CLINICAL APPLICATION OF BODY DIFFUSION WEIGHTED MR IMAGING IN THE DIAGNOSIS AND PREOPERATIVE N STAGING OF CERVICAL CANCER

Objective To evaluate the clinical impact of body diffusion weighted imaging (DWI) on the diagnosis and preoperative N staging of cervical cancer. Methods Twenty-four patients (mean age 37.9 years old) with proved cervical cancer by cervical biopsy and 24 female patients with other suspected pelvic abnormalities received preoperative body DWI scan. Results of body DWI were compared with pathological findings. The apparent diffusion coefficient (ADC) values of normal cervix and different pathological types of cervical cancer were compared. ADC value of normal or inflammatory lymph nodes was also compared with that of metastatic ones. Student's t test was used for statistical analysis. Results There were 5 adenocarcinomas and 19 epitheliomas showed with biopsy results, and DWI showed 21 cervical lesions out of them (87.5%). ADC values of the normal cervix (n = 24), epithelioma (n = 19), and adenocar- cinoma (n = 5) were (1.73 ± 0.31) ×10-3, (0.88 ± 0.22) ×10-3, and (1.08 ± 0.12) ×10-3 mm2/s, respectively. Statistical analysis showed significant difference in ADC value between normal cervical tissue and either tumor tissues (both P < 0.01). In patients had lymphadenectomy (n = 24), totally 67 lymph nodes including 16 metastatic lymph nodes were pathologically analyzed, and DWI showed 66 (98.5%) out of them. ADC values of normal/inflammatory and metastatic lymph nodes were (1.07 ± 0.16) ×10-3 and (0.77 ± 0.13) ×10-3 mm2/s (P < 0.01). Receiver operating characteristic (ROC) curve of ADC value of metastatic lymph node showed that area under curve was 0.961. Conclusions ADC value in cervical carcinoma is lower than that in normal cervix, and ADC may have predictive value in subtype discrimination. ADC value may improve the preoperative characterization of lymph node metastasis. And at least abdominal and pelvic DWI scan is suggested for N staging evaluation in such patients.

Clinical Value of Whole-body Magnetic Resonance Diffusion Weighted Imaging on Detection of Malignant Metastases

Objective To evaluate the value of whole-body diffusion weighted imaging(WB-DWI) on detection of malignant metastasis.Methods Forty-six patients with malignant tumors underwent WB-DWI examinations between April 2007 and August 2007 in our hospital.Before WB-DWI examination,the primary cancers of all the patients were confirmed by pathology,and the TNM-stage was assessed with conventional magnetic resonance imaging(MRI) or computed tomography(CT).WB-DWI was performed using short TI inversion recovery echo-planar imaging(STIR-EPI) sequence.Abnormal high signal intensities on WB-DWI were considered as metastases.The results of WB-DWI were compared with other imaging modalities.For the assessment of the diagnostic capability of WB-DWI,WB-DWI were compared with CT for demonstrating mediastinal lymph node metastases and lung metastases,and with conventional MRI for demonstrating metastases in other locations.Results WB-DWI demonstrated 143 focuses,14 of which were diagnosed to be benign lesions in routine imaging.The number of bone metastases depicted on WB-DWI and routine imaging was 85 and 86;lymph node metastases was 17 and 18;liver metastases was 14 and 14;lung metastases was 4 and 8;and brain metastases was 6 and 8,respectively.WB-DWI failed to detect 12 metastatic lesions including 3 osteoplastic bone metastases,4 lung metastases,3 mediastinal lymph node metastases,and 2 brain metastases.Four metastatic lesions including 2 deltopectoral lymph nodes and 2 rib metastases were detected with WB-DWI alone,all of which evolved greatly during clinical follow-up for more than 6 months.WB-DWI had higher detection rates for metastatic lesions in liver,bone,and lymph nodes than those in lung and brain(χ2=30,P<0.001).Conclusions WB-DWI could detect most of metastatic lesions that were diagnosed with conventional MRI and CT.The limitations of WB-DWI might be had high false-positive rate and low efficiency in detecting mediastinal lymph node,brain,and lung metastases.

