Turbulent flow artefact mimicking central pulmonary emboli in pulmonary hypertension: A report of two cases

Many artefacts can mimic pulmonary emboli (PE) on CT pulmonary angiography (CTPA), most commonly in the peripheral pulmonary arteries (PA's). We describe flow‐related artefact mimicking PE in the central PA's of two patients, both with pulmonary arterial hypertension (PAH). To our knowledge, this is the first report of this PE mimic in the central PA's.     

Fast CT metal artefacts correction based on derivative and region-based filling

Introduction: Metal artefacts seriously degrade the quality of the CT images. Blurring around the junctions between metal and non‐metal regions in CT images, metal artefacts often prevent right diagnoses, and even lead to misdiagnoses of patients. The aim of the study was to devise a fast and robust method to improve the quality of the artefact‐contaminated CT images. Methods: The proposed artefact correction includes the following five steps: metal object segmentation, forward projection, region‐based filling, adaptive scaling and final image reconstruction. Results: The feasibility of the proposed method in correcting metal artefacts was validated by experiments on both simulated and clinical images. Experiments showed the proposed correction could lead to fast and effective reduction of metal artefacts in CT images. Conclusions: Compared with other methods, the proposed method has less computational cost and allows a feasible and easy implantation into current CT imaging systems.     

早期周围型肺癌的X线与CT诊断分析

目的:分析早期周围型肺癌的X线与CT征像特点,探讨X线与CT检查在早期周围型肺癌诊断中的作用。方法:对65例直径<3cm,经手术病理证实的周围型肺癌的X线胸片及CT扫描征象进行回顾性分析。对两种检查方法的定性准确率进行统计学检验。结果:分叶征、毛刺征、空气支气管征、血管集束征及胸膜凹陷征为早期周围型肺癌的基本征象。对病灶的定性诊断CT扫描明显优于普通X线检查(x=5.47 P<0.025)。结论:胸部X线检查是发现病变的基本首选方法,发现病变后进行CT扫描对早期周围型肺癌的确诊有重要意义,熟悉并掌握早期周围型肺癌的基本X线及CT征象是提高肺癌早期诊断水平的关键。     

Metallic implants and CT artefacts in the CTV area: Where are we in 2020?

Radiation therapy (RT) is one of the main modalities of cancer treatment worldwide with computed tomography (CT), as the most commonly used imaging method for treatment planning system (TPS). Image reconstruction errors may greatly affect all the radiation therapy planning process, such as target delineation, dose calculation and delivery, particularly with particle therapy. Metallic implants, such as hip and spinal implants, and dental filling significantly deteriorate image quality. These hardware structures are often very complex in geometry leading to geometric complex artefacts in the clinical target volume (CTV) area, rendering the delineation of CTV challenging. In our review, we focus on the methods to overcome artefact consequences on CTV delineation: 1– medical approaches anticipating issues associated with imaging artefacts during preoperative multidisciplinary discussions while following standard recommendations; 2– common metal artefact reduction (MAR) methods such as manually override artefact regions, ballistics avoiding beam paths through implanted materials, megavoltage-CT (MVCT); 3– prospects with radiolucent implants, MAR algorithms and various methods of dual energy computed tomography (DECT). Despite substantial and broad evidence for their benefits, there is still no universal solution for cases involving implanted metallic devices. There is still a high need for research efforts to adapt technologies to our issue: “how do I accurately delineate the ideal CTV in a metal artefact area?”     

High-resolution sonography of sublingual space

Ultrasound examination of the sublingual region is a non-invasive, safe, inexpensive and widely available procedure, unaffected by the amalgam in teeth which is a source of considerable artefact on CT and MRI images. With a little practice and good understanding of the anatomy, ultrasound can be a very helpful primary examination. If the lesion is clearly seen, no further imaging may be required.     

