosis of major trauma: time to revisit ATLS imaging approach?

BACKGROUND AND OBJECTIVE: Pneumothorax (PNX) detection is of the utmost clinical relevance because it may quickly progress to cause hemodynamic instability as a consequence of invasive ventilation. Radiography is characterized by a low sensitivity to detect this disease; in recent years, chest ultrasound (US) has gained increased visibility in the diagnosis of acute respiratory emergencies including PNX. The aim of this retrospective study was to evaluate the clinical impact of extended focused assessment with sonography in trauma (E-FAST) during the past 6 years of experience with this technique in our Level I trauma center. METHODS: Between January 2013 and December 2018, we performed a retrospective case-series study including 3320 consecutive patients admitted to the emergency department of our hospital because of major trauma. Extended-US was always performed and reported immediately after FAST during primary survey and before multidetector computed tomography (MDCT) scans. The presence of PNX was determined using the well-known accepted US criteria. US findings were compared with computed tomography (CT) findings, the reference standard for PNX detection. RESULTS: Of the 6640 lungs observed with E-FAST, there were 1244 PNX cases, while 1328 PNX cases were detected either on the basis of MDCT or on the basis of the presence of air flush during the thoracic decompression in the emergency room. Among the 84 false negatives, 12 patients had subcutaneous emphysema, 38 had a body mass index higher than 27, 6 had a thoracic wall hematoma, and 4 had chest penetrating trauma. There were 10 false positives in the diagnosis of PNX at US examination, with mild extension and not clinically significant. The overall sensitivity of E-FAST for PNX detection was 93.6% (1244/1328), the specificity of E-FAST was 99.8% (5312/5322), the negative predictive value (NPV) was 98.4% (5312/5396), and the positive predictive value (PPV) was 99.2% (1328/1338). CONCLUSION: Our results demonstrate that bedside thoracic US is characterized by a very good accuracy in the diagnostic work-up of major trauma patients, even in difficult conditions, allowing rapid diagnosis of PNX. ADVANCES IN KNOWLEDGE: The novelty of this research lies in the possibility of diagnosing potential life-threatening conditions in a very short time by means of US, thus proposing a revision of the Advanced Trauma Life Support (ATLS) guidelines in order to incorporate it in the work-up of high-energy injured patients.

Contrast-enhanced ultrasound (CEUS) in pediatric blunt abdominal trauma.

Baseline ultrasound is the first-choice technique in traumatic hemodynamically stable children, and is essential in the early assessment of unstable patients to detect hemoperitoneum or other potentially fatal conditions. Despite the technological advancements in new ultrasound equipment and the experience of the operators, it is not always possible to rule out the presence of parenchymal traumatic lesions by means of baseline ultrasound nor to suspect them, especially in the absence of hemoperitoneum. For this reason, in the last decades, basic ultrasound has been associated with contrast-enhanced ultrasound (CEUS) to evaluate the stable little patient in cases such as low-energy blunt abdominal trauma. Because it relies on second-generation contrast agents, the CEUS technique allows for better detection of parenchymal injuries. CEUS has been demonstrated to be almost as sensitive as contrast-enhanced CT in the detection of traumatic injuries in patients affected by low-energy isolated abdominal trauma, with levels of sensitivity and specificity up to 95%. A very important point in favor of CEUS is its capacity to help distinguish the healthy patient, who can be discharged, from the one needing prolonged monitoring, operative management or hospitalization. Finally, we also have the ability to follow-up on low-grade traumatic lesions using CEUS, always keeping in mind patients' clinical conditions and their hemodynamics.

Role of contrast-enhanced ultrasound (CEUS) in the diagnosis and management of traumatic splenic injuries.

