Histogram analysis in the differentiation between adrenal adenomas and pheochromocytomas: the value of a single measurement.

Objective: To assess the diagnostic accuracy of histogram analysis on unenhanced computed tomography (CT) for differentiating between adrenal adenomas and pheochromocytomas (PCCs). Materials and Methods: We retrospectively identified patients with proven PCCs who had undergone CT examinations between January 2009 and July 2019 at one of two institutions. For each PCC, we selected one or two adenomas diagnosed within two weeks of the date of diagnosis of the PCC. For each lesion, two readers scored the size, determined the mean attenuation, and generated a voxel histogram. The 10th percentile (P10) was obtained from the conventional histogram analysis, as well as being calculated with the following formula: P10 = mean attenuation - (1.282 × standard deviation). The mean attenuation threshold, histogram analysis (observed) P10, and calculated P10 (calcP10) were compared in terms of their diagnostic accuracy. Results: We included 52 adenomas and 29 PCCs. The sensitivity, specificity, and accuracy of the mean attenuation threshold were 75.0%, 100.0%, and 82.5%, respectively, for reader 1, whereas they were 71.5%, 100.0%, and 81.5%, respectively, for reader 2. The sensitivity, specificity, and accuracy of the observed P10 and calcP10 were equal for both readers: 90.4%, 96.5%, and 92.6%, respectively, for reader 1; and 92.3%, 93.1%, and 92.6%, respectively, for reader 2. The increase in sensitivity was significant for both readers (p = 0.009 and p = 0.005, respectively). Conclusion: For differentiating between adenomas and PCCs, the histogram analysis (observed P10 and calcP10) appears to outperform the mean attenuation threshold as a diagnostic criterion.

Objetivo: Avaliar a acurácia diagnóstica da análise por histograma na tomografia computadorizada (TC) sem contraste para a diferenciação entre adenomas adrenais e feocromocitomas (FCCs). Materiais e Métodos: Identificamos, retrospectivamente, pacientes com diagnóstico de FCC confirmado que foram submetidos a exames de TC entre janeiro de 2009 e julho de 2019 em duas instituições distintas. Para cada FCC, selecionamos um ou dois adenomas diagnosticados em até duas semanas da data do diagnóstico do FCC. Para cada lesão, dois leitores pontuaram o tamanho, determinaram a atenuação média e geraram um histograma com os voxels das imagens. O percentil 10 (P10) foi obtido a partir da análise convencional do histograma, além de ser calculado com a seguinte fórmula: P10 = atenuação média - (1,282 × desvio-padrão). O limiar de atenuação média, o P10 da análise por histograma (P10 observado) e o P10 calculado (P10calc) foram comparados em termos de acurácia diagnóstica. Resultados: Foram incluídos 52 adenomas e 29 FCCs. A sensibilidade, especificidade e acurácia do limiar de atenuação média foram de 75,0%, 100,0% e 82,5% para o leitor 1, respectivamente, e de 71,5%, 100,0% e 81,5% para o leitor 2, respectivamente. A sensibilidade, especificidade e acurácia do P10 observado e do P10calc foram idênticas para os dois leitores: 90,4%, 96,5% e 92,6%, respectivamente, para o leitor 1; e 92,3%, 93,1% e 92,6%, respectivamente, para o leitor 2. O aumento da sensibilidade foi significativo para ambos os leitores (p = 0,009 e p = 0,005, respectivamente). Conclusão: Para a diferenciação entre adenomas e FCCs, a análise por histograma (P10 observado ou P10calc) parece superar o limiar de atenuação média como critério diagnóstico.

Histogram analysis in the differentiation between adrenal adenomas and pheochromocytomas: the value of a single measurement / Análise por histograma para diferenciação entre adenomas da adrenal e feocromocitomas: o valor de uma medida única

