新生儿缺氧缺血性脑病CT与临床分度的相关性

目的研究新生儿缺氧缺血性脑病（HIE）CT与临床分度间的相互关系,并评价CT对预测新生儿HIE预后的意义。方法对169例HIE患儿行头颅CT检查,并对CT结果分为轻、中、重度与HIE临床分度进行对照比较,并对107例患儿复查CT片进行分析。结果CT分度轻度与临床符合率为80.7％,CT中、重度与临床符合率分别为94％、43.7％。本组轻度HIE复查CT时病灶多已吸收,无明显后遗症;中、重度HIE大多数亦可治愈,少数形成外部性脑积水,而且外部性脑积水可以逐步吸收直至痊愈。结论HIE患儿头颅CT分型与临床分度有一定相关性,但也有差异性,两者综合评价可作出较明确诊断,为临床的早期治疗提供重要依据。CT对HIE预后评估有重要价值。     

Visual grading regression: analysing data from visual grading experiments with regression models

For visual grading experiments, which are an easy and increasingly popular way of studying image quality, hitherto used data analysis methods are often inadequate. Visual grading analysis makes assumptions that are not statistically appropriate for ordinal data, and visual grading characteristic curves are difficult to apply in more complex experimental designs. The approach proposed in this paper, visual grading regression (VGR), consists of an established statistical technique, ordinal logistic regression, applied to data from single-image and image-pair experiments with visual grading scores selected on an ordinal scale. The approach is applicable for situations in which, for example, the effects of the choice of imaging equipment and post-processing method are to be studied simultaneously, while controlling for potentially confounding variables such as patient and observer identity. The analysis can be performed with standard statistical software packages using straightforward coding of the data. We conclude that the proposed statistical technique is useful in a wide range of visual grading studies.Visual grading experiments have recently increased in popularity for studying image quality in medical imaging systems [1–10]. With a limited amount of work, requiring access only to images from the routine workflow, the rating by a number of experienced observers may result in information that is highly relevant for evaluating the diagnostic quality of an imaging procedure to be used in clinical practice and for comparisons between alternative techniques.In a typical experiment, each image is graded in one or more respects by a number of observers who select a score reflecting the general quality of the image or the fulfilment of a specific criterion such as the visibility of a certain anatomical structure. Well-defined criteria, such as the EU criteria [11–13], are often used, and the score is typically set on a scale with a limited number of steps where, for example, 0 denotes the lowest and 4 the highest category. Although the values on the scale have a natural ordering, there is no guarantee that the difference between 0 and 1 is equivalent to that between 1 and 2 or between 3 and 4. In statistical terms, the score is defined on an ordinal scale.A variant of the method, intended to increase the sensitivity to small differences in image quality, involves simultaneous viewing of two images, where the score is meant to express a comparison of the two images, such as −2 for “certainly better in left image than in right image”, −1 for “probably better in left image than in right image”, 0 for “equivalent”, +1 for “probably better in right image than in left image” and +2 for “certainly better in right image than in left image”. Again, this judgement may refer to a general concept of image quality or to a single well-defined criterion.Both of these experimental set-ups present the observers with a simple and easily understood task. When it comes to analysing the data, e.g. to compare two imaging methods with each other, however, the task is less straightforward. Applying common statistical methods relying on least-squares estimation, such as t-tests or analysis of variance (ANOVA), might be tempting, but these techniques, which seek to minimise the sum of squared distances between predicted and observed values, assume that the dependent variable is defined on an interval scale, so that a certain difference in score always has the same meaning. From a statistical point of view, it is not acceptable to use these methods on ordinal-type data.A way to overcome this problem has been suggested by Båth and Månsson [14], who use a mathematical formalism similar to that of receiver operating characteristic (ROC) curves to create a visual grading characteristic (VGC) curve. Assuming normal distributions of two underlying (unobserved) variables, their method treats the ordinal-scale data in an irreproachable manner and is easy to apply in situations in which two procedures are to be compared. However, in many situations, researchers may want to assess simultaneously the effect of several factors potentially influencing the grading and their interaction, e.g. to compare the relative importance of the choice of imaging equipment and the choice of post-processing method. In such situations, application of the VGC approach is not straightforward.A different statistical technique, designed to handle situations with dependent variables defined on an ordinal scale, is ordinal logistic regression [15, 16]. Ordinal logistic regression models easily handle situations involving several factors potentially influencing the outcome variable, and the technique now belongs to the standard statistical armamentarium. We have, however, been able to find only two publications in which it was applied to visual grading studies of image quality [17, 18]. Occasionally, researchers have applied dichotomisation of ordinal visual grading data prior to analysis with binary logistic regression, i.e. recoding the scores into two categories such as good and poor, and thus part of the information has been discarded [19].The purpose of this article, therefore, is to point out how established statistical methods involving ordinal logistic regression models may be applied to the analysis of visual grading experiments. It is not, however, meant to replace standard statistical textbooks.     

Postmortem grading of cerebral contusions

In the 1970s, J. H. Adams and other researchers at the Institute of Neurological Sciences, Glasgow, Scotland introduced a grading system for the quantification and analysis of contusions of the brain. They derived a brain contusion index based on regional surface distribution and parenchymal depth of contusions of the brain. Following a subsequent modification of this scheme in the 1980s, they recommended evolving modifications that will fit a variety of possible applications. Having tested the applicability of this grading system for the forensic/medico-legal autopsy, we have encountered some applied anatomic limitations and have derived a modification that addresses these limitations in reference to the forensic/medico-legal autopsy. We recommend a two-tier system based on the Adams’ system, which quantifies contusions of the brain by the gyral spread of contusions and by the parenchymal depth of penetration of contusions with a re-definition of the lobar distinctions and classifications of the brain. Gyral spread is assigned a grading scheme of 0–3 and the parenchymal depth of contusions is assigned a grading scheme of 0–4. A lobar contusion score is derived by multiplying the two assigned grades. A total brain contusion index is derived by summating all the lobar contusion scores. This reproducible grading system can be applied to routine bench forensic neuropathology reporting, court room illustrations and in comparative research analysis of brain trauma subjects.     

New similarity search based glioma grading

Introduction

MR-based differentiation between low- and high-grade gliomas is predominately based on contrast-enhanced T1-weighted images (CE-T1w). However, functional MR sequences as perfusion- and diffusion-weighted sequences can provide additional information on tumor grade. Here, we tested the potential of a recently developed similarity search based method that integrates information of CE-T1w and perfusion maps for non-invasive MR-based glioma grading.

Methods

We prospectively included 37 untreated glioma patients (23 grade I/II, 14 grade III gliomas), in whom 3T MRI with FLAIR, pre- and post-contrast T1-weighted, and perfusion sequences was performed. Cerebral blood volume, cerebral blood flow, and mean transit time maps as well as CE-T1w images were used as input for the similarity search. Data sets were preprocessed and converted to four-dimensional Gaussian Mixture Models that considered correlations between the different MR sequences. For each patient, a so-called tumor feature vector (= probability-based classifier) was defined and used for grading. Biopsy was used as gold standard, and similarity based grading was compared to grading solely based on CE-T1w.

Results

Accuracy, sensitivity, and specificity of pure CE-T1w based glioma grading were 64.9%, 78.6%, and 56.5%, respectively. Similarity search based tumor grading allowed differentiation between low-grade (I or II) and high-grade (III) gliomas with an accuracy, sensitivity, and specificity of 83.8%, 78.6%, and 87.0%.

Conclusion

Our findings indicate that integration of perfusion parameters and CE-T1w information in a semi-automatic similarity search based analysis improves the potential of MR-based glioma grading compared to CE-T1w data alone.     

