OBJECTIVE: To report an experiment involving the introduction of a protocol utilizing commercially available three-dimensional 1H magnetic resonance spectroscopy imaging (3D 1H MRSI) method in patients diagnosed with prostatic tumors under suspicion of neoplasm. MATERIALS AND METHODS: Forty-one patients in the age range between 51 and 80 years (mean, 67 years) were prospectively evaluated. The patients were divided into two groups: patients with one or more biopsies negative for cancer and high specific-prostatic antigen levels (group A), and patients with cancer confirmed by biopsy (group B). The determination of the target-area (group A) or the known cancer extent (group B) was based on magnetic resonance imaging and MRSI studies. RESULTS: The specificity of MRSI in the diagnosis of prostate cancer was lower than the specificity reported in the literature (about 47%). On the other hand, for tumor staging, it corresponded to the specificity reported in the literature. CONCLUSION: The introduction and standardization of 3D 1H MRSI has allowed the obtention of a presumable diagnosis of prostate cancer, by a combined analysis of magnetic resonance imaging and metabolic data from 3D 1H MRSI.

Keywords: Magnetic resonance spectroscopy imaging, Prostate, Prostatic neoplasm

OBJECTIVE: To evaluate the interobserver agreement on non-contrast computed tomography interpretation by a group of experienced abdominal radiologists, for the study of urolithiasis in patients presenting acute flank pain. MATERIALS AND METHODS: Prospective study of 52 patients submitted to non-contrast enhanced helical computed tomography. The images were subsequently analyzed by three independent observers, with the interobserver agreement assessed by means of the kappa (kappa) statistical method. The following parameters were analyzed: a) presence, localization and measurement of ureteral calculi; b) intrarenal calyceal system dilatation; c) perirenal fat heterogeneity; d) ureteral dilatation; e) ureteral wall edema (halo sign). RESULTS: Ureteral calculi were found in 40 of 52 patients (77%). The interobserver agreement was almost perfect as regards identification of ureteral calculi (kappa = 0.89) and ureteral dilatation (kappa = 0.87), substantial for calyceal system dilatation (kappa = 0.77), and moderate for perirenal fat heterogeneity (kappa = 0.55) and ureteral wall edema (kappa = 0.56). CONCLUSION: Non-contrast-enhanced abdominal computed tomography presents high reproducibility in the evaluation of urolithiasis and secondary signs of the calyceal system obstruction.

Keywords: Lithiasis, Ureteral calculi, Flank pain, Computed tomography

The most important diagnostic sign of ureterolithiasis is the direct visualization of the stone within the ureter. However, in some patients with ureterolithiasis stone visualization may be impaired due to stone small size or low attenuation, respiratory artifacts between data acquisitions, low amount of retroperitoneal fat or recent elimination of the stone. In this context, we describe many secondary computed tomography signs of ureteral obstruction that may useful in the diagnosis of inconclusive cases, and also quantify the degree of urinary obstruction.

Keywords: Computed tomography, Acute flank pain, Ureteral stone

OBJECTIVE: To determine the frequency and to assess the interobserver agreement of identification of muscular and ligamentous pelvic floor structures using magnetic resonance imaging. METHOD: Twenty asymptomatic female volunteers (aged 20--80 years old; mean: 50) were submitted to magnetic resonance imaging (1.5 T) examinations of the pelvis. Turbo spin-echo sequences were employed to obtain T1 and T2 weighted images on axial and sagittal planes. Two independent observers evaluated the scans in order to identify the levator ani (coccygeal, pubococcygeal, iliococcygeal and puborectalis muscles), obturatorius internus and urethral sphincter muscles, and the pubovesical and pubourethral ligaments. The frequency and the interobserver agreement of the identification of the anatomical structures were assessed (kappa statistic -- kappa). RESULTS: The frequency of identification of the structures ranged from 50 to 100%, and was slightly lower for identification of the ligaments. Interobserver agreement was as follows: levator ani and obturatorius internus muscle (kappa=1), pubococcygeal (kappa=0.62), iliococcygeal (kappa=0.86), puborectalis (kappa= 0.27), coccygeal (kappa=0) and urethral sphincter muscles (kappa=1), pubovesical (kappa=0.50) and pubourethral (kappa=0.58) ligaments. CONCLUSION: Magnetic resonance imaging of the pelvis allowed precise identification of the main muscular and ligamentous pelvic floor structures in most individuals, whereas interobserver agreement was considered good.