肺癌侵犯中央肺动脉继发肺动脉高压影像学初步研究

目的：探讨肺癌侵犯国脉继发肺动脉高压的发生率并评估T诊断价值。方法：C地20例肺癌侵犯中央肺动脉（肺癌CICP）患者行右心导管术及CT检查。右心导管术测量肺动脉压力。用盲法判断患者的CT表现并与右心导管检查结果对照,评价CT诊断价值。结果：肺癌CICPA癌肿侵犯近端者中有3例例（15％）出现轻度肺动脉高压。CT表为主肺动脉扩张,主动脉与同层面降主动脉直径比值增大,CT诊断肺动脉高压准确性为90％（18／20）。结论：肺癌CICPA继发肺动脉高压少见。CT在肺癌CICPA继发肺动脉高压诊断中具有重要价值。     

螺旋CT肺三期扫描对直径≤3 cm周围型肺癌的诊断价值

目的 探讨螺旋CT肺三期扫描对直径≤3cm周围型肺癌的诊断价值。方法 仪60例患者的孤立性肺结节(sPNs,直径均≤3cm)病灶行螺旋CT动态强化扫描,根据主动脉、肺动脉强化CT值的特点,建立螺旋cr肺三期扫描时相,分析60例SPNs肺三期扫描强化形态与程度。结果 螺旋凹肺三期扫描延迟时间：肺动脉期15s,支气管动脉期36s,平衡期9HDs。肺癌螺旋CT肺二期扫描病灶强化变化的主要形式为无明显强化、显著强化和中等强化,肺炎性结节肺三期扫描病灶强化变化的主要形式为轻度或中等强化、显著强化和显著强化。肺结核球及转移瘤肺二期扫描密度变化较小。本组82,9％的肺癌支气管动脉期可见不规则条状及斑点状强化血管影。结论 螺旋CT肺三期扫描能反映直径≤3cm周围型肺癌支气管动脉供血及其强化的变化状况,有助于病变的早期诊断与鉴别诊断。     

^18F-FDG PET/CT联合胸部薄层CT诊断肺部病灶的价值

[目的]探讨18F-FDGPET/CT联合胸部薄层CT诊断肺部病灶的准确性。[方法]50例患者（其中肺癌34例,肺良性病变16例）行单纯18F-FDGPET/CT或胸部薄层CT及两者联合检查,评价各检查方法的诊断准确性。[结果]18F-FDGPET/CT和18F-FDGPET/CT联合胸部薄层CT两种方法诊断结果相同,灵敏度、特异性、阳性预测值、阴性预测值、准确率均分别为91.2%、93.8%、96.9%、83.3%和92.0%,而胸部薄层CT分别为76.5%、43.8%、74.3%、46.7%和66.0%。18F-FDGPET/CT和18F-FDGPET/CT联合胸部薄层CT的诊断特异性、阳性预测值、阴性预测值均优于胸部薄层CT（P〈0.05）。以病理或临床诊断为标准的一致性分析显示,18F-FDGPET/CT和18F-FDGPET/CT联合胸部薄层CT的一致性好（Kappa值均为0.82）,胸部薄层CT的一致性差（Kappa值为0.21）。胸部薄层CT显示了更多的CT征象。[结论]18F-FDGPET/CT和18F-FDGPET/CT联合胸部薄层CT对肺部病灶诊断有一定价值。加行胸部薄层CT有助于做出符合病理类型的影像学判断。     

PET/CT对981例肺结节的良恶性诊断价值分析

目的 探讨健康体检PET/CT对恶性肺结节的诊断意义,通过18F-脱氧葡萄糖(18F-FDG)高代谢灶摄取度判定肺部恶性肿瘤的价值.方法 回顾性分析981例肺结节患者的病例资料,包括良性肺结节966例,恶性肺结节15例.比较良恶性结节间病灶最大标准摄取值(SUVmax)之间的差异.结果 SUVmax≥2.5为PET/CT诊断恶性肿瘤的重要参考指标,PET/CT诊断灵敏度、特异度、准确度、阳性预测值及阴性预测值分别为86.7%(13/15)、99.4%(960/966)、99.2%(973/981)、68.4%(13/19)、99.8%(960/962).良性肺结节患者检查结果显示SUVmax为0~6.5,中位数为0.7,其中被误诊为恶性肺结节的患者分别是4例良性GGN经病理证实为坏死性肉芽肿(3例)/机化性肺炎(1例)、2例良性结节经病理证实为肺炎(1例)/纤维组织增生(1例);恶性肺结节患者检查结果显示SUVmax为0.8~16.3,中位数为4.7,其中恶性肺结节患者中2例肺泡癌患者漏诊.结论 18F-FDG PET/CT在筛 查肺部结节良、恶性诊断中有重要意义,SUVmax 对良、恶性程度的判断有指导意义.     

