肺部孤立结节钙化征象的HRCT评价

目的：本文旨在评价良恶性孤立结节（ＳＰＮＳ）的钙化征象在高分辨率ＣＴ（ＨＲＣＴ）上的差异。材料和方法：分析一组连续的资料，共５９例，其中４３例经病理学证实，１６例经临床诊断和随访明确。结果：３０例良性中的１２例（４０％），２９例恶性中的４例（１３石的）可见钙化征象（Ｐ＜０．０５）。钙化的形态有三种，１）结节状或斑炔状，２）点状，３）沙粒状。结节状或斑块状钙化是良性的特征。良恶性钙化分布不同，良性多位于中央，恶性则为偏心性的。ＨＲＣＴ所显示的１６例钙化中普通ＣＴ扫描仅显示３例。结论：ＨＲＣＴ上钙化征象多见于良性ＳＰＮＳ．但并非良性病变所特有，钙化对良恶性结节的鉴别有一定的参考价值。在钙化的显示上，ＨＲＣＴ明显优于普通Ｘ线及常规ＣＴ扫描。     

Small solitary pulmonary nodule and high-resolution CT: a preliminary report

In the attempt to separate primary lung cancers and benign lesions presenting as solitary pulmonary nodules (SPNs) the authors studied prospectively 52 SPNs less than 30 mm in diameter by means of high-resolution (HRCT). Patients with known cancer were excluded. Margins, internal structure, bronchus sign, calcifications, pleural tag and gross morphology of SPN were considered. Spiculation, air inside the nodule and bronchus sign were found in cancer and in one benign lesion (spiculation). All other benign SPNs presented smooth margins without bronchus sign or air inside the mass. Final diagnosis was obtained with surgery, fine-needle-aspiration biopsy or 12-month follow-up. Of 52 nodules, 28 proved malignant, and 24 of 52 proved benign. Sensitivity and specificity of HRCT for diagnosing malignancy of the nodule were 100% and 96%, respectively. In conclusion, we think that HRCT is useful in the differentiation of cancers from benign lesions presenting as SPNs in the majority of patients without known neoplasm. Correspondence to: L. Volterrani     

18F-FDG PET/CT结合高分辨率CT对孤立性肺结节的

 目的 探讨18F-FDG PET/CT显像结合高分辨率CT(high resolution CT,HRCT)对孤立性肺结节(solitary pulmonary nodule,SPN)的诊断价值。方法 回顾性分析124例SPN患者的18F-FDG PET/CT检查资料,其中76例加做HRCT扫描,所有病例经病理或临床随访证实。18F-FDG PET/CT通过目测法和半定量法判断病灶的代谢情况,结合CT或HRCT病灶的形态学特征判断良、恶性。结果 48例仅行18F-FDG PET/CT检查的SPN患者,正确诊断32例为恶性,8例为良性,假阳性与假阴性各4例。76例加做HRCT的患者,正确诊断62例恶性与8例良性,假阳性与假阴性分别为2例和4例。18F-FDG PET/CT 结合HRCT与单纯18F-FDG PET/CT诊断SPN的灵敏度、特异性及准确率分别为94%、80%、90%与89%、67%、83%。结论 18F-FDG PET/CT协同HRCT可提高对SPN性质判断的灵敏度、特异性及准确率。     

Radiologists' performance for differentiating benign from malignant lung nodules on high-resolution CT using computer-estimated likelihood of malignancy