Abstract Objective: To assess the diagnostic accuracy of histogram analysis on unenhanced computed tomography (CT) for differentiating between adrenal adenomas and pheochromocytomas (PCCs). Materials and Methods: We retrospectively identified patients with proven PCCs who had undergone CT examinations between January 2009 and July 2019 at one of two institutions. For each PCC, we selected one or two adenomas diagnosed within two weeks of the date of diagnosis of the PCC. For each lesion, two readers scored the size, determined the mean attenuation, and generated a voxel histogram. The 10th percentile (P10) was obtained from the conventional histogram analysis, as well as being calculated with the following formula: P10 = mean attenuation - (1.282 × standard deviation). The mean attenuation threshold, histogram analysis (observed) P10, and calculated P10 (calcP10) were compared in terms of their diagnostic accuracy. Results: We included 52 adenomas and 29 PCCs. The sensitivity, specificity, and accuracy of the mean attenuation threshold were 75.0%, 100.0%, and 82.5%, respectively, for reader 1, whereas they were 71.5%, 100.0%, and 81.5%, respectively, for reader 2. The sensitivity, specificity, and accuracy of the observed P10 and calcP10 were equal for both readers: 90.4%, 96.5%, and 92.6%, respectively, for reader 1; and 92.3%, 93.1%, and 92.6%, respectively, for reader 2. The increase in sensitivity was significant for both readers (p = 0.009 and p = 0.005, respectively). Conclusion: For differentiating between adenomas and PCCs, the histogram analysis (observed P10 and calcP10) appears to outperform the mean attenuation threshold as a diagnostic criterion.

Resumo Objetivo: Avaliar a acurácia diagnóstica da análise por histograma na tomografia computadorizada (TC) sem contraste para a diferenciação entre adenomas adrenais e feocromocitomas (FCCs). Materiais e Métodos: Identificamos, retrospectivamente, pacientes com diagnóstico de FCC confirmado que foram submetidos a exames de TC entre janeiro de 2009 e julho de 2019 em duas instituições distintas. Para cada FCC, selecionamos um ou dois adenomas diagnosticados em até duas semanas da data do diagnóstico do FCC. Para cada lesão, dois leitores pontuaram o tamanho, determinaram a atenuação média e geraram um histograma com os voxels das imagens. O percentil 10 (P10) foi obtido a partir da análise convencional do histograma, além de ser calculado com a seguinte fórmula: P10 = atenuação média - (1,282 × desvio-padrão). O limiar de atenuação média, o P10 da análise por histograma (P10 observado) e o P10 calculado (P10calc) foram comparados em termos de acurácia diagnóstica. Resultados: Foram incluídos 52 adenomas e 29 FCCs. A sensibilidade, especificidade e acurácia do limiar de atenuação média foram de 75,0%, 100,0% e 82,5% para o leitor 1, respectivamente, e de 71,5%, 100,0% e 81,5% para o leitor 2, respectivamente. A sensibilidade, especificidade e acurácia do P10 observado e do P10calc foram idênticas para os dois leitores: 90,4%, 96,5% e 92,6%, respectivamente, para o leitor 1; e 92,3%, 93,1% e 92,6%, respectivamente, para o leitor 2. O aumento da sensibilidade foi significativo para ambos os leitores (p = 0,009 e p = 0,005, respectivamente). Conclusão: Para a diferenciação entre adenomas e FCCs, a análise por histograma (P10 observado ou P10calc) parece superar o limiar de atenuação média como critério diagnóstico.

Histopathological Criteria for Paediatric Adrenocortical Carcinoma.

INTRODUCTION: Adrenocortical carcinoma (ACC) is diagnosed in paediatric patients at 5 months after symptom onset on average, and 38% die during the first 2.5 years of follow-up. This study aimed to compare the accuracy of Weiss, Van Slooten, and Wieneke histopathological ACC classifications for predicting follow-up prognosis in a paediatric population. METHODS: Data were retrieved from medical records of 57 patients aged <18 years who underwent surgical treatment for ACC with surgical follow-up over 6 months or death due to ACC. They were classified into either good (without recurrence/death due to ACC) or poor (with recurrence/death due to ACC) prognosis group. Two expert pathologists classified the ACC surgical specimens according to the Weiss, Van Slooten, and Wieneke criteria. RESULTS: The median follow-up duration was 126 (18-225) months in 38 males (66.7%) and 19 females (33.3%) (median age: 3 [1-6.5] years). The good prognosis group was younger than the poor prognosis group (median age: 3 [1.5-6.2] years vs. 5 [2-10] years). Seventeen (29.8%) patients in the poor prognosis group died due to ACC within the first 50 months of surgical follow-up; the earliest death occurred in the fourth follow-up month, and the majority of deaths occurred within 24 months of follow-up. The accuracies of Weiss, Van Slooten, and Wieneke classification systems were 40%, 47%, and 77%, respectively. DISCUSSION/CONCLUSION: The Wieneke classification showed the best accuracy but was not sufficiently precise to establish reliable prognosis for ACC in the paediatric population. The Wieneke classification had approximately 95% sensitivity and negative predictive value.

