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1.
目的探讨直接三维增强MRV技术在下肢静脉血管造影中的应用。方法使用GE公司S igna 1.0T磁共振成像系统,对15例经手术、DSA或超声多普勒证实的下肢静脉疾病患者行MRV检查,观察直接三维增强MRV对下肢静脉病变的显示。结果15例患者均获得轮廓清晰、伪影少、信号强,且直观完整三维立体下腹、盆腔和下肢的深、浅静脉图像。结论直接三维增强MRV技术为一种良好的下肢静脉造影方法。  相似文献   

2.
目的探讨直接法对比增强磁共振静脉血管成像(CE-MRV)在诊断下肢深静脉血栓中的应用价值。资料与方法对临床高度怀疑下肢静脉血栓疾病的27例患者进行直接法减影CE-MRV,将采集的原始数据减影后导入后处理工作站行最大密度投影(MIP),多平面重组(MPR)及表面遮盖(SSD)法重组,分析下肢深静脉血栓形成的影像学表现。结果 27例患者双侧下肢深静脉重组图像显示清晰,重组血管对比度良好,背景抑制满意,6例正常,表现为静脉显影完整,走行自然,原始轴位显示管壁光滑。21例显示不同部位、不同程度的血栓形成,CE-MRV原始轴位图像呈偏心性的充盈缺损,重组图像上显示管腔狭窄、节段性中断或变细、浅静脉代偿扩张、深浅静脉交通支明显增多,侧支循环开放,直接造影法引起的边流效应一般表现为较长节段的中心性充盈缺损,连续断层或MPR图像显示无基底附着于管壁。结果直接法减影CE-MRV检查技术可准确地显示下肢静脉血栓性病变情况,有效避免动脉伪影及周围组织的干扰,图像清晰度及可靠性高,可明确病灶的范围和程度及侧支循环的建立与否,有重要临床应用价值。  相似文献   

3.
脑内静脉窦血栓形成MRI表现的再探讨和MR静脉成像的选择   总被引:2,自引:0,他引:2  
目的:明确脑内静脉血栓形成的脑内MRI表现和MR血管造影的诊断及检查方法。材料和方法:共9例病人,男性2例,女性7例。年龄30-56岁,平均38.2岁。使用Siemens-vision-plus超导高场MRI系统,场强1.5T。采用常规SE序列,tuberSE,TOF血管成像(用于动脉血管显示),PC法20静脉血管成像和增强3D静脉血管成像(用于矢状窦显示)。结果:MR的动脉血管成像显示阳性率为0%,2D和3D静脉血管成像阳性率为100%,3D增强静脉血管造影可更好地显示阻塞的静脉。脑实质内均有阳性表现,表现为矢状窦旁白质区对称或非对称性异常改变,呈斑片状和片状,T1W为低信号,T2W为高信号。增强后脑膜强化2例。合并脑内出血5例。结论:MRI结合MR静脉血管造影,尤其增强3D静脉血管造影是诊断脑内静脉血栓形成的有效手段。  相似文献   

4.
ObjectiveTo compare multidetector computed tomography (MDCT) and MRI for lesion conspicuity, as well as the detection and characterization of small solid pancreatic lesions (SPLs).ResultsThe sensitivity of MRI for "detection of SPL per se" was significantly higher than that of CT in both reviewers: 92.7% (179/193) and 97.9% (189/193), respectively, for reviewer 1 (p = 0.031) and 90.7% (175/193) and 99.5% (192/193), respectively, for reviewer 2 (p < 0.001). In addition, MRI provided better lesion conspicuity than MDCT for both reviewers (p < 0.001). However, CT and MRI did not show significant difference in sensitivity for "detection of SPL in consideration of secondary features", specificity for SPL detection, and differentiation of PDAC vs. non-PDAC (p > 0.05). The accuracies of CT and MRI for making a specific diagnosis were as follows: 85.7% (210/245) vs. 86.9% (213/245), respectively, for reviewer 1 (p = 0.736), and 91.8% (225/245) vs. 93.5% (229/245), respectively, for reviewer 2 (p = 0.454).ConclusionMRI showed better lesion conspicuity than MDCT, but did not show significantly different diagnostic performance compared with MDCT for detecting and characterizing small SPLs.  相似文献   