Lumbosacral epidural lipomatosis: MRI grading

Lumbosacral epidural lipomatosis (LEL) is characterized by excessive deposition of epidural fat (EF). The purpose of our retrospective study was to quantify normal and pathologic amounts of EF in order to develop a reproducible MRI grading of LEL. In this study of 2528 patients (1095 men and 1433 women; age range 18–84 years, mean age 47.3 years) we performed a retrospective analysis of MRI exams. We obtained four linear measurements at the axial plane parallel and tangent to the superior end plate of S1 vertebral body: antero-posterior diameter of dural sac (A-Pd DuS), A-Pd of EF, located ventrally and dorsally to the DuS, and A-Pd of the spinal canal (Spi C). We calculated (a) DuS/EF index and (b) EF/Spi C index. We developed the following MRI grading of LEL: normal, grade 0: DuS/EF index ≥1.5, EF/Spi C index ≤40%; LEL grade I: DuS/EF index 1.49–1, EF/Spi C index 41–50% (mild EF overgrowth); LEL grade II: DuS/EF index 0.99–0.34, EF/Spi C index 51–74% (moderate EF overgrowth); LEL grade III: DuS/EF index ≤0.33, EF/Spi C index ≥75% (severe EF overgrowth). The MRI exams were evaluated independently by three readers. Intra- and interobserver reliabilities were obtained by calculating Kappa statistics. The MRI grading showed the following distribution: grade 0, 2003 patients (79.2%); LEL grade I, 308 patients (12.2%); LEL grade II, 165 patients (6.5%); and LEL grade III, 52 patients (2.1%). The kappa coefficients for intra- and interobserver agreement in a four-grade classification system were substantial to excellent: intraobserver, kappa range 0.79 [95% confidence interval (CI), 0.65–0.93] to 0.82 (95% CI, 0.70–0.95); interobserver, kappa range 0.76 (95% CI, 0.62–0.91) to 0.85 (95% CI, 0.73–0.97). In LEL grade I, there were no symptomatic cases due to fat hypertrophy. LEL grade II was symptomatic in only 24 cases (14.5%). In LEL grade III, all cases were symptomatic. A subgroup of 22 patients (42.3%) showed other substantial spinal pathologies (e.g., disk herniation). By means of simple reproducible measurements and indexes MRI grading enables a distinction between mild, moderate, and severe EF hypertrophy. Kappa statistics indicate that LEL can be reliably classified into a four-grade system by experienced observers.     

Susceptibility-weighted imaging in grading brain astrocytomas

Objective

To evaluate the value of intratumoral vessels and micro-hemorrhage shown in susceptibility weighted imaging (SWI) for grading brain astrocytomas and to analyze the difference between SWI and conventional imaging techniques.

Methods

22 patients with astrocytomas were diagnosed with surgical specimens, 9 of which were grades I-II, and 13 were grades III-IV. All examinations were performed on Signa DEx 3.0 T MRI scanner. Conventional imaging techniques (T1WI, T2WI, T2FLAIR, CE-T1WI) and SWI sequence were used. The parameters of SWI sequence were the following: TR = 35 ms, TE = 20 ms, FA = 15°, slice thickness = 2 mm. The small vessels and blood products of the tumors in SW images were analyzed. The differences between the two groups in SW images were analyzed statistically.

Results

The findings in SW images of brain astrocytomas were correlated strongly with pathology. SWI was more sensitive compared to conventional imaging techniques for showing small vessels and micro-hemorrhage in brain astrocytomas. Statistical comparison showed that the small vessels and micro-hemorrhage of two groups of brain astrocytomas in SW images differed significantly.

Conclusion

SWI is superior to conventional imaging techniques at showing the small vessels and micro-hemorrhage in brain astrocytomas, which plays an important role in the tumor grading.     

Pre-operative grading of intracranial glioma.

