OBJECTIVE: To assess the performance of the Ovarian-Adnexal Reporting and Data System Magnetic Resonance Imaging (O-RADS MRI) score in the evaluation of adnexal masses and to provide technical notes about its current MRI parameters and concepts. MATERIALS AND METHODS: This was a prospective study of 226 patients with 287 adnexal masses (190 submitted to surgery or biopsy and 97 followed for at least one year). We calculated the sensitivity, specificity, positive predictive value, and negative predictive value for the O-RADS MRI score, using ≥ 4 as the cutoff for malignancy. We performed a technical analysis of the main updates to the score, announced in September 2020 by the American College of Radiology, in comparison with the original (2013) version. RESULTS: We found that an O-RADS MRI score of 4 or 5 was associated with malignancy of an adnexal mass, with a sensitivity of 91.11% (95% CI: 83.23–96.08), specificity of 94.92% (95% CI: 90.86–97.54), positive predictive value of 89.13% (95% CI: 81.71–93.77), negative predictive value of 95.90% (95% CI: 92.34–97.84), and overall accuracy of 93.73% (95% CI: 90.27–96.24). CONCLUSION: Our findings support the use of the O-RADS MRI score for evaluating adnexal masses, especially those considered indeterminate on ultrasound. The updates made recently to the O-RADS MRI score facilitate its interpretation and will allow its more widespread use, with no loss of diagnostic accuracy.

Keywords: Magnetic resonance imaging; Adnexal diseases/diagnostic imaging; Ovarian neoplasms/diagnostic imaging.

OBJECTIVE: To estimate the frequency of lipid-poor adenomas (LPAs) in magnetic resonance imaging (MRI) examinations. MATERIALS AND METHODS: We retrospectively investigated adrenal lesions on MRI examinations performed in a total of 2,014 patients between January 2016 and December 2017. After exclusions, the sample comprised 69 patients with 74 proven adenomas. Two readers (reader 1 and reader 2) evaluated lesion size, laterality, homogeneity, signal drop on out-of-phase (OP) images, and the signal intensity index (SII). An LPA was defined as a lesion with no signal drop on OP images and an SII < 16.5%. For 68 lesions, computed tomography (CT) scans (obtained within one year of the MRI) were also reviewed. RESULTS: Of the 69 patients evaluated, 42 (60.8%) were women and 27 (39.2%) were men. The mean age was 59.2 ± 14.1 years. Among the 74 confirmed adrenal adenomas evaluated, the mean lesion size was 18.5 ± 7.7 mm (range, 7.0–56.0 mm) for reader 1 and 21.0 ± 8.3 mm (range, 7.0–55.0 mm) for reader 2 (p = 0.055). On the basis of the signal drop in OP MRI sequences, both readers identified five (6.8%) of the 74 lesions as being LPAs. When determined on the basis of the SII, that frequency was three (4.0%) for reader 1 and four (5.4%) for reader 2. On CT, 21 (30.8%) of the 68 lesions evaluated were classified as LPAs. CONCLUSION: The prevalence of LPA was significantly lower on MRI than on CT. That prevalence tends to be even lower when the definition of LPA relies on a quantitative analysis rather than on a qualitative (visual) analysis.

Keywords: Adenoma/diagnostic imaging; Adrenal gland neoplasms/diagnostic imaging; Incidental findings; Magnetic resonance imaging; Tomography, X-ray computed.

OBJECTIVE: To investigate the utility of computed tomography (CT) scans to detect and assess the margin status of pulmonary nodules that were insufflated after being resected by video-assisted thoracic surgery. MATERIALS AND METHODS: This was a novel multicenter study conducted at two national referral centers for thoracic diseases. Patients suspected of having lung cancer underwent video-assisted thoracic surgery for the resection of pulmonary nodules, which were submitted to postoperative CT. Measurements from the CT scans were compared with the results of the histopathological analysis. RESULTS: A total of 37 pulmonary nodules from 37 patients were evaluated. The mean age of the patients was 65 years (range, 36–84 years), and 27 (73%) were female. A CT analysis of insufflated specimens identified all 37 nodules, and 33 of those nodules were found to have tumor-free margins. The histopathological analysis revealed lung cancer in 30 of the nodules, all with tumor-free margins, and benign lesions in the seven remaining nodules. CONCLUSION: Postoperative CT of insufflated suspicious lung lesions provides real-time detection of pulmonary nodules and satisfactory assessment of tumor margins. This initial study shows that CT of insufflated lung lesions can be a valuable tool at centers where intraoperative histopathological analysis is unavailable.

