The thickness of the roof of the glenoid fossa in the temporomandibular joint: relationship to the MRI findings

OBJECTIVES: The purpose of this study was to clarify the relationship between the thickness of the roof of the glenoid fossa (RGF) and magnetic resonance imaging (MRI) findings of temporomandibular joint (TMJ) disorders (TMDs). METHODS: Eighty-seven patients with symptoms and indications of TMD in one or both TMJs were referred for MRI. Cone-beam CT (3DX) was used to measure the thickness of the RGF at its thinnest point. Linear measurements were made three times on the monitor by three separate investigators and the mean values obtained were used for the statistical analyses. RESULTS: The joints were categorised as normal (70 joints), anterior disc displacement with reduction (ADWR; 53 joints) or anterior disc displacement without reduction (ADWOR; 51 joints). The joint disorders were also categorised into the following subgroups: with osteoarthritis (OA) (21 joints), without OA (153 joints), with disc deformation (33 joints), without disc deformation (141 joints), with joint effusion (JE) (61 joints) and without JE (113 joints). The average minimum thickness of the RGF was 0.85 mm for normal joints, 0.90 mm with ADWR, 0.93 mm with ADWOR, 0.99 mm with OA, 0.87 mm without OA, 0.87 mm with disc deformation and 0.89 mm without disc deformation. There was no significant difference between these figures. There was a significant difference in the thickness of the RGF with (0.97 mm) and without (0.84 mm) JE. CONCLUSIONS: These results suggest that RGF thickness is influenced by JE, but is unaffected by disc position and configuration.     

Relationship between patient characteristics, mandibular head morphology and thickness of the roof of the glenoid fossa in symptomatic temporomandibular joints

OBJECTIVE: The purpose of this clinical study was to investigate the minimum thickness of the roof of the glenoid fossa (RGF) of grossly normal temporomandibular joints (TMJ) and to correlate this with patient gender, age and the morphological classification of the mandibular head. METHODS: The study was performed on 191 TMJs from 109 patients (25 male and 84 female, age range 3-79 years, mean age 28.1 years) who visited Nihon University Dental Hospital, Japan with suspected TMJ disorders. The patients underwent cone beam computed tomography (3DX CT) to enable observation of the morphological features of the mandibular head. The minimum thickness of the RGF was measured using frontal section images acquired by CT. The morphology of the mandibular heads was classified according to the method of Yale and colleagues. Mean linear measurements were used for statistical analyses of patient gender, age and mandibular head morphology. RESULTS: The average minimum thickness of the RGF was 0.79 mm. No significant difference in thickness was found between male and female patients. In addition, no differences were recorded as a result of variation in age or mandibular head morphology. CONCLUSIONS: These results indicate that RGF thickness is not significantly correlated with gender, age, or mandibular head morphology, at least in this cohort of patients.     

Relationship between the thickness of the roof of glenoid fossa,condyle morphology and remaining teeth in asymptomatic European patients based on cone beam CT data sets

Objectives:

The aim of this study was to examine the relationship between the roof of the glenoid fossa (RGF) thickness and condyle morphology and the influence of the number of remaining teeth and age.

Methods:

Cone beam CT data sets from 77 asymptomatic European patients were analysed retrospectively in this study. The thinnest area of RGF was identified among the sagittal and coronal slices on a computer screen; distance measurement software was used to measure the thickness. Moreover, we applied a free digital imaging and communications in medicine viewer for classification of condyle head type. It was also used to analyse any relation between RGF thickness and the number of remaining teeth. We performed a correlation analysis for RGF, age and missing teeth. Finally, we investigated combining sagittal condyle morphological characterization with coronal condyle morphology in relation to the number of joints and RGF thickness.

Results:

The Kruskal–Wallis test revealed no significant differences in RGF thickness among any of the coronal condyle head morphology groups (p > 0.05). There were significant differences in the thinnest part of RGF in relation to the sagittal plane for condyle morphological characterization, because we observed increased RGF thickness in joints with osteoarthritis features (p < 0.05). There is a non-significant correlation between the thinnest part of the RGF and the number of remaining teeth (p > 0.05).

Conclusions:

We found that the RGF thickness is unaffected by the coronal condyle head morphology and the number of remaining teeth. Osteoarthritic changes (sagittal condyle morphology) have an effect on RGF.     

