OBJECTIVE: To assess the impact of magnetic resonance imaging (MRI) on the locoregional staging of breast cancer. MATERIALS AND METHODS: We evaluated 61 patients with breast cancer who underwent pre-treatment breast MRI, between August 2015 and April 2016. An experienced breast surgeon determined the surgical treatment, on the basis of the findings of conventional imaging examinations, and made a subsequent treatment recommendation based on the MRI findings, then determining whether the MRI changed the approach, as well as whether it had a positive or negative impact on the treatment. RESULTS: The mean age was 50.8 years (standard deviation, 12.0 years). The most common histological type was invasive breast carcinoma of no special type (in 68.9%), and the most common molecular subtype was luminal B (in 45.9%). Breast MRI modified the therapeutic management in 23.0% of the cases evaluated, having a positive impact in 82.7%. CONCLUSION: Breast MRI is an useful tool for the locoregional staging of breast cancer, because it provides useful information that can have a positive impact on patient treatment.

Keywords: Breast neoplasms; Magnetic resonance imaging; Neoplasm staging; Breast/diagnostic imaging.

OBJECTIVE: To evaluate the correlation of morphological criteria of the cecal appendix using computed tomography (CT) and the possible risk of developing acute appendicitis. MATERIALS AND METHODS: Cases were defined as patients with surgically confirmed acute appendicitis who had undergone CT at least twice: at diagnosis and at least one month prior. Controls were defined as emergency patients with abdominal pain who had undergone abdominal CT that excluded acute appendicitis and had also undergone CT at least one month before. RESULTS: 100 cases and 100 controls were selected for inclusion in the final analysis. Comparisons between the cases and controls revealed the following: mean transverse diameter of 0.6 cm (range, 0.4–1.0 cm) versus 0.6 cm (range, 0.6–0.8 cm; p = 0.37); mean length of 6.6 cm (range, 3.5–9.7 cm) versus 6.6 cm (range, 4.5–8.3 cm; p = 0.87); mean angle of 100º (range, 23–178º) versus 86º (range, 43–160º; p = 0.01); vertical descending orientation in 56% versus 45% (p = 0.2); absence of gas in 69% versus 77% (p = 0.34); and presence of an appendicolith in 17% versus 8% (p = 0.08). CONCLUSION: Hypothetical risk factors for obstruction of the vermiform appendix detected on CT were not associated with acute appendicitis. That suggests that factors other than those related to mechanical obstruction are implicated in the pathogenesis of acute appendicitis.

Keywords: Appendicitis; Appendix; Multidetector computed tomography; Emergency medicine.

OBJECTIVE: To evaluate the accuracy of percutaneous transhepatic biliary biopsy (PTBB) in patients with suspected biliary obstruction. MATERIALS AND METHODS: This was a retrospective analysis of 18 patients with obstructive jaundice who underwent PTBB. In each patient, three to ten fragments were collected from the lesion. The final diagnosis was confirmed in the pathology report. We also reviewed analyses of the results of laboratory tests performed before the procedure, as well as the Bismuth classification, clinical outcome, complications occurring during the procedure, access route, and materials used. RESULTS: Technical success was achieved in 100% of the PTBB procedures. Among the 18 patients clinically diagnosed with bile duct stenosis, the pathological analysis confirmed that diagnosis in 17. In one case, the pathological findings were considered false-negative. The predominant tumor was cholangiocarcinoma (seen in 50% of the cases). Sixteen of the procedures (88.9%) were performed without complications. Transient hemobilia occurred in one case, and cholangitis occurred in another. CONCLUSION: PTBB is a safe, viable, simple technique with a high rate of true-positive results for the definitive diagnosis of obstructive jaundice.

Keywords: Jaundice, obstructive; Biliary tract; Biopsy/methods; Biopsy, needle/methods; Cholangiography.

OBJECTIVE: To evaluate the added value of diffusion-weighted imaging (DWI) in the preoperative assessment of myometrial invasion in endometrial cancer, in comparison with T2-weighted imaging (T2WI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). MATERIALS AND METHODS: This was a retrospective study involving 44 women with endometrial cancer who underwent preoperative 1.5 T MRI. Two radiologists, both of whom were blinded to the histopathology reports, performed a consensus interpretation of the depth of myometrial invasion and of the stage of the cancer, considering three sets of sequences: T2WI, DCE-MRI+T2WI, and DWI+T2WI. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each set. The accuracy was compared with p-value adjustment by the Benjamini-Hochberg procedure. RESULTS: Among the 44 patients evaluated, DWI+T2WI demonstrated better diagnostic performance in assessing deep myometrial invasion and correctly staged more patients (n = 41) than did DCE-MRI+T2WI (n = 34) and T2WI (n = 22). The superior diagnostic accuracy of DWI+T2WI was statistically significant in comparison with T2WI (p < 0.05) but not in comparison with DCE-MRI+T2WI (p > 0.05). CONCLUSION: The addition of DWI apparently improves the diagnostic accuracy of MRI in the preoperative assessment of the depth of myometrial invasion in endometrial cancer, which may be particularly helpful in patients for whom contrast agents are contraindicated.

