Craniometric parameters for the evaluation of platybasia and basilar invagination on magnetic resonance imaging: a reproducibility study.

OBJECTIVE: The present study aims to perform a reproducibility study of the clivus-canal angle (CCA), Welcker's basal angle (WBA), and the distance from the odontoid process to Chamberlain's line (DOCL) on magnetic resonance imaging (MRI). MATERIALS AND METHODS: Two medical students and two radiologists respectively evaluated 100 and 50 consecutive MRI scans of adult skulls, selected randomly. Each examiner, working independently and blinded to the previous results, performed readings for each patient on two different occasions. Measurements were performed in T1-weighted sequences acquired in the midsagittal plane. The levels of intraobserver reproducibility and interobserver agreement were evaluated by calculating the intraclass correlation coefficients (ICCs) and the corresponding 95% confidence intervals. RESULTS: The mean values obtained by the examiners were 150º for the CCA, 130º for the WBA, and 2.5 mm for the DOCL. The ICC for interobserver agreement was 0.980, 0.935, and 0.967, for the CCA, WBA, and DOCL, respectively, for the students, compared with 0.977, 0.941, and 0.982, respectively, for the radiologists, and 0.980, 0.992, and 0.990, respectively, for all of the examiners together. In the analysis of intraobserver agreement, the ICC ranged from 0.929 to 0.959 for the CCA, from 0.918 to 0.964 for the WBA, and from 0.918 to 0.981 for the DOCL. CONCLUSION: The measurement of the CCA, WBA, and DOCL appears to show excellent intraobserver reproducibility and interobserver agreement on MRI.

OBJETIVO: Realizar um estudo de reprodutibilidade do ângulo clivocanal (ACC), ângulo basal de Welcker (ABW) e distância do odontoide à linha de Chamberlain (DOLC) em ressonância magnética (RM). MATERIAIS E MÉTODOS: Quatro examinadores, dois graduandos de medicina e dois radiologistas, avaliaram, respectivamente, 100 e 50 indivíduos adultos submetidos a RM de crânio, consecutiva e aleatoriamente. Cada um realizou duas leituras para cada paciente em diferentes ocasiões, de forma cega e independente. As análises de concordância intraobservador e interobservador foram realizadas pelo coeficiente de correlação intraclasse (CCI), com intervalo de confiança de 95%. RESULTADOS: As medidas médias, considerando todos os examinadores, foram: ACC = 150º, ABW = 130º, DOLC = 2,5 mm. A análise interobservador entre os estudantes revelou CCI de 0,980, 0,935 e 0,967 para ACC, ABW e DOLC, respectivamente, e para os radiologistas, CCI de 0,977, 0,941 e 0,982, respectivamente. A análise interobservador entre estudantes e radiologistas revelou CCI de 0,980, 0,992 e 0,990, respectivamente. Em relação à análise intraobservador, as medidas do ACC tiveram CCI variando entre 0,929 e 0,959, ABW entre 0,918 e 0,964 e DOLC entre 0,918 e 0,981. CONCLUSÃO: ACC, ABW e DOLC obtiveram excelentes reprodutibilidades intraobservador e interobservador na RM.

Multidetector computed tomography angiography of the renal arteries: normal anatomy and its variations.

Conventional angiography is still considered the gold standard for the study of the anatomy and of vascular diseases of the abdomen. However, the advent of multidetector computed tomography and techniques of digital image reconstruction has provided an alternative means of performing angiography, without the risks inherent to invasive angiographic examinations. Therefore, within the field of radiology, there is an ever-increasing demand for deeper knowledge of the anatomy of the regional vasculature and its variations. Variations in the renal vascular system are relatively prevalent in the venous and arterial vessels. For various conditions in which surgical planning is crucial to the success of the procedure, knowledge of this topic is important. The aim of this study was to familiarize the general radiologist with variations in the renal vascular system. To that end, we prepared a pictorial essay comprising multidetector computed tomography images obtained in a series of cases. We show patterns representative of the most common anatomical variations in the arterial blood supply to the kidneys, calling attention to the nomenclature, as well as to the clinical and surgical implications of such variations.