EXPERIMENTAL STUDY OF INFLAMMATORY AND METASTATIC LYMPH NODES WITH DIFFUSION WEIGHTED IMAGING ON ANIMAL MODEL: COMPARISON WITH CONVENTIONAL METHODS

Objective To investigate the feasibility of magnetic resonance (MR) diffusion weighted imaging (DWI) in discriminating inflammatory from VX2 carcinoma metastatic lymph nodes in rabbit model. Methods Twenty New Zealand white rabbits were randomly divided into 2 groups. Complete Freund's adjuvant was injected into the bilateral dorsal footpads to set up ipsilateral lymphadenitis model (n = 10), and the other 10 rabbits received a subcutaneous implantation of VX2 tumor cell suspension (1.5×107 cells/mL) in both thighs to set up metastatic lymph node model. MR imaging scan covering the popliteal fossa and iliac fossa including short time inversion recovery echo-planar imaging DWI (STIR-EPI-DWI), T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI) was performed 2 weeks after injection. T2WI signal intensity (SI), DWI SI, long/short axial ratio (LSR) and apparent diffusion coefficient (ADC) values of the lymph nodes were evaluated in all cases. Right after MR imaging scan, popliteal and iliac fossa lymph nodes were collected for hematoxylin-eosin staining. Results Totally 33 lymph nodes larger than 5 mm, including 22 inflammatory and 11 metastatic ones, were successfully isolated and taken into pathological analysis. LSR showed no significant difference between the inflammatory and malignant lymph nodes (P > 0.05). Both benign and malignant lymph nodes appeared iso-intense on T1WI and hyperintense on both T2WI and DWI images with an even lower T1WI and higher T2WI SI core at the hilum. Both T2WI and DWI SI showed no significant difference between two pathological groups (P > 0.01) in popli- teal fossa. The mean ADC value of inflammatory nodes [(1.199 ± 0.281) ×10-3 mm2/s] was significantly higher than that of metastatic nodes [(0.858 ± 0.090) ×10-3 mm2/s, P < 0.01]. On ADC map, a high ADC value central area could be seen in most of the lymph nodes no matter benign or malignant. ADC value gave out the largest area under curve (AUCADC = 0.955) compared with other three indexes (AUCLSR = 0.488; AUCT2WI SI = 0.727; AUCDWI SI = 0.822) and gave the best sensitivity and specificity in lymph node differential diagnosis compared with the other three indexes. Conclusions High quality DWI image can be obtained using STIR-EPI-DWI sequence in rabbit model. DWI is a new promising technique for differentiating inflammatory from metastatic lymph nodes. Compared with routine MR sequence, DWI could provide more useful physiological and functional information for diagnosis.

SPECTRUM OF FUNCTIONING ISLET CELL TUMOR ON MULTISLICE COMPUTED TOMOGRAPHY:EXPERIENCE ON 70 PATIENTS

Objective To review experience in preoperative detection of islet cell tumors using multislice computed tomography (MSCT) and summarize various imaging features of functioning islet cell tumors on enhanced MSCT.Methods Seventy patients with clinical or pathological diagnosis of functioning pancreatic islet cell tumor between October 2003 and February 2007 were included in this retrospective study. Seventy-four enhanced MSCT scans in these patients were identified. All MSCT scans were interpreted by two experienced radiologists by consensus interpretation. Surgery and pathology reports were used to confirm the diagnosis, localization, and size of tumors.Results Totally, 73 functioning islet cell tumors including 65 benign insulinomas, 2 benign glucagonomas, 3 malignant insulinomas, and 3 malignant glucagonomas were pathologically diagnosed. Tumors in only two cases were not found by MSCT. In 67 benign lesions, 32 showed typical enhancement style, 21 showed prolonged enhancement in portal venous phase, 4 showed delayed enhancement, 4 had iso-dense enhancement with normal pancreatic parenchyma, 2 had no enhancement at all in arterial phase and portal venous phase, and 4 had inhomogeneous enhancement with necrosis or cyst-formation. Patchy or spotty calcifications were found in 3 of the 67 tumors. In 6 malignant islet cell tumors, vessel invasion (2/6) and bowel invasion (1/6) were seen. Different enhancement patterns were shown. All hepatic metastases showed hyper-enhancement during their arterial phase. ConclusionsPancreatic islet cell tumor may display a wide spectrum of presentations in MSCT. Tumors with unusual appearances often present as diagnostic challenges. Non-contrast and post-contrast multiphase scans are recommended for the localization of functioning islet cell tumors.