OBJECTIVE: The purpose of our study was to evaluate whether a computer-aided diagnosis (CAD) scheme can assist radiologists in distinguishing small benign from malignant lung nodules on high-resolution CT (HRCT). MATERIALS AND METHODS: We developed an automated computerized scheme for determining the likelihood of malignancy of lung nodules on multiple HRCT slices; the likelihood estimate was obtained from various objective features of the nodules using linear discriminant analysis. The data set used in this observer study consisted of 28 primary lung cancers (6-20 mm) and 28 benign nodules. Cancer cases included nodules with pure ground-glass opacity, mixed ground-glass opacity, and solid opacity. Benign nodules were selected by matching their size and pattern to the malignant nodules. Consecutive region-of-interest images for each nodule on HRCT were displayed for interpretation in stacked mode on a cathode ray tube monitor. The images were presented to 16 radiologists-first without and then with the computer output-who were asked to indicate their confidence level regarding the malignancy of a nodule. Performance was evaluated by receiver operating characteristic (ROC) analysis. RESULTS: The area under the ROC curve (Az value) of the CAD scheme alone was 0.831 for distinguishing benign from malignant nodules. The average Az value for radiologists was improved with the aid of the CAD scheme from 0.785 to 0.853 by a statistically significant level (p = 0.016). The radiologists' diagnostic performance with the CAD scheme was more accurate than that of the CAD scheme alone (p < 0.05) and also that of radiologists alone. CONCLUSION: CAD has the potential to improve radiologists' diagnostic accuracy in distinguishing small benign nodules from malignant ones on HRCT.     

Image analysis methods for solitary pulmonary nodule characterization by computed tomography.

Computer software was designed for classifying solitary pulmonary nodules (SPNs) into benign and malignant from their CT images, using image analysis methods. The system made use of three features, computed from the CT density matrix of the SPN, and a class-discriminating algorithm. System evaluation was performed on 51 histologically confirmed SPNs of indeterminate CT diagnosis. Overall classification accuracy in distinguishing benign and malignant SPNs was 90.2%, while 83.3% of the benign and 93.9% of the malignant SPNs were correctly classified. The proposed system may be of value to the radiologist in assessing the probability of malignancy in patients with a solitary pulmonary nodule.     

Dynamic magnetic resonance imaging of solitary pulmonary nodules: utility of kinetic patterns in differential diagnosis

OBJECTIVE: The aim of this study was to evaluate the clinical feasibility of dynamic magnetic resonance (MR) imaging with a 3-dimensional (3D) gradient recalled echo (GRE) volumetric interpolated breath-hold examination (VIBE) sequence to differentiate between benign and malignant solitary pulmonary nodules (SPNs). METHODS: Dynamic 3D GRE VIBE was performed in 45 patients with SPNs. For each lesion, the morphologic parameters, including the edge configuration, presence of peripheral enhancement (PE), and an internal signal on T2-weighted images, and the kinetic enhancement parameters were evaluated. RESULTS: All 29 of the malignant SPNs had internal enhancement, whereas 13 (81%) of the benign SPNs did not exhibit internal enhancement. A washout pattern was only observed in the malignant SPNs. The presence of PE was found in 56% of the benign SPNs and in 50% of the malignant SPNs. The lesion size was significantly different between malignant SPNs with PE and those without PE (P <0.01). The positive predictive value for malignancy was 91% (29 of 32 malignant SPNs). The negative predictive value was 100% (13 of 13 benign SPNs). CONCLUSIONS: A combination of morphologic criteria and kinetic information is useful for differentiating between benign and malignant SPNs. In particular, internal enhancement with PE and positive visual washout is thought be a useful tool.     

Standardized uptake value-based evaluations of solitary pulmonary nodules using F-18 fluorodeoxyglucose-PET/computed tomography