A angiografia convencional ainda é considerada o exame padrão ouro no estudo da anatomia e das doenças vasculares do abdome. Entretanto, com o advento da tomografia computadorizada com multidetectores e técnicas de reconstrução de imagens digitais, este exame tem-se tornado uma opção, com a vantagem de não ter os riscos habituais dos exames angiográficos invasivos. Com isso, o aprofundamento do conhecimento dos detalhes anatômicos da vasculatura regional e suas variações é cada vez mais exigido nesta área da radiologia. As variações do sistema vascular renal são relativamente prevalentes, tanto no leito venoso quanto no arterial. O conhecimento do tema é de importância nas várias condições em que o prévio planejamento cirúrgico é crucial para o sucesso do procedimento. Para familiarizar o radiologista geral, enriquecendo sua experiência sobre o tópico, os autores elaboraram um ensaio iconográfico a partir de uma série de casos extraídos do banco de imagens de tomografia computadorizada com multidetectores da região abdominal, com os padrões representativos das mais frequentes variações anatômicas da irrigação arterial renal, chamando a atenção para sua designação terminológica e para suas implicações clinicocirúrgicas.

Multidetector computed tomography angiography of the celiac trunk and hepatic arterial system: normal anatomy and main variants.

Although digital angiography remains as the gold standard for imaging the celiac arterial trunk and hepatic arteries, multidetector computed tomography in association with digital images processing by software resources represents a useful tool particularly attractive for its non invasiveness. Knowledge of normal anatomy as well as of its variations is helpful in images interpretation and to address surgical planning on a case-by-case basis. The present essay illustrates several types of anatomical variations of celiac trunk, hepatic artery and its main branches, by means of digitally reconstructed computed tomography images, correlating their prevalence in the population with surgical implications.

Embora a angiografia digital permaneça como padrão ouro no estudo do tronco celíaco e sistema arterial hepático, o exame por tomografia multidetectores associada às ferramentas informáticas de reconstrução de imagens digitais tem representado uma alternativa útil, principalmente por serem métodos não invasivos. O conhecimento detalhado tanto da anatomia normal quanto das variações anatômicas ajuda na interpretação de exames radiológicos e na adequação do planejamento cirúrgico para cada paciente. Este texto ilustra uma série de variações anatômicas do tronco celíaco e sistema arterial hepático, por meio de imagens tomográficas com reconstruções digitais, correlacionando as prevalências populacionais e implicações cirúrgicas.

Anatomical variations of the celiac trunk and hepatic arterial system: an analysis using multidetector computed tomography angiography.

OBJECTIVE: To analyze the prevalence of anatomical variations of celiac arterial trunk (CAT) branches and hepatic arterial system (HAS), as well as the CAT diameter, length and distance to the superior mesenteric artery. MATERIALS AND METHODS: Retrospective, cross-sectional and predominantly descriptive study based on the analysis of multidetector computed tomography images of 60 patients. RESULTS: The celiac trunk anatomy was normal in 90% of cases. Hepatosplenic trunk was found in 8.3% of patients, and hepatogastric trunk in 1.7%. Variation of the HAS was observed in 21.7% of cases, including anomalous location of the right hepatic artery in 8.3% of cases, and of the left hepatic artery, in 5%. Also, cases of joint relocation of right and left hepatic arteries, and trifurcation of the proper hepatic artery were observed, respectively, in 3 (5%) and 2 (3.3%) patients. Mean length and caliber of the CAT were 2.3 cm and 0.8 cm, respectively. Mean distance between CAT and superior mesenteric artery was 1.2 cm (standard deviation = 4.08). A significant correlation was observed between CAT diameter and length, and CAT diameter and distance to superior mesenteric artery. CONCLUSION: The pattern of CAT variations and diameter corroborate the majority of the literature data. However, this does not happen in relation to the HAS.

OBJETIVO: Analisar a prevalência de variações anatômicas da ramificação do tronco arterial celíaco (TAC) e do sistema arterial hepático (SAH), o diâmetro e comprimento do TAC e sua distância para a artéria mesentérica superior. MATERIAIS E MÉTODOS: Estudo retrospectivo, transversal, predominantemente descritivo, baseado na análise de imagens de tomografia computadorizada de 60 pacientes. RESULTADOS: A anatomia do TAC foi normal em 90% dos casos. Cinco (8,3%) pacientes apresentaram o tronco hepatoesplênico e um (1,7%) apresentou o tronco hepatogástrico. O SAH variou em 21,7% dos casos. Desses, 8,3% foram na localização anômala da artéria hepática direita e 5% da artéria hepática esquerda. Ainda foram encontrados 3 (5%) casos de relocalização conjunta da artéria hepática direita e artéria hepática esquerda e 2 (3,3%) de trifurcação da artéria hepática própria. A média de comprimento e o calibre médio do TAC foram, respectivamente, 2,33 cm e 0,8 cm. A distância média entre o TAC e a artéria mesentérica superior foi 1,2 cm, com desviopadrão de 4,08. Houve correlação significativa entre diâmetro e comprimento do TAC, e diâmetro do TAC e distância deste para a artéria mesentérica superior. CONCLUSÃO: O padrão de variação do TAC e seu diâmetro corroboram a maioria dos dados da literatura, embora o mesmo não tenha ocorrido em relação ao SAH.