Splenic injuries are common emergencies in the setting of abdominal trauma, as the spleen is the second most frequently injured abdominal organ after the liver. The treatment of splenic injuries underwent a severe shift from operative to non-operative due to an increased awareness of the double physiological function, both immunological and hematological, of the spleen. This, in turn, led to an increased application of splenic preservation techniques. The non-operative approach has been strengthened through radiological imaging and interventional radiology. While multidetector computed tomography is mandatory in the evaluation of hemodynamically stable patients after high-energy trauma, one ultrasound (US) can be used as a first-line technique to examine patients in cases of low-energy trauma. Unfortunately, baseline US has low sensitivity in the detection of traumatic injuries. With the introduction of contrast-enhanced ultrasound (CEUS) as a reliable alternative to baseline ultrasound for low-grade abdominal trauma, the sensitivity of the US technique in recognizing traumatic abdominal lesions has strongly increased, reaching levels of accuracy similar to those of the CT. It has also been strongly recommended for use with children, as it allows for the performance of imaging techniques with the lowest dose of radiation possible. In this review, the authors aim to present the typical appearance of traumatic splenic injuries, using enhanced CEUS capability to overcome baseline US limits, and to describe the different techniques applied according to the hemodynamic stability of the patient.

Radiological Patterns of Lung Involvement in Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a form of chronic inflammation of the gastrointestinal tract, including two major entities: ulcerative colitis and Crohn's disease. Although intestinal imaging of IBD is well known, imaging of extraintestinal manifestations is not extensively covered. In particular, the spectrum of IBD-associated or related changes in the chest is broad and may mimic other conditions. The common embryonic origin of intestine and lungs from the foregut, autoimmunity, smoking, and bacterial translocation from the colon may all be involved in the pathogenesis of these manifestations in IBD patients. Chest involvement in IBD can present concomitant with or years after the onset of the bowel disease even postcolectomy and can affect more than one thoracic structure. The purpose of the present paper is to present the different radiological spectrum of IBD-related chest manifestations, including lung parenchyma, airways, serosal surfaces, and pulmonary vasculature. The most prevalent and distinctive pattern of respiratory involvement is large airway inflammation, followed by lung alterations. Pulmonary manifestations are mainly detected by pulmonary function tests and high-resolution computed tomography (HRCT). It is desirable that radiologists know the various radiological patterns of possible respiratory involvement in such patients, especially at HRCT. It is essential for radiologists to work in multidisciplinary teams in order to establish the correct diagnosis and treatment, which rests on corticosteroids at variance with any other form of bronchiectasis.

Diagnostic Imaging in pediatric thoracic trauma.

Thoracic trauma accounts for approximately 14% of blunt force traumatic deaths, second only to head injuries. Chest trauma can be blunt (90% of cases) or penetrating. In young patients, between 60 and 80% of chest injuries result from blunt trauma, with over half as a consequence of impact with motor vehicles, whereas in adolescents and adults, penetrating trauma has a statistically more prominent role. Pulmonary contusions and rib fractures are the most frequent injuries occurring. Chest X-ray is the first imaging modality of choice to identify patients presenting with life-threatening conditions (i.e., tension pneumothorax, huge hemothorax, and mediastinal hematoma) and those who require a CT examination. Multi-Slice Computed Tomography is the gold standard to evaluate chest injuries. In fact, the high spatial resolution, along with multiplanar reformation and three-dimensional (3D) reconstructions, makes MDCT the ideal imaging method to recognize several chest injuries such as rib fractures, pneumothorax, hemothorax, lung contusions and lacerations, diaphragmatic rupture, and aortic injuries. Nevertheless, when imaging a young patient, one should always keep into account the ALARA concept, to balance an appropriate and low-dose technique with imaging quality and to reduce the amount of ionizing radiation exposure. According to this concept, in the recent years, the current trends in pediatric imaging support the rising use of alternative imaging modalities, such as US and MRI, to decrease radiation exposure and to answer specific clinical questions and during the observation period also. As an example, ultrasound is the first technique of choice for the diagnosis and treatment of pleural and pericardial effusion; its emerging indications include the evaluation of pneumothoraces, costocondral and rib fractures, and even pulmonary contusions.

Preoperative local staging of endometrial cancer: the challenge of imaging techniques and serum biomarkers.

