Neurofibromatosis type 1 is one of the most common genetic diseases with autosomic dominant inheritance pattern in humans. The main radiological findings are: scoliosis, kyphoscoliosis, bone erosions, abnormal osseous growth, pseudarthrosis, meningeal cysts, deformity of the posterior wall of the vertebral bodies ("scalloping"), pectus excavatum, osteolytic lesions in the long bones and central nervous system abnormalities. The authors present the statistical data from the analysis of the radiological findings in 82 patients with neurofibromatosis type 1 attending the "Centro de Pesquisa e Atendimento em Neurofibromatose", in São José do Rio Preto, SP, Brazil, a multidisciplinary center for the study and treatment of neurofibromatosis.

Keywords: Neurofibromatosis, Neurofibromatosis type 1, Radiology, Phacomatosis

Primary urethral calculi are uncommon in the Western world. Stone formation is frequently associated with prior disorders affecting the urinary flow such as urethral diverticula, stenosis of the urethra and impacted foreign bodies. The authors report a case of a 77-year-old man, who complained of acute urinary retention and pain on the genital area. The diagnosis of urethral lithiasis was established and radiological studies revealed a wood cylindrical foreign body inside the stone.

Keywords: Calculus, Urethra, Foreign body

OBJECTIVE: To determine the positive predictive value (PPV) and likelihood ratio for magnetic resonance imaging (MRI) characteristics of category 4 lesions, as described in the Breast Imaging Reporting and Data System (BI-RADS^®) lexicon, as well as to test the predictive performance of the descriptors using multivariate analysis and the area under the curve derived from a receiver operating characteristic (ROC) curve. MATERIALS AND METHODS: This was a double-blind review study of 121 suspicious findings from 98 women examined between 2009 and 2013. The terminology was based on the 2013 edition of the BI-RADS. RESULTS: Of the 121 suspicious findings, 53 (43.8%) were proven to be malignant lesions, with no significant difference between mass and non-mass enhancement (p = 0.846). The PPVs were highest for masses with a spiculated margin (71%) and round shape (63%), whereas segmental distribution achieved a high PPV (80%) for non-mass enhancement. Kinetic analyses performed poorly, except for type 3 curves applied to masses (PPV of 73%). Logistic regression models were significant for both patterns, although the results were better for masses, particularly when kinetic assessments were included (p = 0.015; pseudo R² = 0.48; area under the curve = 90%). CONCLUSION: Some BI-RADS MRI descriptors have high PPV and good predictive performance-as demonstrated by ROC curve and multivariate analysis-when applied to BI-RADS category 4 findings. This may allow future stratification of this category.

Keywords: Magnetic resonance imaging; Breast neoplasms; Predictive value of tests; Likelihood functions.

OBJECTIVE: To test the use of diffusion-weighted imaging (DWI) in stratifying suspicious breast lesions (BI-RADS 4), correlating them with histopathology. We also investigated the performance of DWI related to the main enhancement patterns (mass and non-mass) and tested its reproducibility. MATERIALS AND METHODS: Seventy-six patients presented 92 lesions during the sampling period. Two independent examiners reviewed magnetic resonance imaging studies, described the lesions, and determined the apparent diffusion coefficient (ADC) values. Differences among benign, indeterminate- to high-risk, and malignant findings, in terms of the ADCs, were assessed by analysis of variance. Using receiver operating characteristic (ROC) curves, we compared the performance of ADC values in masses and non-mass lesions, and tested the reproducibility of measurements by determining the coefficient of variation and smallest real difference. RESULTS: Among the 92 lesions evaluated, the histopathology showed that 37 were benign, 11 were indeterminate- to high-risk, and 44 were malignant. The mean ADC differed significantly among those histopathological groups, the value obtained for the malignant lesions (1.10 × 10^-3 mm²/s) being significantly lower than that obtained for the other groups (p < 0.001). ROC curves demonstrated that DWI performed better when applied to masses than when applied to non-mass lesions (area under the curve, 0.88 vs. 0.67). Reproducibility was good (coefficient of variation, 7.03%; and smallest real difference, ± 0.242 × 10^-3 mm²/s). CONCLUSION: DWI can differentiate between malignant and nonmalignant (benign or indeterminate- to high-risk) lesions, showing better performance for masses. Nevertheless, stratification based on histopathological criteria that are more refined has yet to be achieved.

Keywords: Magnetic resonance imaging; Breast neoplasms; Diffusion magnetic resonance imaging/methods; Neoplasms/pathology.

OBJECTIVE: To compare the pain expected to that effectively caused by magnetic resonance arthrography of the shoulder and, secondarily, to describe a simplified approach to the technique for articular access. MATERIALS AND METHODS: We prospectively evaluated 40 participants who used a visual analog scale and a simplified categorical scale to indicate the level of pain expected and that experienced after the procedure, comparing the two with the Wilcoxon matched-pairs test. We also determined gender-related differences in pain conditions using the Mann–Whitney U test. In addition, we described a modified technique involving radiographic localization and the use of standard puncture needles for articular access. RESULTS: Analysis of the visual analog scales showed that the pain experienced was less than had been expected, with median scores of 1.75 and 3.75, respectively (p < 0.001). The level of pain expected was higher among women than among men, with median scores of 8.0 and 3.0, respectively (p = 0.014), as was the level of pain experienced, with median scores of 3.0 and 1.5, respectively (p = 0.139). The overall categorical evaluation corroborated that difference (p = 0.03). Articular access with the modified technique was successful in all patients. CONCLUSION: Magnetic resonance arthrography of the shoulder is less painful than patients expect. In addition, digital radiographic guidance combined with the use of standard puncture needles appears to improve the efficiency of the method.

Keywords: Magnetic resonance imaging; Arthrography; Shoulder; Pain; Visual analog scale.