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ABSTRACT Objective: This study assessed the cost-effectiveness of radiofrequency ablation compared with percutaneous ethanol injection in patients with early hepatocellular carcinoma in relation to the objective response rate and costs related to the procedure. Methods: This was a prospective single-center randomized trial. The primary outcome was cost-effectiveness. Secondary outcomes were the complete response rate according to the modified response evaluation criteria in solid tumors 60 days after randomization and the complication rate within 180 60 days. Results: Fifty patients were placed into the following groups: percutaneous ethanol injection (n=23) and radiofrequency ablation (n=27). Fifty-four nodules were randomized (mean follow-up: 205.37 days). The estimated mean hospital cost was US$ 1854.11 and US$ 2770.96 for the Radiofrequency Ablation and Percutaneous Ethanol Injection Groups, respectively. The incremental cost-effectiveness ratio was US$ -2674.59, which is advantageous for radiofrequency ablation. After 60 d, 28 of 29 nodules in the Radiofrequency Ablation Group achieved complete response versus 12 of 22 in the Percutaneous Ethanol Injection Group (RD, 42.01 [95%CI= 20.55–63.24]; p0.05), respectively. Conclusion: Radiofrequency ablation was more cost-effective and achieved higher complete response and lower complication rates than the Percutaneous Ethanol Injection Group within this cohort. Registry of Clinical Trials: NCT06450613 more...

Abstract Objective To evaluate whether there is a significant difference in somatostatin analog uptake in meningiomas treated or not with radiation therapy. Methods A cross-sectional study was performed comparing measurements of somatostatin analog (68Ga-DOTATATE) uptake in two independent groups of ten patients each - one consisting of patients with meningiomas previously treated with radiation therapy and another comprising patients who had never been submitted to radiation therapy. All patients underwent PET/CT and MRI scans in an interval shorter than 24 hours between exams. Results A total of 32 meningiomas from 20 patients were analyzed, all presenting significant somatostatin analog uptake in different degrees. The uptake levels of somatostatin analog were similar between the lesions treated or not with radiation therapy, and the mean values of SUVmax were 27.62 and 24.82, respectively (p=0.722). For SUVmean, the values were 16.20 and 14.82, respectively (p=0.822). Conclusion Comparative analysis between the groups showed no significant differences in degree of somatostatin analog uptake in successfully irradiated and non-irradiated meningiomas. more...

ABSTRACT Objective To evaluate whether the presence of a hypointense signal at T2-weighted imaging in a solid ovarian lesion on magnetic resonance imaging is a predictor of stability and benignity. Methods This is a single center study, prospectively read with retrospective acquired data. The database was searched for patients who underwent magnetic resonance imaging between January 2008 and October 2019 and whose reports mentioned solid ovarian lesions with low signal on T2-weighted imaging. A total of 47 nodules were included. A radiologist who was blinded to the clinical indication for magnetic resonance imaging and original reports evaluated the cases. Objective and subjective criteria of ovarian lesions in magnetic resonance imaging were evaluated. Results Thirty-five nodules were considered benign/stable and 12 were considered non-stable. The analysis showed that the non-stable lesions showed statistically more hyperintensity at T1-weighted imaging compared to the stable lesions. Conclusion T2-weighted imaging hypointensity can be considered a predictor of stability in solid ovarian lesions when associated with iso/hypointensity in T1-weighted imaging. more...

ABSTRACT Objective To evaluate the predictive value of positron emission computed tomography or magnetic resonance (PET-CT and PET-MRI) using gallium-68-labeled prostate-specific membrane antigen (68Ga-PSMA) in lymph node involvement in prostate cancer. Methods A retrospective study comprising 91 patients diagnosed with prostate cancer between 2016 to 2020, who underwent 68Ga-PSMA PET-CT or PET-MRI for staging before prostatectomy. The patients were divided into Group 1, with 65 patients with satisfactory pathological lymph node analysis, and Group 2, with 91 patients representing the sum of patients with pathological lymph node analysis and those with postoperative prostate-specific antigen within 60 days after surgery. Receiver Operating Characteristic curves were used to assess accuracy of predictive capacity of imaging exams for lymph node involvement. Results Regarding local clinical staging, the groups showed similar results, and 50% were classified as staging T2a. The accuracy of 68Ga-PSMA PET-CT for prostate cancer lymph node staging was 86.5% (95%CI 0.74-0.94; p=0.06), with a sensitivity of 58.3% and specificity of 95%. The accuracy of 68Ga-PSMA PET-MRI was 84.6% (95%CI 0.69-0.94; p=0.09), with a sensitivity of 40% and specificity of 100%. Considering both 68Ga-PSMA PET-CT and PET-MRI, the accuracy was 85.7% (95%CI 0.76-0.92; p=0.015), with sensitivity of 50% and specificity of 97%. Conclusion The imaging tests 68Ga-PSMA PET-CT and PET-MRI were highly accurate to detect preoperative lymph node involvement, and could be useful tools to indicate the need for extended lymph node dissection during radical prostatectomy. more...

