Inter-Fraction Analysis of One Week Hypo-Fractionation of Deep Inspiration Breath Hold (DIBH) Technique for Left Sided Breast Cancer Radiation Treatment

The aim of this study was to investigate the inter-fraction variations, patient comfort and knowledge at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). The differences in set-up that occurred between treatment sessions for the left sided breast patients were observed and recorded. Measurements of routine set-up variation for 24 patients were performed by matching the cone beam computed tomography (CBCT) and the planning computed tomography (CT). Scans of all five fractions per patient were used to quantify the setup variations with standard deviation (SD) in all the three directions (anterior posterior, left right, and superior inferior). The patients DIBH comfort and knowledge was also evaluated. The average translational errors for the anterior posterior (AP, z), left-right (LR, x), and Superior-inferior (SI, y) directions were 0.40 cm, 0.40 cm, and 0.40 cm, respectively. The translation variation of the three directions showed statistical significance (P < 0.05). On comfort and knowledge investigation, among all participants, 80% moderately agreed that the therapist’s instructions for operating the deep inspiration breath hold (DIBH) technique were easy to understand, and 63.33% indicated that their comfort with the DIBH technique was neutral or average. The inter-fraction variations in patients with left-sided breast cancer were qualitatively analyzed. Significant shifts between CBCT and planning CT images were observed. The daily treatment verification could assist accurate dose delivery.

Assessment of cerebrovascular reserve impairment using the breath-holding index in patients with leukoaraiosis

Many studies have demonstrated that leukoaraiosis is associated with impaired cerebrovascular reserve function. However, the definitive hemodynamic changes that occur in leukoaraiosis are not clear, and there are many controversies. This study aimed to investigate hemodynamic changes in symptomatic leukoaraiosis using transcranial Doppler ultrasonography and the breath-holding test in a Chinese Han population, from northern China. A total of 203 patients who were diagnosed with ischemic stroke or clinical chronic progressive ischemic symptoms were enrolled in this study, including 97 males and 106 females, with an age range of 43-93 years. The severity of leukoaraiosis was evaluated according to the Fazekas grading scale, and patients were divided into four groups accordingly. Grade 0 was no leukoaraiosis, and grades I, II, and III were mild, moderate, and severe leukoaraiosis, respectively, with 44, 79, 44, and 36 cases in each group. Transcranial Doppler ultrasonography and the breath-holding test were performed. The mean blood flow velocity of the bilateral middle cerebral artery was measured and the breath-holding index was calculated. The breath holding index was correlated with leukoaraiosis severity and cognitive impairment. Patients with a low breath holding index presented poor performance in the Montreal Cognitive Assessment (MoCA) and executive function tests. That is, the lower the breath holding index, the lower the scores for the MoCA and the higher for the trail-making test Parts A and B. These results indicate that the breath-holding index is a useful parameter for the evaluation of cerebrovascular reserve impairment in patients with leukoaraiosis. In addition, the breath-holding index can reflect cognitive dysfunction, providing a new insight into the pathophysiology of leukoaraiosis. This study was approved by the Ethics Committee of the Fifth Peoples Hospital of Shenyang, China (approval No. 20160301) and registered in the Chinese Clinical Trial Registry (registration number: ChiCTR1800014421).

Lesion discrimination with breath-hold hepatic diffusionweighted imaging:A meta-analysis

AIM:To investigate the diagnostic capability of breathhold diffusion-weighted imaging(DWI) for differentiation between malignant and benign hepatic lesions.METHODS:A total of 614 malignant liver lesions(132 hepatocellular carcinomas,468 metastases and 14 intrahepatic cholangiocarcinomas) and 291 benign liver lesions(102 hemangiomas,158 cysts,24 focal nodular hyperplasia,1 angiomyolipoma and 6 hepatic adenomas) were included from seven studies(eight sets of data).RESULTS:The pooled sensitivity and specificity of breath-hold DWI were 0.93 [95% confidence interval(CI):0.91-0.95] and 0.87(95%CI:0.83-0.91),respectively.The positive likelihood ratio and negative likelihood ratio were 7.28(95%CI:4.51-11.76) and 0.09(95%CI:0.05-0.17),respectively.The P value for χ2 heterogeneity for all pooled estimates was < 0.05.From the fitted summary receiver operating characteristic curve,the area under the curve and Q * index were 0.96 and 0.91,respectively.Publication bias was not present(t = 0.49,P = 0.64).The meta-regression analysis indicated that evaluated covariates including magnetic resonance imaging modality,echo time,mean age,maximum b factor,and number of b factors were not sources of heterogeneity(all P > 0.05).CONCLUSION:Breath-hold DWI is useful for differentiating between malignant and benign hepatic lesions.The diffusion characteristics of benign lesions that mimic malignant ones have rarely been investigated.