Keywords: Endometrial neoplasms; Magnetic resonance imaging; Gynecology; Neoplasms; Endometrium/pathology.

OBJECTIVE: To determine the size of the ischiofemoral space (IFS) and quadratus femoris space (QFS) in patients with and without ischiofemoral impingement (IFI). MATERIALS AND METHODS: Case-control study including consecutive patients submitted to magnetic resonance imaging (MRI) of the hip joint during a three-month period. Patients with deep gluteal pain who tested positive for IFI on at least one clinical test and showed signal changes in the quadratus femoris muscle on MRI were categorized as having a confirmed diagnosis of IFI. RESULTS: Final sample comprised 50 patients submitted to unilateral MRI of the hip joint. The mean age was 47.3 ± 14.0 years (range, 22–76 years), and 33 (66%) of the patients were women. A diagnosis of IFI was made in 6 patients (12%), all of whom were female. On average, IFS and QFS were significantly smaller in IFI group than in control group (11.1 ± 2.7 mm versus 27.5 ± 6.5 mm and 5.3 ± 1.8 mm versus 18.8 ± 4.8 mm, respectively; p < 0.001 for both). CONCLUSION: Results of specific clinical tests and MRI findings indicate that the IFS and QFS are significantly reduced in patients with IFI.

Keywords: Hip joint; Ischium/pathology; Joint diseases/diagnostic imaging; Arthralgia/etiology; Magnetic resonance imaging.

The elastic properties of tissue have always been of interest in clinical practice. In the past, the identification of structures that were stiffer on physical palpation would raise the suspicion that "there was something wrong". With the development and advancement of medicine, there proved to be a true correlation in the prediction of malignancy of a lesion: malignant disease tends to stiffen the affected tissue, either by increased cell proliferation or fibrosis. Palpation is the oldest method for the detection of thyroid nodules, which is informed by the knowledge that malignant thyroid lesions tend to be much harder than benign ones. Unfortunately, palpation is a highly subjective method that is dependent on the size and location of the lesion, as well as on the skill of the physician. In cases where these nodules are very small or are located in deep regions, their detection by palpation is difficult or even impossible. In addition, although a malignant lesion differs in terms of elasticity, it may not have echogenic properties, preventing its detection by conventional ultrasound. Imaging that indicates the stiffness or deformation of tissues, through the use of ultrasound elastography techniques, adds new information related to their structural formation. In this article, we review the basic physical principles of elastography and the evolution of the method for the evaluation of thyroid nodules, as well as the limitations of and future perspectives for its use.

Keywords: Thyroid gland; Elasticity imaging techniques/methods; Ultrasonography/methods; Thyroid nodule/diagnostic imaging; Shear wave elastography.

More than half of patients over 50 years of age have had at least one focal renal lesion detected as an incidental finding during an ultrasound, computed tomography, or magnetic resonance imaging examination. Although the majority of such lesions can be easily detected and correctly characterized, misdiagnoses may occur and are often related to methodological limitations, inappropriate imaging protocols, or misinterpretation. This pictorial essay provides recommendations on how to recognize benign and malignant renal processes that can be potentially missed or mischaracterized in imaging studies.

Keywords: Kidney neoplasms/diagnostic imaging; Magnetic resonance imaging; Ultrasonography; Computed tomography.

Snapping scapula syndrome manifests as an audible or palpable crackling during the sliding movements of the scapula over the rib cage, often perceived during physical or professional activities. It can be caused by morphological alteration of the scapula and rib cage, by an imbalance in periscapular musculature forces (dyskinesia), or by neoplasia (bone tumors or soft tissue tumors). In this pictorial essay, we review the main causes of snapping scapula syndrome, exemplified by a collection of didactic cases.

Keywords: Scapula; Joint diseases/diagnostic imaging; Shoulder.

Primary extranodal lymphoma is defined as a lymphoma at a solitary extranodal site, with or without involvement of the lymph nodes. The clinical and radiological features of extranodal lymphoma have been documented in recent studies. In this pictorial essay, we reviewed imaging findings of extranodal lymphoma in the head and neck region.

Keywords: Intraocular lymphoma; Tomography, X-ray computed; Magnetic resonance imaging; Head and neck neoplasms; Lymphoma.