ABSTRACT Objective To evaluate the ability of blood-oxygen-level-dependent (BOLD) magnetic resonance imaging at 3 Tesla to measure tissue oxygen bioavailability based on R2* values, and to differentiate between acute tubular necrosis and acute rejection compared to renal biopsy (gold standard). Methods A prospective, single-center study, with patients submitted to renal transplantation between 2013 and 2014, who developed graft dysfunction less than 4 weeks after transplantation. All patients were submitted to abdominal magnetic resonance imaging at 3 Tesla using the same protocol, followed by two BOLD sequences and kidney biopsy. Results Twelve male (68.75%) and three female (31.25%) patients were included. A total of 19 percutaneous renal biopsies were performed (four patients required a second biopsy due to changes in clinical findings). Pathological findings revealed ten cases of acute tubular necrosis, four cases of acute rejection, and five cases with other (miscellaneous) diagnoses. Comparison between the four groups of interest failed to reveal significant differences (p=0.177) in cortical R2* values, whereas medullary R2* values differed significantly (p=0.033), with lower values in the miscellaneous diagnoses and the acute tubular necrosis group. Conclusion BOLD magnetic resonance imaging at 3 Tesla is a feasible technique that uses indirect tissue oxygen level measurements to differentiate between acute rejection and acute tubular necrosis in renal grafts. more...

ABSTRACT Objective: To evaluate anatomic factors and radiologist's experience in the detection of solid renal masses on ultrasonography. Methods: We searched for solid renal masses diagnosed on cross-sectional imaging from 2007 to 2017 that also had previous ultrasonography from the past 6 months. The following features were evaluated: nodule size, laterality, location and growth pattern, patient body mass index and radiologist's experience in ultrasound. In surgically resected cases, pathologic reports were evaluated. Unpaired t test and χ2 test were used to evaluate differences among subgroups, using R-statistics. Statistical significance was set at p more...

ABSTRACT Objective To assess accuracy of multiparametric magnetic resonance of the prostate to estimate gland volume, comparing the results with transrectal ultrasound and surgical specimen. Methods A retrospective study of 85 patients who underwent multiparametric magnetic resonance and transrectal ultrasound (for fusion image-guided biopsy) before radical prostatectomy. Prostate measurements were obtained from magnetic resonance axial and sagittal T2-weighted images and ultrasound; the prostate volume was determined using the ellipsoid formula. The results were compared with the surgical specimen weight. Maximum interval between multiparametric magnetic resonance imaging, transrectal ultrasound, and prostatectomy was 6 months. Results The prostate volume measured by multiparametric magnetic resonance imaging was 18-157cm3 (mean of 49.9cm3) and by transrectal ultrasound, 22-165cm3 (mean of 54.9cm3); the surgical specimen weight was 20-154g (mean of 48.6g), with no statistical differences. Based on the values obtained from imaging examinations, the prostate volume obtained was very close to the real prostatic weight, and the measures by multiparametric magnetic resonance were slightly more precise. Conclusion Prostate volume measured by multiparametric magnetic resonance imaging and transrectal ultrasound showed similar values, and excellent agreement with real prostate weight of the surgical specimens. Prostate volume measured by magnetic resonance has been increasingly used in the clinical practice, and its value enables appropriate therapeutic planning and control of patients. more...