OBJECTIVE: The aim of this study is to prospectively evaluate and compare the accuracy of high-frequency TVS and of two type of MRI (dynamic contrast-enhanced MRI or diffusion-weighted MRI), in association with HE4 in preoperative endometrial cancer (EC) staging. STUDY DESIGN: Starting from January 2012 to February 2015, all patients with EC at prior endometrial biopsy, referred to the Division of Gynaecologic Oncology of the University Campus Bio-Medico of Rome, were prospectively included in the study. All of them underwent complete surgical staging hysterectomy and bilateral oophorectomy, pelvic and lumboaortic lymphadenectomy, according to 2011 NCCN guidelines. The day before surgery, patients underwent to transvaginal ultrasonography (TVS), HE4 serum dosage, and using a computer-based random procedure, to dynamic contrast-enhanced MRI (Group A) or to diffusion-weighted MRI (Group B), to assess myometrial invasion and cervical involvement. RESULTS: Starting from January 2012 to February 2015, a total of 79 patients were considered for the analysis and randomly divided into Group A (n = 38) and Group B (n = 41). Regarding myometrial invasion, MRI and TVS resulted comparable in terms of preoperative detection. Concerning the cervical infiltration, the association between TVS and HE4 is characterized by a better preoperative diagnostic validity (TVS + HE4 96.3 vs. 91 % for MRI and 85 % for the TVS). CONCLUSION: Our results, even the low number of enrolled patients, are promising and may lead to a greater efficiency and lower health care costs in identifying those women who require radical surgery and pelvic lymphadenectomy and should be addressed, in specialized centers.

Diagnostic imaging of blunt abdominal trauma in pediatric patients.

Trauma is a leading cause of morbidity and mortality in childhood, and blunt trauma accounts for 80-90 % of abdominal injuries. The mechanism of trauma is quite similar to that of the adults, but there are important physiologic differences between children and adults in this field, such as the smaller blood vessels and the high vasoconstrictive response, leading to the spreading of a non-operative management. The early imaging of children undergoing a low-energy trauma can be performed by CEUS, a valuable diagnostic tool to demonstrate solid organ injuries with almost the same sensitivity of CT scans; nevertheless, as for as urinary tract injuries, MDCT remains still the technique of choice, because of its high sensitivity and accuracy, helping to discriminate between an intra-peritoneal form a retroperitoneal urinary leakage, requiring two different managements. The liver is the most common organ injured in blunt abdominal trauma followed by the spleen. Renal, pancreatic, and bowel injuries are quite rare. In this review we present various imaging findings of blunt abdominal trauma in children.

First-line diagnosis of paediatric pneumonia in emergency: lung ultrasound (LUS) in addition to chest-X-ray (CXR) and its role in follow-up.

OBJECTIVE: The role of lung ultrasound (LUS) integrated with chest X-ray (CXR) for the first-line diagnosis of paediatric pneumonia; to define its role during the follow-up to exclude complications. METHODS: We performed a retrospective review of a cohort including 84 consecutive children (age range: 3-16 years; mean age: 6 years; 44 males, 40 females) with clinical signs of cough and fever. All the patients underwent CXR at admission integrated with LUS. Those positive at LUS were followed up with LUS until the complete resolution of the disease. RESULTS: CXR showed 47/84 pneumonic findings. LUS showed 60/84 pneumonic findings; 34/60 pneumonic findings had a typical pattern of lung consolidation; 26/60 pneumonic findings showed association of multiple B-lines, findings consistent with interstitial involvement, and small and hidden consolidations not achievable by CXR. One case was negative at LUS because of retroscapular location. 60 patients were followed up with LUS; 28/60 patients showed a complete regression of the disease; 23/60 patients had a significant decrease in size of consolidation; 9/60 patients showed disease stability or insignificant decrease in size, thus requiring adjunctive LUS examinations. CONCLUSION: LUS, integrated with CXR, revealed to be an accurate first-line technique to identify small pneumonic consolidations, especially for "CXR-occult" findings, and for early diagnosis of pleural effusion; furthermore, LUS follow-up allows complications to be verified and additional radiation exposures to be avoided. ADVANCES IN KNOWLEDGE: The effective role of LUS in the diagnosis and follow-up of lung consolidations and pleural effusions in paediatric patients in an emergency setting.

Contrast-enhanced ultrasound (CEUS) in blunt abdominal trauma.