5.
Vena Cava 3D Contrast-Enhanced MR Venography: A Pictorial Review   总被引:2,自引:0,他引:2  
Three-dimensional contrast-enhanced magnetic resonance venography (CE MRV) is a sensitive and accurate method for diagnosing vena cava pathologies. The commonly used indirect approach involves a nondiluted gadolinium contrast agent injected into an upper limb vein or, occasionally, a pedal vein for assessment of the superior or inferior vena cava. In our studies, a coronal 3D fast multi-planar spoiled gradient-echo acquisition was used. A pre-contrast scan was obtained to ensure correct coverage of the region of interest. We initiated contrast-enhanced acquisition 15 sec after the start of contrast agent injection and performed the procedure twice. The image sets were obtained during two 20–30-sec breath hold, with a breathing rest of 5–6 sec, to obtain the first-pass and delayed arteriovenous phases. For patients with Budd-Chiari syndrome, a third acquisition coinciding with late venous phase was collected to visualize the hepatic veins, which was carried out by one additional acquisition after a 5–6-sec breathing time. This review describes the clinical application of 3D CE MRV in vena cava congenital anomalies, superior and inferior vena cava syndrome, Budd-Chiari syndrome, peripheral vein thrombosis extending to the vena cava, pre-operational evaluation in portosystemic shunting and post-surgical follow-up, and road-mapping for the placement and evaluation of complications of central venous devices.  相似文献   

6.
Deep veins (DVs) can be compressed by a uterus enlarged with fibroids. The purpose of this study was to assess the degree of luminal narrowing of DVs caused by a myomatous uterus, and the change in DV narrowing in women with symptomatic fibroids after embolization using time-of-flight (TOF)-magnetic resonance venography (MRV). Twenty-nine consecutive women with symptomatic uterine fibroids underwent TOF-MRV and pelvic MRI before and 4 months after embolization. Based on the TOF-MRV, we evaluated the luminal narrowing of three DVs, including the inferior vena cava, and the bilateral common and external iliac veins, and divided the findings into three grades. The scores for each DV were added for each patient (lowest, 0; highest, 6). DV scores and symptom severity (SS) scores were compared between the baseline and 4 months after embolization using the paired t-test. The relationship between DV scores and uterine volume was investigated using Pearson’s test. DV scores decreased significantly, from 1.52 ± 1.70 at baseline to 0.93 ± 1.56 at 4 months after embolization (p = 0.004). The uterine volume decreased from 948 ± 647 mL at baseline to 617 ± 417 mL at 4 months after embolization (p < 0.001). DV score correlated with uterine volume (r = 0.856, < 0.001). SS scores decreased from 54.5 ± 14.6 at baseline to 26.8 ± 15.4 at 4 months after embolization (p < 0.001). In conclusion, the degree of luminal narrowing of DVs caused by a uterus with fibroids is correlated with the uterine volume. Uterine artery embolization may induce an improvement of luminal narrowing of DVs due to a reduction of the myomatous uterus volume.  相似文献   

7.

Objective

To compare the diagnostic performance of high-resolution ultrasound (HRUS) with contrast-enhanced CT and contrast-enhanced magnetic resonance imaging (MRI) with MR cholangiopancreatography (MRCP) to differentiate between adenomyomatosis (ADM) and gallbladder cancer (GBCA).

Materials and Methods

Forty patients with surgically proven ADM (n = 13) or GBCA at stage T2 or lower (n = 27) who previously underwent preoperative HRUS, contrast-enhanced CT, and contrast-enhanced MRI with MRCP were retrospectively included in this study. According to the well-known diagnostic criteria, two reviewers independently analyzed the images from each modality separately with a five-point confidence scale. The interobserver agreement was calculated using weighted κ statistics. A receiver operating characteristic curve analysis was performed and the sensitivity, specificity, and accuracy were calculated for each modality when scores of 1 or 2 indicated ADM.

Results

The interobserver agreement between the two reviewers was good to excellent. The mean Az values for HRUS, multidetector CT (MDCT), and MRI were 0.959, 0.898, and 0.935, respectively, without any statistically significant differences between any of the modalities (p > 0.05). The mean sensitivity of MRI with MRCP (80.8%) was significantly higher than that of MDCT (50.0%) (p = 0.0215). However, the mean sensitivity of MRI with MRCP (80.8%) was not significantly different from that of HRUS (73.1%) (p > 0.05). The mean specificities and accuracies among the three modalities were not significantly different (p > 0.05).

