The aim of this study is to describe the clinical, mammography and ultrasound findings of three cases of idiopathic granulomatous mastitis. This disease can mimic breast carcinoma on clinical and mammographic examinations. However, ultrasound examinations showing multiple clustered and often contiguous tubular hypoechoic lesions in young women with history of recent lactation suggest the diagnosis of idiopathic granulomatous mastitis.

Keywords: Idiopathic granulomatous mastitis, Mammography, Ultrasound

This paper describes the operational characteristics of the final process of implementation of a quality control program using routine mechanical and radiation tests. The quality control program was performed during 35 months and demonstrated the excellent stability of this accelerator.

Keywords: Linear accelerator, Quality control, Photon radiation

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

The authors report a case of a 20-year-old patient with the following clinical features: a) complete rotation of the liver into the left upper quadrant; b) severe hypotension secondary to inferior vena cava compression; c) congenital malformation of falciform and coronary ligaments; d) obstruction of the transverse colon due to congenital peritoneal fibrotic bands; e) massive colonic dilatation in the right upper quadrant. The patient was treated by resection of the pericolonic bands, and during the operation the liver returned to its anatomic position, in the right upper abdomen. This unique condition, and the three other similar cases reported in the world literature are discussed.

Keywords: Hepatic torsion. Transverse colon. Obstructive band.

With the steep increase in the use of cross-sectional imaging in recent years, the incidentally detected adrenal lesion, or "incidentaloma", has become an increasingly common diagnostic problem for the radiologist, and a need for an approach to classifying these lesions as benign, malignant or indeterminate with imaging has spurred an explosion of research. While most incidentalomas represent benign disease, typically an adenoma, the possibility of malignant involvement of the adrenal gland necessitates a reliance on imaging to inform management decisions. In this article, we review the literature on adrenal gland imaging, with particular emphasis on computed tomography, magnetic resonance imaging, and photon-emission tomography, and discuss how these findings relate to clinical practice. Emerging technologies, such as contrast-enhanced ultrasonography, dual-energy computed tomography, and magnetic resonance spectroscopic imaging will also be briefly addressed.

Keywords: Adrenal gland; Adenoma; Cancer; Diagnosis; Radiology.

The Bosniak classification for renal cysts was developed in the late 1980s in an attempt to standardize the description and management of complex cystic renal lesions. Alterations were made to such a classification in the 1990s and, the last one, in 2005. Currently, five categories of cystic renal lesions are defined - namely, I, II, II-F, III and IV –, according to their degree of complexity and likelihood of malignancy. Despite being initially described for computed tomography, this classification has been also utilized with some advantages also for magnetic resonance imaging. The present article reviews the different phases of this classification, its diagnostic efficacy and the most controversial features of its use.

Keywords: Renal cysts; Bosniak; Computed tomography; Magnetic resonance imaging.

Renal cell carcinoma (RCC) is the seventh most common histological type of cancer in the Western world and has shown a sustained increase in its prevalence. The histological classification of RCCs is of utmost importance, considering the significant prognostic and therapeutic implications of its histological subtypes. Imaging methods play an outstanding role in the diagnosis, staging and follow-up of RCC. Clear cell, papillary and chromophobe are the most common histological subtypes of RCC, and their preoperative radiological characterization, either followed or not by confirmatory percutaneous biopsy, may be particularly useful in cases of poor surgical condition, metastatic disease, central mass in a solitary kidney, and in patients eligible for molecular targeted therapy. New strategies recently developed for treating renal cancer, such as cryo and radiofrequency ablation, molecularly targeted therapy and active surveillance also require appropriate preoperative characterization of renal masses. Less common histological types, although sharing nonspecific imaging features, may be suspected on the basis of clinical and epidemiological data. The present study is aimed at reviewing the main clinical and imaging findings of histological RCC subtypes.

Keywords: Renal cell carcinoma; Kidney cancer; Computed tomography; Magnetic resonance imaging.