ABSTRACT Objectives: To evaluate the use of magnetic resonance imaging in patients with β-thalassemia and to compare T2* magnetic resonance imaging results with serum ferritin levels and the redox active fraction of labile plasma iron. Methods: We have retrospectively evaluated 115 chronically transfused patients (65 women). We tested serum ferritin with chemiluminescence, fraction of labile plasma iron by cellular fluorescence and used T2* MRI to assess iron content in the heart, liver, and pancreas. Hepatic iron concentration was determined in liver biopsies of 11 patients and the results were compared with liver T2* magnetic resonance imaging. Results: The mean serum ferritin was 2,676.5 +/- 2,051.7 ng/mL. A fraction of labile plasma iron was abnormal (> 0,6 Units/mL) in 48/83 patients (57%). The mean liver T2* value was 3.91 ± 3.95 ms, suggesting liver siderosis in most patients (92.1%). The mean myocardial T2* value was 24.96 ± 14.17 ms and the incidence of cardiac siderosis (T2* < 20 ms) was 36%, of which 19% (22/115) were severe cases (T2* < 10 ms). The mean pancreas T2* value was 11.12 ± 11.20 ms, and 83.5% of patients had pancreatic iron deposition (T2* < 21 ms). There was significant curvilinear and inverse correlation between liver T2* magnetic resonance imaging and hepatic iron concentration (r= −0.878; p < 0.001) and moderate correlation between pancreas and myocardial T2* MRI (r = 0.546; p < 0.0001). Conclusion: A high rate of hepatic, pancreatic and cardiac impairment by iron overload was demonstrated. Ferritin levels could not predict liver, heart or pancreas iron overload as measured by T2* magnetic resonance imaging. There was no correlation between liver, pancreas, liver and myocardial iron overload, neither between ferritin and fraction of labile plasma iron with liver, heart and pancreas T2* values more...

ABSTRACT Pericardial cysts account for 12-18% of all mediastinal masses. They are usually asymptomatic and incidentally detected. However, when large, they can cause symptoms. Most pericardial cysts are located in the right cardiophrenic angle, but they can be anywhere in the mediastinum. We reported a pleuropericardial cyst torsion after physical stress, a very rare complication of this condition. The diagnosis was made by computed tomography and confirmed by video-assisted thoracoscopy. more...

ABSTRACT Adnexial torsion is an unusual event, but a major cause of abdominal pain in women. It is often associated with ovarian tumor or cyst, but can occur in normal ovaries, especially in children. The twisting of adnexial structures may involve the ovary or tube, but frequently affects both. In most cases, it is unilateral, with slight predilection for the right side. In imaging findings, increased ovarian volume and adnexial masses are observed, with reduced or absent vascularization. In cases of undiagnosed or untreated complete twist, hemorrhagic necrosis may occur leading to complications; in that, peritonitis is the most frequent. Early diagnosis helps preventing irreversible damage with conservative treatment, thereby saving the ovary. Limitations in performing physical examination, possible inconclusive results in ultrasound and exposure to radiation in computed tomography makes magnetic resonance imaging a valuable tool in emergency assessment of gynecological diseases. The objective of this study was to report two confirmed cases of adnexial twist, emphasizing the contribution of magnetic resonance imaging in the diagnosis of this condition. more...

Objective: To show that it is possible to reduce the radiation dose in the examination of potential kidney donors by splitting the contrast injection followed by a single scanning, enabling evaluation of vascular structures, renal parenchyma and collecting system/ureters, using computed tomography protocols with reduced mAs. Methods: Twenty-six potential donors were evaluated based on the following criteria: image quality, radiation dose reduction, and complications associated with the exam. The criteria were scored by two examiners, and the differences were resolved by consensus. Rresults: For each item assessed, 85 to 90% of studies were scored as very good or excellent with regards to image quality. There was excellent interobserver agreement, and there were no significant differences between the exams with low radiation dose compared to those with the conventional dose. No exam-related complications were observed. Cconclusions: The CT scan study with triple-split bolus technique and low dose is effective for reducing the dose of radiation to potential kidney donors. more...