Comparisons of Image Quality and ADCs in Breath-Hold, Respiratory-Triggered and Free-Breathing DWI of Pancreas at 3-T

Objective: To compare image quality and apparent diffusion coefficients (ADC) of the normal pancreas parenchymas in breath-hold, respiratory-triggered and free-breathing diffusion weighted imaging (DWI) at 3.0-Tesla. Methods: DWI of the pancreas was performed at 3.0-Tesla in 21 healthy volunteers with breath-hold, respiratory-triggered and free-breathing using b-values of 0 and 500 s/mm2. For all three sequences, two readers assigned an image quality score to images at b0 and b500, and two independent readers measured ADCs for the head, body and tail of pancreas. Image quality scores and ADCs of pancreas in the three DWIs were compared. Results: For b0, image quality scores was not significantly different among the three sequences (p = 0.103). For b500, image quality score was significantly lower in free-breathing DWI than breath-hold or respiratory-triggered DWI (p = 0.000), and not significantly different between breath-hold and respiratory-triggered DWI (p = 0.212). Mean ADCs differed significantly among the anatomical regions with the lowest values measured in the pancreatic tail both at breath-hold and respiratory-triggered DWIs whereas no significant difference was found at free-breathing DWI. Conclusion: Breath-hold or respiratory-triggered technique provided DW images of pancreas with acceptable quality at 3.0-Tesla. Breath-hold is the preferred DWI technique for ADC measurements of pancreas.

Benefits of Radiotherapy with Indigenous Tools Aiding Deep Inspiration Breath Holding Technique Compared to Free Breathing Technique among Breast Cancer Patients in Bangladesh

Background: Post-operative breast radiotherapy is used to reduce recurrence. The aim of this study was to investigate the outcomes of Deep Inspiration Breath-Hold (DIBH) technique with indigenous breath holding indicator scale in 3DCRT for breast cancer radiotherapy over Free Breathing (FB) technique. Methods: An observational study conducted at the Department of Radiation Oncology at National Institute of Cancer Research and Hospital, Dhaka and Square Hospital Limited, Dhaka, Bangladesh from June 2015 to May 2016. A total of 60 confirmed breast cancer patients who underwent adjuvant radiotherapy were included. An indigenous reproducible plastic tool (Perspex) was used as breath holding indicator scale with DIBH technique in 3DCRT. Paired sample t-test was used to compare with FB technique. Results: The mean age of patients was 47.32 (SD ± 8.33) years. In FB technique, Mean Heart Dose (MHD) was 413.27 cGy while in DIBH technique, it was 254.91 cGy (P < 0.001). The mean heart V20 and V30 were 5.5%, 4.37% in FB and 3.13%, 2.36% in DIBH respectively. In FB technique LADMD, LAD 0.2 cm3, ILMD and ILV20 were 1698.17 cGy, 2852.53 cGy, 1155.31 cGy and 28.62% while in DIBH technique, it was reduced to 1164.01 cGy, 2132.24 cGy, 1007.98 cGy and 23.39% respectively. Similarly, the lung-CLMD and breast-CLMD were reduced from 38.37 cGy and 55.18 cGy to 24.64 cGy and 33.82 cGy respectively (P < 0.001). The mean difference for breast-CLMD was 21.36 cGy. Conclusion: The use of indigenous breath holding indicator scale with DIBH had better outcomes on breast cancer radiotherapy.