OBJECTIVE: Combined positron emission tomography and computed tomography (PET/CT) might improve the accuracy of PET tracer quantification by providing the exact tumour contour from coregistered CT images. We compared various semiquantitative approaches for the characterization of solitary pulmonary nodules (SPNs) using F-18 fluorodeoxyglucose PET/CT. METHODS: The final diagnosis of 49 SPNs (46 patients) was based on histopathology (n=33) or patient follow-up (n=16). The regions of interest (ROIs) were drawn around lesions based on the CT tumour contour and mirrored to the coregistered PET images. Quantification of F-18 fluorodeoxyglucose uptake was accomplished by calculating the standardized uptake value (SUV) using three different methods based on: activity from the maximum-valued pixel within the tumour (SUV-max); the mean ROI activity within the transaxial slice containing the maximum-valued pixel (SUV-mean); and the mean activity over the full tumour volume (SUV-vol). SUVs were corrected for partial volume effects and normalized by body surface area, lean body weight, and blood glucose. Recovery coefficients for partial-volume correction were derived from phantom studies. The ability of various SUVs to differentiate between benign and malignant SPNs was determined by calculating the area under the receiver operating characteristic (ROC) curves. RESULTS: Twenty-six SPNs were malignant and 23 were benign. The area under the ROC curve was 0.78 for SUV-mean, 0.83 for SUV-max, and 0.78 for SUV-vol. SUV-max and its normalizations yielded the highest area under the ROC curve (0.83-0.85); SUV-mean-partial volume corrected-lean body weight resulted in the lowest area under the ROC curve (0.76). At a specificity of 80%, SUV-max-body surface area provided the highest sensitivity (81%) and accuracy (80%) to detect malignant SPN. Using SUV-max with a cutoff of 2.4 at a specificity of 80% resulted in a sensitivity of 62% (accuracy 71%). CONCLUSION: Various normalizations applied to SUV-max provided the highest diagnostic accuracy for characterization of SPNs. Quantification methods using the exact tumour contour derived from CT in combined PET/CT imaging (ROI mean activity within a single transaxial slice and mean tumour volume activity) did not result in improved differentiation between benign and malignant SPN. Obtaining SUV-max might be sufficient in the clinical setting.     

Automated volumetry of pulmonary nodules on multidetector CT: influence of slice thickness, reconstruction algorithm and tube current. Preliminary results

PURPOSE: To evaluate the influence of slice thickness, reconstruction algorithm and tube current (mA) on the performance of a software package in determining the volume of solid pulmonary nodules on multidetector-row computed tomography (MDCT). MATERIALS AND METHODS: A chest phantom containing artificial solid nodules with known volume was imaged with two MDCT scans at 100 and 40 mAs (200 mA and 80 mA, 0.5-s rotation time), respectively. Data were reconstructed with slice thicknesses of 1.25 and 2.5 mm and five different algorithms. The volumes of three nodules (juxtavascular, intraparenchymal, juxtapleural) were calculated using three-dimensional (3D) volumetric software. Differences between estimated and real volume were reported for each nodule and reconstruction set. RESULTS: The software segmented all nodules on 1.25-mm-thick reconstructions, independently from the mAs. It did not segment the juxtapleural nodule on 2.5-mm-thick reconstructions at 40 mAs. Mean values of the differences, which better approximated the real volume of the nodules, were obtained with high-spatial-resolution algorithms on both 100 and 40 mAs images at 1.25-mm slice thickness. CONCLUSIONS: Slice thickness, reconstruction algorithm and tube current can affect the 3D volume measurement of solid nodules. The best performance of the software, on both 100 and 40 mAs images, was observed with a slice thickness of 1.25 mm and high-spatial-resolution algorithms.     

CT diagnosis of solitary pulmonary nodule]

The CT (including HRCT) findings of solitary pulmonary nodule (SPN) were reviewed. CT currently is the imaging modality of choice for the evaluation of SPN. Important roles of CT are detecting pulmonary nodules and distinguishing malignant nodules from other benign tumors or inflammatory masses. To differentiate malignancy from benignancy, it is necessary to evaluate the CT findings of SPN, including morphology using HRCT, attenuation of the nodules using thin-section CT, and enhancement effect on contrast-enhanced CT. Also important in this distinction is the evaluation of satellite lesions around SPN and the relationships between bronchus, artery, vein, pleura, and interlobular septum. Spiral CT has greatly expanded the usefulness of CT in the evaluation of SPN and has become the imaging modality of choice for SPN by combining the advantages of a single breath-hold acquisition and improved MPR and three-dimensional reconstruction capabilities. MPR and three-dimensional images of spiral CT can also be used to display the three-dimensional relationship between SPNs and bronchus, vessels, or pleura.     

