Valid and reliable diagnostic performance of dual-energy CT in anterior cruciate ligament rupture.

OBJECTIVES: To determine whether dual-energy CT (DECT) can be used to accurately and reliably detect anterior cruciate ligament (ACL) rupture. MATERIALS AND METHODS: Participants with unilateral ACL rupture were prospectively enrolled, and the bilateral knees were scanned by DECT. A tissue-specific mapping algorithm was applied to improve the visualization of the ACLs. The 80-keV CT value, mixed-keV CT value, electron density (Rho), and effective atomic number (Zeff) were measured to quantitatively differentiate torn ACLs from normal ACLs. MRI and arthroscopy served as the reference standards. RESULTS: Fifty-one participants (mean age, 27.0 ± 8.7 years; 31 men) were enrolled. Intact and torn ACLs were explicitly differentiated on color-coded DECT images. The 80-keV CT value, mixed-keV CT value, and Rho were significantly lower for the torn ACLs than for the intact ACLs (p < 0.001). The optimal cutoff values were an 80-keV CT value of 61.8 HU, a mixed-keV CT value of 60.9 HU, and a Rho of 51.8 HU, with AUCs of 98.0% (95% CI: 97.0-98.9%), 99.2% (95% CI: 98.6-99.7%), and 99.8% (95% CI: 99.6-100.0%), respectively. Overall, DECT had almost perfect reliability and validity in detecting ACL integrity (sensitivity = 97.1% [95% CI: 88.1-99.8%]; specificity = 98.0% [95% CI: 89.5-99.9%]; PPV = 98.0% [95% CI: 93.0-99.8%]; NPV = 97.1% [95% CI: 91.7-99.4%]; accuracy = 97.5% [95% CI: 94.3-99.2%]). There was no evidence of a difference between MRI and DECT in the diagnostic performance (p > 0.99). CONCLUSION: DECT has excellent diagnostic accuracy and reliability in qualitatively and quantitatively diagnosing ACL rupture. CLINICAL RELEVANCE STATEMENT: DECT could validly and reliably diagnose ACL rupture using both qualitative and quantitative methods, which may become a promising substitute for MRI to evaluate the integrity of injured ACLs and the maturity of postoperative ACL autografts. KEY POINTS: • On color-coded DECT images, an uncolored ACL was a reliable sign for qualitatively diagnosing ACL rupture. • The 80-keV CT value, mixed-keV CT value, and Rho were significantly lower for the torn ACLs than for the intact ACLs, which contributed to the quantitative diagnosis of ACL rupture. • DECT had an almost perfect diagnostic performance for ACL rupture, and diagnostic capability was comparable between MRI and DECT.

Accelerated loss of trunk muscle density and size at L1 vertebral level in male patients with COPD.

Background and purpose: Weight loss and muscle mass loss are common in patients with chronic obstructive pulmonary disease (COPD). Muscle density and fat infiltration based on CT images may be more sensitive than muscle mass by DXA in the assessment of sarcopenia for COPD patients. However, the age-related changes of cross-sectional trunk muscle compositions based on lung CT scans are still unknown. Thus, we aimed to investigate over time the change in muscle density, size, and fat deposition of L1-level trunk muscles in patients with COPD. Materials and methods: 129 male COPD patients with a second chest CT scan (from 2013-2019 to 2014-2020) were enrolled. The CT images at first and second CT scans are analyzed by OsiriX software. Trunk muscles at the level of the 1st lumbar vertebrae were selected for analysis. Attenuation of lumbar vertebrae 1 was also measured from chest CT images. The pulmonary function values were calculated based on forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC). Results: The mean age of the 129 patients with COPD was 69.7 years. The durations of COPD of this cohort were from 8-17 years. The mean area and density of L1 trunk muscles were 85.5 cm2 and 36.4 HU. At baseline, muscle area and density and vertebral density were negatively associated with age (p<0.0001), while the intermuscular fat area and the fat infiltration ratio were not significantly associated with age (p>0.05). The per-year loss of trunk muscle area was 2.83 cm2 (p<0.0001) which accounts for 3.3% decrease per year, and the per-year decrease of trunk muscle density was 2.41 HU (p<0.0001) which accounts for 6.6% decrease per year. The per-year increase of intermuscular fat in trunk muscles was 0.57 cm2 (p=0.006) which accounts for 11.1% increase per year. The bone density loss was 5.63 HU/per year (p<0.0001). Conclusion: Men with COPD had accelerated muscle loss as well as increased fat infiltration. Compared to muscle quantity loss, the decline in muscle quality is much larger, indicating the importance of relevant interventions focusing on improving muscle quality.