A Half-Arc Multiple Deep-Inspiration Breath-Hold Volumetric Modulated Arc Therapy for a Lung Tumor with 10 MV Flattening-Filter-Free Beams and an Image Sensor Measuring a Distance Map to Thorax Surface: An Initial Clinical Experience

A technique for multiple deep-inspiration breath-hold (DIBH) volumetric modulated arc therapy (VMAT) for a lung tumor has been proposed with 10 MV flattening-filter-free beams and an image sensor measuring a distance map to thorax surface. Planning CT images were acquired under a DIBH condition and a clinical target volume (CTV) was contoured. This procedure was repeated five times and an internal target volume (ITV) among the multiple DIBHs was created by integrating the five CTVs. A planning target volume (PTV) was defined by adding an isotropic margin of 5 mm to the ITV. Immediately before treatment, a 30-second half-arc cone-beam computer tomography (CBCT) imaging was performed under another DIBH condition, and the couch was repositioned so that tumor may be located inside the PTV contours. An infrared distance measurement device having laser diodes and an image sensor was attached to the couch, and a distance map to the patient thorax surface was recorded as a reference during still another DIBH condition. A half-arc segmented VMAT beams with two beam interrupts were delivered to the patient under multiple DIBHs, where the delivery time of each of the three segmented beams was 30 seconds. During the beam delivery, the distance map was monitored in real time to confirm that the distance to the thorax surface remained unchanged. In-treatment CBCT images suggested that the tumor position at the time of tumor registration was accurately reproduced during the DIBH VMAT delivery.

A Longitudinal Study of Clinical Benefits with Implementation of the Deep Inspiration Breath-Hold Technique in Post-Operative Radiotherapy for Left-Sided Breast Cancer

Purpose/Objectives: We aimed to report clinical effects on critical organ dose and cardiac toxicity from implementation of the deep inspiration breath-hold (DIBH) technique in post-operative extern-beam radiotherapy of patients with left-sided breast cancer, using longitudinal clinical data. Materials/Methods: We retrieved three groups of patients who received post-operative radiotherapy of left-sided breast cancer in our institution in recent years: Groups A and B consist of patients whose treatment did not include internal mammary nodes (IMN) and who were treated with the free breathing technique and with the DIBH technique, respectively, and Group C consists of patients whose radiotherapy included internal mammary nodes with the DIBH technique. Dose parameters for the heart and left lung were retrieved from the treatment plans. Radiation-induced cardiac risks were estimated using existing risk models. Results: The average heart dose was 2.65 ± 0.98 Gy, 1.10 ± 0.29 Gy, and 1.26 ± 0.25 Gy in Groups A, B, and C, respectively. The average heart volumes receiving at least 25 Gy were 7.10 ± 9.79 cc in Group A, 0.07 ± 0.22 cc in Group B, and 0.03 ± 0.08 cc in Group C. On average, the excessive risk of having ischemic heart disease was estimated to be 19.6%, 8.1%, and 9.3% in Groups A, B, and C, respectively. The mean left lung doses were 5.73 ± 1.86 Gy, 5.93 ± 1.55 Gy, and 9.13 ± 1.57 Gy in Groups A, B, and C, respectively. Conclusion: Implementation of the DIBH technique significantly lowered heart dose and decreased the ischemic heart disease risk in patients receiving post-operative radiotherapy for left-sided breast cancer, without significant increase in left lung dose.

Deep Inspiration Breath Hold Reduces Dose to the Left Ventricle and Proximal Left Anterior Descending Artery during Radiotherapy for Left-Sided Breast Cancers