OBJECTIVE: The present study is aimed at contributing to identify the most appropriate OSEM parameters to generate myocardial perfusion imaging reconstructions with the best diagnostic quality, correlating them with patients' body mass index. MATERIALS AND METHODS: The present study included 28 adult patients submitted to myocardial perfusion imaging in a public hospital. The OSEM method was utilized in the images reconstruction with six different combinations of iterations and subsets numbers. The images were analyzed by nuclear cardiology specialists taking their diagnostic value into consideration and indicating the most appropriate images in terms of diagnostic quality. RESULTS: An overall scoring analysis demonstrated that the combination of four iterations and four subsets has generated the most appropriate images in terms of diagnostic quality for all the classes of body mass index; however, the role played by the combination of six iterations and four subsets is highlighted in relation to the higher body mass index classes. CONCLUSION: The use of optimized parameters seems to play a relevant role in the generation of images with better diagnostic quality, ensuring the diagnosis and consequential appropriate and effective treatment for the patient.

Keywords: Nuclear cardiology; Myocardial perfusion imaging; Iterative methods; Image reconstruction; Nuclear medicine.

OBJECTIVE: To examine the potential of two magnetic resonance imaging (MRI) techniques—dynamic contrast enhancement (DCE) and diffusion-weighted imaging (DWI)—for the detection of malignant cervical lymph nodes. MATERIALS AND METHODS: Using DCE and DWI, we evaluated 33 cervical lymph nodes. For the DCE technique, the maximum relative enhancement, relative enhancement, time to peak enhancement, wash-in rate, wash-out rate, brevity of enhancement, and area under the curve were calculated from a semi-quantitative analysis. For the DWI technique, apparent diffusion coefficients (ADCs) were acquired in the region of interest of each lymph node. Cystic or necrotic parts were excluded. All patients underwent neck dissection or node biopsy. Imaging results were correlated with the histopathological findings. None of the patients underwent neoadjuvant treatment before neck dissection. RESULTS: Relative enhancement, maximum relative enhancement, and the wash-in rate were significantly higher in malignant lymph nodes than in benign lymph nodes (p < 0.009; p < 0.05; and p < 0.03, respectively). The time to peak enhancement was significantly shorter in the malignant lymph nodes (p < 0.02). In the multivariate analysis, the variables identified as being the most capable of distinguishing between benign and malignant lymph nodes were time to peak enhancement (sensitivity, 73.7%; specificity, 69.2%) and relative enhancement (sensitivity, 89.2%; specificity, 69.2%). CONCLUSION: Although DCE was able to differentiate between benign and malignant lymph nodes, there is still no consensus regarding the use of a semi-quantitative analysis, which is difficult to apply in a clinical setting. Low ADCs can predict metastatic disease, although inflammatory processes might lead to false-positive results.

Keywords: Lymph nodes/diagnostic imaging; Lymphatic metastasis/diagnostic imaging; Magnetic resonance imaging/methods; Diffusion magnetic resonance imaging.

Hip arthroplasty is a widely used and successful orthopedic procedure for the treatment of degenerative, inflammatory, or traumatic joint disease. The procedure promotes significant pain relief, as well as recovery of limb function, reduction of disability, and better quality of life. However, there are related complications, which have characteristic imaging aspects. In the present study, we review the literature and exemplify such complications using images obtained at our facility, illustrating the main radiological aspects of complications such as heterotopic ossification, periprosthetic fractures, osteolysis, infection, wear, and dislocation.

Keywords: Hip joint/physiopathology; Hip joint/diagnostic imaging; Arthroplasty, replacement, hip/diagnostic imaging; Arthroplasty, replacement, hip/adverse effects.

OBJECTIVE: To determine the best cutoff value for classifying breast masses by ultrasound elastography, using dedicated software for strain elastography, and to determine the level of interobserver agreement. MATERIALS AND METHODS: We enrolled 83 patients with 83 breast masses identified on ultrasound and referred for biopsy. After B-mode ultrasound examination, the lesions were manually segmented by three radiologists with varying degrees of experience in breast imaging, designated reader 1 (R1, with 15 years), reader 2 (R2, with 2 years), and reader 3 (R3, with 8 years). Elastography was performed automatically on the best image with computer-aided diagnosis (CAD) software. Cutoff values of 70%, 75%, 80%, and 90% of hard areas were applied for determining the performance of the CAD software. The best cutoff value for the most experienced radiologists was then compared with the visual assessment. Interobserver agreement for the best cutoff value was determined, as were the interclass correlation coefficient and concordance among the radiologists for the areas segmented. RESULTS: The best cutoff value of the proportion of hard area within a breast mass, for experienced radiologists, was found to be 75%. At a cutoff value of 75%, the interobserver agreement was excellent between R1 and R2, as well as between R1 and R3, and good between R2 and R3. The interclass concordance coefficient among the three radiologists was 0.950. When assessing the segmented areas by size, we found that the level of agreement was higher among the more experienced radiologists. CONCLUSION: The best cutoff value for a quantitative CAD system to classify breast masses was 75%.