The thymus is located in the anterior portion of the upper mediastinum, immediately behind the sternal manubrium, and extends to the anterior mediastinum, anteriorly to the pericardium. Two patients were evaluated due to nodulations at the transition from the cervical region to the anterior mediastinum, which simulated lymphadenomegaly. The first patient, a seven-year-old male, presented with a rhabdomyosarcoma of the masticatory space; during progressive follow-up, a nodule was noted with FDG uptake on the positron emission tomography coupled with the computed tomography (PET-CT). The second patient, a 51-year-old female, presented with a nodulation characterized on the magnetic resonance image for follow-up of a papilliferous carcinoma of the thyroid. In both cases, the nodulation displayed an upper prolongation of the thymus. These nodulations showed the same density on the computed tomography and the same signal intensity on the magnetic resonance image as the adjacent thymic tissue, and there was no adipose tissue layer between the nodulations and the thymus. Knowledge of the upper prolongation of the thymus as an anatomical variation is vital for differentiating it from mediastinal lymphadenomegaly, thus avoiding unnecessary biopsies or procedures. more...

Objectives: To describe tomographic findings in Petersen’s herniaassociated with laparoscopic Roux-en-Y gastric bypass surgery.Methods: Two radiologists, experts in abdominal radiology,independently and retrospectively reviewed four cases of Petersen’shernia confirmed surgically in three patients, between March 2007and July 2008, who had undergone laparoscopic Roux-en-Y gastricbypass surgery with an antecolic anastomosis for treating morbidobesity. The main imaging findings were the presence and locationof abdominal distention, the herniated intestinal loop segment, thepresence of mesenteric vessel rotation and haziness of mesentericfat, the position of the Treitz angle ligament and the course of theileum. Results: In all cases, abdominal distention was located inthe upper abdomen; the herniated jejunal loop was located abovethe gastric level; mesenteric vessel rotation was associated withmesenteric fat haziness; the middle/distal ileum descended from theleft hypochondrium; and the Treiz angle was displaced anteriorly andto the right. Both examiners fully agreed with the analysis of findings.Conclusions: The association of computed tomography findingsdescribed in patients with a history of bariatric surgery is a strongpredictor of Petersen’s hernia. more...

This article presents three cases of gastrointestinal stromal tumorswith clinical manifestations and pathological features, along withdifferential diagnoses, with special emphasis on multislicecomputed tomography and magnetic resonance imaging findings. more...

ABSTRACT Objective: To describe the imaging findings of prostatic tumors nonadenocarcinoma on multiparametric magnetic resonance imaging. Methods: A total of 200 patients underwented multiparametric magnetic resonance imaging of the prostate for screening for prostate cancer, from August 2013 to September 2014, followed by biopsy with ultrasound/magnetic resonance imaging fusion. Results: We found three pathologic proved cases of prostatic pure leiomyomas (0.02%) in our series and described the multiparametric magnetic resonance imaging features of these prostatic leiomyomas. The imaging findings had similar features to lesions with moderate or high suspicion for significant cancer (Likert 4 or 5) when localized both in the transitional zone or in the peripheral zone of the gland. Conclusion: Pure prostatic leiomyomas had imaging findings on multiparametric magnetic resonance imaging that mimicked usual adenocarcinomas on this test. Radiologists, urologists and pathologists must be aware of this entity and its imaging features. more...

ABSTRACT In recent years, medical imaging with hybrid techniques has widely accepted and employed in clinical routine. PET/MRI offers significant advantages, including excellent contrast and resolution and reduced ionizing radiation, as compared to well-established PET/CT. Therefore, PET/MRI is a promising modality for oncologic imaging of some regions, such as brain, head and neck, liver and pelvis. This article set out to analyze clinical conditions that could benefit from PET/MRI imaging based on our caseload. The potential of PET/MRI to become the imaging modality of choice for assessment of neurologic and oncologic conditions associated with soft tissues is highlighted. Clinical aspects of PET/MRI and its application to clinical cases are illustrated with examples extracted from the authors’ preliminary experience. more...

ABSTRACT The hepatobiliary-specific contrast medium (gadoxetic acid – Primovist®) is primarily used to improve detection and characterization of focal hepatic lesions, such as in chronic liver disease patients with suspected hepatocellular carcinoma. Since the contrast medium is selectively taken up by functioning hepatocytes in the late hepatobiliary phase, it helps to detect typical hepatocellular carcinoma, which show low signal intensity on this phase. This imaging feature also assists in differentiating regenerative/dysplastic nodules from early hepatocellular carcinomas (with over 90% accuracy), as well as hypervascular hepatocellular carcinomas from arterial pseudo-enhancement foci. Future perspectives include its use in quantification of hepatic function and fibrosis. more...