Comparison of quantitative cartilage measurements acquired on two 3.0T MRI systems from different manufacturers

PURPOSE: To investigate the comparability of two osteoarthritis (OA) surrogate endpoints--average cartilage thickness and cartilage volume--acquired from healthy volunteers on two 3.0T magnetic resonance imaging (MRI) systems from different manufacturers. MATERIALS AND METHODS: Ten knees of five healthy volunteers were scanned on a 3.0T General Electric (GE) and a 3.0T Philips scanner using a fast three-dimensional fat-suppressed spoiled gradient (SPGR) imaging sequence. The acquisition parameters were optimized beforehand and were kept as comparable as possible on both scanners. For quantitative analysis, the average cartilage thickness and volume of the load-bearing regions of the femoral condyles were compared. Data were analyzed using a univariate repeated-measures analysis of variance (ANOVA) to examine the effects of position, condyle, and imaging system on the measurements. RESULTS: The average cartilage thickness and volume of the load-bearing regions of the femoral condyles did not differ between the two different 3.0T MRI systems (P > 0.05). There was no significant effect of position or condyle on the average cartilage thickness measurements (P > 0.05; range = 0.41-0.93) or cartilage volume (P > 0.05; range = 0.14-0.87). CONCLUSION: Two OA surrogate endpoints--average cartilage thickness and cartilage volume--acquired on two 3.0T MRI systems from different manufacturers are comparable.     

Reproducibility and accuracy of measuring unerupted teeth using limited cone beam X-ray CT

OBJECTIVE: The purpose of this investigation was to determine the reproducibility among observers and accuracy of the measurement of the tooth crown width of unerupted teeth using limited area cone beam X-ray CT. METHODS: 3DX multi-image micro-CT (3DX, Morita Co., Kyoto, Japan) images of impacted supernumerary teeth in the median maxillary region taken prior to extraction were used for the samples. The width of the tooth on the 3DX image was measured five times by five individual observers. Significant differences in values among the observers in the measurement were determined by one-way analysis of variance for examining reproducibility. The measurement results of the ten samples on 3DX images were compared with the laboratory measurements using a three-dimensional co-ordinate measuring apparatus, using the Wilcoxon signed-rank sum test. RESULTS: There was no significant difference among the observers in the measurement (P>0.05). The measurement results shown on 3DX images were significantly larger than those of the laboratory measurements (P<0.05). The mean difference was +0.088 mm. CONCLUSIONS: 3DX has high reproducibility for measuring the tooth crown width of unerupted teeth. While 3DX measurement values were larger than the laboratory measurements, the difference is clinically insignificant.     

Pulmonary metastases: effect of CT section thickness on measurement--initial experience

PURPOSE: To assess the effect of commonly used computed tomographic (CT) section thicknesses on metastatic tumor measurements calculated with unidimensional, bidimensional, area, and volumetric methods. MATERIALS AND METHODS: Analysis and data collection were approved by the Institutional Review Board, with waived informed patient consent. Forty-two pulmonary metastases in 10 patients (three men and seven women; age range, 43-83 years; mean age, 65.4 years) were analyzed on CT scans obtained with 3.75-, 5.0-, and 7.5-mm section thicknesses. The lesions were automatically delineated by using a three-dimensional multicriteria segmentation algorithm. Unidimensional (the largest diameter), bidimensional (the product of the two maximal perpendicular diameters), maximal cross-sectional area, and volumetric measurements were automatically obtained for each pulmonary lesion on each section thickness. Means and variances were calculated, and the differences across the three section thicknesses for each of the four measurements were studied by using linear mixed-effects models. The Levene test was used to study the equality of variances. RESULTS: Differences in the means for unidimensional, bidimensional, and area measurements were significant between a section thickness of 3.75 and 5.0 mm (unidimensional, P=.05; bidimensional, P=.05; area, P=.01) and 3.75 and 7.5 mm (unidimensional, P=.06; bidimensional, P=.03; area, P=.02), but not 5.0 and 7.5 mm. There was a significant difference in volumetric measurement as section thickness decreased from 7.5 to 5.0 mm (P <.001) and from 7.5 to 3.75 mm (P <.001). Although there was a slight trend for differences in the variances across section thickness for each measurement, none of the differences were significant. CONCLUSION: Volumetric tumor measurements change with a reduction in section thickness from 7.5 to 5.0 and 3.75 mm. For unidimensional measurement, no change was found when thickness decreased from 7.5 to 5.0 mm.     

Helical computed tomography of urinary tract stones: Accuracy and diagnostic value of stone size and density measurements

This study was carried out to determine the accuracy and diagnostic utility of ureteral stone size and density measurements at helical computed tomography (CT). Sixteen calciumcontaining and eight non-calciumcontaining ureteral stones of varying size and composition were examined in vitro with helical CT. Scans were obtained with 10-,5-,3-, and 1-mm collimation. Stone size was determined with CT calipers at each collimation thickness. Stone density was determined by using the maximum value obtained at pixelgram analysis, measured in Hounsfield units.Stone size measured with CT cursors closely matched actual stone size with 10-, 5-, 3-,and 1-mm collimation. Pixelgram density measurements steadily increased as slice thickness decreased. There was better separation of calciumcontaining from non-calcium-containing stones with thinner slices.CT stone size measurement does not vary significantly with slice thickness. CT stone density measurement in Hounsfield units does vary with slice thickness; the highest density numbers were recorded with the thinnest slice thicknesses. Density measurements did not reliably separate calciumcontaining from non-calcium-containing stones, but the amount of density overlap between the two stone types was diminished on the thinnest slices.     

Prediction rule for diagnosis of arrhythmogenic right ventricular dysplasia based on wall thickness measured on MR imaging.

MRI is seeing an increasing role in the evaluation of suspected arrhythmogenic right ventricular dysplasia (ARVD). Our aims were to establish wall thickness criteria for diagnosis of ARVD based on MR imaging measurements. A cross-sectional case-control retrospective study of 21 cardiac MR exams over a 3 year period identified five patients (two men, three women) of average age 43 years (range 36-48) who were diagnosed with ARVD and 16 patients (nine men, seven women) of average age 52 years (range 25-78) who were diagnosed with normal right ventricular wall motion. Patient demographic characteristics (age, sex) and right ventricular free wall thickness (RVFWT) were evaluated for predictive ability. Calculated RVFWT was (mean+/-SD, in mm); (4.4+/-1.4) for ARVD, and (7.8+/-2.9), controls with P<0.001. Logistic regression analysis indicated that sex and age were not significant independent predictors (P>0.05). RVFWT allowed for a prediction rule with Area under the receiver operator curve of 0.94 to be generated. In our study, measurement of the thickness of the right ventricular free wall using cardiac-gated MRI proved to be a statistically significant predictor of ARVD.     

Decreased thickness of primary motor cortex in primary lateral sclerosis

BACKGROUND AND PURPOSE: Primary lateral sclerosis (PLS) is a rare form of motor neuron disease characterized by upper motor neuron dysfunction. Because pathologic examination has revealed a loss of neurons in the motor cortex of patients with PLS, we sought to confirm and extend this finding by using MR imaging to measure cortical thickness. METHODS: Seven patients with PLS and 7 age-matched neurologically normal control subjects were examined with heavily T1-weighted short-tau inversion recovery (STIR) MR imaging performed at 3T. Cortical thickness in the anterior and posterior banks of both the central and precentral sulci were measured. RESULTS: Primary motor cortex (M1) was significantly thinner in patients with PLS than M1 in healthy control subjects, measuring 2.32 +/- 0.21 mm compared with 2.79 +/- 0.18 mm (P = .0008). Cortical thickness did not differ between the 2 groups for primary sensory cortex or for the anterior or posterior banks of the precentral sulcus. Therefore, loss of gray matter was specific to motor cortex. Although this difference was modest, cortical thickness discriminated between the 2 groups; only 1 PLS case was within the range of normal measurements. CONCLUSION: Decreased thickness of M1 on the anterior bank of the precentral sulcus in patients with PLS, demonstrable by MR imaging, indicates a selective loss of upper motor neurons in this disease. Measurements of cortical thickness by MR imaging may provide a useful biomarker for diagnosis and study of upper motor neuron diseases.     

Measurement of carotid wall volume and maximum area with contrast-enhanced 3D MR imaging: initial observations

PURPOSE: To investigate whether postcontrast three-dimensional (3D) magnetic resonance (MR) imaging would yield more accurate measurement of carotid artery wall volume and maximum wall area, which are both measures of plaque burden, than precontrast 3D MR imaging. MATERIALS AND METHODS: Eleven consecutive patients scheduled to undergo carotid endarterectomy were recruited for the study. A 3D fast gradient-recalled-echo sequence was applied to acquire both precontrast and postcontrast images of the carotid artery wall. The same sequence was used to image the ex vivo excised plaque as a reference for measurement of carotid wall volume and maximum wall area. RESULTS: The mean difference in maximum wall area between the precontrast in vivo measurements and the ex vivo measurements (mean +/- SD, 18.22 mm2 +/- 15.61) was significantly larger than that between the postcontrast in vivo measurements and the ex vivo measurements (12.33 mm2 +/- 14.49) (P =.02). The difference in wall volume between the precontrast in vivo measurements and the ex vivo measurements (41.81 mm3 +/- 36.51) was larger than that between the postcontrast in vivo measurements and the ex vivo measurements (32.73 mm3 +/- 35.00) (P =.004). Postcontrast images yielded better correlation with ex vivo images than did precontrast images, in both carotid luminal area (R = 0.88 for postcontrast images, R = 0.80 for precontrast images) and outer wall boundary area (R = 0.79 for postcontrast images, R = 0.71 for precontrast images) measurements. CONCLUSION: Postcontrast 3D MR imaging may be useful in the measurement of carotid artery plaque burden.     

CT features of congenital nasal piriform aperture stenosis: initial experience.

PURPOSE: To describe the computed tomographic (CT) measurements and features that enable accurate diagnosis of congenital nasal piriform aperture stenosis (CNPAS). MATERIALS AND METHODS: The clinical and imaging features of six patients (age range, 0-11 months) with CNPAS were retrospectively evaluated and compared with those of 61 control subjects younger than 24 months. RESULTS: The average widths of the piriform aperture in patients aged 0-3, 4-6, and 10-12 months were 4.8, 7.0, and 6.0 mm, respectively, compared with 13.4 (P < .001), 14.9, and 15.6 mm, respectively, in the age-matched control subjects. The average areas of the piriform aperture in patients in the three age groups measured 0.24, 0.46, and 0.36 cm2, respectively, compared with 0.67 (P < .001), 0.86, and 1.11 cm2, respectively, in the age-matched control subjects. The width of the nasal cavity in patients with CNPAS was in the less than 5th percentile compard with that in the control subjects. Abnormal dentition and a midline bone ridge projecting from the inferior palate were present in all six patients. CONCLUSION: CT measurement of the piriform aperture width is a simple and accurate method for diagnosing CNPAS; a width less than 11 mm in a term infant is considered to be diagnostic. An abnormal dentition and a bone ridge along the underside of the palate are confirmatory imaging findings.     

Accurate quantification of right ventricular mass at MR imaging by using cine true fast imaging with steady-state precession: study in dogs

PURPOSE: To assess the accuracy of cine magnetic resonance (MR) imaging with a segmented true fast imaging with steady-state precession (FISP) technique for right ventricular (RV) mass quantification. MATERIALS AND METHODS: Fourteen dogs were imaged with a 1.5-T clinical MR imaging unit by using an electrocardiographically gated true FISP sequence. Contiguous segmented k-space cine images were acquired from the base of the RV to the apex during suspended respiration (repetition time msec/echo time msec, 3.2/1.6; section thickness, 5 mm; in-plane resolution, 1.0 x 1.3 mm2). After imaging, each dog was sacrificed, and the RV free wall was isolated and weighed. Each MR imaging data set was analyzed twice by each of two independent observers who were blinded to the results of RV mass measurement at autopsy, and the mass measurements at MR imaging were compared with the autopsy results by using linear regression and Bland-Altman analysis. RESULTS: RV mass measurements calculated by using the true FISP cine MR images were nearly identical to those at autopsy (R = 0.82, standard error of the estimate = 1.7 g, P >.05), with a mean difference between the autopsy and MR imaging measurements of 0.3 g +/- 1.7 (1.9% +/- 8.2) (P >.05). Inter- and intraobserver variations were small, with a mean interobserver variability of -0.1 g +/- 2.3 and a mean intraobserver variability of 0.2 g +/- 1.6 at every-section analysis. CONCLUSION: In this animal model, true FISP cine MR imaging enabled accurate quantification of RV mass.     

Hyaline cartilage thickness in radiographically normal cadaveric hips: comparison of spiral CT arthrographic and macroscopic measurements

PURPOSE: To assess spiral multidetector computed tomographic (CT) arthrography for the depiction of cartilage thickness in hips without cartilage loss, with evaluation of anatomic slices as the reference standard. MATERIALS AND METHODS: Permission to perform imaging studies in cadaveric specimens of individuals who had willed their bodies to science was obtained from the institutional review board. Two independent observers measured the femoral and acetabular hyaline cartilage thickness of 12 radiographically normal cadaveric hips (from six women and five men; age range at death, 52-98 years; mean, 76.5 years) on spiral multidetector CT arthrographic reformations and on coronal anatomic slices. Regions of cartilage loss at gross or histologic examination were excluded. CT arthrographic and anatomic measurements in the coronal plane were compared by using Bland-Altman representation and a paired t test. Differences between mean cartilage thicknesses at the points of measurement were tested by means of analysis of variance. Interobserver and intraobserver reproducibilities were determined. RESULTS: At CT arthrography, mean cartilage thickness ranged from 0.32 to 2.53 mm on the femoral head and from 0.95 to 3.13 mm on the acetabulum. Observers underestimated cartilage thickness in the coronal plane by 0.30 mm +/- 0.52 (mean +/- standard error) at CT arthrography (P < .001) compared with the anatomic reference standard. Ninety-five percent of the differences between CT arthrography and anatomic values ranged from -1.34 to 0.74 mm. The difference between mean cartilage thicknesses at the different measurement points was significant for coronal spiral multidetector CT arthrography and anatomic measurement of the femoral head and acetabulum and for sagittal and transverse CT arthrography of the femoral head (P < .001). Changes in cartilage thickness from the periphery to the center of the joint ("gradients") were found by means of spiral multidetector CT arthrography and anatomic measurement. CONCLUSION: Spiral multidetector CT arthrography depicts cartilage thickness gradients in radiographically normal cadaveric hips.     

Quantitative assessment of patellar cartilage volume and thickness at 3.0 tesla comparing a 3D-fast low angle shot versus a 3D-true fast imaging with steady-state precession sequence for reproducibility

OBJECTIVES: We sought to compare patellar cartilage volume and thickness measurement between 3D-FLASH and 3D-True fast imaging with steady-state precession (FISP) image data at 3.0 T. MATERIALS AND METHODS: One knee each of 6 healthy adults was examined by axial magnetic resonance imaging (MRI) performed with a 3D-fast flow angle shot (FLASH) water-excitation sequence and a 3D-TrueFISP water-excitation sequence (spatial resolution 0.31 x 0.31 x 1.5 mm3). Patellar cartilage volume and mean/maximum thickness were calculated. Intraindividual/average reproducibility and interindividual variability were determined from 3 consecutive data sets acquired for each volunteer and sequence. RESULTS: Patellar cartilage volume and thickness as well as reproducibility was slightly but not significantly lower for the 3D-TrueFISP data than for the 3D-FLASH data (volume: 3.4-6.3 mL (3D-FLASH)/3.1-6.0 mL (3D-TrueFISP), average reproducibility 1.8% (3D-FLASH)/4.4% (3D-TrueFISP); mean thickness: 2.1-2.8 mm (3D-FLASH)/1.9-2.6 mm (3D-TrueFISP), average reproducibility 2.8% (3D-FLASH)/3.8% (3D-TrueFISP); maximum thickness: 4.7-6.6 mm (3D-FLASH)/4.5-6.2 mm (3D-TrueFISP), average reproducibility 2.6% (3D-FLASH)/4.1% (3D-TrueFISP)). Interindividual variability was comparable for both sequence techniques. CONCLUSION: At 3.0 T, the 3D-FLASH sequence showed tendency to be slightly superior to the 3D-TrueFISP sequence considering robust and valid assessment of quantitative cartilage parameters in young healthy adults, although there was found no significant statistical difference between both imaging techniques. However, in patients suffering from osteoarthritis (OA), the 3D-TrueFISP sequence might prove advantageous for monitoring of disease progression and evaluation of therapy success, particularly because the substantially higher signal to noise ratio/contrast to noise ratio values might allow for higher spatial resolution and hence for improvement of the accuracy of segmentation process especially at the articular surface.     