What is the impact of dynamic contrast-enhancement sequence in the Vesical Imaging, Reporting and Data System (VI-RADS)? A subgroup analysis.

BACKGROUND: A scoring system focusing on the risk of muscle layer invasion by Bladder cancer (BCa) has been released, Vesical Imaging - Radiological and Data System (VI-RADS), with a growing interest in evaluating its diagnostic accuracy. Our goal was to assess the accuracy and reproducibility of the VI-RADS score for assessment of the vesical muscular layer with (multiparametric-mp) and without (biparametric-bp) a dynamic-contrast enhancement (DCE) sequence. METHODS: Retrospective study conducted from July 2018 to July 2020. All patients had suspicions of BCa and underwent Magnetic Resonance Imaging (MRI) before any intervention. MRI was interpreted by two radiologists with different levels of experience, and a VI-RADS score assigned in two different sessions (3 months apart) without and with DCE. After exclusions, 44 patients with 50 lesions were enrolled. The standard of reference was transurethral resection in 18 patients (40.9%) and cystectomy in 26 patients (59.1%). RESULTS: Twenty-five lesions (50%) were muscle-invasive. There was no significant difference between the two groups for gender and presence of a stalk, but mean age of NMIBCa group was significantly higher (p = 0.01). The sizes of lesions were significantly different between groups for both readers at 2.42+/- 1.58 vs. 5.70+/- 2.67 cm for reader 1 (p < 0.0001) and 2.37+/- 1.50 vs. 5.44 +/- 2.90 cm for reader 2 (p = 0.001). The area under the curve (AUC) for muscle invasion with mpVI-RADS, considering all lesions, was 0.885 +/- 0.04 (95% CI-0.79-0.98) for reader 1 and 0.924 +/- 0.04 (0.84-0.99) for reader 2, and for bpVI-RADS was 0.879+/- 0.05 and 0.916 +/- 0.04 (0.85-0.99), respectively, both differences not statistically significant (p = 0.24 and 0.07, respectively). When considering only small lesions (< 3.0 cm), the accuracy for mpVI-RADS was 0.795 +/- 0.11 (0.57-1.0) for reader1, and 0.80 +/- 0.11(0.57-1.0) for reader 2, a non-significant difference (p = 0.56) and for bpVI-RADS was 0.747 +/- 0.12 (0.50-0.99) for reader 1 and 0.80 +/- 0.11(0.57-1.0) for reader 2, a significant difference (p = 0.04). The intraclass correlation coefficient for the final score was 0.81 (0.60-1.0) for mpVI-RADS and 0.85 (0.63-1.0) for bpVI-RADS. CONCLUSION: The VI-RADS system was accurate in demonstrating muscle-invasive BCa, for both experienced and less experienced reader, regardless of the use of a DCE sequence. However, when only small lesions were assessed the difference between the two readers was significant only for the biparametric analysis. The reproducibility was similar between multiparametric and biparametric approach.

Early Renin Recovery After Adrenalectomy in Aldosterone-Producing Adenomas: A Prospective Study.

The aim of the study was to clarify the relationship and the time of aldosterone and renin recoveries at immediate and long-term follow-up in aldosterone-producing adenoma (APA) patients who underwent adrenalectomy. Prospective and longitudinal protocol in a cohort of APA patients was followed in a single center. Among 43 patients with primary aldosteronism (PA), thirteen APA patients were enrolled in this study. Blood was collected for aldosterone, renin, potassium, creatinine, cortisol, and ACTH before and 1, 3, 5, 7, 15, 30, 60, 90, 120, 180, 270, 360 days after adrenalectomy. At diagnosis, most patients (84%) had hypokalemia and high median aldosterone levels (54.8; 24.0-103 ng/dl) that decreased to undetectable (<2.2) or very low (<3.0) levels between fifth to seventh days after surgery; then, between 3-12 months, its levels gradually increased to the lower normal range. The suppressed renin (2.3; 2.3-2.3 mU/l) became detectable between the fifteen and thirty days after surgery, remaining normal throughout the study. The aldosterone took longer than renin to recover (60 vs.15 days; p<0.002) and patients with higher aldosterone had later recovery (p=0.03). The cortisol/ACTH levels remained normal despite the presence of a post-operative hypoaldosteronism. Blood pressure and antihypertensive requirement decreased after adrenalectomy. In conclusion, our prospective study shows the borderline persistent post-operative hypoaldosteronism in the presence of early renin recovery indicating incapability of the zona glomerulosa of the remaining adrenal gland to produce aldosterone. These findings contribute to the comprehension of differences in renin and aldosterone regulation in APA patients, although both are part of the same interconnected system.