Keywords: Tomography, X-ray computed; Thoracic surgery, video-assisted; Lung neoplasms/diagnostic imaging.

OBJECTIVE: To compare the degree of coronary stenosis (≥ 50% luminal narrowing) determined by coronary computed tomography angiography (CCTA) with that determined by invasive coronary angiography (ICA), using segment-by-segment analysis. MATERIALS AND METHODS: This was a retrospective study of the records of patients who underwent CCTA and ICA between January 2014 and June 2018 at a general hospital in Brazil. Receiver operating characteristic curve analysis was applied, and the areas under the curve were used in order to assess the overall accuracy of the methods. RESULTS: The degree of coronary stenosis was evaluated in a total of 844 arterial segments. The diagnostic performance of CCTA was good, with a sensitivity of 82.3%, a specificity of 96.4%, and a negative predictive value of 97.7% (95% CI: 96.5–98.5). In the segment-by-segment analysis, CCTA had excellent accuracy for the left main coronary artery and for other segments. CONCLUSION: In clinical practice at general hospitals, CCTA appears to have diagnostic performance comparable to that of ICA.

Keywords: Multidetector computed tomography; Coronary angiography/methods; Coronary artery disease/diagnostic imaging.

OBJECTIVE: To measure the transit times (TTs) of contrast agents among the injection site (antecubital vein), superior vena cava, pulmonary trunk, and ascending aorta, in coronary computed tomography angiography (CTA) examinations of outpatients with no history of cardiovascular or lung disease, thus defining reference values for those TTs. MATERIALS AND METHODS: The contrast TTs from the injection site (antecubital vein) to the superior vena cava, from the superior vena cava to the pulmonary trunk, and from the pulmonary trunk to the ascending aorta were measured by monitoring contrast enhancement in real time (bolus tracking). Cardiac output was measured by the geometric method during the CTA examination and was correlated with the contrast TT. RESULTS: Forty-three individuals were analyzed. The mean contrast TT was 13.1 s overall (from the antecubital vein to the ascending aorta), 3.0 s from the superior vena cava to the pulmonary trunk, and 7.2 s from the pulmonary trunk to the ascending aorta. There was a tendency toward a correlation between contrast TT and cardiac output (p = 0.055). CONCLUSION: The reference values established here for contrast TTs among the superior vena cava, pulmonary trunk, and ascending aorta will serve as a basis for clinical evaluation.

Keywords: Cardiac output; Contrast media; Computed tomography angiography.

OBJECTIVE: To examine the relationship that the types and locations of fractures of the sternum have with mortality and morbidity. MATERIALS AND METHODS: We analyzed the records of 115 patients diagnosed with fracture of the sternum, due to blunt trauma, between 2007 and 2018. Records of computed tomography studies were obtained from the radiology archive of a tertiary teaching hospital. The type of fracture was classified as linear, displaced, or comminuted, whereas the fracture location was classified as the manubrium, body, or xiphoid process. RESULTS: A total of 108 patients were included in the study. Of those patients, 92 (85.2%) were male and 16 (14.8%) were female. The etiology was a traffic accident in 72 cases (62.6%) and a fall from height in 36 (31.3%). The mean age was 42.1 ± 17.7 years for males and 53.9 ± 20.0 years for females. The mortality rate was 11.1%. Among the 12 deceased patients, the mean age was 44.4 ± 18.3 years. The fracture was located exclusively in the manubrium in 64 patients (59.3%), exclusively in the body of the sternum in 41 (38.0%), and in both locations in three (2.7%), whereas none were located in the xiphoid process. Morbidity rates were higher in the patients with fractures of the manubrium than in those with fractures of the body of the sternum, as was the incidence of accompanying bone fractures and organ injuries. The fracture was linear in 44 patients (40.7%), displaced in 62 (57.4%), and comminuted in 30 (27.8%). The mortality was significantly higher for comminuted fractures than for the other fracture types (p = 0.045; β = 4.40). CONCLUSION: Fracture of the manubrium can be indicative of the severity of trauma and has a poor prognosis.