Conclusion

High-resolution ultrasound and MRI with MRCP have comparable sensitivity and accuracy and MDCT has the lowest sensitivity and accuracy for the differentiation of ADM and GBCA.  相似文献   

8.
ObjectiveFew attempts have been made to investigate the prognostic value of dynamic contrast-enhanced (DCE) MRI or dynamic susceptibility contrast (DSC) MRI of non-enhancing, T2-high-signal-intensity (T2-HSI) lesions of glioblastoma multiforme (GBM) in newly diagnosed patients. This study aimed to investigate the prognostic values of DCE MRI and DSC MRI parameters from non-enhancing, T2-HSI lesions of GBM.Materials and MethodsA total of 76 patients with GBM who underwent preoperative DCE MRI and DSC MRI and standard treatment were retrospectively included. Six months after surgery, the patients were categorized into early progression (n = 15) and non-early progression (n = 61) groups. We extracted and analyzed the permeability and perfusion parameters of both modalities for the non-enhancing, T2-HSI lesions of the tumors. The optimal percentiles of the respective parameters obtained from cumulative histograms were determined using receiver operating characteristic (ROC) curve and univariable Cox regression analyses. The results were compared using multivariable Cox proportional hazards regression analysis of progression-free survival.ResultsThe 95th percentile value (PV) of Ktrans, mean Ktrans, and median Ve were significant predictors of early progression as identified by the ROC curve analysis (area under the ROC curve [AUC] = 0.704, p = 0.005; AUC = 0.684, p = 0.021; and AUC = 0.670, p = 0.0325, respectively). Univariable Cox regression analysis of the above three parametric values showed that the 95th PV of Ktrans and the mean Ktrans were significant predictors of early progression (hazard ratio [HR] = 1.06, p = 0.009; HR = 1.25, p = 0.017, respectively). Multivariable Cox regression analysis, which also incorporated clinical parameters, revealed that the 95th PV of Ktrans was the sole significant independent predictor of early progression (HR = 1.062, p < 0.009).ConclusionThe 95th PV of Ktrans from the non-enhancing, T2-HSI lesions of GBM is a potential prognostic marker for disease progression.  相似文献   

9.
Objectives:To assess the feasibility of a rapid, focused ferumoxytol-enhanced MR angiography (f-FEMRA) protocol in patients with claustrophobia.Methods:In this retrospective study, 13 patients with claustrophobia expressed reluctance to undergo conventional MR angiography, but agreed to a trial of up to 10 min in the scanner bore and underwent f-FEMRA. Thirteen matched control patients who underwent gadolinium-enhanced MR angiography (GEMRA) were identified for comparison of diagnostic image quality. For f-FEMRA, the time from localizer image acquisition to completion of the angiographic acquisition was measured. Two radiologists independently scored images on both f-FEMRA and GEMRA for arterial and venous image quality, motion artefact and diagnostic confidence using a 5-point scale, five being best. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in the aorta and IVC were measured. The Wilcoxon rank-sum test, one-way ANOVA with Tukey correction and two-tailed t tests were utilized for statistical analyses.Results:All scans were diagnostic and assessed with high confidence (scores ≥ 4). Average scan time for f-FEMRA was 6.27 min (range 3.56 to 10.12 min), with no significant difference between f-FEMRA and GEMRA in diagnostic confidence (4.86 ± 0.24 vs 4.69 ± 0.25, p = 0.13), arterial image quality (4.62 ± 0.57 vs 4.65 ± 0.49, p = 0.78) and motion artefact score (4.58 ± 0.49 vs 4.58 ± 0.28, p > 0.99). f-FEMRA scored significantly better for venous image quality than GEMRA (4.62 ± 0.42 vs 4.19 ± 0.56, p = 0.04). CNR in the IVC was significantly higher for steady-state f-FEMRA than GEMRA regardless of the enhancement phase (p < 0.05).Conclusions:Comprehensive vascular MR imaging of the thorax, abdomen and pelvis can be completed in as little as 5 min within the magnet bore using f-FEMRA, facilitating acceptance by patients with claustrophobia and streamlining workflow.Advances in knowledge:A focused approach to vascular imaging with ferumoxytol can be performed in patients with claustrophobia, limiting time in the magnet bore to 10 min or less, while acquiring fully diagnostic images of the thorax, abdomen and pelvis.  相似文献   