OBJETIVO: Avaliar alterações endometriais relacionadas à embolização de artérias uterinas para tratamento da leiomiomatose uterina sintomática (dor pélvica e/ou sangramento uterino), por meio de ressonância magnética de alto campo (3 Tesla). MÉTODOS: Estudo longitudinal e prospectivo, no qual foram incluídas 94 pacientes com diagnóstico clínico e por imagem de leiomiomatose uterina sintomática, todas tratadas por meio de procedimento de embolização das artérias uterinas. As pacientes foram submetidas a avaliações por ressonância magnética de alto campo da pelve antes e 6 meses após o procedimento. Foram realizadas avaliações específicas do endométrio nas sequências ponderadas em T2 e nas sequências ponderadas em T1, antes e após a infusão endovenosa dinâmica do meio de contraste paramagnético. Diante dos resultados dessas medidas, foram realizadas análises estatísticas por meio de teste t de Student para comparação dos resultados obtidos antes e após o procedimento. RESULTADOS: Observou-se um aumento médio de 20,9% no sinal endometrial nas imagens ponderadas em T2 obtidas após o procedimento de embolização das artérias uterinas, quando comparadas com a avaliação pré-procedimento (p=0,0004). Nas imagens obtidas com a infusão endovenosa do meio de contraste paramagnético, foi observado um aumento médio de 18,7% na intensidade de sinal endometrial pós-embolização de artérias uterinas, quando comparadas com a medida pré-embolização (p more...

ABSTRACT The COVID-19 became a pandemic in early 2020. It was found, at first, that the main manifestations of this new virus occur through respiratory and constitutional symptoms. Therefore, chest tomography was elected as the best imaging test to assess the extent of pulmonary involvement and as a good prognostic predictor for the disease. However, as new studies were produced, the gastrointestinal involvement of COVID-19 becomes more evident, with reports from patients who manifested mainly or only gastrointestinal symptoms in the course of the disease. Thus, in some cases, the initial investigation is carried out at the emergency department with an abdominal computed tomography. We report a case series of ten patients who came to the emergency department of our institution with a chief gastrointestinal complaint, and were initially submitted to an abdominal computed tomography as the first investigation. Although most of the patients did not have significant changes in the abdominal images, most reported patients had pulmonary findings visualized at the lung bases, which were later designated as typical COVID-19 pulmonary findings on chest computed tomography. Only one patient had atypical COVID-19 lung changes on chest computed tomography. All patients had a positive real-time polymerase chain reaction for COVID-19. It is imperative to alert radiologists, especially abdominal radiologists, with the possibility of COVID-19 isolated gastrointestinal symptoms. Besides, it must become a habit to radiologists to assess the pulmonary basis on abdominal scans, a site commonly affected by the new coronavirus. more...

ABSTRACT Objective: To compare qualitatively and quantitatively, in terms of image quality, a new biexponential diffusion sequence protocol with the standard monoexponential diffusion protocol on multiparametric prostate magnetic resonance imaging. Methods: This study had a prospective data collection and cross-sectional analysis. Between August and November 2017, a total of 70 patients who underwent multiparametric prostate magnetic resonance imaging due to clinical suspicion of prostatic neoplasia were recruited. The images obtained were evaluated by two independent readers regarding subjective/qualitative criteria (six criteria) and objective/quantitative criteria (three criteria), always comparing the monoexponential to biexponential acquisition protocols. The results were compared by statistical analysis (interobserver agreement − Gwet coefficient; analysis of the qualitative variables − Stuart-Maxwell test; and analysis of the quantitative variables − Wilcoxon test). Results: After exclusion of four patients, the final sample consisted of 66 patients. A good/excellent inter observer agreement was stablished for subjective criteria (except in one criteria). For the qualitative analysis the amount of good or excellent evaluations was higher for the monoexponential protocol (except in one category), with evidence of significant differences for three criteria (diffusion weighted imaging global quality; diffusion weighted imaging signal-to-noise ratio; and apparent diffusion coefficient signal-to-noise ratio). For the quantitative data analysis, the monoexponential protocol showed less variability of the anteroposterior diameters, meaning less distortion of the images, and better estimated signal-to-noise ratio. Conclusion: In our data, the quality of the images of the monoexponential standard diffusion sequence was qualitatively and quantitatively superior to those of the biexponential diffusion weighted imaging sequence. more...