长期吸烟者合并肺纤维化的孤立性肺结节18F-FDG PET/CT恶性风险预测模型的建立

目的构建并验证长期吸烟者肺间质纤维化背景下的孤立性肺结节(SPNs)18F-脱氧葡萄糖(FDG)PET/CT恶性风险预测模型。方法收集2011年1月至2019年12月间于青岛大学附属医院PET/CT中心行18F-FDG PET/CT显像,且有明确吸烟史、同机CT示有肺间质纤维化合并SPNs的169例患者进行回顾性分析,均为男性,年龄68(63,75)岁。以病理学诊断结果或肺内病灶随访的影像学资料(随访时间≥2年)为标准,判断结节良恶性;运用χ²检验、Mann-Whitney U检验比较良恶性病灶的临床特征(年龄、吸烟指数)、形态特征(病灶最大径、密度、位置、分布、与纤维化区域相对位置、毛刺征、分叶征、钙化、空泡征、血管集束征、胸膜凹陷征、肺气肿及双肺纤维化严重程度)和代谢特征[病灶最大标准摄取值(SUVmax)],将具有统计学意义的差异变量纳入多因素logistic回归,筛选结节恶性的独立危险因素并建立风险预测模型。以受试者工作特征(ROC)曲线的曲线下面积(AUC)及k折交叉验证(k=10)验证模型。结果共发现SPNs 222个,其中恶性157个、良性65个。单因素分析显示,吸烟指数,结节是否伴毛刺征、分叶征、血管集束征、钙化、肺气肿,结节大小,与纤维化区域的相对位置,SUV_max,双肺纤维化严重程度在良恶性结节中差异均有统计学意义(z值:2.514~9.858,χ²值:4.353~18.442,均P<0.05)。多因素logistic回归分析显示,钙化、血管集束征及SUV_max为肺间质纤维化背景下恶性结节的独立危险因素[比值比(OR):0.048~2.534,均P<0.05],据此构建的预测模型为:恶性概率P=1/(1+e-x),x=-1.839-3.033×钙化+0.930×血管集束征+0.754×SUV_max(结节具有钙化或血管集束征赋值为1,否则赋值为0)。自身验证ROC曲线下面积为0.932(95%CI:0.895~0.969),模型灵敏度、特异性分别为87.9%、86.2%。k折交叉验证示,测试组预测准确性为0.847±0.075,训练组预测准确性为0.862±0.010。结论钙化、血管集束征和SUVmax是长期吸烟者肺间质纤维化背景下恶性SPNs的独立危险因素,基于上述指标的模型判断恶性SPNs具有较高的诊断效能。     

高分辨螺旋CT增强扫描诊断肺内孤立小结节

目的 :评价高分辨螺旋CT增强扫描诊断肺内孤立小结节的价值。材料和方法 :直径小于 3cm的肺内孤立小结节患者 40例 ,其中周围性肺癌 2 9例 ,转移瘤 1例 ,肺炎性肿块 5例 ,结核瘤 2例 ,肺错构瘤、肺囊肿及肺血管瘤各 1例。40例患者先行常规CT扫描 ,发现病变后局部行高分辨螺旋CT扫描 ,仍不能定性诊断时行高分辨螺旋CT增强扫描。 40例病例均行前瞻性对比研究。结果 :高分辨螺旋CT增强扫描诊断肺内孤立性小结节的正确率为 81% ,肺内恶性结节大多均匀增强且增强CT值大于 2 0Hu ,平均增强CT值为 3 6Hu。良性结节多周边增强且增强CT值小于 10Hu。结论 :高分辨螺旋CT增强扫描有助于肺内孤立性小结节定性诊断 ,同时强调必须结合病变的基本形态特征综合考虑。     

Evaluation of image quality and dose in renal colic: comparison of different spiral-CT protocols

The aim of this study was to test different technical spiral-CT parameters to obtain optimal image quality with reduced X-ray dose. Images were acquired with a spiral-CT system Philips Tomoscan AVE1, using 250 mA, 120 kV, and 1-s rotational time. Three protocols were tested: protocol A with 5-mm thickness, pitch 1.6, slice reconstruction every 2.5 mm; protocol B with 3-mm thickness, pitch 1.6, slice reconstruction every 1.5 mm; and protocol C with 3-mm thickness, pitch 2, slice reconstruction every 1.5 mm. Two phantoms were employed to evaluate the image quality. Axial images were acquired, then sagittal and coronal images were reconstructed. Finally, the absorbed X-ray dose for each protocol was measured. Regarding image quality, 5-mm-thick images (protocol A) showed greater spatial resolution and lower noise compared with 3-mm-thick images (protocols B and C) on the axial plane; 3-mm reconstructed sagittal and coronal images (protocols B and C) showed an improved image quality compared with 5-mm reformatted images (protocol A). Concerning X-ray dose, the mean dose was: protocol A 19.6 +/- 0.8 mGy; protocol B 14.4 +/- 0.6 mGy; protocol C 12.5 +/- 1.0 mGy. Our study supports the use of thin slices (3 mm) combined with pitch of 1.6 or 2 in renal colic for X-ray dose reduction to the patient and good image quality.     

肺内孤立性小结节的HRCT和病理相关性的研究

目的前瞻性研究52例肺内孤立性结节的高分辨力CT-病理相关性.方法双盲法观察所有的HRCT扫描图像,记录结节的部位、内部和周围特征.手术后标本按Heitzmam标准方法制备标本,再行横断面CT扫描,对比观察结节的HRCT征象.结果52例肺内孤立性小结节HRCT-病理对照研究表明良恶性结节的大小和分布无显著差异;良性结节的密度较恶性结节内部密度均匀;51%恶性结节的边缘不规则,呈浅分叶性改变;良性结节周围出现CT晕征和周围性肺气肿征.结论HRCT对于肺内＜3cm的恶性结节内部低密度的显示有重要的价值;对于难定义的无钙化＜2cm的光滑结节,周围出现多支异常血管,晕征和周围性肺气肿时,良性结节的诊断较肯定.     

Solitary pulmonary nodules: a comparative study evaluated with contrast-enhanced dynamic MR imaging and CT

OBJECTIVE: The aim of this prospective study was to compare the diagnostic performances of dynamic MR imaging and CT for the differentiation of benign and malignant solitary pulmonary nodules (SPNs). METHODS: Eighty-one patients with SPNs (32 malignant, 49 benign) underwent dynamic MR imaging (n=31), dynamic CT (n=27), or both (n=23). The degree of peak enhancement of benign and malignant SPNs was compared on both dynamic MR imaging and CT. Receiver operating characteristic (ROC) analysis was performed to compare the diagnostic performances of dynamic MR imaging and CT. RESULTS: The malignant SPNs revealed significantly greater degrees of peak enhancement on dynamic MR imaging (mean +/- SD [p%SI] 131.2 +/- 46.1 versus 54.2 +/- 45.3; range [p%SI] 82.6-260.0 versus -0.7-171.7; P <0.0001) and CT (mean +/- SD [DMI] 37.8 +/- 15.1 versus 17.9 +/- 21.8; range [DMI] 14.1-68.2 versus -5.4-107.6; P=0.0004). Although dynamic MR imaging was somewhat superior to dynamic CT, the diagnostic performances of the 2 modalities based on ROC analysis were not statistically significant. CONCLUSIONS: Dynamic MR imaging and CT seem to be equally well suited for the differentiation between benign and malignant SPNs.     

