CT诊断甲状腺癌价值分析及临床意义

目的:探究、总结CT影像技术对于甲状腺癌的诊断价值和意义。方法:通过CT对62例病理证实甲状腺癌患者进行分析,均进行平扫和增强扫描自舌骨水平至主动脉弓上缘,评价CT强化方式及特点。结果:通过不同强化密度的甲状腺癌各型CT影像技术,能有助于对病变良恶性诊断。结论:甲状腺癌CT扫描可较为准确地提示病变良恶性质及强化特征,对临床医生诊断及制定手术等治疗方案有显著意义。     

The Effect of Aromatase Inhibition on the Cognitive Function of Older Patients With Breast Cancer

IntroductionThis study evaluated the association between aromatase inhibitor (AI) therapy and cognitive function (over a 6-month period) in a cohort of patients aged ≥ 60 years compared with an age-matched healthy control group, and it evaluated changes in regional cerebral metabolism as measured by positron emission tomography (PET) scans of the brain done in a subset of the patient cohort.Patients and MethodsThirty-five patients (32 evaluable) and 35 healthy controls were recruited to this study. Patients with breast cancer completed a neuropsychological battery, self-reported memory questionnaire, and geriatric assessment before initiation of AI therapy and again 6 months later. Age-matched healthy control participants completed the same assessments at the same time points as the patient group.ResultsNo significant decline in cognitive function was seen among individuals receiving an AI from pretreatment to 6 months later compared with healthy controls. In the PET cohort over the same period, both standardized volume of interest and statistical parametric mapping analyses detected specific changes in metabolic activity between baseline and follow-up uniquely in the AI patients, most significantly in the medial temporal lobes.ConclusionAlthough patients undergoing AI treatment had few changes in neuropsychological performance compared with healthy controls over a 6-month period, regionally specific changes in cerebral metabolic activity were identified during this interval in the patient group. Additional longitudinal follow-up is needed to understand the potential clinical implications of these findings.     

Assessment of motor unit loss in patients with spinal muscular atrophy

ObjectiveTo assess motor unit (MU) changes in patients with spinal muscular atrophy (SMA) using compound muscle action potential (CMAP) scans.MethodsWe performed CMAP scan recordings in median nerves of 24 treatment-naïve patients (median age 39; range 12–75 years) with SMA types 2–4. From each scan, we determined maximum CMAP amplitude (CMAP_max), a motor unit number estimate (MUNE), and D50 which quantifies the largest discontinuities within CMAP scans.ResultsMedian CMAP_max was 8.1 mV (range 0.9–14.6 mV), MUNE was 29 (range 6–131), and D50 was 25 (range 2–57). We found a reduced D50 (<25) in patients with normal CMAP_max (n = 12), indicating MU loss and enlarged MUs due to reinnervation. Lower D50 values were associated with decreased MUNE (P < 0.001, r = 0.68, n = 43). CMAP_max, MUNE and D50 values differed between SMA types (P < 0.001). Lower motor function scores were related to patients with lower CMAP_max, MUNE and D50 values (P < 0.001).ConclusionsThe CMAP scan is an easily applicable technique that is superior to routine assessment of CMAP_max in SMA.SignificanceThe detection of pathological MU changes across the spectrum of SMA may provide important biomarkers for evaluating disease course and monitoring treatment efficacy.     

Prediction of the Risk of Malignancy Among Detected Lung Nodules in the National Lung Screening Trial

ObjectivesThis study aimed to investigate nodule features and patient-specific characteristics associated with improvement in predictive ability of lung cancer screening while maintaining the sensitivity of low-dose CT intact.MethodsAll authors were approved to use data from the National Lung Screening Trial, a previously conducted randomized clinical trial, through submission of a proposal to the Cancer Data Access System. The National Lung Screening Trial had a multilevel design with nodules nested within rounds and rounds nested within individuals; hence, to incorporate nodule-level features, multilevel logistic regression was used. Both nodule-level features and patient characteristics were included for model construction. Model construction was based on improvement in predictive ability of the model, and there were no restrictions to any significance level on variable inclusion.ResultsA total of 32,746 nodules for 9,728 patients were included in the analysis. With a sensitivity value equal to that of the National Lung Screening Trial (93.6%), positive predictive value was improved to 7.94%, which was more than twice that of the National Lung Screening Trial (3.6%). Area under receiver operating characteristic curve was 91.7% (95% confidence interval: 90.6-92.8).ConclusionsIncrement in positive predictive value of lung cancer screening with sensitivity same as National Lung Screening Trial is feasible, and inclusion of other nodule size dimensions plus longest diameter to the model significantly improves the predictive ability of models.     

Testing a parametric function against a non‐parametric alternative in IV and GMM settings

Summary This paper develops a specification test for functional form for models identified by a conditional moment restriction, including IV and GMM settings. The framework is one where the moment restriction is specified as a function of data, a finite‐dimensional parameter vector and a non‐parametric function (an infinite‐dimensional parameter vector). The null hypothesis is that the moment restriction does not depend on the non‐parametric function. The test is relatively easy to implement and its asymptotic distribution is known. The test performs well in simulation experiments.