Comparison of image validity between cone beam computed tomography for dental use and multidetector row helical computed tomography

OBJECTIVES: To evaluate and compare the image validity of a cone beam CT machine for dental use (3DX) and the latest medical CT system, multidetector row helical CT (MDCT). METHODS: A dried right maxilla of an Asian adult was used as a phantom. It was cut from the zygomatic process towards the midline, parallel to the midline plane, into eight slices of 2 mm thickness. This phantom was imaged with the 3DX and MDCT machines. Images were evaluated by comparing them with one selected bone slice from the phantom. In this comparison, two types of MDCT images were used: one with the window level (WL) and window width (WW) suitable for observing teeth (MDCT tooth image), and the other appropriate for observing bone (MDCT bone image). Three dentists and one radiographer then used our reported subjective five-level scale to evaluate and compare images generated by the two systems in terms of validity. Cancellous bone as well as enamel, dentin, pulp cavity, periodontal ligament space, lamina dura and overall impression were evaluated. RESULTS: Statistically significant differences (P<0.05) were found for almost all observation items. Our subjective evaluation clarified that 3DX was superior to MDCT in terms of image validity. Few significant intra- or interevaluator errors were found. CONCLUSIONS: Our subjective evaluation of image validity clarified 3DX as being superior to MDCT. Taken together with the low skin dose we previously reported for 3DX, the results demonstrate 3DX to be beneficial for imaging diagnosis of hard tissues in the maxillofacial region.     

Thickened stomach--an ultrasound sign of portal hypertension

Congestive gastrophy occurs with portal hypertension and is associated with vascular changes including dilatation and tortuosity of the submucous veins. Transabdominal ultrasound measurements of the stomach were made to determine whether these changes resulted in increased thickness of the stomach in patients with established cirrhosis and portal hypertension. Mean thickness of the antrum and body was 22.15 mm (range 13-31 mm) and 22.2 mm (range 13-31 mm) respectively in patients with portal hypertension: in the control group measurements of the antrum and body were 13.8 mm (range 8-20 mm) and 14.05 mm (range 11-19 mm) respectively (P less than 0.01 for both antrum and body). A thickened stomach may indicate the presence of portal hypertension.     

Role of the inflamed synovial volume of the wrist in defining remission of rheumatoid arthritis with gadolinium-enhanced 3D-SPGR MR imaging.

The purpose of this study was to assess the role of inflamed synovial volume (ISV) in defining a state of remission in rheumatoid arthritis (RA) with contrast-enhanced, fat-suppression, three-dimensional (3D) gradient-recalled acquisition in the steady state with radiofrequency spoiling (SPGR) magnetic resonance (MR) imaging. Sixteen patients with RA (5 remission and 11 non-remission patients) were enrolled in this study. Contrast-enhanced, fat-suppression, 3D-SPGR MR imaging was performed before (n = 12) and after (n = 16) a mean 17 months of disease-modifying antirheumatic drugs (DMARDs). ISV was calculated by using a segmentation method. Statistical analysis of changes in ISVs and residual ISVs between the remission and the non-remission groups was performed. Intra- and inter-observer reproducibility was tested. Residual ISVs and relative changes in ISVs were 3.23 +/- 1.84 cm(3) and 51.4% (range 47.6-55.2%) in the remission group and 6.26 +/- 2. 03 cm(3)and 31.4% (range -73.5-53.5%) in the non-remission group. Both values were significantly different between the two groups (P < 0.05 and 0.05, respectively). Volume measurement showed high reproducibility: Intra- and inter-observer mean percentage errors were 5.04, 7.06, and 5.09%, respectively. Residual ISVs and relative changes in ISVs measured by MR imaging may provide objective and quantitative parameters in defining a state of remission in RA after therapy; however, the clinical utility of these measurements remains to be verified. J. Magn. Reson. Imaging 1999;10:202-208.     