Clinical application of pharmacokinetic analysis as a biomarker of solitary pulmonary nodules: Dynamic contrast-enhanced MR imaging

The purpose of this study is to evaluate perfusion indices and pharmacokinetic parameters in solitary pulmonary nodules (SPNs). Thirty patients of 34 enrolled with SPNs (15–30 mm) were evaluated in this study. T1 and T2‐weighted structural images and 2D turbo FLASH perfusion images were acquired with shallow free breathing. B‐spline nonrigid image registration and optimization by χ² test against pharmacokinetic model curve were performed on dynamic contrast‐enhanced MRI. This allowed voxel‐by‐voxel calculation of k_ep, the rate constant for tracer transport to and from plasma and the extravascular extracellular space. Mean transit time, time‐to‐peak, initial slope, and maximum enhancement (E_max) were calculated from time–intensity curves fitted to a gamma variate function. After blinded data analysis, correlation with tissue histology from surgical resection or biopsy samples was performed. Histologic evaluation revealed 25 malignant and five benign SPNs. All benign SPNs had k_ep < 1.0 min^?1. Nineteen of 25 (76%) malignant SPNs showed k_ep > 1.0 min^?1. Sensitivity to diagnose malignant SPNs at a cutoff of k_ep = 1.0 min^?1 was 76%, specificity was 100%, positive predictive value was 100%, negative predictive value was 45%, and accuracy was 80%. Of all indices studied, k_ep was the most significant in differentiating malignant from benign SPNs. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.     

双能CT虚拟平扫鉴别良恶性孤立肺结节的临床应用价值

目的：探讨双能CT虚拟平扫技术鉴别孤立性肺结节(SPN)良恶性的准确性及辐射剂量。方法 61例SPN患者,其中经病理证实恶性39例,良性18例。经对比增强双能CT扫描,使用Liver VNC处理程序测量虚拟平扫图像和增强图像中SPN的CT值,同时获得两者差值。将CT值差值≥20 HU的SPN确定为恶性,计算诊断准确性。使用配对t检验对其中28例患者的常规CT平扫和虚拟平扫图像的噪声进行评价(1 ～5)分,使用Mann- Whitney U检验对图像质量及每例患者的辐射剂量进行评价。结果 使用虚拟平扫图像为基线进行SPN良、恶性判断的敏感度、特异度、准确度分别为89.7％( 35/39)、72.2％ (13/18)、84.2％ (48/57)。常规平扫图像和虚拟平扫图像的噪声分别为(8.49±1.94)、(10.14±2.18) HU,t ＝9.45,P＜0.01;图像质量评分分别为(4.71±0.46)、(4.42±0.57)分,U＝290.00,P＞0.05。单次常规平扫和双能CT扫描患者接受辐射的有效剂量分别为(3.72±0.48)、(3.78±0.45) mSv,U＝350.50,P＞0.05。结论 双能CT胸部扫描可有效降低对患者的放射性辐射;以虚拟平扫图像为基线判断SPN的良恶性具有较高的准确性。     

多层螺旋CT动态增强在孤立性肺结节的应用

目的:探讨良恶性孤立性肺结节(SPNs)的动态强化模式,以期提高SPNs的诊断符合率。方法:对96例经病理或随访证实的96例SPNs进行动态扫描,测定SPNs的强化值、灌注值、血流量、血容量及时间密度曲线等动态强化参数指标,比较不同性质SPNs的动态强化参数及其价值。结果:恶性结节的平均强化值高于良性结节,但差异无显著性意义(P>0.05);恶性结节及良性结节A的强化程度明显高于良性结节B(P<0.01)。恶性结节与良性结节A的灌注值显著高于良性结节B(P<0.01);恶性结节血流量及血容量高于良性结节,并且差异有显著性意义(P<0.05);恶性结节与良性结节A的血流量及血容量显著高于良性结节B(P<0.01);良性结节A的血流量及血容量均稍高于恶性结节,但差异无显著性意义(P>0.05)。结论:动态增强CT扫描有助于鉴别孤立性肺结节的性质,结节增强值在20HU以下提示良性,结节增强值≥20HU,可作为诊断恶性结节的一个参考指标。     

A comparison of the diagnostic accuracy of 18F-FDG PET and CT in the characterization of solitary pulmonary nodules.

