磁共振尿路成像在小儿尿路梗阻诊断中的应用

目的:探讨磁共振尿路成像(MRU)在小儿尿路梗阻诊断中的价值。方法:31例尿路梗阻患儿分别作静脉尿路造影(IVP)、腹部超声(BUS)和磁共振尿路成像(MRU)检查,对照手术结果,观察MRU尿路梗阻的表现。结果:31例尿路梗阻患儿中经MRU诊断为肾盂输尿管连接部狭窄24例,输尿管口囊肿3例,壁段狭窄2例,原发性巨输尿管症2例。诊断正确率100%。结论:MRU具有无创,诊断准确率高的优点,非常适合用于小儿尿路梗阻疾病的诊断。     

What Does Magnetic Resonance Imaging Add to the Prenatal Sonographic Diagnosis of Ventriculomegaly?

OBJECTIVE: The purpose of this study was to determine the contribution of magnetic resonance imaging (MRI) in evaluating fetuses with the sonographic diagnosis of ventriculomegaly (VM). METHODS: Over 4 years, consecutive fetuses with the sonographic diagnosis of VM at 1 facility who underwent prenatal MRI at a second facility were included. The roles of MRI and follow-up sonography were tabulated. The patients were analyzed in 2 groups based on the presence or absence of other central nervous system (CNS) abnormalities. RESULTS: Twenty-six fetuses with a gestational age range of 17 to 37 weeks had sonographically detected VM (atria > or =10-29 mm), including 19 with mild VM (atria 10-12 mm). In group 1, 14 had isolated VM, 6 of which reverted to normal by the third trimester. Magnetic resonance imaging showed cerebellar hypoplasia not shown by sonography in 1 fetus and an additional finding of a mega cisterna magna in a second fetus. In group 2, 12 fetuses had VM and other CNS anomalies on sonography. Additional findings were seen with MRI in 10 of these fetuses, including migrational abnormalities (n = 4), porencephaly (n = 4), and 1 diagnosis each of abnormal myelination, hypoplasia of the corpus callosum, microcephaly, a kinked brain stem, cerebellar hypoplasia, and congenital infarction. There were significantly more fetuses with additional CNS anomalies found by MRI among those in group 2 compared with those in group 1 (Fisher exact test, P = .001). CONCLUSIONS: Although sonography is an accurate diagnostic modality for the evaluation of fetuses with VM, MRI adds important additional information, particularly in fetuses in whom additional findings other than an enlarged ventricle are seen sonographically.     

Comparison of Sonography and Magnetic Resonance Imaging for Spring Ligament Abnormalities

Objective. The purpose of this study was to determine whether sonography is as accurate as magnetic resonance (MR) imaging for depicting abnormalities of the spring ligament in patients with symptomatic posterior tibial tendon (PTT) dysfunction. Methods. Sixteen patients (18 ligaments) with symptomatic PTT dysfunction were prospectively evaluated with sonography and MR imaging. Results. Magnetic resonance imaging showed spring ligament tears in 8 of 18 feet, including 6 incomplete tears and 2 complete tears. Sonography showed spring ligament tears in 7 of 18 feet, including 6 incomplete tears and 1 complete tear. The findings of sonography and MR imaging were concordant in 17 of 18 feet (94%). Six of the 8 spring ligament tears on MR imaging were associated with posterior tibial tendinosis or tears. Conclusions. Sonography is an effective imaging option in assessing spring ligament abnormalities in patients with symptomatic PTT dysfunction.     

Role of Sonography and Magnetic Resonance Imaging in Detecting Deltoideal Acromial Enthesopathy

The acromial origin of the deltoid is a target structure of ankylosing spondylitis and related spondyloarthritis, which are often overlooked and underdiagnosed as causes of posterior shoulder pain. The objective of this article is to review the roles of sonography and magnetic resonance imaging in detecting deltoideal acromial enthesopathy and their importance for optimizing management in individuals with posterior shoulder pain. Adequate awareness of such enthesopathy as a potential manifestation of inflammatory rheumatic disorders is critical for early diagnosis of spondyloarthritis.     

Fetal magnetic resonance imaging enhances detection of spinal cord anomalies in patients with sonographically detected bony anomalies of the spine.