Computed tomography pulmonary angiogram diagnosis of pulmonary embolism

Over the last decade, contrast‐enhanced spiral CT has been established as a non‐invasive alternative to catheter angiography and is now regarded as the first‐line imaging investigation for the diagnosis of pulmonary embolism (PE). The reported sensitivities for the diagnosis of PE of spiral CT vary from 45 to 100% and the specificities vary from 78 to 100%. Prospective outcome studies have shown a high negative predictive value for a single‐detector spiral CT for PE. Patients’ outcomes were not adversely affected in these studies when anticoagulation was withheld after a negative CT pulmonary angiogram. The main limitation of single‐detector spiral CT has been its limited ability to detect isolated subsegmental PE. However, multidetector spiral CT allows evaluation of pulmonary vessels down to sixth‐order branches and significantly increases the rate of detection of PE in segmental and subsegmental levels. The interobserver correlations for diagnosis of subsegmental PE with multidetector spiral CT exceed the reproducibility of selective pulmonary angiography. If appropriate equipment is available (multidetector CT), then CT pulmonary angiogram is safe to be used as the first‐line imaging investigation for the diagnosis of PE.     

Computed tomographic fluoroscopy-guided transthoracic needle biopsy for diagnosis of pulmonary nodules

BACKGROUND: The purpose of this study was to evaluate the usefulness of computed tomographic (CT) fluoroscopy-guided transthoracic needle biopsy (TTNB) with an 18-gauge automatic biopsy gun for the diagnosis of pulmonary nodules. METHODS: Between March 1996 and January 1998, 50 patients in whom pulmonary lesions could not be diagnosed cytopathologically with fiberoptic bronchoscopy or were not clearly visualized with fluoroscopy underwent CT fluoroscopy-guided TTNB. RESULTS: Final pathological diagnoses were 23 lung carcinomas, five pulmonary metastases and 22 benign lesions. Sufficient tissue for analysis was obtained from 48 of the 50 lesions (96%). The overall diagnostic yield of CT fluoroscopy-guided TTNB was 90%. The sensitivity, specificity and accuracy for malignancy were 89%, 100% and 94%, respectively. In 20 of the 22 cases (91%) of benign lesions, histological analysis yielded correct and specific diagnoses. Complications occurred in 22 of the 50 cases (44%). The most common complication was pneumothorax, which occurred in 21 of the 50 cases (42%). Chest tube insertion was required in 6 (12%). CONCLUSIONS: Although CT fluoroscopy could not decrease the complication rate, CT fluoroscopy-guided TTNB with an automatic biopsy gun appears to be a promising technique for diagnosing pulmonary lesions, particularly benign lesions.     

超声与CT引导经皮穿刺活检在肺周围型新生物诊断中的应用

目的:分析超声和CT引导经皮穿刺活检在肺周围型新生物诊断中的应用。方法:回顾性总结因肺周围型新生物入院,行超声或CT引导经皮穿刺活检患者140例,依据穿刺方式分为超声引导组（67例）与CT引导组（73例）,分析两组确诊率、并发症发生率、医疗费用和操作时间。结果:恶性肿瘤诊断率超声组（86.6%）高于CT组（76.7%）,并发症发生率超声组（9.0%）小于CT组（15.1%）,但差异均无统计学意义。穿刺操作时间超声组［（22.64±3.18） min］小于CT组［（25.45±3.25） min］,差异有统计学意义,超声组医疗费用小于CT组。结论:肺周围型新生物的超声与CT引导经皮穿刺活检均安全有效,超声引导更简单、快速和经济。贴近胸壁的肺脏周围型新生物,可首选超声引导;而非贴近胸壁的较深处病变,应首选CT引导。     

CT增强薄层扫描异形血管强化征对小肺癌诊断的价值

目的：探讨ＣＴ增强薄层扫描图像上显示的异形血管强化征对小肺癌诊断和鉴别诊断的临床价值。方法：用ＣＴ增强薄层扫描和常规ＣＴ增强扫描对比研究３７例直径＜３ｃｍ的小肺癌,并同期研究１８例需鉴别的肺炎性假瘤和肺结核球作对照,分析这３种病变的ＣＴ增强薄层扫描征象特点。结果：①ＣＴ增强薄层扫描能清晰显示小肺癌病灶内肿瘤血管的特征性表现一异形血管强化征,而常规ＣＴ扫描难以显示该征象;②肺炎性假瘤和肺结核球病灶内一般不出现该种病理血管征象。结论：异形血管强化征对小肺癌的诊断和鉴别诊断具有特殊意义。     