Independent external validation of nomogram to predict extracapsular extension in patients with prostate cancer.

INTRODUCTION: The objective of this study was to perform an independent external validation of the Giganti-Coppola nomogram (GCN), which uses clinical and radiological parameters to predict prostate extracapsular extension (ECE) on the final pathology of patients undergoing radical prostatectomy (RP). MATERIAL AND METHODS: Seventy-two patients diagnosed with prostate cancer (PCa), who were RP candidates from two institutions, were prospectively included. All patients underwent preoperative multi-parametric magnetic resonance imaging (mpMRI) at 1.5 T, without the use of an endorectal coil, with multiplanar images in T1WI, T2WI, DWI, and DCE. The AUC and a calibration graph were used to validate the nomogram, using the regression coefficients of the Giganti-Coppola study. RESULTS: The original nomogram had an AUC of 0.90 (p = 0.001), with a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 5.1%, 47.1%, 100%, and 48%, respectively. The calibration graph showed an overestimation of the nomogram for ECE. CONCLUSION: The GCN has an adequate ability in predicting ECE; however, in our sample, it showed limited accuracy and overestimated likelihood of ECE in the final pathology of patients with PCa submitted to RP. KEY POINTS: • Knowledge of preoperative local staging of prostate cancer is essential for surgical treatment. Extracapsular extension increases the chance of positive surgical margins. • Imaging modalities such as mpMRI alone does not have suitable accuracy in local staging. • Giganti-Coppola's nomogram achieved an adequate ability in predicting ECE.

Diagnostic accuracy of signal loss in in-phase gradient-echo images for differentiation between small renal cell carcinoma and lipid-poor angiomyolipomas.

OBJECTIVES: To assess the diagnostic accuracy of signal loss on in-phase (IP) gradient-echo (GRE) images for differentiation between renal cell carcinomas (RCCs) and lipid-poor angiomyolipomas (lpAMLs). METHODS: We retrospectively searched our institutional database for histologically proven small RCCs (<5.0 cm) and AMLs without visible macroscopic fat (lpAMLs). Two experienced radiologists assessed MRIs qualitatively, to depict signal loss foci on IP GRE images. A third radiologist drew regions of interest (ROIs) on the same lesions, on IP and out-of-phase (OP) images to calculate the ratio of signal loss. Diagnostic accuracy parameters were calculated for both techniques and the inter-reader agreement for the qualitative analysis was evaluated using the κ test. RESULTS: 15 (38.4%) RCCs lost their signal on IP images, with a sensitivity of 38.5% (95% CI = 23.4-55.4), a specificity of 100% (71.1-100), a positive predictive value (PPV) of 100% (73.4-100), a negative predictive value (NPV) of 31.4% (26.3-37.0), and an overall accuracy of 52% (37.4-66.3%). In terms of the quantitative analysis, the signal intensity index (SII= [(SIIP - SIOP) / SIOP] x 100) for RCCs was -0.132 ± 0.05, while for AMLs it was -0.031 ± 0.02, p = 0.26. The AUC was 0.414 ± -0.09 (0.237-0.592). Using 19% of signal loss as the threshold, sensitivity was 16% and specificity was 100%. The κappa value for subjective analysis was 0.63. CONCLUSION: Signal loss in "IP" images, assessed subjectively, was highly specific for distinction between RCCs and lpAMLs, although with low sensitivity. The findings can be used to improve the preoperative diagnostic accuracy of MRI for renal masses. ADVANCES IN KNOWLEDGE: Signal loss on "IP" GRE images is a reliable sign for differentiation between RCC and lpAMLs.

Renal cell carcinoma: histological classification and correlation with imaging findings.

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.

Os carcinomas de células renais (CCRs) são o sétimo tipo histológico de câncer mais comum no mundo ocidental e vêm apresentando uma tendência mantida de aumento em sua prevalência. A classificação histológica dos CCRs é de extrema importância, uma vez que a determinação dos subtipos histológicos tem significativas implicações prognósticas e terapêuticas. Os métodos de imagem têm destacada importância no diagnóstico, estadiamento e seguimento dos pacientes com CCR. As variantes histológicas mais comuns são células claras, papilífero e cromófobo. A caracterização radiológica dos subtipos de CCRs, seguida ou não de biópsia percutânea confirmatória, é particularmente útil em pacientes sem adequadas condições cirúrgicas, pacientes com doença metastática, pacientes com rim único e lesão central, e em pacientes candidatos a terapia de alvo molecular. As novas estratégias, recentemente desenvolvidas, para o tratamento do câncer renal, como crio e radiofrequência, terapia molecular alvo e vigilância ativa também exigem adequada caracterização pré-operatória das massas renais. Os subtipos histológicos menos comuns, apesar de não terem achados de imagem específicos, podem ser suspeitados com base em dados clínicos e epidemiológicos.

Renal cell carcinoma: histological classification and correlation with imaging findings / Carcinoma de células renais: classificação histológica e correlação com métodos de imagem

Abstract 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.

Resumo Os carcinomas de células renais (CCRs) são o sétimo tipo histológico de câncer mais comum no mundo ocidental e vêm apresentando uma tendência mantida de aumento em sua prevalência. A classificação histológica dos CCRs é de extrema importância, uma vez que a determinação dos subtipos histológicos tem significativas implicações prognósticas e terapêuticas. Os métodos de imagem têm destacada importância no diagnóstico, estadiamento e seguimento dos pacientes com CCR. As variantes histológicas mais comuns são células claras, papilífero e cromófobo. A caracterização radiológica dos subtipos de CCRs, seguida ou não de biópsia percutânea confirmatória, é particularmente útil em pacientes sem adequadas condições cirúrgicas, pacientes com doença metastática, pacientes com rim único e lesão central, e em pacientes candidatos a terapia de alvo molecular. As novas estratégias, recentemente desenvolvidas, para o tratamento do câncer renal, como crio e radiofrequência, terapia molecular alvo e vigilância ativa também exigem adequada caracterização pré-operatória das massas renais. Os subtipos histológicos menos comuns, apesar de não terem achados de imagem específicos, podem ser suspeitados com base em dados clínicos e epidemiológicos.

Classificação de Bosniak para cistos renais complexos: histórico e análise crítica / Bosniak classification for complex renal cysts: history and critical analysis

A classificação de Bosniak para cistos renais surgiu na década de 1980 para tentar padronizar a descrição e condutas em relação às lesões renais císticas complexas. Esta classificação sofreu alterações na década de 1990 e, a última, em 2005. Atualmente, são definidas cinco categorias de lesões císticas renais – I, II, II-F, III e IV –, de acordo com o grau de complexidade e maior probabilidade de malignidade. Apesar de inicialmente ter sido descrita para a tomografia computadorizada, esta classificação é utilizada, com algumas vantagens, também na ressonância magnética. O presente artigo revisa as diferentes fases desta classificação, sua eficácia diagnóstica e os aspectos mais controversos de sua utilização.

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.

Imaging of the adrenal gland lesions / Imaginologia das lesões das glândulas adrenais

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.

O crescente uso da tomografia computadorizada e da ressonância magnética levou a um aumento na identificação de nódulos adrenais incidentais, também chamados de incidentalomas, gerando um impasse diagnóstico para o radiologista, bem como um número significativo de pesquisas a fim de caracterizar essas lesões como benignas ou malignas. Apesar de a maioria dos incidentalomas representar um processo benigno, geralmente um adenoma, a possibilidade de a lesão ser maligna requer suficiente acurácia dos métodos de imagem para que esses possam auxiliar no manejo dos pacientes. Neste artigo nós apresentamos uma revisão da literatura dedicada à investigação radiológica das lesões adrenais, com ênfase na tomografia computadorizada, ressonância magnética e tomografia por emissão de prótons, e discutimos como os achados de imagem relacionam-se com a prática clínica. Tecnologias recentes, como a ultrassonografia com uso de contraste, a tomografia computadorizada com dupla fonte de energia e a espectroscopia de prótons por ressonância magnética são brevemente discutidas.