OBJECTIVE: Although fetal magnetic resonance imaging (MRI) is being increasingly used to evaluate sonographically suspected abnormalities, its utility in the evaluation of the spinal canal is not well studied. Because it is not susceptible to the limitations of fetal position, oligohydramnios, and shadowing from bony structures, we hypothesize that fetal MRI is better suited to assess the contents of the spinal canal compared with prenatal sonography. The purpose of this investigation was to determine whether fetal MRI could detect spinal abnormalities in cases in which they had not been originally suspected on prenatal sonography. METHODS: Fetal spine MR images were retrospectively reviewed over a 42-month period. Corresponding sonographic images were then rereviewed to determine whether there were findings in retrospect that might have suggested the cord abnormalities. Cases of myelomeningocele were counted as a spinal cord abnormality only if fetal MRI showed a cord anomaly other than the myelomeningocele. RESULTS: Of 33 cases referred for bony anomalies of the spine, fetal MRI showed additional abnormalities involving the spinal cord in 3 patients. These included diastematomyelia in 2 cases and segmental spinal dysgenesis in the third case. One case of diastematomyelia occurred in association with a lumbosacral myelomeningocele. The spinal cord anomalies were not visible on any of the prenatal sonograms, even in retrospect. CONCLUSIONS: Additional spinal cord anomalies were detected in 10% of cases reviewed. Fetal MRI can be useful in assessing the spinal cord in fetuses with bony spinal anomalies. Our findings suggest that fetuses with sonographically diagnosed bony abnormalities of the spine may benefit from further evaluation with fetal MRI.     

Community‐Based Practice Experience of Unsuspected Breast Magnetic Resonance Imaging Abnormalities Evaluated With Second‐Look Sonography

Objective. The purpose of this study was to assess the utility and efficacy of second‐look breast sonography in the evaluation of abnormalities identified on presurgical breast magnetic resonance imaging (MRI) examinations. Methods. A retrospective review was performed of 152 presurgical breast MRI examinations having 196 unsuspected abnormalities to identify findings that underwent subsequent breast sonography. Eligible examinations had a suspicious abnormality identified on presurgical MRI and documentation of the location and size of the finding on MRI and subsequent second‐look sonography. Fourteen examinations not meeting the criteria were excluded, with 182 abnormalities remaining. Patient medical records were reviewed. Results. Seventy percent (128 of 182) of breast MRI lesions were visible at second‐look sonography; 30% (54 of 182) were sonographically occult. Ninety‐five percent (121 of 128) of sonographically visible abnormalities underwent breast biopsy. Pathologic examinations of sampled sonographically visible lesions revealed 39 cancers, 9 high‐risk lesions, 72 benign lesions, and 1 lesion not specified at surgery; 23% (9 of 128) of cancers were in the contralateral breast. Fifty‐four lesions were sonographically occult. Needle biopsy was performed for 93% (50 of 54) of occult lesions, revealing 8 cancers, 1 high‐risk lesion, and 41 benign lesions; 3 of the benign lesions did not have sufficient pathologic specimens but were benign at follow‐up. Magnetic resonance imaging guidance was used in 86% (43 of 50) of these biopsies. One contralateral cancer was identified in the sonographically occult subset. Of the 182 lesions that underwent second‐look sonography, 20% (36 of 182) had a change in management. Conclusions. Second‐look sonography has value in the evaluation of abnormalities found on breast MRI. We found enhancements in 70% (128 of 182), yielding 39 cancers.     

Fine‐tuning the Diagnosis of Fetal Scalp Cysts

Objective. The purpose of this series is to emphasize the importance of an exhaustive and appropriately conducted sonographic examination in the correct diagnosis of fetal cystic scalp lesions and the place of magnetic resonance imaging (MRI) in the diagnostic sequence. Methods. Transabdominal and transvaginal 2‐ and 3‐dimensional sonography with color and power Doppler imaging as well as 3‐dimensional rendering techniques such as inversion and Doppler angiography were used. In 1 case, an MRI study was performed. Results. In 1 case, the MRI missed and the different sonographic techniques correctly made the diagnosis of a meningocele. In the second case, sonography was sufficient to establish the diagnosis of an epidermal cyst. Conclusions. These 2 cases show the value of going the distance with the newly available high‐frequency sonography. Ultimately, the correct diagnoses were made with the tools offered by sonography without the need for any other imaging modality.     

Magnetic Resonance Imaging vs. Transvaginal Ultrasound for Cervical Length Assessment in the Second Half of Pregnancy

The purpose of this cross-sectional study involving 42 women between 20 and 39 weeks gestation was to compare transvaginal ultrasound (TVUS) vs. magnetic resonance imaging (MRI) in the assessment of cervical length measurement during the second half of pregnancy and to evaluate the reproducibility of cervical measurements obtained through MRI. Cervical length was measured through TVUS by a single examiner. On the same day, all women also had MRI and cervical length was assessed by two independent blinded observers. There were no significant differences in the mean cervical length obtained through TVUS and MRI (paired t-test, p = 0.191). The Bland-Altman test indicated concordance between measurements obtained through methods as well as good intra- and interobserver reproducibility for MRI measurements. Intraclass correlation coefficient was 0.990 (95% confidence interval [CI]: 0.982 to 0.995; p < 0.001) for measurements performed using MRI by two different observers and 0.995 (95% CI: 0.991 to 0.997; p < 0.001) for measurements performed using the same method by a single operator. Cervical length measured through TVUS and MRI does not differ significantly. There is a good reproducibility of cervical measurements obtained through MRI. (E-mail: crpires@uol.com.br)     

Role of First‐Trimester Sonography in the Diagnosis of Aneuploidy and Structural Fetal Anomalies

Objective. We sought to determine the sensitivity of the first‐trimester scan in the early diagnosis of aneuploidy and structural fetal anomalies in an unselected low‐risk population. Methods. This was a retrospective chart review of all patients having first‐trimester scans between 2002 and 2009. At our center, a survey of fetal anatomy is performed at the time of nuchal translucency assessment at 11 weeks to 13 weeks 6 days. A second‐trimester scan is done at 20 to 23 weeks and a third‐trimester scan at 32 to 35 weeks. Isolated sonographic findings of choroid plexus cysts and echogenic intracardiac foci were excluded. Lethal anomalies and those requiring immediate surgical intervention at birth were considered major structural anomalies. All scans were performed by a single sonologist certified by the Fetal Medicine Foundation. All neonates were examined at birth by a pediatrician. Results. Our study included 1370 fetuses. Six cases of aneuploidy (0.4%) were detected. The first‐trimester scan detected 5 of 6 cases of aneuploidy (83%), confirmed by karyotype. There were 36 cases of structural fetal anomalies (2.6%); 20 (1.5%) were major anomalies. The first‐trimester scan detected 16 of 36 (44%); 20 (56%) were identified by second‐ or third‐trimester scans. The first‐trimester scan detection rate for major structural anomalies was 14 of 20 (70%). The 5 that were missed by the first‐trimester scan were detected by a second‐trimester scan. Conclusions. Our study emphasizes the importance of the first‐trimester scan in the early detection of aneuploidy and structural fetal anomalies. In this small unselected low‐risk population, the first‐trimester scan detected 83% of aneuploidies and 70% of major structural anomalies. Our results are comparable to previously published studies from other centers and further exemplify the invaluable role of the first‐trimester scan in the early detection of aneuploidy and structural anomalies in an unselected low‐risk population.     

The Study of Deep Brain Structures by Transcranial Duplex Sonography and Imaging Resonance Correlation

Transcranial duplex sonography (TCS) currently provides us with images of deep brain structures with sufficient resolution. We chose 2 sonographic quantitative parameters: the diameter of the third ventricle and a measurement not used by TCS to date, the midbrain area. Their reliability and reproducibility were assessed using magnetic resonance imaging (MRI) as the reference. A total of 99 patients free from neurodegenerative disorders were examined using TCS, and both parameters were measured by 2 independent explorers. Measurements of third-ventricle diameter by TCS showed very good correlation (r = 0.80) and agreement (ICC = 0.89) with measurements obtained by MRI. Measurements of the midbrain area by TCS also provided acceptable values with moderate correlation (r = 0.36) and agreement (ICC = 0.53). Interexplorer correlation values were good (ICC = 0.98 and 0.79 for the third ventricle and midbrain areas, respectively). Further studies will be required to determine the potential diagnostic usefulness of these parameters.