Performance of magnetic resonance imaging in pulmonary fungal disease compared to high‐resolution computed tomography

To evaluate the performance of magnetic resonance imaging (MRI) compared to computed tomography (CT) in patients diagnosed with pulmonary mycosis. We prospectively included 21 patients diagnosed with pulmonary mycosis between January 2013 and October 2014. Inclusion criteria were presence of respiratory symptoms, histopathological diagnosis of mycosis and absence of mycosis treatment. Reviewers identified one predominant imaging pattern per patient: nodular, reticular or airspace pattern. Afterwards, all CT findings were analysed separately per lobe and compared to MRI. Nodular pattern was the most common found (CT: 76.20%; MRI: 80.96%), followed by airspace pattern (CT and MRI: 9.52%) and reticular (CT: 9.52%; MRI: 4.76%). Compared to CT, MRI performance varied according to radiological finding and pulmonary region. For nodules, MRI presented high sensitivity (100% [95% CI: 93.52‐100]) and specificity (100% [95% CI: 92.00‐100]). For bronchiectasis and septal thickening, there were poorer positive predictive values (33.33% [95% CI: 1.77‐87.47]; and 83.33% [95% CI: 50.88‐97.06] respectively). As specificity and negative predictive value had superior results than sensitivity and positive predictive value, rather than for diagnosis of this condition, MRI might be more considered for the follow‐up of patients with pulmonary mycosis, an alternative to multiple radiation exposures with CT follow‐up.     

Prognostic factors and imaging patterns of recurrent pulmonary nodules after thoracotomy in children with osteosarcoma

BACKGROUND: In children with osteosarcoma who have undergone thoracotomy, it often is difficult to distinguish metastatic from benign recurrent pulmonary nodules. The authors of this study sought to identify any computed tomography (CT) imaging pattern of recurrent pulmonary metastases in this patient population. The authors also sought to identify associated prognostic factors. METHODS: CT scans obtained after thoracotomy were available for 35 patients with osteosarcoma who had undergone resection of presumed pulmonary metastases at St. Jude Children's Research Hospital (Memphis, TN). CT scans obtained before the initial thoracotomy were available for 33 of the 35. The authors recorded location, histologic diagnosis, and time of development of the original pulmonary nodules, time of recurrence of pulmonary disease; the location of recurrent nodules, and the presence of calcification, adenopathy, or progressive pleural disease, as well as patient demographic data, survival data, and location of the primary tumor site. RESULTS: Pulmonary nodules recurred in 32 of the 35 patients after thoracotomy. Nineteen of these patients underwent resection of the recurrent lesions and 1 who died underwent an autopsy; 18 of the 20 patients had metastatic disease. The only CT finding consistently associated with recurrent metastatic disease was progressive pleural thickening, which predicted a poor outcome. The occurrence of a solitary pulmonary nodule in the lung contralateral to the previous surgery was associated almost always with a benign process. CONCLUSIONS: CT imaging cannot distinguish reliably between benign and metastatic recurrent pulmonary disease after thoracotomy in patients with osteosarcoma. Recurrent pulmonary disease in this set of patients is likely to be metastatic, and aggressive surgical intervention is probably warranted. In this study, patients who had progressive pleural disease after thoracotomy consistently experienced pulmonary metastatic recurrence and had a poor prognosis.     

Identification of small lung nodules at autopsy: implications for lung cancer screening and overdiagnosis bias.

