Imaging of intradermal tattoos by optical coherence tomography

BACKGROUND/PURPOSE: Tattoos have become increasingly popular followed by a growing demand for tattoo removal, and yet there is little knowledge and monitoring of tattoo pigment deposition in skin layers. The purpose of this pilot study is to describe optical coherence tomography image characteristics of intradermal tattoos. METHODS: We included five black tattoos in 3 female volunteers, 39, 35 and 30 years old. In vivo imaging of tattoo pigments in the skin is possible with optical coherence tomography (OCT), a novel non-invasive, in vivo optical imaging technology with a resolution and a penetration in skin high enough for visualization of tattoo pigment in the dermis. RESULTS: In optical coherence tomography images tattoo pigments clusters appear as dark, homogenous vertical columns and structures in the papillary dermis. OCT-scanned normal skin (without tattoos) appeared to be free of this dark structure. CONCLUSION: We have demonstrated that OCT can be used to visualize clusters of light absorbing pigments in a predictable manner.     

皮层下动脉硬化性脑病的影像学诊断

目的 探讨皮层下动脉硬化性脑病（SAE）的影像学诊断价值。方法 选择经影像学检查结合临床资料确诊的病例，其中单做CT检查84例，单做MRI检查14例，既做MRI检查对照24例进行分析。另又对某一时期内60岁以上（不管什么原因）做头颅CT检查患者，只有2例有痴呆，CT分型Ⅰ型47例，Ⅱ型13例，Ⅲ型为24例；同一时期头颅CT检查患者中，有SAE表现42例，无SAE表现42例；24例CT与MRI检查对照。MRI优于CT。结论 CT与MRI检查可以对SAE作出早期诊断，有助于早期治疗。     

螺旋CT三维重建成像在先天性高肩胛症手术方式选择中的作用

[目的]探讨螺旋CT三维重建技术在先天性高肩胛症分度和手术方式选择中的作用。[方法]22例先天性高肩胛症术前应用螺旋CT对病变部位进行扫描并三维重建，测量以肩胛骨肩胛冈内侧缘为参照点，两侧肩胛骨高度差。根据测量结果依据Cavendish分度将其分类，并根据三维重建成像选择不同的矫形手术术式。[结果]本组22例病人，随访2—4年，外观及功能均有不同程度的改善，未出现神经、血管和椎体等的损伤。[结论]根据螺旋CT扫描和三维重建检查结果，术前即可直观的明确先天性高肩胛症的病变程度，相互关系，伴发畸形，患侧肩胛骨与正常对侧肩胛骨的外观差异等，便于手术操作方案的制定，避免了手术操作的盲目性，减少医源性并发症的发生。     

肺泡蛋白沉积症的X线与CT诊断(附4例报告并文献复习)

目的分析肺泡蛋白沉积症的X线与CT表现,提高对本病的认识。方法回顾性分析4例经X线与CT检查并经病理证实的肺泡蛋白沉积症,分析其X线与CT征象。结果4例病变中皆见到弥漫性斑片影与磨玻璃影,CT扫描病灶呈地图样分布。结论CT对肺泡蛋白沉积症的范围、程度及病变轮廓的显示较X线平片准确,根据CT和HRCT表现的典型特征,可以作出可靠的诊断。     

Three-dimensional assessment of urinary stone on non-contrast helical computed tomography as the predictor of stonestreet formation after extracorporeal shock wave lithotripsy for stones smaller than 20 mm

The incidence of stonestreet formation after extracorporeal shock wave lithotripsy (ESWL) rises with increasing stone burden. However, stonestreet after ESWL is often experienced even in stones smaller than 20 mm. To examine whether the non-contrast helical computed tomography (CT) data could predict stonestreet formation in these stones, 53 radiopaque stones of 5-20 mm treated with ESWL were evaluated. Maximal dimension was measured on plain radiograph. From an attenuation value histogram graphed from the CT data, total stone volume and mean attenuation value were calculated. Seven stonestreets longer than 25 mm developed. There was no significant difference in maximal dimension and total stone volume between stones that did and stones that did not develop stonestreet. Mean attenuation value was the sole significant predictive factor. Application of mean attenuation value with cut-off level of 650 HU would anticipate stonestreet formation with a sensitivity of 85.7% and a specificity of 71.7%. The estimated risk of stonestreet formation is high in the treatment of stones with higher mean attenuation value.     

腹膜转移瘤的影像学诊断

目的探讨腹膜转移瘤的影像学表现特点。方法回顾性分析经手术及穿刺活检证实的35例腹膜转移瘤的影像学表现,并与手术结果对照,35例做CT平扫及增强扫描,5例行MR I检查。结果(1)腹膜转移瘤常表现为大量腹水(22/35);(2)腹膜结节状增厚(23/35);(3)大网膜饼形增厚(16/35)和大网膜污垢样改变(12/35);(4)肠系膜污垢样改变(12/35)及结节状改变(9/35);(5)腹腔单发或多发囊性改变,有占位效应(4/35)。结论CT/MR I是发现腹膜转移灶的重要影像学方法。     

Densities in dependent lung regions during anaesthesia: atelectasis or fluid accumulation?

In previous studied with computed tomography (CT) prior to and during general anaesthesia, we found that densities developed in dependent parts of the lungs immediately after induction of anaesthesia in all examined patients. It was suggested that the densities were atelectases created by compression of lung tissue but an alternative explanation could be accumulation of extravascular fluid in the lung tissue and/or in the pleural space. In the present study the nature of the densities was analysed in further detail. Injections of contrast medium into the pleural space revealed that the densities were located in the lung tissue and not in the pleural space. By injecting contrast medium intravenously and repeating the CT scanning over a 2-min period the passage of contrast through the major vessels and the lung densities could be studied. The transit time of the contrast medium was of the same magnitude in the densities and the major lung vessels. This indicates that there were no regions with an increased amount of extravascular fluid to delay the contrast passage. These findings oppose the idea of fluid accumulation as the cause of the densities, while atelectasis remains the most plausible explanation.     

Interobserver and interstudy variability of myocardial blood flow and flow-reserve measurements with nitrogen 13 ammonia-labeled positron emission tomography

Background  

Experimental studies have shown that positron emission tomography (PET) with ¹³N-labeled ammonia provides accurate quantification of regional myocardial blood flow (MBF) under rest and stress conditions. To establish the clinical utility of this method, the interobserver variability and the temporal variability of serial measurements of blood flow and coronary flow reserve (CFR) must be known. This study investigated the interobserver and temporal reproducibility of ¹³N-labeled PET for measurement of MBF and CFR.