Keywords: Pelvic structures, Magnetic resonance imaging, Pelvic floor

OBJECTIVE: The present article is aimed at reporting the author's experience with transcatheter arterial embolization using a lipiodol-ethanol mixture in three cases of unresectable symptomatic giant hepatic hemangiomas. MATERIALS AND METHODS: The cases of three patients with giant unresectable symptomatic hepatic hemangiomas embolized in the period 2009-2010 were retrospectively reviewed. In all the cases, transarterial embolization was performed with an ethanol-lipiodol mixture. RESULTS: Symptoms regression and quality of life improvement were observed in all the cases. No complications were observed and all the patients were discharged within 12 hours after the procedure. CONCLUSION: Transcatheter arterial embolization using ethanol mixed with lipiodol was a safe and effective treatment for symptomatic giant hepatic hemangiomas in this small series of patients.

Keywords: Hemangioma; Therapeutic embolization; Ethanol; Ethiodized oil.

Low back pain is often managed at all levels of healthcare. In general, diagnostic investigation begins with radiography of the lumbar spine. In addition to the most common findings, radiologists can identify increased density of a vertebral body, referred to as ivory vertebra. The objective of this study was to describe the main diseases that can present with this radiologic sign, such as Hodgkin lymphoma, Paget's disease, metastatic prostate cancer, breast cancer, and osteomyelitis. It is extremely important that radiologists be aware of this finding in order to inform the requesting physician of the possible etiologies, given that it can be the initial radiologic presentation for these diseases.

Keywords: Spine; Lymphoma; Neoplasm metastasis; Osteitis deformans; Osteomyelitis.

OBJECTIVE: To evaluate the percutaneous transhepatic approach to the treatment of biliary strictures in pediatric patients undergoing liver transplantation. MATERIALS AND METHODS: This was a retrospective study of data obtained from the medical records, laboratory reports, and imaging examination reports of pediatric liver transplant recipients who underwent percutaneous transhepatic cholangiography, because of clinical suspicion of biliary strictures, between 1st September 2012 and 31 May 2015. Data were collected for 12 patients, 7 of whom were found to have biliary strictures. RESULTS: In the 7 patients with biliary strictures, a total of 21 procedures were carried out: 2 patients (28.6%) underwent the procedure twice; 3 (42.8%) underwent the procedure three times; and 2 (28.6%) underwent the procedure four times. Therefore, the mean number of procedures per patient was 3 (range, 2–4), and the average interval between them was 2.9 months (range, 0.8–9.1 months). The drainage tube remained in place for a mean of 5.8 months (range, 3.1–12.6 months). One patient presented with a major complication, hemobilia, which was treated with endovascular embolization. Clinical success was achieved in all 7 patients, and the mean follow-up after drain removal was 15.4 months (range, 5.3–26.7 months). CONCLUSION: The percutaneous transhepatic approach to treating biliary strictures in pediatric liver transplant recipients proved safe, with high rates of technical and clinical success, as well as a low rate of complications.

Keywords: Liver transplantation; Biliary atresia; Constriction, pathologic/therapy; Cholangiography; Drainage.

OBJECTIVE: To evaluate the computed tomography characteristics of patients admitted with clinical suspicion of acute adrenal hemorrhage at three centers over a 3-year period and in whom that diagnosis was ultimately confirmed. MATERIALS AND METHODS: This was a retrospective analysis of computed tomography findings in patients with suspected acute adrenal hemorrhage. We included only those cases in which the diagnosis was confirmed. Patients with aortic rupture and retroperitoneal hemorrhage were excluded. The images were analyzed by an experienced radiologist and by two radiology residents. RESULTS: Six cases of unilateral adrenal hemorrhage (three on the left and three on the right) were analyzed. On computed tomography, each appeared as a rounded, oval mass altering the usual anatomy of the adrenal gland. The maximum diameter was 12.2 cm, and attenuation ranged from 45 to 70 HU. There was no appreciable contrast enhancement. No calcifications were observed. CONCLUSION: Adrenal hemorrhage, albeit rare, is potentially fatal. Early diagnosis is essential. Therefore, recognition of the possible presentations of these lesions by radiologists may help prevent hemorrhage from progressing to adrenal insufficiency and death.

Keywords: Adrenal glands; Hemorrhage; Tomography, X-ray computed.