Keywords: Sternum/injuries; Fractures, bone/mortality; Wounds and injuries.

Chest scans usually include the upper abdomen, leading radiologists to evaluate the upper abdominal structures. The aim of this article is to summarize the most common incidental upper abdominal findings that do not require further imaging or management in patients undergoing unenhanced computed tomography of the chest for the investigation of thoracic symptoms or diseases. We review common incidental findings of the liver, gallbladder, spleen, adrenal glands, kidney, and retroperitoneum, as well as findings that mimic other lesions. Thoracic radiologists should be aware of such typical findings and report when no further investigation is needed, thus avoiding unnecessary imaging examinations, protecting patients from additional medical interventions, and allaying patient concerns.

Keywords: Incidental findings; Diagnostic imaging; Abdomen/diagnostic imaging; Tomography, X-ray computed.

Placenta accreta spectrum disorders are characterized by abnormal adhesion of the placenta that can be subdivided into three categories according to degree of invasion: placenta accreta (passing through the decidua basalis and adhering to the myometrium); placenta increta (penetrating the myometrium); and placenta percreta (invading the uterine serosa or adjacent tissues or organs). The incidence of placenta accreta has increased significantly in recent decades, mainly because of an increase in the rates of cesarean section, which is its main risk factor. Accurate prenatal identification makes it possible to institute the ideal treatment with a multidisciplinary team, significantly minimizing maternal morbidity and mortality. The examinations of choice are ultrasound and magnetic resonance imaging (MRI). When the ultrasound evaluation is inconclusive, as well as when the patient has risk factors for the condition or the placenta is in a posterior location, MRI is indicated. In cases of placental invasion of the adjacent pelvic organs, MRI is also preferable because it provides a broader field of view, which improves surgical planning. Numerous features of placenta accreta spectrum disorders are discernible on MRI, including dark intraplacental bands, uterine bulging, and heterogeneous placenta. Knowledge of these findings and the combination of two or more of them increase confidence in the diagnosis.

Keywords: Placenta accreta; Placenta diseases; Magnetic resonance imaging.

Von Hippel-Lindau (VHL) disease is a rare, autosomal dominant inherited syndrome that affects the germline of the VHL gene, a tumor suppressor gene. VHL disease is characterized by the multisystemic development of a variety of benign and malignant tumors, especially in the central nervous system (CNS). Such tumors include retinal and CNS hemangioblastomas, as well as endolymphatic sac tumors. The various tumor sites are responsible for the diversity of signs and symptoms related to the disease. The mean age at symptom onset is 33 years. Despite medical advances, the average life expectancy of patients with VHL disease is 49 years. Imaging plays a pivotal role in the clinical diagnosis and is essential to the follow-up of patients with VHL disease. This pictorial essay describes characteristic CNS manifestations of VHL disease-related tumors that all radiology residents should be aware of.

Keywords: von Hippel-Lindau disease; Hemangioblastoma; Endolymphatic sac/pathology; Magnetic resonance imaging; Tomography, X-ray computed.

Mucoceles of the appendix are rare and can have quite variable imaging and clinical presentations, sometimes mimicking an adnexal mass. The underlying cause can be neoplastic or non-neoplastic. The typical imaging appearance of a mucocele of the appendix is that of a cystic structure with a tubular morphology. This structure is defined by having a blind-ending and being contiguous with the cecum. Radiologists should be familiar with key anatomical landmarks and with the various imaging features of mucoceles of the appendix, in order to provide a meaningful differential diagnosis of a lesion in the right lower abdominal quadrant. In addition, a neoplastic mucocele can rupture, resulting in pseudomyxoma peritonei, which will change the prognosis dramatically. Therefore, prompt diagnostic imaging is crucial.

Keywords: Mucocele/diagnostic imaging; Appendiceal neoplasms/diagnostic imaging; Adenocarcinoma, mucinous/diagnostic imaging; Cystadenoma, mucinous/diagnostic imaging; Pseudomyxoma peritonei/etiology.

The image-guided gastrostomy techniques, as transoral and transabdominal, can be performed when there is a failure of the endoscopic procedure or in some specific clinical scenarios. This pictorial essay intends to show the percutaneous gastrostomy techniques, indications, technical approaches, post-procedure care, and complications.

Keywords: Gastrostomy; Radiology, interventional; Fluoroscopy; Tomography, X-ray computed.