10.
Our initial experience with low dose contrast-enhanced (LCE) peripheral MR venography (MRV) is presented. Five subjects were studied using three-dimensional (3D) fast imaging with a steady-state precession (FISP) sequence. A dose of 60 ml of gadopentetate dimeglumine diluted 1:20 was used. A tourniquet was applied during lower extremity MR venography. The venous anatomy was well depicted with the 3D LCE technique in all subjects. Compared to the two-dimensional (2D) time-of-flight (TOF) technique, acquisition time of 3D LCE MRV was much shorter, images looked sharper, and more veins could be seen. It is not affected by in-plane saturation and can be performed repeatedly because of the low dose of contrast. This technique holds promise for the detection of venous thrombosis and other disorders.  相似文献   

11.

Objective

To identify and evaluate the lateral border zone by comparing the size and distribution of the abnormal signal area demonstrated by MR imaging with the infarct area revealed by pathological examination in a reperfused myocardial infarction cat model.

Materials and Methods

In eight cats, the left anterior descending coronary artery was occluded for 90 minutes, and this was followed by 90 minutes of reperfusion. ECG-triggered breath-hold turbo spin-echo T2-weighted MR images were initially obtained along the short axis of the heart before the administration of contrast media. After the injection of Gadomer-17 and Gadophrin-2, contrast-enhanced T1-weighted MR images were obtained for three hours. The size of the abnormal signal area seen on each image was compared with that of the infarct area after TTC staining. To assess ultrastructural changes in the myocardium at the infarct area, lateral border zone and normal myocardium, electron microscopic examination was performed.

Results

The high signal area seen on T2-weighted images and the enhanced area seen on Gadomer-17-enhanced T1WI were larger than the enhanced area on Gadophrin-2-enhanced T1WI and the infarct area revealed by TTC staining; the difference was expressed as a percentage of the size of the total left ventricle mass (T2= 39.2%; Gadomer-17 =37.25% vs Gadophrin-2 = 29.6%; TTC staining = 28.2%; p < 0.05). The ultrastructural changes seen at the lateral border zone were compatible with reversible myocardial damage.

Conclusion

In a reperfused myocardial infarction cat model, the presence and size of the lateral border zone can be determined by means of Gadomer-17- and Gadophrin-2-enhanced MR imaging.  相似文献   

12.
ObjectiveIntracranial stenting for stent-assisted coiling of aneurysms requires adequate follow-up imaging. The aim of this in vitro study was to compare in-stent artificial luminal narrowing on contrast-enhanced MR angiograms (CE-MRA) when applying Neuroform® and Enterprise® stents for stent-assisted coiling.ResultsLower magnetic field strength, axial plane perpendicular to axis of stent, and wider bandwidth resulted in a lower ALN on CE-MRA for both stents. Larger voxel size resulted in lower ALN for Neuroform® stent. The parallel imaging acceleration factor did not affect ALN. The mean ALN was lower for Neuroform®, but it was not significant by a paired t test.ConclusionCE-MRA of the stented lumen of vascular phantom was partially impaired with ALN. Consequently, image plane orientation, magnetic field strength, bandwidth, and voxel size should be adjusted appropriately to reduce ALN.  相似文献   