Deep Learning for Classification of Bone Lesions on Routine MRI.

BACKGROUND: Radiologists have difficulty distinguishing benign from malignant bone lesions because these lesions may have similar imaging appearances. The purpose of this study was to develop a deep learning algorithm that can differentiate benign and malignant bone lesions using routine magnetic resonance imaging (MRI) and patient demographics. METHODS: 1,060 histologically confirmed bone lesions with T1- and T2-weighted pre-operative MRI were retrospectively identified and included, with lesions from 4 institutions used for model development and internal validation, and data from a fifth institution used for external validation. Image-based models were generated using the EfficientNet-B0 architecture and a logistic regression model was trained using patient age, sex, and lesion location. A voting ensemble was created as the final model. The performance of the model was compared to classification performance by radiology experts. FINDINGS: The cohort had a mean age of 30±23 years and was 58.3% male, with 582 benign lesions and 478 malignant. Compared to a contrived expert committee result, the ensemble deep learning model achieved (ensemble vs. experts): similar accuracy (0·76 vs. 0·73, p=0·7), sensitivity (0·79 vs. 0·81, p=1·0) and specificity (0·75 vs. 0·66, p=0·48), with a ROC AUC of 0·82. On external testing, the model achieved ROC AUC of 0·79. INTERPRETATION: Deep learning can be used to distinguish benign and malignant bone lesions on par with experts. These findings could aid in the development of computer-aided diagnostic tools to reduce unnecessary referrals to specialized centers from community clinics and limit unnecessary biopsies. FUNDING: This work was funded by a Radiological Society of North America Research Medical Student Grant (#RMS2013) and supported by the Amazon Web Services Diagnostic Development Initiative.

Deep learning-based classification of primary bone tumors on radiographs: A preliminary study.

BACKGROUND: To develop a deep learning model to classify primary bone tumors from preoperative radiographs and compare performance with radiologists. METHODS: A total of 1356 patients (2899 images) with histologically confirmed primary bone tumors and pre-operative radiographs were identified from five institutions' pathology databases. Manual cropping was performed by radiologists to label the lesions. Binary discriminatory capacity (benign versus not-benign and malignant versus not-malignant) and three-way classification (benign versus intermediate versus malignant) performance of our model were evaluated. The generalizability of our model was investigated on data from external test set. Final model performance was compared with interpretation from five radiologists of varying level of experience using the Permutations tests. FINDINGS: For benign vs. not benign, model achieved area under curve (AUC) of 0•894 and 0•877 on cross-validation and external testing, respectively. For malignant vs. not malignant, model achieved AUC of 0•907 and 0•916 on cross-validation and external testing, respectively. For three-way classification, model achieved 72•1% accuracy vs. 74•6% and 72•1% for the two subspecialists on cross-validation (p = 0•03 and p = 0•52, respectively). On external testing, model achieved 73•4% accuracy vs. 69•3%, 73•4%, 73•1%, 67•9%, and 63•4% for the two subspecialists and three junior radiologists (p = 0•14, p = 0•89, p = 0•93, p = 0•02, p < 0•01 for radiologists 1-5, respectively). INTERPRETATION: Deep learning can classify primary bone tumors using conventional radiographs in a multi-institutional dataset with similar accuracy compared to subspecialists, and better performance than junior radiologists. FUNDING: The project described was supported by RSNA Research & