Precision and Accuracy of Measurements on CT Scout View

ObjectivesThe purposes of this study were to (1) investigate the limits of measurements on scout view in three computed tomography axes, x, y and z and (2) develop a model to provide better understanding of measurement accuracy.MethodsFor the first objective, anteroposterior and lateral scout views of a Catphan phantom 200 mm in diameter and length were acquired with a GE scanner at 21 different table heights. Phantom measurements on scout view were performed by two experienced readers. The comparison of their measures provided estimation of precision. The accuracy was assessed by determining the bias, calculated as the difference between the values measured on scout view and the real phantom size. Second, a model was developed investigating the relationship between the dimensions of the object, its image, and the table height. This relationship was tested on our data.ResultsScout view measurements were precise, with less than 0.53% difference between readers. In addition, small biases of about 1 mm were detected in the z-axis, whatever the table height. In the other axes, serious biases from −13 to +73 mm were measured. Furthermore, at isocentre, overestimations up to 7 mm were shown. The results also indicated that biases in scout view measurements are because of the geometrical projection related to the object-detector distance.ConclusionsMeasurements in the table movement axis are precise and accurate, conferring to scout views an added value for preoperative planning in orthopedic surgery.     

薄层扫描法测定益肾胶囊中大黄素

应用薄层扫描法对益肾胶囊中大黄素进行了定性定量方法研究，对实验条件进行优选，排除了干扰，结果满意，加样回收率为98．66％，RSD＝1．04％。     

Synovial lipoma arborescens of the hip

Summary Lipoma arborescens is a rare intra-articular tumor usually found in the knee joint. The reported lesion involved the inferomedial recess of the right hip synovium, in a 29-year-old male. The clinical findings were nonspecific. Both arthrography and computerized tomography (CT) of the hip disclosed the tumor which, on CT examination, showed an inhomogeneous low density, due to its fat content. The final diagnosis was given by histological examination of the resected mass. No recurrence was observed after one year. The long-term prognosis probably depends more on the underlying disorder of the joint than on the lipoma itself.     

Multislice computed tomography to detect coronary stenosis among asymptomatic patients with cardiovascular risk factors and equivocal prior stress test: preliminary study

Multislice computed tomography (MSCT) is a non-invasive and validated technique to detect coronary stenoses. Some questions remain about its accuracy to detect coronary stenoses (CS), especially for asymptomatic patients (P) when a prior stress test isn't conclusive. METHODS: MSCT was performed among 45 asymptomatic men (mean age: 58,3 +/- 16), with a high ten year risk of fatal cardiovascular disease (SCORE 2003 data for low-risk regions of Europe), without any previous coronary history and with previous non conclusive exercise testing. When significant (> 50%) CS was suspected at MSCT, an angiocoronarography (AC) was done. RESULTS: Eighteen MSCT were normal, unsignificant CS (< 50%) were detected on 14 MSCT and significant coronary stenoses (SCS) for 13 P. Among this 13 P, 19 SCS were identified: 2 SCS of left main coronary artery (CA), 9 of the left descending CA, 6 of the right CA and 2 of the left circumflex CA. 13 CS were confirmed at AC. Finally, because of critical angiographic lesions +/- ischemia at nuclear tomoscintigraphy (NT), 9 P had coronary revascularization (7 catheter based, 2 surgical bypass), 4 P had medical treatment. DISCUSSION: Benefits of this preliminary study are obvious: 9 coronary revascularization/45 P. However, the place of MSCT for the screening of CS is uncertain, but may be usefull as a complement for the screening of coronary arterial disease.     

不同扫描仪构建的结直肠癌全切片数字病理图像中人工标注迁移的研究

目的研究结直肠癌人工智能病理诊断模型构建过程中,病理医师对数字切片癌组织的人工标注在不同扫描仪构建的全切片图像（WSI）中准确迁移的方法。 方法在本研究中,我们提出了一种基于图像配准的标注迁移方法,在来自不同扫描仪的WSI之间建立仿射映射。通过多分辨率最小化两个WSI缩略图之间的互信息来估计最佳仿射映射参数,以避免和改变扫描仪特定特性的影响,减少计算时间。我们使用了181张结直肠癌病理切片,使用两个品牌的扫描仪获得相应的WSI,对上述标注迁移方法进行测试。 结果181张HE切片的扫描结果表明,同一张切片由不同扫描仪构建的WSI在颜色、位置、大小等属性上都有不同的表现。使用我们提出的标注迁移方法,其中179张图像的人工标注成功地在不同扫描仪构建的WSI中迁移,其中125对使用单个CPU核心的计算时间不到1分钟。 结论我们提出了一种快速、准确的全自动的标注迁移方法,用于在不同扫描仪构建的WSI之间传递人工标注。在准备深度学习训练数据过程中,既可以避免病理医师对新图像的重新标注,也可以避免病理医师之间在标注上的差异。     

Intérêt du coroscanner en urgence pour l’exclusion de la maladie coronaire chez les patients souffrant de douleur thoracique à risque faible ou intermédiaire

Purpose

To demonstrate the usefulness of the multislice computer tomography coronary angiography (CCTA) in patients with suspected acute chest pain without electrical changes or enzyme rise, and with low cardiovascular risk.

Patients and methods

Fifty-three patients at low or intermediate risk for coronary artery disease, who were admitted in the emergency department for an acute chest pain, and who underwent a CCTA, were included in the study. Results of the CCTA were classified as normal, non-obstructive stenosis (≤ 50% stenosis in diameter), obstructive stenosis (> 50% stenosis in diameter). The mortality was assessed during a 4-years follow-up period.

Results

Mean age was 61 years (36–86), 43% of patients were women. The CCTA was normal in 35 patients (66%), seven patients (13%) had non-obstructive stenosis and 11 (21%) had obstructive stenosis. In the group of normal CCTA, 8.5% of patients were admitted in cardiac intensive care unit, 57.1% in the non-obstructive stenosis and 90.9% in the group of obstructive stenosis. No deaths occurred during the 4-year follow up in the group of patients with normal CCTA.

Conclusion

This study confirms the negative predictive value of CCTA for the diagnosis of coronary artery disease and for further clinical events in patients at low or intermediate risk referred to emergency department for an acute chest pain.     

Multicystic lung revealing a Sjogren's syndrome

The Sjogren's syndrome is a chronic inflammatory autoimmune disease that affects primarily the exocrine glands, but can affect other organs particularly the lungs. Cystic lung disease is very significant but exceptionally recounted in the literature. We report the case of a patient, 54 years old, whose disease was discovered incidentally after a routine chest radiograph. The diagnosis of cystic lung revealing a primary Sjogren's syndrome was held before a group of radio-clinical, immunological and histological arguments. Through our observation, the diagnosis of Sjogren's syndrome should be included in the list of diagnoses to raise in a multicystic lung.     

Intraoperative 3D imaging control during subthalamic Deep Brain Stimulation procedures using O-arm® technology: Experience in 15 patients

ObjectiveO-arm^® now gives us the opportunity not only to perform 2D but also 3D scans during deep brain stimulation (DBS) procedures. We present our experience with the intraoperative use of this device. Our objective was to measure the geometrical accuracy of electrode placement during surgical procedures driven under O-arm^® control.MethodsFifteen patients underwent STN-DBS. For the first 4 patients, 3D scans were performed at the end of the procedure. We calculated the accuracy of electrode positioning, i.e. the distance between final electrode positioning and the planned trajectory. For the next 11 patients, who underwent both intraoperative and final 3D scan, we also calculated the accuracy of the microelectrode positioning.ResultsAverage stimulation-induced improvement of UPDRS-III score was 52.5 ± 15%. For the first 4 patients, the mean electrode positioning accuracy was 1.46 ± 0.56 mm. For the 11 patients who underwent intraoperative 3D scan, the mean microelectrodes positioning accuracy was 1.59 ± 1.1 mm. Aberrant positioning was detected in two cases, and was analyzed by fusing 3D scan with preoperative MR images. The definite electrodes positioning accuracy was 1.05 ± 0.54 mm.ConclusionIntraoperative 3D scan is feasible, and can help us detect and correct early aberrant trajectories.     

Post-operative small bowel obstruction: spiral computed tomography

INTRODUCTION: The aim of this study was to evaluate prospectively the impact of the routine use of abdominal spiral computed tomography (SCT) in patients with postoperative small bowel obstruction (SBO) for whom initial conservative treatment was proposed. PATIENTS AND METHODS: We have compared the management of SBO in patients with clinical stable condition in two successive periods : from 1989 to 1998, 127 patients (preSCT group) for whom management was based on standard clinical-biological-radiological assessment (CBRA) et from 1999 to 2000, 30 patients (SCT group) for whom management included SCT. The decision of surgical team was correlated with the type of small bowel obstruction at laparotomy : closed-loop obstruction without intestinal necrosis (true-positive), intestinal necrosis as a consequence of delayed diagnosis defined as false-negative, diffuse adhesion defined as false-positive et patient non operated defined as true-negative. RESULTS: Among the 127 patients from the preSCT group, 87 were treated conservatively and 40 were operated : SBO with closed-loop obstruction without intestinal necrosis (n = 29,72%), SBO with diffuse adhesion (n = 4, 10%) and SBO with intestinal necrosis (n = 7, 17%). Among the 30 patients from the SCT group, 16 were treated conservatively and 14 were operated: SBO with closed-loop obstruction without intestinal necrosis (n = 8, 57%), SBO with diffuse adhesion (n = 6,43%) and SBO with intestinal necrosis (n = 0,0%; NS). Both groups were similar for rates of patients with SBO with or without necrosis and rate of patients treated conservatively (NS). In SCT group, there was significantly more patients operated for diffuse adhesions (p < 0,01). Negative predictive value of CBRA + TDM was significantly higher than those of CBRA alone (p = 0,041). CONCLUSION: Due to a very high sensibility, TDM increase probably the rate of early laparotomies, maybe unnecessary, in patients without any sign of SBO due to closed-loop obstruction. Thus, systematic use of TDM in patients with clinical suspicion of SBO remains to be evaluated.     

Pterygoïdien hydatid cyst

INTRODUCTION: The cervico-facial hydatid cyst is rare. It accounts for 1% echinococcisis locations and usually involves the salivary gland and the thyroid. Pterygoid muscle involvement is exceptional. CASE REPORT: We report the case of a patient presenting a hydatid cyst of the pterygoid muscle. The patient presented a non specific progressive tumor syndrome. DISCUSSION: This case illustrates the importance of CT scans. Surgery is always required. We emphasize the risk of complications when the diagnosis is missed.