The purpose of this study was to analyze motion of the left anterior descending coronary artery (LAD) and left ventricle during normal breathing and deep inspiration breath hold (DIBH). This is a dosimetric study utilizing free-breathing and static DIBH scans from eleven patients treated with radiotherapy for breast cancer. The anterior-posterior displacement along the length of the LAD was measured in each respiratory phase. Standard treatment plans targeting the whole breast without treatment of the internal mammary lymph nodes were generated and dose to the LAD and LV calculated. Non-uniform movement of the LAD during respiratory maneuvers with the proximal third exhibiting the greatest displacement was observed. In DIBH compared to end-expiration (EP), the mean posterior displacement of the proximal 1/3 of the LAD was 8.99 mm, the middle 1/3 of the artery was 6.37 mm, and the distal 1/3 was 3.27 mm. In end-inspiration (IP) compared to end-expiration the mean posterior displacements of the proximal 1/3 of the LAD was 2.08 mm, the middle 1/3 of the artery was 0.91 mm, and the distal 1/3 was 0.97 mm. Mean doses to the LAD using tangential treatment fields and a prescribed dose of 50.4 Gy were 11.32 Gy in EP, 8.98 Gy in IP, and 3.50 Gy in DIBH. Mean doses to the LV were 2.38 Gy in EP, 2.31 Gy in IP, and 1.24 Gy in DIBH. In conclusion, inspiration and especially DIBH, cause a displacement of the origin and proximal 2/3 of the LAD away from the chest wall, resulting in sparing of the most critical segment of the artery during tangential radiotherapy.

Application of Deep Inspiration Breath Hold Technique in Radiotherapy After Breast- Conserving Surgery for Left Breast Cancer and Its Improvement on Cardiac Dose

Objective:To analyze the application of deep inspiration breath hold technique in radiotherapy after breast-conserving surgery for left breast cancer and the improvement of cardiac dose.Methods:A total of 45 patients with left breast cancer treated in our hospital after breast-conserving surgery were selected,and the selection time was set from January 2020 to August 2022.All patients received radiotherapy.The right breast,heart,and lung volumes,and dose parameters of the heart,lungs,right breast,and left anterior descending coronary artery were compared under free breathing(FB)and deep inspiration breath hold(DIBH)technical modes.Results:The heart volume of the DIBH group was smaller than that of the FB group,and the left and right lung volumes were significantly larger than those of the FB group.In the DIBH group,the heart dose parameters V5,proper lung dose parameters,and left anterior descending coronary artery dose parameters were found lower than that of the FB group,and the differences were statistically significant(P<0.05).Conclusion:Compared with FB,the DIBH technique can reduce the heart’s size and increase the lung volume when used for radiotherapy after breast-conserving surgery for left breast cancer.It also reduces the dose to the heart,right lung,and left anterior descending coronary artery,thus protecting the heart and lungs.

A Region Holds Its Breath

Death of Ethiopian leader Meles Zenawi brings stability concerns in the Horn THERE＇s no doubt that Ethiopia＇s deceased prime Minister Meles Zenawi was a key cog in the stability, development and security in the Horn of Africa. His footprints, for the 21 years that he was

深吸气屏气技术对乳腺癌术后放疗靶区剂量及摆位误差的影响

目的:探讨深吸气屏气技术对乳腺癌术后放疗患者靶区剂量及摆位误差的影响,为临床治疗提供参考依据。方法:于2021年01月至2023年07月入组60例需要行乳腺癌术后放射治疗的患者,将患者随机分为深吸气屏气组和对照组(自由呼吸组),深吸气屏气组30例,对照组30例,均采用容积调强放射治疗(volumetric modulated arc therapy,VMAT)技术进行计划设计,比较两组计划临床靶区(clinical target volume,CTV)、计划靶区(planning target volume,PTV)的体积及剂量学差异,肺的V_(20)、V_(5)及平均剂量,心脏V_(20)、V_(30)、V_(40)及平均剂量,脊髓的平均剂量、最大剂量,健侧乳腺平均剂量,深吸气屏气前后肺体积变化,靶区适形度指数(conformability index,CI)及靶区均匀性指数(homogeneity index,HI)。结果:将纳入的两组放疗计划方案进行对比,两组的摆位误差无统计学差异(P>0.05)。在保乳术后患者中,深吸气屏气组靶区PTV接受的平均剂量D_(mean)、最小剂量D_(min)、D_(95)、D_(5)相较于对照组增大,差异有统计学意义(P<0.05);两组的CTV体积、PTV体积、D_(5)0、D_(max)、HI及CI之间比较,差异无统计学意义(P>0.05)。在根治术后患者中,PTV的平均剂量D_(mean)、最大剂量D_(max)、最小剂量D_(min)、D_(95)、D_(5)、D_(5)0与对照组比较,差异无统计学意义(P>0.05);两组的CTV体积、PTV体积、HI及CI之间比较,差异也无统计学意义(P>0.05)。在保乳术后和根治术后患者中,深吸气屏气组的双肺V_(5)、V_(20)及患侧肺V_(5)、V_(20)、平均剂量D_(mean)相较于对照组减小,差异有统计学意义(P<0.05);双肺D_(mean)两组之间比较,差异无统计学意义(P>0.05)。深吸气屏气组的心脏V_(20)、V_(30)、V_(40)、心脏D_(mean)均较对照组下降,差异有统计学意义(P<0.05)。两组的脊髓D_(max)、D_(mean)和健侧乳腺D_(mean)差异无统计学意义(P>0.05)。在深吸气屏气患者中,深吸气后左、右肺的体积与深吸气前比较,有统计学差异(P<0.05)。结论:应用深吸气屏气技术进行乳腺癌术后辅助放射治疗能够改善保乳术后患者靶区剂量分布,明显降低心脏、肺等危及器官的受照剂量。