High-resolution computed tomography in patients with atypical 'cardiac' chest pain: a study investigating patients at 10-year cardiovascular risks defined by the Framingham and PROCAM scores

Background and objective Atypical 'cardiac' chest pain (ACCP) is not usually caused by myocardial ischaemia. Current noninvasive investigations for these symptoms are not yet as accurate as invasive coronary angiography. The latest 64-row multi-detector computed tomography (MDCT) technology is non-invasive, has high specificity and negative predictive values for the detection of significant coronary disease. Our aim was to investigate if this modality can provide more information in the assessment of outpatients with ACCP in addition to established cardiovascular risk scores. Methods Seventy consecutive patients presenting to the outpatient clinic with ACCP underwent 64-row MDCT scan of the coronary arteries. They were categorized into low, medium or high risk groups based upon the Framingham and PROCAM scores. We defined a clinically abnormal MDCT scan as coronary stenosis =50% or calcium score ＞400 Agatston. Results Fifty-three (75.7%) patients did not have clinically abnormal scans. Framingham score classified 43 patients as low-risk while PROCAM classified 59 patients as low-risk. MDCT scans were abnormal for 18.6% and 22.0% of the respective low-risk group of patients. For patients with medium-to-high risk, 33.3% and 36.4% of Framingham and PROCAM patient groups respectively had abnormal MDCT scans. Conclusion MDCT adds valuable information in the assessment of patients with ACCP by identifying a significant proportion of patients categorized as low-risk to have underlying significant coronary stenosis and coronary calcification by established cardiovascular risk scores.

Image Quality Stability of Whole-body Diffusion Weighted Imaging

Objective To assess the reproducibility of whole-body diffusion weighted imaging(WB-DWI) technique in healthy volunteers under normal breathing with background body signal suppression.Methods WB-DWI was performed on 32 healthy volunteers twice within two-week period using short TI inversion-recovery diffusion-weighted echo-planar imaging sequence and built-in body coil.The volunteers were scanned across six stations continuously covering the entire body from the head to the feet under normal breathing.The bone apparent diffusion coefficient(ADC) and exponential ADC(eADC) of regions of interest(ROIs) were measured.We analyzed correlation of the results using paired-t-test to assess the reproducibility of the WB-DWI technique.Results We were successful in collecting and analyzing data of 64 WB-DWI images.There was no significant difference in bone ADC and eADC of 824 ROIs between the paired observers and paired scans(P>0.05).Most of the images from all stations were of diagnostic quality.Conclusion The measurements of bone ADC and eADC have good reproducibility.WB-DWI technique under normal breathing with background body signal suppression is adequate.

Three-Dimensional Rotational Angiography in Congenital Heart Disease:Estimation of Radiation Exposure

Objectives: There is an increasing use of three-dimensional rotational angiography (3D-RA) during catheterization of congenital heart disease. Dose-area-product (DAP) measured by the angiography system and computed-tomography dose index (CTDI) do not appear practical for dose assessment. Hence, we performed real dose measurements in anthropomorphic phantoms. Methods: Three different anthropomorphic phantoms (10 kg, 19 kg and 73 kg bodyweight) equipped with thermoluminescent dosimeters (TLD) were used. We used a typical standard diagnostic program and a low-dose program. The effective dose (ED) was calculated according to the International Commission on Radiological Protection (ICRP) 103. The 3D distribution of radiation in the body was assessed. Results: ED for the male 10 kg phantom was 0.192 mSv in the diagnostic program and 0.050 mSv (male) in the low-dose program. The 19 kg phantom received an ED of 0.205 mSv (male) in the diagnostic program. In the low-dose program the ED reached 0.058 mSv (male). The male adult 73 kg phantom was exposed with an ED of 0.730 mSv in the diagnostic program and 0.282 mSv in the low-dose program. ED for the female phantoms was slightly higher for both acquisition-programs. Dose distribution was inhomogeneous with a dose maximum in the esophageal region behind the heart, whereas in the brain, intestine and gonads we found nearly no radiation. Conclusions: 3D-RA imaging in the interventional catheter laboratory is possible with an effective dose lower than 1 mSv. With its potential to reduce fluoroscopic time and the number of control angiographies in catheterization and intervention in complex anatomy, it can decrease the radiation dose.

心脏MR压缩感知超快速电影序列评价左右心室收缩功能的应用价值

目的对比传统分段采集电影序列(Seg), 探讨心脏MR(CMR)压缩感知(CS)超快速电影序列评价左右心室收缩功能的临床应用价值。方法前瞻性纳入2021年12月至2022年1月在阜外医院进行CMR检查的心脏疾病患者27例。随机顺序进行Seg、屏气下CS(bhCS)和自由呼吸下CS(fbCS)覆盖左右心室的多层短轴电影扫描。采用Friedman检验评价3种方法的总体图像质量、血池心肌信号比(BMC)和边缘锐度。分别测量3种方法的左心室舒张末期容积(EDV)、收缩末期容积(ESV)、每博输出量(SV)、射血分数(EF)、心肌质量(mass)及右心室EDV、ESV、SV、EF, 并用Bland-Altman分析bhCS与Seg、fbCS与Seg间测量结果的一致性, 并做相关性检验。结果 24例患者3种方法所有总体图像质量≥2分, 有诊断意义, 纳入后续分析。Seg、bhCS和fbCS的成像时间不同且依次降低, 分别为375.0(332.0, 405.6)、50.0(47.8, 53.7)和20.0(17.8, 23.7)s, 差异有统计学意义(χ^(2)=48.00, P<0.001)。总体图像质量fbCS略低于Seg(Z=-2.67, P=0.023), Seg和bhCS(Z=-1.44, P=0.447)、bhCS和fbCS(Z=1.23, P=0.660)之间差异无统计学意义。Seg、bhCS和fbCS的边缘锐度(χ^(2)=0.58, P=0.747)和BMC(χ^(2)=1.08, P=0.582)差异无统计学意义。Bland-Altman分析表明bhCS和Seg、fbCS和Seg之间左右心室各参数均具有良好的一致性。相关性分析结果显示bhCS和Seg、fbCS和Seg的各心功能参数均呈高度相关(r>0.96, P<0.001)。结论 CS超快速电影序列比传统序列节省了扫描时间且提供了相似的图像质量, 且无论是否屏气, CS序列心功能结果与传统电影序列具有良好的一致性和高度的相关性。

定量临床核心脏病学(第1部分):已明确的临床应用

SPECT心肌灌注显像作为确诊或可疑冠状动脉粥样硬化性心脏病(简称冠心病)患者诊疗流程中必不可少的一项技术,已获得临床的广泛认可。计算机技术为SPECT心肌灌注显像的标准化提供了客观的定量评价,极大地推动了其临床推广和应用。软件平台已成为为临床提供经过研究、开发并验证具有临床实用性的定量算法的1个重要渠道,可以让世界各地的临床专家都能从中受益。该篇医学继续教育文章(第1部分)介绍了诸多临床上已明确并应用的定量工具,更为重要的是描述了临床医师如何将其常规用于对冠心病患者的诊断、临床管理和指导治疗方案的制定。

Diagnostic performance of magnetic resonance venography in the detection of recanalization in patients with chronic cerebral venous sinus thrombus

Background In the chronic stage of cerebral venous sinus thrombosis （CVST）, recanalization can result in disparate MR appearances. We aimed to prospectively investigate the diagnostic accuracy of magnetic resonance venography （MRV） in the evaluation of the recanalization of CVST. Methods This study prospectively evaluated the diagnostic performance of 2-dimensional time-of-flight （2D-TOF） MRV in thirty-two consecutive patients during a threeto six-month follow-up for CVST. Both 2D-TOF MRV and digital substraction angiography （DSA） were undertaken. Diagnostic accuracy of 2D-TOF MRV in the detection of recanalized thrombus was evaluated using DSA as the reference standard. Results MRV and DSA were completed without complications in all 32 patients. The sensitivity, specificity, positive predictive value, and negative predictive value of 2D-TOF MRV for the detection of recanalization on a segmental basis were 91% （62/68）, 93% （37/40）, 95% （62/65）, and 86% （37/43） respectively. Conclusion 2D-TOF MRV provides high sensitivity and specificity for the diagnosis of recanalized CVST segments.

定量临床核心脏病学(第2部分):应用进展及新技术

定量分析已广泛用于核心脏病学图像的处理和解读、改进疾病诊断和危险分层。该文为继续教育文章(含2部分)的第2部分,将对新兴的定量分析工具的临床潜在应用进行综述,介绍机械运动同步性、心室功能、灌注和融合显像定量分析技术,对PET和SPECT评估心肌血流量的新方法进行讨论。心肌活性、微钙化定量检测及心脏结节病和心脏淀粉样变的定量评估亦在文中描述。人工智能在改善图像分析、提高疾病诊断效能和风险预测方面的潜在作用将在文末进行论述。上述新技术的临床潜在应用及优化实施方法将在文中重点阐述。

Case study approach to modeling historical disinfection by-product exposure in Iowa drinking waters

In the 1980 s, a case–control epidemiologic study was conducted in Iowa（USA） to analyze the association between exposure to disinfection by-products（DBPs） and bladder cancer risk. Trihalomethanes（THMs）, the most commonly measured and dominant class of DBPs in drinking water, served as a primary metric and surrogate for the full DBP mixture.Average THM exposure was calculated, based on rough estimates of past levels in Iowa. To reduce misclassification, a follow-up study was undertaken to improve estimates of past THM levels and to re-evaluate their association with cancer risk. In addition, the risk associated with haloacetic acids, another class of DBPs, was examined. In the original analysis, surface water treatment plants were assigned one of two possible THM levels depending on the point of chlorination. The re-assessment considered each utility treating surface or groundwater on a case-by-case basis. Multiple treatment/disinfection scenarios and water quality parameters were considered with actual DBP measurements to develop estimates of past levels. The highest annual average THM level in the re-analysis was156 μg/L compared to 74 μg/L for the original analysis. This allowed the analysis of subjects exposed at higher levels（〉 96 μg/L）. The re-analysis established a new approach, based on case studies and an understanding of the water quality and operational parameters that impact DBP formation, for determining historical exposure.

Proteomics reveals differential adsorption of angiogenic platelet lysate proteins on calcium phosphate bone substitute materials

Protein adsorption on biomaterials for bone substitution,such as calcium phosphates(CaP),evokes biological responses and shapes the interactions of biomaterials with the surrounding biological environment.Proteins adsorb when CaP materials are combined with growth factor-rich hemoderivatives prior to implantation to achieve enhanced angiogenesis and stimulate new bone formation.However,the identification of the adsorbed proteins and their angiogenic effect on bone homeostasis remain incompletely investigated.In this study,we analyzed the adsorbed complex protein composition on CaP surfaces when using the hemoderivatives plasma,platelet lysate in plasma(PL),and washed platelet lysate proteins(wPL).We detected highly abundant,non-regenerative proteins and anti-angiogenic proteins adsorbed on CaP surfaces after incubation with PL and wPL by liquid chromatography and mass spectrometry(LC–MS)proteomics.Additionally,we measured a decreased amount of adsorbed pro-angiogenic growth factors.Tube formation assays with human umbilical endothelial cells demonstrated that the CaP surfaces only stimulate an angiogenic response when kept in the hemoderivative medium but not after washing with PBS.Our results highlight the necessity to correlate biomaterial surfaces with complex adsorbed protein compositions to tailor the biomaterial surface toward an enrichment of pro-angiogenic factors.