CT and PET are widely used to characterize solitary pulmonary nodules (SPNs). However, most CT accuracy studies have been performed with outdated technology and methods, and previous PET studies have been limited by small sample sizes and incomplete masking. Our objective was to compare CT and PET accuracy in veterans with SPN. METHODS: Between January 1999 and June 2001, we recruited 532 participants with SPNs newly diagnosed on radiography and untreated. The SPNs were 7-30 mm. All patients underwent (18)F-FDG PET and CT. A masked panel of 3 PET and 3 CT experts rated the studies on a 5-point scale. SPN tissue diagnosis or 2-y follow-up established the final diagnosis. RESULTS: A definitive diagnosis was established for 344 participants. The prevalence of malignancy was 53%. The average size was 16 mm. Likelihood ratios (LRs) for PET and CT results for combined ratings of either definitely benign (33% and 9% of patients, respectively) or probably benign (27% and 12%) were 0.10 and 0.11, respectively. LRs for PET and CT results for combined ratings of indeterminate (1% and 25%), probably malignant (21% and 39%), or definitely malignant (35% and 15%) were 5.18 and 1.61, respectively. Area under the receiver operating characteristic curve was 0.93 (95% confidence interval, 0.90-0.95) for PET and 0.82 (95% confidence interval, 0.77-0.86) for CT (P < 0.0001 for the difference). PET inter- and intraobserver reliability was superior to CT. CONCLUSION: Definitely and probably benign results on PET and CT strongly predict benign SPN. However, such results were 3 times more common with PET. Definitely malignant results on PET were much more predictive of malignancy than were these results on CT. A malignant final diagnosis was approximately 10 times more likely than a benign final diagnosis in participants with PET results rated definitely malignant.     

Development of a novel computer-aided diagnosis system for automatic discrimination of malignant from benign solitary pulmonary nodules on thin-section dynamic computed tomography

OBJECTIVES: As an application of the computer-aided diagnosis of solitary pulmonary nodules (SPNs), 3-dimensional contrast-enhanced (CE) dynamic helical computed tomography (HCT) was performed to evaluate temporal changes in the internal structure of nodules to differentiate between benign nodules (BNs) and malignant nodules (MNs). METHODS: There were 62 SPNs (35 MNs and 27 BNs) included in this study. Scanning (2-mm collimation) was performed before and 2 and 4 minutes after CE dynamic HCT. The CT data were sent to a computer, and the pixels inside the nodule were characterized in terms of 3 parameters (attenuation, shape index, and curvedness value). RESULTS: Based on the CT data at 4 (MN: 1.81-27.1, BN: -42.8 to -3.29) minutes after CE-dynamic HCT, a score of 0 or higher can be assumed to indicate an MN. CONCLUSIONS: Three-dimensional computer-aided diagnosis of the internal structure of SPNs using CE dynamic HCT was found to be effective for differentiating between BNs and MNs.     

MR imaging of the temporomandibular joint: a validation experiment in vitro

RATIONALE AND OBJECTIVES: The authors compared magnetic resonance (MR) image quality obtained from 3- and 1-mm-thick sections in the depiction of the temporomandibular joint (TMJ) and its adjacent structures. MATERIALS AND METHODS: Eight TMJ specimens from four adult cadaver heads were depicted with MR imaging. Both 3- and 1-mm-thick sections were generated. One oral and maxillofacial radiologist, who was blinded to section thickness, evaluated the anatomic details of the images. Subsequently, the joints were surgically explored by two oral and maxillofacial surgeons, and the physical findings were recorded. RESULTS: Some statistically significant differences were found between the physical findings and the 3-mm-thick section images, while no significant differences were found with the 1-mm-thick sections. CONCLUSION: The TMJ and its adjacent structures were better depicted by thinner MR images.