单次屏气3D-GRASE序列在MRI胰胆管成像的应用

目的探讨MRI单次屏气3D-GRASE成像技术在胰胆管的应用价值。方法选取本院57例胰胆管疾病患者,所有患者均进行自由呼吸自旋回波技术(3D-RT-TSE)和屏气梯度-自旋回波技术(3D-BH-GRASE)胰胆管水成像,分别记录两种成像方法的扫描时间;测量计算图像胆总管信噪比(SNR)、胆总管与其周围组织对比度(CR)及胆总管和肝脏之间对比噪声比(CNR),并由2位高年资医师分别对图像质量、伪影、背景抑制及胰胆管的显示进行评分。结果与3D-RT-TSE技术比较,3D-BH-GRASE技术扫描时间明显缩短,差异有统计学意义(t=70.995,P<0.001);3D-BH-GRASE的整体图像质量、伪影、胰胆管的效果评分均高于3D-RT-TSE,两种方法差异均有统计学意义(P均<0.05)。3D-BH-GRASE图像SNR、CR、CNR及图像背景抑制方面均小于3D-RT-TSE,差异均有统计学意义(P均<0.001)。结论相比呼吸触发(3D-RTTSE)序列,3D-BH-GRASE序列扫描时间更短,整体图像质量和胰胆管显示更好,值得进一步推广应用。

腹式深吸气屏气技术在左侧乳腺癌改良根治术后放疗中的应用

目的探讨腹式深吸气屏气(ADIBH)技术在左侧乳腺癌改良根治术后内乳链放射治疗中的剂量学优势。方法纳入20例左侧乳腺癌改良根治术后需行内乳链放疗的患者,比较ADIBH和自由呼吸(FB)两种呼吸模式在逆向调强放疗(IMRT)技术中的剂量学差异,包括靶区均匀性(HI)参数,肺、心脏、冠状动脉左前降支(LAD)以及右侧乳腺剂量比较。结果ADIBH呼吸模式下心脏、LAD、左肺受照射剂量(D_(mean))较FB模式下均有明显下降(P<0.05)。结论即使包含内乳区域淋巴放疗,采用ADIBH呼吸模式下的调强放疗可以减少心脏、左侧冠状动脉和肺等重要器官的靶区照射,带来临床获益。