MRI在小肠疾病诊断中的应用价值

目的 探讨MRI在小肠疾病诊断中的可能性及其临床应用价值.方法 63例临床怀疑有小肠疾病的患者及3名志愿者进行了小肠MR平扫及对比增强T_1WI,并对肠管显示质量进行评分.将31例经手术或临床证实患者的MR影像诊断结果与临床最终诊断结果相比较,评价MRI诊断的敏感性与准确性;对肿瘤性与非肿瘤性病变肠壁的平均厚度进行Wilcoxon秩和检验,对两者的肠系膜肿大淋巴结、肠壁周围浸润及肠腔狭窄情况分别采用Fisher精确检验.结果 66例小肠MR检查均获得成功,图像质量达2分和3分者共62例,占93.9%(62/66).MR发现病变的敏感性为100%(31/31),诊断的准确率为77.4%(24/31).31例经手术或临床证实的患者中,肿瘤性病变10例,非肿瘤性病变21例,两者病变肠壁的平均厚度分别为23.0 mm(7.0～65.0 mm)及5.0 mm(2.0～35.0 mm),差异有统计学意义(Z=-2.949,P<0.01);周围肠系膜淋巴结肿大分别为7及4例,差异有统计学意义(P<0.05);肠腔狭窄均为10例,差异有统计学意义(P<0.01);病变周围的浸润性病变分别为5及17例,差异无统计学意义(P>0.05).结论 小肠MR检查安全可靠,能清楚地显示小肠病变的部位与范围,对病变定性诊断具有较高的准确性,是诊断小肠疾病的一种有效的检查方法.     

MRI在小肠疾病诊断中的应用价值

目的 探讨MRI在小肠疾病诊断中的可能性及其临床应用价值.方法 63例临床怀疑有小肠疾病的患者及3名志愿者进行了小肠MR平扫及对比增强T1WI,并对肠管显示质量进行评分.将31例经手术或临床证实患者的MR影像诊断结果与临床最终诊断结果相比较,评价MRI诊断的敏感性与准确性;对肿瘤性与非肿瘤性病变肠壁的平均厚度进行Wilcoxon秩和检验,对两者的肠系膜肿大淋巴结、肠壁周围浸润及肠腔狭窄情况分别采用Fisher精确检验.结果 66例小肠MR检查均获得成功,图像质量达2分和3分者共62例,占93.9%(62/66).MR发现病变的敏感性为100%(31/31),诊断的准确率为77.4%(24/31).31例经手术或临床证实的患者中,肿瘤性病变10例,非肿瘤性病变21例,两者病变肠壁的平均厚度分别为23.0 mm(7.0～65.0 mm)及5.0 mm(2.0～35.0 mm),差异有统计学意义(Z=-2.949,P<0.01);周围肠系膜淋巴结肿大分别为7及4例,差异有统计学意义(P<0.05);肠腔狭窄均为10例,差异有统计学意义(P<0.01);病变周围的浸润性病变分别为5及17例,差异无统计学意义(P>0.05).结论 小肠MR检查安全可靠,能清楚地显示小肠病变的部位与范围,对病变定性诊断具有较高的准确性,是诊断小肠疾病的一种有效的检查方法.     

Fetal lung volume measurements: determination with MR imaging--effect of various factors

PURPOSE: To retrospectively determine the effect of gestational age (GA), imaging plane, section thickness, and inter- and intraobserver variability on fetal lung volume (FLV) measurements obtained with magnetic resonance (MR) imaging in a cohort of fetuses without thoracic abnormalities. MATERIALS AND METHODS: Institutional review board approval was obtained. Informed consent for this retrospective cohort study was waived, and the conduct of this study was HIPAA compliant. FLV was measured in 30 fetuses (GA, 17-36 weeks) referred for MR imaging for indications other than pulmonary abnormalities. Measurements were made on single-shot fast spin-echo images by tracing free-form regions of interest on individual consecutive sections in the transverse, sagittal, and coronal planes. Measurements were performed twice by two observers independently. Correlations between FLV and GA, imaging plane, and section thickness were assessed, as were intra- and interobserver variability. Time to perform FLV was assessed in a subset of fetuses. RESULTS: Total FLV ranged from 2 to 110 mL. Mixed-effects regression model showed significant quadratic trend in FLV with increasing GA, with comparable strength of correlation (r = 0.89-0.91) in the three imaging planes of measurement. Intraobserver agreement was good in all three planes (r = 0.65-0.83) and was highest in the transverse plane. Interobserver agreement was good in all three planes (r = 0.68-0.76). FLV showed no significant dependence on section thickness (P = .23) or imaging plane (P = .82). Mean time to obtain FLV measurements ranged from 48 seconds at GA of 21 weeks to 77 seconds at GA of 29-30 weeks. CONCLUSION: GA-based FLV measurements obtained with MR images are independent of section thickness and imaging plane and can be performed with good inter- and intraobserver agreement in less than 2 minutes.