Imaging of the adrenal gland lesions.

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.

O crescente uso da tomografia computadorizada e da ressonância magnética levou a um aumento na identificação de nódulos adrenais incidentais, também chamados de incidentalomas, gerando um impasse diagnóstico para o radiologista, bem como um número significativo de pesquisas a fim de caracterizar essas lesões como benignas ou malignas. Apesar de a maioria dos incidentalomas representar um processo benigno, geralmente um adenoma, a possibilidade de a lesão ser maligna requer suficiente acurácia dos métodos de imagem para que esses possam auxiliar no manejo dos pacientes. Neste artigo nós apresentamos uma revisão da literatura dedicada à investigação radiológica das lesões adrenais, com ênfase na tomografia computadorizada, ressonância magnética e tomografia por emissão de prótons, e discutimos como os achados de imagem relacionam-se com a prática clínica. Tecnologias recentes, como a ultrassonografia com uso de contraste, a tomografia computadorizada com dupla fonte de energia e a espectroscopia de prótons por ressonância magnética são brevemente discutidas.

Bosniak classification for complex renal cysts: history and critical analysis.

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.

A classificação de Bosniak para cistos renais surgiu na década de 1980 para tentar padronizar a descrição e condutas em relação às lesões renais císticas complexas. Esta classificação sofreu alterações na década de 1990 e, a última, em 2005. Atualmente, são definidas cinco categorias de lesões císticas renais ­ I, II, II-F, III e IV ­, de acordo com o grau de complexidade e maior probabilidade de malignidade. Apesar de inicialmente ter sido descrita para a tomografia computadorizada, esta classificação é utilizada, com algumas vantagens, também na ressonância magnética. O presente artigo revisa as diferentes fases desta classificação, sua eficácia diagnóstica e os aspectos mais controversos de sua utilização.

Breast imaging: is the sonographic descriptor of orientation valid for magnetic resonance imaging?

PURPOSE: To evaluate if the Breast Imaging Reporting and Data System (BI-RADS) ultrasound descriptor of orientation can be used in magnetic resonance imaging (MRI). MATERIALS AND METHODS: We conducted a retrospective study to evaluate breast mass lesions identified by MRI from 2008 to 2010 who had ultrasound (US) and histopathologic confirmation. Lesions were measured in the craniocaudal (CC), anteroposterior (AP), and transverse (T) axes and classified as having a nonparallel orientation, longest axis perpendicular to Cooper's ligaments, or in a parallel orientation when the longest axis is parallel to Cooper's ligaments. The MR image data were correlated with the US orientation according to BI-RADS and histopathological diagnosis. RESULTS: We evaluated 71 lesions in 64 patients. On MRI, 27 lesions (38.0%) were nonparallel (8 benign and 19 malignant), and 44 lesions (62.0%) were parallel (33 benign and 11 malignant). There was significant agreement between the lesion orientation on US and MRI (kappa value = 0.901). The positive predictive values (PPV) for parallel orientation malignancy on MR and US imaging were 70.4% and 73.1%, respectively. CONCLUSION: A descriptor of orientation for breast lesions can be used on MRI with PPV for malignant lesions similar to US.

Anterior shoulder instability: correlation between magnetic resonance arthrography, ultrasound arthrography and intraoperative findings.

The purpose of the present study was to determine ultrasound (US) arthrography diagnostic accuracy in patients with recurrent shoulder dislocation by comparing US arthrography and magnetic resonance arthrography (MRA) with intraoperative findings. Fifty-six consecutive patients with diagnosis of chronic anterior instability of the shoulder were evaluated for assessment of bone and soft tissue lesions by three radiologists. Twenty-five cases were confirmed by surgery. Sensitivity, specificity, inter- and intraobserver agreement were calculated. Ultrasound sensitivity ranged from 20% to 100% and specificity from 25% to 90%. MRA sensitivity ranged from 80% to 100% and specificity from 50% to 100%. Interobserver agreement was good for MRA (0.54-0.70) and fair for US arthrography (0.19-0.40). Despite a higher interobserver variability for US arthrography than for MRA, our results indicate that US is capable of demonstrating bone and soft tissue lesions related to chronic instability of the shoulder in the presence of intra-articular fluid.