Magnetic resonance imaging of the hila and mediastinum

In the diagnosis of chest diseases, MR imaging has been shown to be most helpful in the evaluation of hilar and mediastinal lesions. The detection of intrathoracic abnormalities is technique-dependent, and imaging with both short and long repetition and echo times is necessary. ECG gating and sagittal or coronal images supplement transaxial scans in some patients. MR allows the diagnosis of mediastinal vascular lesions and the differentiation of mediastinal mass and vessel without contrast agents. It provides diagnostic information quite similar to that of CT in patients with mediastinal mass, but spatial resolution is somewhat poorer. In patients with hilar mass, MR is superior to CT in identifying the mass and distinguishing it from normal structures.     

胸部Castleman病的X线和CT表现与病理对照

目的 讨论胸部Castleman病X线和CT表现以及病理特征。资料与方法 胸部Castleman病12例，男5例，女7例，平均年龄35岁，局限型10例，弥漫型2例，均经手术和病理证实。结果 病理上包括透明血管型10例和浆细胞型2例。X线和CT扫描；10例局限型为平均直径4.9cm大小的单发软组织肿块，位于中纵隔或肺门者4例，前纵隔和后纵隔各3例，平扫CT值平均40HU，增强扫描呈早期显著均匀强化，CT值平均133HU，延迟扫描仍持续强化，CT值平均92HU，2例伴有中央区分支状钙化，2例弥漫型表现为双侧中等量胸腔积液，纵隔内多个直径1-2cm大小的淋巴结，胸膜下小结节影和支气管血管束周围结节影，术前CT误诊率为83.3%。结论 胸部局限型Castleman病以强化明显或中央伴有分支状钙化的巨大孤立肿物为特征，CT增强扫描有助于明确诊断和临床分型，弥漫型Castleman病的影像学表现复杂多样，确诊主要依靠病理和免疫组织化学检查。     

A phantom study of the performance of model-based iterative reconstruction in low-dose chest and abdominal CT: When are benefits maximized?

IntroductionThe aim of this study was to assess and compare the effects of CT image reconstruction techniques on low-dose CT image quality using phantoms.MethodsAnthropomorphic torso and spatial/contrast-resolution phantoms were scanned at decreasing tube currents between 400 and 10 mA. CT thorax and abdomen/pelvis series were reconstructed with filtered back projection (FBP) alone, combined 40% adaptive statistical iterative reconstruction & FBP (ASIR40), and model-based iterative reconstruction (MBIR) [(resolution-preference 05 (RP05) and RP20 in the thorax and RP05 and noise-reduction 05 (NR05) in the abdomen)]. Two readers rated image quality quantitatively and qualitatively.ResultsIn thoracic CT, objective image noise on MBIR RP05 data sets outperformed FBP at 200, 100, 50 and 10 mA and outperformed ASIR40 at 50 and 10 mA (p < 0.001). MBIR RP20 outperformed FBP at 50 and 10 mA and outperformed ASIR40 at 10 mA (p < 0.001). Compared with both FBP and ASIR40, MBIR RP05 demonstrated significantly better signal-to-noise ratio (SNR) at 10 mA. In abdomino-pelvic CT, MBIR RP05 and NR05 outperformed FBP and ASIR at all tube current levels for objective image noise. NR05 demonstrated greater SNR at 200, 100, 50 and 10 mA and RP05 demonstrated greater SNR at 50 and 10 mA compared with both FBP and ASIR. MBIR images demonstrated better subjective image quality scores. Spatial resolution, low-contrast detectability and contrast-to-noise ratio (CNR) were comparable between image reconstruction techniques.ConclusionCTs reconstructed with MBIR have lower image noise and improved image quality compared with FBP and ASIR. These effects increase with reduced radiation exposure confirming optimal use for low-dose CT imaging.     

Radiotherapy for Tracheal–Bronchial Cystic Adenoid Carcinomas

Aims

Primary tracheal–bronchial adenoid cystic carcinoma (thoracic adenoid cystic carcinoma; TACC) is a rare and aggressive malignant tumour. Radiotherapy results have not been previously individualised in this setting.