AIM: To compare the accuracy of MR-determined cerebral blood volume (CBV) maps with SPECT imaging with thallium-201 in pre-operative grading of intracranial glioma. MATERIAL AND METHODS: Nineteen patients (7 female and 12 male, mean age 46.8 years) with intracranial gliomas were examined with MR perfusion imaging pre-operatively. Sixteen of these patients were also examined with SPECT imaging with thallium-201. The tumour to contralateral white matter NI (negative integral) and tracer uptake ratios were evaluated. The ratios in high-grade and low-grade tumours were compared. RESULTS: The maximum CBV ratios of grades I and II gliomas (2.958+/-2.217) were significantly lower than the maximum CBV ratio of grades III and IV (9.484+/-4.520), p<0.001. There was no statistical difference when CBV ratios of grades I and II (p=0.381), grades II and III (p=0.229) and grades III and IV (p=0.476) gliomas were compared. Thallium SPECT imaging showed no difference in tumour uptake ratio between low-grade and high-grade gliomas (p=0.299). CONCLUSION: MR-determined NI was useful for pre-operative grading of intracranial gliomas but SPECT thallium-201 imaging was not.     

Liver trauma grading and biochemistry tests

Among solid organ blunt traumas, the liver and spleen are mostly subject to injury. In addition, the liver is also commonly injured in penetrating traumas because of its size, location, and the ease of injury to the “Glisson Capsule”. Several enzymes are known to be elevated following trauma. In our study, we evaluated the correlation between the levels of serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and gamma-glutamyl transpeptidase in 57 patients with blunt trauma to the liver and compared these values to the American Association for the Surgery of Trauma trauma grading system. Additionally, we compared the enzyme level elevations in these patients to the enzyme levels of 29 healthy subjects. As expected, we found significant elevations in enzyme levels of trauma patients compared to the control group. The calculated point estimates were not significantly different between grades 1 and 2 trauma. However, grade 3 trauma group showed a significant increase in enzyme levels.     

Recommendations for grading of concussion in athletes

Mild sports-related concussions, in which there is no loss of consciousness, account for >75% of all sports-related brain injury. Universal agreement on concussion definition and severity grading does not exist. Grading systems represent expertise of clinicians and researchers yet scientific evidence is lacking. Most used loss of consciousness and post-traumatic amnesia as markers for grading concussion. Although in severe head injury these parameters may have been proven important for prognosis, no study has done the same for sport-related concussion. Post-concussion symptoms are often the main features to help in the diagnosis of concussion in sport. Neuropsychological testing is meant to help physicians and health professionals to have objective indices of some of the neurocognitive symptoms. It is the challenge of physicians, therapists and coaches involved in the care of athletes to know the symptoms of concussion, recognise them when they occur and apply basic neuropsychological testing to help detect this injury. It is, therefore, recommended to be familiar with one grading system and use it consistently, even though it may not be scientifically validated. Then good clinical judgement and the ability to recognise post-concussion signs and symptoms will assure that an athlete never returns to play while symptomatic.     

Noninvasive grading of musculoskeletal tumors using PET

Twenty-five patients with mass lesions involving the musculoskeletal system were studied with positron emission tomography (PET) in order to determine if a relationship exists between histologic grade and tumor uptake of [fluorine-18]2-deoxy-2-fluoro-D-glucose (FDG). There were 6 benign lesions and 19 malignant lesions of various grades. A high correlation (Rho = 0.83) was found between the normalized uptake of tracer and the NCl grade. The high-grade malignancies had significantly greater (p = 0.0091) uptake of FDG than the combination of benign lesions and low-grade malignancies. All lesions with a normalized uptake value of 1.6 or greater were high-grade, while all lesions less than 1.6 represented either benign tumors or low grade malignancies. This strong relationship between FDG uptake and grade among neoplasms from a wide variety of cell types within a single organ system suggests that the technique may be useful in predicting grade even when the cell type is unknown.     