OBJECTIVE: To investigate the advantages of using modified signal intensity measurements on chemical shift imaging alone or in conjunction with proton magnetic resonance spectroscopy in the differential diagnosis of adrenal adenomas. MATERIALS AND METHODS: This was a prospective study involving 97 patients with adrenal nodules or masses. The signal intensity index (SII) was calculated as [(signal intensity on the in-phase image − signal intensity on the out-of-phase image) / (signal intensity on the in-phase image)] × 100%. We determined the averages of the minimum, mean, and maximum signal intensity values measured on three consecutive images. When that was not possible (for smaller lesions), we used one or two images. We employed a region of interest that covered one half to two thirds of the mass. All indices were compared with metabolite ratios derived from spectroscopy: lactate/creatine; glutamine-glutamate/creatine; choline/creatine; choline/lipid; 4.0–4.3 ppm/Cr; and lipid/creatine. RESULTS: Of the 97 patients evaluated, 69 were diagnosed with adenomas and 28 were diagnosed with nonadenomas. All SII measurements and spectroscopy-derived metabolite ratios were significant to the differentiation between adenomas and nonadenomas, except for the lipid/creatine and choline/lipid ratios. In 37.8% of the cases, it was not possible to perform spectroscopy. When it was possible, the lactate/creatine ratio was found to have higher accuracy than did the SII. CONCLUSION: Determining the SII and metabolite ratios increased the accuracy of the differential diagnosis of adrenal adenomas.

Keywords: Adrenal glands; Adrenal gland neoplasms; Adenoma/diagnostic imaging; Magnetic resonance imaging/methods; Proton magnetic resonance spectroscopy/methods.

OBJECTIVE: To assess the practical aspects of the use of various gadolinium-based contrast agents (GBCAs) by radiologists. MATERIALS AND METHODS: Ten experienced radiologists from different regions of Brazil participated in a Delphi panel querying their use of various GBCAs, including linear and macrocyclic classes (1.0 and 0.5 M), in terms of the choice of agent, volume and dosage of the agents, and associated safety concerns. RESULTS: The response rate was 100% for all questions. GBCAs are safe in terms of acute adverse reactions, and nephrogenic systemic fibrosis is rare. The deposition of gadolinium in the brain and other tissues is a concern among the experts. Macrocyclic agents are preferable to linear agents; an injection volume below 0.1 mL/kg of a 1.0 M agent could result in good-quality images with additional long-term safety, but there is no published evidence to support this recommendation. The majority of experts preferred not to administer GBCAs to pregnant patients. CONCLUSION: When choosing a GBCA, it is important to consider the characteristics of the gadolinium deposition in patient tissues and minimize potential risks. Furthermore, medical education programs are needed to increase the awareness of the potential risks of gadolinium deposition and thus avoid instances of overexposure to the contrast agent.

Keywords: Contrast media; Gadolinium; Magnetic resonance imaging; Gadolinium-based contrast agents; Safety.

OBJECTIVE: To evaluate the safety and efficacy of using highly compressible calibrated microspheres in uterine artery embolization (UAE) for the treatment of uterine fibroids. MATERIALS AND METHODS: This was a prospective multicenter study. Thirty-two women with symptomatic uterine fibroids were selected for UAE between January 2019 and March 2020. The participants completed the Uterine Fibroid Symptom and Quality of Life (UFS-QOL) questionnaire, underwent contrast-enhanced pelvic magnetic resonance imaging (MRI), and were submitted to anti-Müllerian hormone measurement, subsequently undergoing UAE with Embosoft microspheres. After six months, the patients again completed the UFS-QOL questionnaire and underwent pelvic MRI. RESULTS: The most common symptoms were abnormal uterine bleeding (in 81.3% of the cases), pelvic pain (in 81.3%), and compression (in 46.9%). Of the 32 patients evaluated, 12 (37.5%) had anemia due to abnormal uterine bleeding. Thirty patients completed the study. Among those patients, we observed median reductions of 21.4% in uterine volume and 15.9% in dominant fibroid volume. We identified no adverse events that could be attributed to the material itself, although there were events attributed to the UAE procedure in general. CONCLUSION: For the treatment of uterine fibroids, UAE using Embosoft microspheres shows satisfactory results, providing reductions in uterine and dominant fibroid volumes, with a low rate of adverse events, and improving patient quality of life, as well as demonstrating safety and efficacy.

Keywords: Leiomyoma; Uterine artery; Uterine artery embolization; Microspheres.