Keywords: Ultrasonography; Elasticity imaging techniques; Breast; Diagnosis, computer-assisted; Observer variation.

Cholangiopathies are chronic diseases that affect the bile ducts, comprising a heterogeneous group of progressive and potentially fatal entities. The diagnosis of these diseases is a great challenge for radiologists because of the overlapping of their clinical, biochemical, and imaging findings. Nevertheless, identifying the precise etiology is crucial, given that the therapeutic options are distinct and influence the prognosis of the patient. The purpose of this review article is to discuss some of the non-neoplastic causes of cholangiopathies and to provide a useful diagnostic algorithm.

Keywords: Bile duct diseases; Liver cirrhosis; Cholangiography; Computed tomography; Magnetic resonance imaging.

Soft-tissue calcifications are extremely common. Because the imaging findings are nonspecific, soft-tissue calcifications are often problematic for radiologists, sometimes prompting unnecessary interventions. In addition, the nomenclature is quite confusing. Classically, soft-tissue calcifications are divided into four categories, by mechanism of formation—dystrophic, iatrogenic, metastatic, and idiopathic—depending on the clinical and biochemical correlation. However, it is also possible to classify such calcifications by compartment, and that classification can be quite useful in the radiological diagnostic assessment. In this article, we illustrate the main causes of soft-tissue calcifications, organizing them according to their anatomical and pathophysiological aspects, thus narrowing the differential diagnosis.

Keywords: Calcinosis/diagnostic imaging; Radiography; Diagnosis, differential.

OBJECTIVE: To evaluate the association between shear wave elastography parameters and arterial resistance in kidney transplant recipients. MATERIALS AND METHODS: This was a prospective cross-sectional study involving consecutive adult kidney transplant recipients. All patients underwent color Doppler to evaluate the resistive index (RI) and ultrasound shear wave elastography for the quantification of renal allograft stiffness. RESULTS: We evaluated 55 patients, of whom 9 (16.4%) had an RI defined as abnormal (≥ 0.79) and 46 (83.6%) had an RI defined as normal (< 0.79). The mean age was higher in the abnormal RI group than in the normal RI group (68.0 ± 8.6 years vs. 42.6 ± 14.1 years; p < 0.001), as was the mean shear wave velocity (2.6 ± 0.4 m/s vs. 2.2 ± 0.4 m/s; p = 0.013). Multivariate analysis identified two independent predictors of arterial resistance: age (OR = 1.169; 95% CI: 1.056 to 1.294; p = 0.003) and shear wave velocity (OR = 17.1; 95% CI: 1.137 to 257.83; p = 0.040). CONCLUSION: We observed an association between rigidity in the cortex of the transplanted kidney, as evaluated by shear wave elastography, and arterial resistance, as evaluated by color Doppler, in kidney transplant recipients.

Keywords: Kidney transplantation; Elasticity imaging techniques; Ultrasonography, Doppler, color.

Deformities of the lower limbs are a common condition and can lead to changes in gait, as well as affecting the function and longevity of the hips, knees, and spine. A systematic approach is essential to achieve the desired therapeutic result with the lowest rate of complications. Panoramic radiography is a widely available, low-cost method that is commonly used in order to assess the length and angular deformities of the lower limbs, by measuring the length and angular deviations of the axes. However, because the combination of lower limb deformities in two or three orthogonal planes is common, conventional radiography lacks accuracy because it is a two-dimensional imaging method. Therefore, the measurements of valgus/varus deformities on X-rays restricted to the coronal plane will present increasing variations in measurements depending on the degree of flexion/recurvatum alignment, anomalous bone torsions, or, last but not least, inappropriate patient positioning. Low-dose biplanar stereoradiography using three-dimensional models increases the accuracy of the measurement of several parameters used in the evaluation of lower limb alignment, including lengths, axes, and tibial/femoral torsions, parameters that could previously be evaluated only by computed tomography. Stereoradiography also makes it possible to perform a head-to-toe evaluation, as well as to evaluate the interactions among the lower limbs, pelvis, and spine.

Keywords: Radiography; Lower limb; Lower extremity deformities; Diagnostic imaging.