Trunk flexion during walking in people with knee osteoarthritis

BackgroundOver 50% of the body’s mass is concentrated within the head, arms and trunk. Thus, small deviations in the orientation of the trunk, during normal walking, could influence the position of the centre of mass relative to the lower limb joint centres and impact on lower limb biomechanics. However, there are minimal data available on sagittal kinematics of the trunk in people with knee osteoarthritis (OA) during walking.Research questionDo people with knee OA have altered kinematic patterns of the trunk, pelvis or hip compared with healthy control participants during walking?MethodsStatistical parametric mapping was used to compare sagittal and frontal plane kinematic patterns, during walking, between a healthy group and cohort of people with knee OA.ResultsIndividuals with knee OA walked with a mean increase in trunk flexion of 2.6°. Although this difference was more pronounced during early stance, it was maintained across the whole of stance phase. There were no differences, between the groups, in sagittal plane pelvic or hip kinematics. There were also no differences in trunk, pelvic or hip kinematics in the frontal plane.SignificanceMost previous gait research investigating trunk motion in people with knee OA has focused on the frontal plane. However, our data suggest that an increase in sagittal trunk flexion may be a clinical hallmark of people with this disease. Altered trunk flexion could affect joint moments and muscle patterns and therefore our results motivate further research in this area.     

恶性胸腔积液实验室检查进展

<正>胸腔积液是常见的临床症状之一,由多种原因引起,因此胸腔积液的实验室诊断十分重要。近年来胸腔积液的实验室检查取得了重要进展,本文将做一简要综述如下。1细胞学检查1.1肿瘤细胞学检查胸腔积液中找到典型恶性肿瘤细胞     

The role of clinical history in the interpretation of chest radiographs

ObjectiveThis review will appraise the literature pertaining to the influences that clinical history has on the action of assessing the chest radiograph.Key findingsThere remains conflicting evidence on the impact of clinical history on chest radiography. Some research suggests that clinical history has the potential to influence the reporter in a negative way by limiting their search strategy to a more focussed search. Image interpretation is more accurate when reporters are allowed to conduct a free search of the chest image, untainted by preconceived concepts.ConclusionClinical history needs to be accessed appropriately to aid and not stifle accurate image interpretation. Reporters need to be aware of the potential bias clinical history can introduce to their reporting and develop strategies to alleviate this as much as possible.Implications for practiceA greater understanding of the potential bias of clinical history on the process of image interpretation is required by all reporters. Reporters need to develop an approach and strategy when accessing clinical history. Novice reporters need to be educated regarding the impact of clinical history on their reporting.     

Optimization of acquisition parameters for reduced-dose thoracic CT: A phantom study

PurposeThe purpose of this study was to analyze the impact of different options for reduced-dose computed tomography (CT) on image noise and visibility of pulmonary structures in order to define the best choice of parameters when performing ultra-low dose acquisitions of the chest in clinical routine.Materials and methodsUsing an anthropomorphic chest phantom, CT images were acquired at four defined low dose levels (computed tomography dose index [CTDI_vol] = 0.15, 0.20, 0.30 and 0.40 mGy), by changing tube voltage, pitch factor, or rotation time and adapting tube current to reach the predefined CTDI_vol-values. Images were reconstructed using two different levels of iteration (adaptive statistical iterative reconstruction [ASIR®]-v70% and ASIR®-v100%). Signal-to-noise ratio (SNR) as well as contrast-to-noise ratio (CNR) was calculated. Visibility of pulmonary structures (bronchi/vessels) were assessed by two readers on a 5-point-Likert scale.ResultsBest visual image assessments and CNR/SNR were obtained with high tube voltage, while lowest scores were reached with lower pitch factor followed by high tube current. Protocols favoring lower pitch factor resulted in decreased visibility of bronchi/vessels, especially in the periphery. Decreasing radiation dose from 0.40 to 0.30 mGy was not associated with a significant decrease in visual scores (P < 0.05), however decreasing radiation dose from 0.30 mGy to 0.15 mGy was associated with a lower visibility of most of the evaluated structures (P < 0.001). While image noise could be significantly reduced when ASIR®-v100% instead of ASIR®-v70% was used, the visibility-scores of pulmonary structures did not change significantly.ConclusionFavoring high tube voltage is the best option for reduced-dose protocols. A decrease of SNR and CNR does not necessarily go along with reduced visibility of pulmonary structures.     

放疗期间运用CBCT调整治疗中心

目的应用锥形束CT（CBCT）评价分析放疗过程中因患者体型变化、肿瘤大小改变等因素导致的摆位误差，并修正治疗等中心。方法80例胸腹部肿瘤患者行调强放射治疗，治疗进行到一半的时候，运用CBCT的图像与靶区勾画轮廓线进行重新匹配，并以新的中心作为后半期放疗的中心。分析两次CBCT的治疗中心点的位置变化，并进行统计学分析。结果分析结果表明，56例患者治疗中心点位移等于或少于5mm，无需调整治疗中心。24例患者中心点位移大于5mm，需调整治疗中心。按调整后的治疗中心完成后期治疗。需调整比例占总病例的30％。结论利用CBCT对放疗摆位的误差测量准确有效。放疗时间跨度长，患者体型、肿瘤在治疗期间变化大，所以在治疗的中期进行合理的调整非常必要。