Baseline ultrasound is essential in the early assessment of patients with a huge haemoperitoneum undergoing an immediate abdominal surgery; nevertheless, even with a highly experienced operator, it is not sufficient to exclude parenchymal injuries. More recently, a new ultrasound technique using second generation contrast agents, named contrast-enhanced ultrasound (CEUS) has been developed. This technique allows all the vascular phase to be performed in real time, increasing ultrasound capability to detect parenchymal injuries, enhancing some qualitative findings, such as lesion extension, margins and its relationship with capsule and vessels. CEUS has been demonstrated to be almost as sensitive as contrast-enhanced CT in the detection of traumatic injuries in patients with low-energy isolated abdominal trauma, with levels of sensitivity and specificity up to 95%. Several studies demonstrated its ability to detect lesions occurring in the liver, spleen, pancreas and kidneys and also to recognize active bleeding as hyperechoic bands appearing as round or oval spots of variable size. Its role seems to be really relevant in paediatric patients, thus avoiding a routine exposure to ionizing radiation. Nevertheless, CEUS is strongly operator dependent, and it has some limitations, such as the cost of contrast media, lack of panoramicity, the difficulty to explore some deep regions and the poor ability to detect injuries to the urinary tract. On the other hand, it is timesaving, and it has several advantages, such as its portability, the safety of contrast agent, the lack to ionizing radiation exposure and therefore its repeatability, which allows follow-up of those traumas managed conservatively, especially in cases of fertile females and paediatric patients.

Comparison between MRI and CEUS in the follow-up of patients with blunt abdominal trauma managed conservatively.

INTRODUCTION: Over the past two decades, there has been a shift toward non-operative treatment of patients undergoing a solid organ injury, thus requiring an increasing number of imaging studies to monitor the healing of lesions, which were performed by computed tomography (CT). In consideration of the use of ionizing radiation and contrast media, nowadays there is a trend toward the use contrast-enhanced ultrasound (CEUS) in the follow-up of blunt abdominal trauma. However CEUS has some limits, especially in the assessments of small lesions and in the evaluation of urinary tract lesions and vascular complications. Magnetic resonance imaging (MRI) is a useful alternative, since its lack of use of ionizing radiation, its panoramicity, the possibility to avoid contrast media and the ability to properly evaluate even small lesions. The aim of this study is to evaluate the usefulness and the feasibility of MRI in the follow-up of patients with low-grade blunt abdominal trauma. MATERIALS AND METHODS: We performed a retrospective review of a cohort including 270 consecutive patients with a history of blunt abdominal trauma; among them, 118 underwent a high-energy trauma, and 152 a low-energy trauma. 124 patients had findings of abdominal injuries at the contrast-enhanced multidetector CT (CE-MDCT), including 68 from the group of major trauma and 56 from the group of minor trauma. 39 patients were operated for incoming lesions. The remaining 85 patients were treated conservatively. Eight patients underwent surgery later for delayed bleeding. The remaining 77 underwent the full follow-up protocol. Follow-up protocol included CEUS at 24 and 72 h and CEUS and MRI at 1 month after trauma; only MRI was performed until the complete resolution. RESULTS: CEUS at 24-h and at 72-h from trauma showed a very good correlation with onset CE-MDCT in lesions staging. With respect to onset CE-MDCT, CEUS did not identified 2 adrenal injuries and 2 lesions of urinary tract, an intrinsic limit of this technique. CEUS performed at 1 month did not show traumatic lesions in 49/77 of patients. In the remaining 28/77 cases, CEUS demonstrated reduction of the size of the lesions ranging from 25 to 50%. MRI performed at 1 month from trauma did not show traumatic injuries in 37/77 patients; it demonstrated persistence of organ lesion in 40/77 patients. Therefore, in 12/77 patients MRI performed at 1-month demonstrated the persistence of minimal or moderate organ injury, while CEUS was completely negative. In addition, MRI allowed to enhance the persistence of adrenal lesions in 2 cases and the integrity of urinary tract in 2. In the remaining 28 patients, in which both CEUS and MRI showed disease persistence, MRI, however, allowed a better definition of injury extension with respect to CEUS, in terms of dimensions, edges, and morphological evolution. DISCUSSION AND CONCLUSIONS: MRI allowed to make a better assessment of injuries than CEUS, allowing also a temporal stage of lesions. Infact, there are different evolution stages corresponding to accurate imaging findings. To our knowledge, this is the first study that describes the evolution of blood collection in parenchymal abdominal organs. Therefore, in patients who underwent abdominal traumatic injuries conservatively treated, the follow-up at 1 month can be made by MRI, due to its panoramicity and its high contrast resolution, which allow a better morphological and temporal trauma staging respect to the CEUS.