13.
Objectives:To compare image quality and radiation dose of CT images reconstructed with model-based iterative reconstruction (MBIR) and hybrid-iterative (HIR) algorithm in oncologic patients.Methods:125 oncologic patients underwent both contrast-enhanced low- (100 kV), and standard (120 kV) dose CT, were enrolled. Image quality was assessed by using a 4-point Likert scale. CT attenuation values, expressed in Hounsfield unit (HU), were recorded within a regions of interest (ROI) of liver, spleen, paraspinal muscle, aortic lumen, and subcutaneous fat tissue. Image noise, expressed as standard deviation (SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. Radiation dose were analyzed. Paired Student’s t-test was used to compare all continuous variables.Results:The overall median score assessed as image quality for CT images with the MBIR algorithm was significantly higher in comparison with HIR [4 (range 3–4) vs 3 (3-4), p = 0.017].CT attenuation values and SD were significantly higher and lower, respectively, in all anatomic districts in images reconstructed with MBIR in comparison with HIR ones (all p < 0.001). SNR and CNR values were higher in CT images reconstructed with MBIR, reaching a significant difference in all districts (all p < 0.001). Radiation dose were significantly lower in the MBIR group compared with the HIR group (p < 0.001).Conclusions:MBIR combined with low-kV setting allows an important dose reduction in whole-body CT imaging, reaching a better image quality both qualitatively and quantitatively.Advances in knowledge:MBIR with low-dose approach allows a reduction of dose exposure, maintaining high image quality, especially in patients which deserve a longlasting follow-up.  相似文献   

14.
ObjectiveTo investigate the accuracy of the Agatston score obtained with the ultra-high-pitch (UHP) acquisition mode using tin-filter spectral shaping (Sn150 kVp) and a kVp-independent reconstruction algorithm to reduce the radiation dose.Materials and MethodsThis prospective study included 114 patients (mean ± standard deviation, 60.3 ± 9.8 years; 74 male) who underwent a standard 120 kVp scan and an additional UHP Sn150 kVp scan for coronary artery calcification scoring (CACS). These two datasets were reconstructed using a standard reconstruction algorithm (120 kVp + Qr36d, protocol A; Sn150 kVp + Qr36d, protocol B). In addition, the Sn150 kVp dataset was reconstructed using a kVp-independent reconstruction algorithm (Sn150 kVp + Sa36d, protocol C). The Agatston scores for protocols A and B, as well as protocols A and C, were compared. The agreement between the scores was assessed using the intraclass correlation coefficient (ICC) and the Bland–Altman plot. The radiation doses for the 120 kVp and UHP Sn150 kVp acquisition modes were also compared.ResultsNo significant difference was observed in the Agatston score for protocols A (median, 63.05; interquartile range [IQR], 0–232.28) and C (median, 60.25; IQR, 0–195.20) (p = 0.060). The mean difference in the Agatston score for protocols A and C was relatively small (−7.82) and with the limits of agreement from −65.20 to 49.56 (ICC = 0.997). The Agatston score for protocol B (median, 34.85; IQR, 0–120.73) was significantly underestimated compared with that for protocol A (p < 0.001). The UHP Sn150 kVp mode facilitated an effective radiation dose reduction by approximately 30% (0.58 vs. 0.82 mSv, p < 0.001) from that associated with the standard 120 kVp mode.ConclusionThe Agatston scores for CACS with the UHP Sn150 kVp mode with a kVp-independent reconstruction algorithm and the standard 120 kVp demonstrated excellent agreement with a small mean difference and narrow agreement limits. The UHP Sn150 kVp mode allowed a significant reduction in the radiation dose.  相似文献   

15.
PURPOSE: To assess diagnostic accuracy and interobserver variability at venous enhanced subtracted peak arterial (VESPA) magnetic resonance (MR) venography compared with those at conventional venography for the diagnosis of femoral and iliac deep venous thrombosis (DVT). MATERIALS AND METHODS: A single anteroposterior maximum intensity projection (MIP) venogram of the femoral and iliac veins was constructed by using VESPA MR venography in 55 symptomatic patients suspected of having lower limb DVT. All patients also underwent conventional venography, results of which were used as the standard of reference. VESPA MR venograms were interpreted by two independent reviewers (reviewers A and B) who were unaware of other results. Sensitivity and specificity of VESPA MR venography for the diagnosis of thrombus in the femoral and iliac veins were calculated. Interobserver variability was calculated for these observations by using weighted kappa with equally spaced weights for positive, nondiagnostic, and negative studies. Nondiagnostic studies were reinterpreted separately by reviewer A on the basis of source data. RESULTS: Sensitivity of VESPA MR venography for the femoral veins (20 of 20) and iliac veins (seven of seven) was 100% for both reviewers. Specificity was 100% (39 of 39 for reviewer A, 40 of 40 for reviewer B) for the iliac veins and 97% (31 of 32) for the femoral veins for both reviewers. Segments in which the VESPA MR venograms were nondiagnostic were excluded from this analysis. Interobserver variability as calculated by using weighted kappa for positive, negative, and nondiagnostic studies was 0.85 for femoral veins and 0.97 for iliac veins. Interpretation of the source data led to correct diagnosis in six of six cases in which the VESPA MR venograms were nondiagnostic. CONCLUSION: VESPA MR venography yielded MIP venograms that were highly accurate for the diagnosis of DVT in femoral and iliac veins. Interpretation of the studies was also highly reproducible.  相似文献   

16.

Objective

We wanted to investigate the accuracy of contrast-enhanced MR imaging for the detection of lymph node metastases in a head and neck cancer rabbit model.

Materials and Methods

The metastatic lymph node model we used was created by inoculating VX2 tumors into the auricles of six New Zealand White rabbits. T1-weighted MR images were obtained before and after injecting gadopentetate dimeglumine at three weeks after tumor cell inoculation. The sizes, signal intensity ratios (i.e., the postcontrast signal intensities of the affected nodes relative to the adjacent muscle) and the enhancement patterns of 36 regional lymph nodes (parotid and caudal mandibular nodes) were evaluated on MR images and then compared with the histopathologic findings.

Results

No statistical difference was found between the sizes of 12 metastatic (10.5±3.2 mm) and 24 hyperplastic (8.0±3.6 mm) lymph nodes (p > 0.05). On the contrast-enhanced T1-weighted MR images, nine metastatic and four hyperplastic lymph nodes had peripheral high and central low signal intensity, whereas three metastatic and 20 hyperplastic lymph nodes had homogeneous high signal intensity. Using a signal intensity ratio less than one as a diagnostic criterion for a metastatic lymph node, the sensitivity, specificity and positive and negative predictive values of the enhanced MR images were 75% (9/12), 83% (20/24), 69% (9/13) and 87% (20/23), respectively, with areas under receiver-operating-characteristic curve values of 0.81.

Conclusion

This experimental study confirms that metastatic and hyperplastic lymph nodes can be differentiated using MR images on the basis of the contrast uptake patterns, but that they cannot be differentiated using any particular size criteria.  相似文献   

17.
We prospectively assessed the diagnostic accuracy of non‐contrast‐enhanced MR venography using both the flow‐refocused fresh‐blood imaging (FR‐FBI) and the swap phase‐encode arterial double‐subtraction elimination (SPADE) techniques for detecting deep vein thrombosis (DVT), as compared using conventional X‐ray venography as the reference standard. Forty‐one legs of 32 consecutive patients (eight men, 24 women; mean age ± standard deviation, 69.4 ± 15.3 years) suspected of having deep vein thrombosis and thus examined using conventional X‐ray venography underwent MR FR‐FBI and SPADE. Twenty‐five of the 32 patients had nonmagnetizing, metal implants they had received during hip or leg surgery. Two radiologists independently assessed the MR venograms as either diagnostic or nondiagnostic and with either the presence or absence of thrombi. The sensitivities of FR‐FBI and SPADE for diagnosing thrombus were 100% (53 of 53) for both reviewers. Nondiagnostic segments were excluded from this analysis. The corresponding specificities were 100% (238 of 238 for reviewer A) and 99.6% (237 of 238 for reviewer B). The interobserver agreement regarding the MR images for the assessment of thrombosis was high (κ = 0.92). Non‐contrast‐enhanced MR venography using SPADE and FR‐FBI is highly accurate and reproducible for diagnosing DVT. This is especially advantageous for patients who have received nonmagnetizing, metal implants during orthopedic surgery. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   