Purpose: Unsuspected cases of lung cancer are reported to be uncommon in autopsy series, and these data have been used to suggest that indolent tumors are rare and that overdiagnosis bias is not an important factor in lung cancer screening. The purpose of this study was to determine if a retrospective autopsy review is indeed accurate in identifying all small lung nodules on CT, and thus provide a true estimate of unsuspected lung tumors. Materials and Methods: We identified all 1047 patients who had an autopsy at our institution from 1994 to 1998. We then reviewed the patients radiology records and found 187 patients with a thoracic CT within 2 months of the postmortem examination. All 187 CT reports were reviewed in order to identify patients with at least one pulmonary nodule. CT studies with reports that described a nodule(s) were then re-reviewed to confirm presence and location of the nodule(s). The CT findings were than compared to the autopsy report to determine if the postmortem examination indeed found the nodule(s). Results: 28 autopsy patients had at least one pulmonary nodule identified on their thoracic CT no more than 2 months before death. Nineteen patients (68%) had nodule(s) recorded on the autopsy report, two ( approximately 10%) of which proved to have undiagnosed squamous cell carcinoma. Nine patients (22%) had no mention of pulmonary nodules seen on the CT recorded on their autopsy report. Conclusions: This study suggests autopsies do not identify all small pulmonary nodules found at CT. The true incidence of clinically insignificant lung cancer is thus uncertain, and overdiagnosis bias in lung cancer screening may be more important than previously recognized.     

FDG-PET for detection of pulmonary metastases from malignant primary?bone tumors: Comparison with spiral CT

Background:The purpose was the comparison of positron emission tomography using F-18-fluorodeoxy-glucose (FDG-PET) and spiral thoracic CT to detect pulmonary metastases from malignant primary osseous tumors. Patients and methods:In 71 patients with histologically confirmed malignant primary bone tumors (32 osteosarcomas, 39 Ewings sarcomas) 111 FDG-PET examinations were evaluated with regard to pulmonary/pleural metastases in comparison with spiral thoracic CT. Reference methods were the clinical follow-ups for 6–64 months (median 20 months) or a histopathologic analysis. Results:In 16 patients (23%) reference methods revealed a pulmonary/pleural metastatic disease. FDG-PET had a sensitivity of 0.50, a specificity of 0.98, and an accuracy of 0.87 on a patient based analysis. Comparable values for spiral CT were 0.75, 1.00, and 0.94. It was shown that no patient who had a true positive FDG-PET had a false negative CT scan, nor was a pulmonary metastases detected earlier by FDG-PET than by spiral CT. Conclusions:There seems to be a superiority of spiral CT in the detection of pulmonary metastases from malignant primary bone tumors as compared with FDG-PET. Therefore, at present a negative FDG-PET cannot be recommended to exclude lung metastases. However, as specificity of FDG-PET is high, a positive FDG-PET result can be used to confirm abnormalities seen on thoracic CT scans as metastatic.     

重建参数对CT肺结节容积测量的影响

背景与目的已有的研究证明:CT肺结节容积测量能够敏感反映结节容积的微小变化,在未定性肺结节的随访观察及良恶性鉴别方面具有重要应用前景。本研究旨在评估不同重建算法和层厚对CT肺结节容积测量的影响。方法对2009年12月-2011年8月在天津医科大学总医院行未定性肺结节CT随访研究的30例患者的CT图像进行后处理分析。共获取52个肺结节,应用3种不同的算法(骨密度算法、标准算法及肺算法)及层厚(0.625 mm、1.25 mm、2.5 mm)进行9次重建。由一位放射科医师应用肺结节容积分析软件进行容积测量。应用重复测量多元方差分析、相关分析及Bland-Altman法评价结节直径、算法、层厚对容积测量的影响。结果不同重建算法(F=13.6,P<0.001)、层厚(F=4.4,P=0.02)条件下测量所得的结节容积之间具有统计学差异。肺结节9次测量所得容积的变异系数和结节直径之间呈负相关(r=-0.814,P<0.001)。应用2.5mm层厚时,结节容积比1.25mm及0.625 mm层厚的一致性差,1.25 mm和0.625 mm层厚在采用骨算法时一致性最好。结论不同重建算法及层厚对肺结节容积测量有影响,尤其是直径较小的结节。在未定性肺结节尤其是肺小结节的随访过程中建议应用相同的重建参数。     

低剂量胸部CT筛查早期肺癌的临床应用研究

目的:探讨低剂量CT(low-dose chest CT,LDCT)胸部平扫在健康体检中筛查早期肺癌的应用效果及价值.方法:收集2018年1月至2018年12月在我院健康体检高危人群,采用低剂量胸部CT 1100例及胸部X线平片750例.结果:低剂量胸部CT与胸部X线片比较,发现肺结节病灶,阳性肺结节以及疑似肺癌的比例...