不同呼吸方式在盆腔磁共振增强中对图像质量的影响

目的:通过与平静呼吸下盆腔磁共振增强扫描比较,探究屏气状态下在盆腔磁共振增强中应用的可行性及图像质量。方法:前瞻性连续收集2019年1月至2023年4月于本院行盆腔磁共振增强检查患者,以平静呼吸下扫描40例作为对照组,同期以屏气状态下扫描40例作为实验组,由2名高年资影像医师采用5分评分标准(1分最差,5分最佳)主观评价两组MRI增强图像的整体图像质量、背景抑制、伪影、生殖系统结构(子宫或前列腺精囊)显示情况,以及客观评价盆腔生殖结构的信噪比(SNR)和对比噪声比(CNR),统计分析两组图像质量的差异性。结果:在主观评价上,以屏气状态下扫描的盆腔磁共振增强图像的整体图像质量、背景抑制、伪影、生殖系统结构显示情况均比平静呼吸下扫描图像质量打分要高,伪影在两组间比较具有统计学差异(P<0.05),其他方面比较没有显著差异(P>0.05)。在客观评价上,屏气状态下扫描的盆腔磁共振增强图像生殖结构的SNR和CNR均比平静呼吸下扫描图像要高,两组比较均具有统计学差异(P<0.05)。另外,2名阅片者之间的主观评分及客观测量SNR和CNR值一致性均较好(Kappa=0.8640.893;ICC=0.897、0.903)。结论:与平静呼吸下盆腔磁共振增强扫描相比,屏气状态下扫描更能活得高质量的图像,而且明显减少图像伪影,满足诊断的要求。

老年人群24h动态血压监测中清晨高血压与脑血管储备功能相关性

目的研究老年人群24 h动态血压监测中清晨高血压与脑血管储备功能(CVR)的相关性。方法回顾性选取2021年1月至12月到济南市妇幼保健院行24 h动态血压监测的300例老年受试者,依据监测结果分为A组、B组和C组。A组158例为清晨血压升高的高血压患者,男88例,女70例,年龄(66.02±4.35)岁;B组74例为清晨血压正常的高血压患者,男41例,女33例,年龄(65.42±4.42)岁;C组68例为血压正常者,男37例,女31例,年龄(65.77±4.38)岁。以两侧大脑中动脉屏气指数均值<0.69%为CVR减低,屏气指数均值≥0.69%为CVR正常,将300例受试者分为CVR降低组(52例)和CVR正常组(248例)。比较A、B、C 3组患者的临床资料,CVR指标;比较CVR降低组、CVR正常组一般资料,行单因素分析、多因素分析和相关性分析。采用F检验、独立样本t检验、χ^(2)检验、logistic回归分析和Pearson相关性分析。结果300例24 h动态血压监测的老年受试者,清晨血压升高的高血压患者158例,占52.67%;清晨血压正常的高血压患者74例,占24.67%;血压正常者68例,占22.67%。3组收缩压(24 h均值、日间均值、夜间均值)、晨峰指数:A组>B组>C组(均P<0.05);舒张压(24 h均值、日间均值、夜间均值):A组>B组、C组(均P<0.05),B组、C组舒张压比较,差异均无统计学意义(均P>0.05)。CVR:A组[(21.37±7.89)%]<B组[(25.58±8.14)%]<C组[(28.56±8.10)%](均P<0.05);屏气指数:A组[(0.89±0.23)%]<B组[(1.13±0.21)%]、C组[(1.20±0.24)%](均P<0.05),B组、C组屏气指数比较,差异无统计学意义(P>0.05);脉动指数:A组[(1.49±0.36)]>B组[(1.15±0.31)]、C组[(1.06±0.29)](均P<0.05),B组、C组脉动指数比较,差异无统计学意义(P>0.05)。CVR降低组年龄[(73.14±3.21)岁]、清晨收缩压[(132.42±9.64)mmHg](1 mmHg=0.133 kPa)、清晨舒张压[(68.85±6.59)mmHg]均高于CVR正常组[(64.28±4.36)岁、(121.58±7.26)mmHg、(65.36±7.23)mmHg](均P<0.05)。logistic回归分析结果显示:年龄、清晨收缩压、清晨舒张压均为CVR降低的影响因素(均P<0.05)。清晨收缩压与屏气指数呈负相关(P<0.05),与脉动指数呈正相关(P<0.05);清晨舒张压与屏气指数呈负相关(P<0.05),与脉动指数呈正相关(P<0.05)。结论老年人群24 h动态血压监测中清晨高血压患者占比较大,清晨高血压患者CVR、屏气指数较低,脉动指数较高,清晨收缩压、清晨舒张压均与屏气指数呈负相关,与脉动指数呈正相关。