18.
PurposeTo study the diagnostic performance of diffusion weighted MR imaging in differentiation of diabetic osteoarthropathy and osteomyelitis in diabetic foot.Patients and methodsThis prospective study was carried out on 41 patients with diabetic foot, 22 males and 19 females with mean age of 51 years. They underwent diffusion-weighted MR imaging of the foot. The apparent diffusion coefficient (ADC) values of the bony lesions were calculated by two reviewers and correlated with the surgical findings or biopsy. The kappa statistic (k) was used to estimate the proportion of inter-observer agreement of two reviewers.ResultsThe mean ADC of acute diabetic osteoarthropathy was 1.27 ± 0.19 × 10−3 mm2/s for reviewer 1 and 1.26 ± 0.21 × 10−3 mm2/s for reviewer 2. The mean ADC value in diabetic osteomyelitis was 0.86 ± 0.11 × 10−3 mm2/s for reviewer 1 and 0.85 ± 0.12 × 10−3 mm2/s for reviewer 2. There was excellent inter-observer agreement of ADC value of bony lesions in diabetic foot by both reviewers (K = 0.93). There was statistically significant difference in the ADC values of both groups (P = 0.001). The cut-off point of ADC value of both reviewers used in differentiating acute diabetic osteoarthropathy and osteomyelitis were 0.98 × 10−3 mm2/s and 1.04 × 10−3 mm2/s with an accuracy of 94% and 93% and area under the curve of 0.94 and 0.93 respectively.ConclusionWe conclude that the ADC value is a non-invasive imaging parameter that can help in differentiation of diabetic osteoarthropathy from osteomyelitis with excellent inter-observer agreement.  相似文献   

19.
PurposeTo study the comparative performance of contrast-enhanced ultrasound (CEUS) and contrast-enhanced CT or MRI (CECT/MR) in evaluating liver lesions using the LI-RADS guidelines.MethodsRetrospective analysis of radiology database from July 2010 to April 2017 revealed 228 patients who had CECT/MR and CEUS. Patients at risk of hepatocellular carcinoma (HCC), had contemporaneous CEUS and CECT/CEMR studies within 3 months and adequate follow up were included; reviewed (2 reviewers) and graded according to the 2017 CEUS and 2018 CECT/MR LI-RADS guidelines. Reference standard was multidisciplinary clinical decisions, histology or follow-up imaging.ResultsThe study cohort consisted of 45 patients with 46 lesions. HCC were significantly larger than non-malignant (mean sizes of 2.5 and 1.4 cm, respectively, p<0.001). Intraclass correlation coefficient for CEUS review (0.941) was higher than of CECT/MR review (0.643). Mean area-under-ROC curve (AUC) for CEUS (0.994) was significantly higher than of CECT/MR (0.760) for all lesions (p=0.01). For lesions scored LR-3 by CECT/MR, the AUC was significantly higher for CEUS (0.978) than CECT/MR (0.500) (p<0.001). Twenty-one (of 27) lesions, classified LR-3 or LR-4 by CECT/MR were upgraded by CEUS and 20 were found to be HCC. Six lesions that were LR-3 on both CECT/MR and CEUS were found to be non-malignant. There was good concordance for LR-5 lesions between both techniques.ConclusionCEUS is useful for reassessment of lesions with intermediate probability (LR-3) or probable for HCC (LR-4) on CECT/MR. Lesions upgraded by CEUS tend to be HCC. Lesions that remain LR-3 on CEUS tend to be non-malignant.  相似文献   

20.
PurposeThe purpose of this quality improvement (QI) initiative was to increase patient access to breast MR while maintaining diagnostic image quality.MethodsInstitutional review board approval was waived for this HIPAA-compliant QI initiative, which was conducted from December 2014 through March 2016. Breast MR wait times, scheduling grids, and staffing models were reviewed to identify root causes of elevated wait times. Breast MR wait times were tracked on a biweekly basis as root causes were identified and action plans were implemented. Patient recall rates for repeat MR imaging were tracked. A retrospective analysis of image quality was performed in a randomly selected sample (20 per month; total: 320 examinations). Wait time and image quality data were analyzed with statistical process control charts and logistic regression.ResultsIn all, 798 breast MR examinations were performed during the study period. Monthly volume increased from 23 in December 2014 to 50 in March 2016 (range: 23-64). Wait time for a routine breast MRI fell from 101 days before implementation to 5 days at study completion. The technical recall rate was 0.5% (4 of 798); no recall was performed for a technologist-related error or scan quality concern. The proportion of examinations with minor (31% [99 of 320]) or major (3% [9 of 320]) image quality impairments did not significantly change during the study period (P = .69-.70).ConclusionA specialized MR examination was transitioned into routine clinical operation while maintaining image quality. This model may be useful for transitioning other specialized diagnostic imaging examinations into routine clinical practice.  相似文献   

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