Reproducibility of renal volume measurement in adults using 3-dimensional sonography.

OBJECTIVES: The purpose of this study was to determine the interobserver reproducibility of renal volume measurement performed by 3-dimensional (3D) sonography. METHODS: We conducted an exploratory, quantitative, observational, and descriptive cross-sectional study. We calculated ranges, means, and standard deviations of the renal volumes obtained with 3D sonography by 2 different examiners from a sample of 30 patients. The interobserver reproducibility was assessed by calculating intraclass correlation coefficients (ICCs) and by construction of Bland-Altman plots. RESULTS: The ICC between the right 3D renal volumes obtained by examiners 1 and 2 was 0.8552 (95% confidence interval, 0.7153-0.9292), showing excellent reproducibility (P < .0001). For the left 3D renal volumes obtained by examiners 1 and 2, the ICC was 0.6411 (95% confidence interval, 0.3652-0.8135), showing average to good reproducibility (P = .0001). The Bland-Altman plots showed mean differences ± SD of -4.8% ± 23.9% between the right renal volumes obtained by examiners 1 and 2 and -2.2% ± 38% between the left renal volumes. The 95% limits of agreement between the right renal volumes obtained by examiners 1 and 2 were -28.7% to 19%, whereas those between the left renal volumes were -40.2% to 35.7%. CONCLUSIONS: Three-dimensional sonography showed good interobserver reproducibility, which was better for the right kidney. It appears necessary to establish standardized techniques for acquisition of sonographic renal volumes.

Reproducibility of three-dimensional power Doppler placental vascular indices in pregnancies between 26 and 35 weeks.

PURPOSE: Assess intra and interobserver reproducibility of three-dimensional power Doppler (3DPD) placental vascular indices in normal pregnancies between 26 and 35 weeks. METHODS: Thirty 3D volumes were captured by one observer and stored for analysis. Vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated from the spherical placental tissue samples obtained through the automatic Virtual Organ Computer-aided AnaLysis (VOCAL). Two observers analyzed the stored volumes and calculated the indices and their findings were compared. Intraclass correlation coefficients (ICCs) were used to analyze intra and interobserver correlations. Data were analyzed using confidence intervals, reliability coefficients and Bland-Altman graphs with concordance limits. RESULTS: All three indices had good intra and interobserver reproducibility. Intraobserver ICCs for the three indices were > 0.90. The FI had the highest ICC (0.99), the highest interobserver ICC (0.98) and the best concordance on the Bland-Altman graphs. CONCLUSION: 3DPD placental vascular indices obtained using the automatic sphere mode had a good intra and interobserver reproducibility for pregnancies between 26 and 35 weeks. The FI obtained the highest reproducibility scores.

Placental blood flow measured by three-dimensional power Doppler ultrasound at 26 to 35 weeks gestation in normal pregnancies.

OBJECTIVE: To evaluate placental vascular indices, in pregnancies between 26 and 35 weeks, using three-dimensional power Doppler (3DPD) ultrasound and the effect of placental location on these indices. METHODS: This was a cross-sectional study involving 283 patients. The placental vascularization index (VI), flow index (FI) and vascularization and flow index (VFI) was obtained using the VOCAL program. Pearson's linear correlation coefficient was used to assess the relationship between gestational age and these indices. Student's parametric t-test and Levene's test were used to analyse the results between VI, FI and VFI and placental location. RESULTS: There was no linear correlation between gestational age (GA) and VI (p = 0.390) and VFI (p = 0.053). Only the FI presented a significant linear correlation (p = 0.004), with a slow increase according to GA. It was possible to construct a reliable nomogram only for this index. There were no significant differences in the VI, FI and VFI according to placental location (p = 0.323, 0.172 and 0.120, respectively). CONCLUSION: Placental FI assessed by 3DPD increases progressively and significantly between 26 and 35 weeks. Placental location has no influence on the three vascular indices studied. The FI reference values obtained in this study can be used as a parameter for future investigations on placental vascularization using 3DPD.