深吸气屏气在乳腺癌放射治疗中应用的研究进展

放射治疗是乳腺癌综合治疗的重要环节,但其心肺剂量则易导致放射性心脏病等并发症的发生。因此,如何减少心脏剂量、降低放疗并发症成为乳腺癌精准放疗的研究重点。深吸气屏气是一类呼吸控制方法,其应用于放疗可减少心肺等危及器官的受照剂量,以期减少放射性心脏损伤、改善患者远期预后。本文旨在概述乳腺癌放疗引起的心脏毒性及保护方法,深吸气屏气技术的剂量优势及应用,为临床和科研工作提供思路及方向。

肺癌B1场校正T_(1)-mapping影像组学特征的可重复性研究

目的:探讨基于B1场校正T_(1)-mapping测量肺癌影像组学特征的一致性及可重复性。方法:回顾性搜集2020年6月-2022年3月在本院经病理确诊的70例肺癌患者的术前胸部T_(1)-mapping和T_(1)加权容积内插屏气检查(T_(1)-VIBE)图像。其中,有41例进行了T_(1)-mapping重复扫描(间隔30 min)。由2位测量者独立采用半自动勾画方法分别在T_(1)-mapping和T_(1)-VIBE图像上逐层沿着病灶边缘勾画ROI,融合生成全病灶的容积ROI(VOI),然后提取原始图像及不同变换预处理图像上病灶VOI的影像组学特征。采用组内相关系数(ICC)评价组学特征在观察者内、观察者间的一致性及重复扫描时的可重复性,以ICC≥0.80为一致性或可重复性好(满足临床要求)。结果:自T_(1)-mapping和T_(1)-VIBE图像分别可提取1906个组学特征(包括一阶特征396个、形态特征14个及纹理特征1496个)。基于T_(1)-mapping提取的组学特征在观察者内及观察者间的ICC的中位数(Q1,Q3)分别为0.94(0.87,0.98)和0.91(0.83,0.96),基于T_(1)-VIBE提取的组学特征在观察者内及观察者间的ICC的中位数(Q1,Q3)均为0.98(0.95,0.99);2个序列分别有1450(72.72%)和1768(91.76%)个组学特征同时满足观察者内和观察者间的一致性要求。T_(1)-mapping重复扫描提取的组学特征的ICC的中位数(Q1,Q3)为0.83(0.69,0.93),有1002(52.57%)个组学特征同时满足重复扫描时的可重复性;其中,形状特征的可重复性表现最佳(ICC≥0.80者达100%),而一阶特征、灰度共生矩阵(GLCM)及灰度级区域矩阵(GLSZM)特征的可重复性相对较差(ICC≥0.80者仅占49.75%~53.98%)。基于不同变换预处理图像提取的组学特征中,Gradient变换明显提高了原始特征的可重复性(ICC≥0.80者达86.05%),而采用Exponential、LBP2D、LBP3D、Logarithm和Square变换方法获得的特征降低了原始特征的可重复性(ICC≥0.80这仅占36.05%~50.00%)。结论:T_(1)-mapping的影像组学特征表现出中等可重复性,在临床应用之前需要首先对其进行可重复性评估。