Vesicoureteral reflux grading in contrast-enhanced voiding urosonography

INTRODUCTION AND OBJECTIVE: The sonographic diagnosis of vesicoureteral reflux (VUR) with contrast-enhanced voiding urosonography (VUS) is gradually increasing. With the introduction of VUS as part of the routine diagnostic imaging modalities for reflux significant reduction in the number of voiding cystourethrographies (VCUG) was possible. Like in VCUG grading of reflux in VUS is becoming more and more relevant. The aim of this study was to find out if there are any sonomorphologic and sonomorphometric parameters that would correlate with reflux grading in VCUG. Furthermore, a reflux grading system for VUS is proposed and the correlation of this grading system tested with the one of VCUG. PATIENTS AND METHODS: In one examination session a total of 186 children underwent both VUS and VCUG of whom 89 had VUR in at least one and the same kidney-ureter-unit (KUU) in both diagnostic imagings. The VUS was conducted with intravesical administration of ultrasound (US) contrast medium (Levovist). Ureteral and pelvicalyceal dilatations before administration of US contrast medium and during reflux were documented. Renal pelvic diameter was measured. The density of microbubbles in the renal pelves was scored on a scale of 1-3 (low to high). A grading system for reflux in VUS was set up similar to the international reflux grading system for VCUG with the addition of one more differentiation parameter, namely whether the reflux was primarily in a dilated or non-dilated urinary tract. Reflux grades in VUS were compared with those in VCUG. RESULTS: None of the sonomorphologic and sonomorphometric parameters demonstrated any clear cut finding that would simplify reflux grading in VUS. In 59/95 (62%) KUUs the reflux grades were the same in both examinations. In 10/95 (11%) and 26/95 (27%) KUUs, the reflux was graded lower or higher, respectively, in VUS than in VCUG. Fifty-seven percent were in a primarily dilated system and the remaining 43% in a non-dilated one. Seventy percent of KUUs diagnosed as having grade I reflux in VCUG, showed as grade 2 on VUS. CONCLUSIONS: A reflux grading system similar to the one used in VCUG can be applied in VUS. Adding the parameter reflux into a primarily dilated or non-dilated ureter and/or pelvicalyceal system may bring in a further dimension to the reflux grading in VUS. Most of the refluxes labelled as grade I in VCUG are actually grade II or higher.     

肝硬化CT分级方法研究

目的 :探讨肝硬化CT分级的可行性及其在肝硬化诊断中的价值。方法 :搜集行CT扫描的肝硬化患者 5 0例 ,由三个观察者双盲法研究肝硬化CT分级的方法 ,并与患者的Child Pugh分级、疗效与预后进行对比研究。结果 :三个观察者双盲两两之间的相关系数r值分别为 0 .89、0 .93和 0 .96(均P <0 .0 0 0 1) ,5 0例肝硬化CT分级与Child Pugh分级等级相关系数RS=0 .8(P <0 .0 0 0 1) ;与患者预后明显相关 (双侧概率 ,P <0 .0 0 0 1) ;随肝硬化CT分级数的提高 ,门脉高压征的程度及征象种数有递增规律。结论 :肝硬化CT分级对肝硬化严重程度及预后的估计有重要价值     

Liver echogenicity: measurement or visual grading?

OBJECTIVE: Two methods to assess liver echogenicity were compared. METHODS: Liver/kidney echogenicity ratio was measured in 41 persons with the ultrasound software and visually graded by two radiologists and a radiographer. These echogenicity ratios and grades were related to risk factors for fatty liver and to liver enzyme levels. RESULTS: These determinants explained 55% of the radiologists' mean grades, 14% of the radiographer's and 31% of the measured echogenicity ratios. CONCLUSION: Radiologists' visual gradings correlated best with the indirect determinants of early liver pathology. Computerized measurements may be inferior to visual grading due to the lack of holistic tissue diagnostics.     

Scoring systems for grading deep leg vein thrombosis

A scoring system could be used in all situations where grading of deep leg vein thrombosis (DVT), including mapping of its distribution, is needed. It should also be used in epidemiological studies of DVT in further analysis of different risk groups suffering from DVT. Several scoring systems have been developed during the last three decades but have resulted in various complex and impractical systems. A scoring system should be easy to follow without any risk of misunderstanding and misinterpretation. All vein segments of importance should be defined and be possible to be included. This review describes and compares the scoring systems according to Marder et al., Arnesen et al., a subcommittee of venous disease and Bj?rgell et al.     

A new quantitative method for pivot shift grading

Purpose  

The purposes of the study were to evaluate and to quantify the pivot shift phenomenon by using a small and easy to handle measuring device for pivot shift quantification.