宽体CT对自由呼吸状态下患者胸部扫描的临床价值

目的:探究16 cm宽体探测器CT扫描对无法配合屏气患者胸部检查的临床应用价值。方法:选取2022年5-8月沈阳医学院附属第二医院收治的100例胸部CT检查中无法配合屏气呼吸的患者,按照随机数表法将其分为观察组和对照组,每组50例。扫描设定观察组为16 cm宽体探测器CT扫描准直宽度256 mm×0.625 mm,对照组为8 cm宽体探测器CT扫描准直宽度128 mm×0.625 mm,其他参数相同;记录患者年龄、身高、体重、体质量指数(BMI)等指标,测量并计算CT剂量指数(CTDI_(vol))、剂量长度乘积(DLP)及有效辐射剂量(ED),对比噪声比(CNR)、信噪比(SNR)及标准差(SD),并对图像质量进行主客观评价。结果:观察组患者平均年龄为(78.81±6.84)岁,平均体重为(64.46±9.86)kg,BMI、CTDI_(vol)、DLP、ED及曝光时间的平均值分别为(22.89±3.09)kg/m^(2)、(4.61±1.00)mGy、(1471.02±345.25)mGy·cm、(20.59±4.83)mSv和(1.01±0.61)s。对照组患者的平均年龄为(77.70±6.76)岁,平均体重为(62.84±4.75)kg,BMI、CTDI_(vol)、DLP、ED及曝光时间的平均值分别为(22.89±2.29)kg/m^(2)、(14.5±0.00)mGy、(4561.70±346.32)mGy·cm、(63.86±4.85)mSv和(4.07±0.12)s。观察组主肺动脉、右下肺静脉干及主动脉弓主观评价与对照组比较,差异无统计学意义(P>0.05)。两组图像质量主观评分均>4分,图像质量均能满足诊断要求。观察组患者的CTDI_(vol)、DLP、ED及曝光时间均低于对照组,差异有统计学意义(t=-69.42、-44.231、-44.234、-107.10,P<0.05)。结论:相比传统8 cm探测器CT扫描,16 cm宽体探测器在自由呼吸的患者胸部CT扫描中可以大幅度缩短扫描时间,降低辐射剂量,且图像质量均满足诊断需求,对临床上急诊的快速诊断具有很高的应用价值。

基于压缩感知技术的自由呼吸DCE-VIBE序列在胃癌MR增强检查中的应用价值

目的通过对比分析常规三维容积内插屏气检查(Volumetric Interpolated Breath-Hold Examination,VIBE)序列与基于压缩感知(Compressed Sensing,CS)技术的动态增强磁共振成像(Dynamic Contrast-Enhanced Magnetic Resonance Imaging,DCE-MRI)VIBE(以下简称“CS-DCE-VIBE”)序列在胃癌MR增强检查中的图像质量,探索CS-DCE-VIBE序列在胃癌MR增强扫描中的的应用价值。方法选取行胃MR扫描的120例胃癌患者为研究对象。根据检查前呼吸训练的情况,将患者分为屏气良好组和屏气不佳组,每组各60例,扫描序列包括常规VIBE和CS-DCE-VIBE序列。获得图像后,由2名经验丰富的放射科医师对这2种图像上可测量的病变进行感兴趣区勾画,分别计算信噪比(Signal to Noise Ratio,SNR)和对比噪声比(Contrast to Noise Ratio,CNR),采用组内相关系数和配对样本t检验进行一致性评估及差异性分析。接着2名医师采用双盲法对2种序列图像进行主观评分,采用加权Kappa检验及Wilcoxon秩和检验进行一致性评估及差异性分析。结果2名医师测量计算SNR、CNR和主观评分的一致性好。屏气良好组和屏气不佳组CS-DCE-VIBE序列图像的SNR及CNR均高于常规VIBE序列,两者间差异均有统计学意义(P<0.001)。对于屏气良好组,CS-DCE-VIBE序列图像的主观评分低于常规VIBE序列,两者间差异有统计学意义(P<0.001);而对屏气不佳组,CS-DCE-VIBE序列图像的主观评分高于常规VIBE序列,两者间差异有统计学意义(P<0.001)。结论CS-DCE-VIBE序列可为胃癌患者术前影像评估提供可靠的扫描方案,尤其为呼吸配合差的胃癌患者提供更好的临床诊断方法。

乳腺癌放射治疗中深吸气屏气技术的研究进展

乳腺癌作为全球女性健康的主要威胁之一,其治疗手段不断革新以应对日益增长的患者数量。放射治疗作为乳腺癌治疗的关键组成部分,其精准性直接影响患者的治疗效果和生活质量。近年来,深吸气屏气技术在乳腺癌放射治疗中的应用引起了广泛关注。文章综述了深吸气屏气技术的原理、优势及其在心脏和肺部保护方面的作用,探讨了该技术在临床实践中的应用进展,并讨论了其面临的挑战和未来的发展方向。通过优化呼吸管理,深吸气屏气技术不仅提升了治疗的精确度,还显著减少了正常组织的放射损伤,对乳腺癌患者的治疗和康复具有重要的临床意义。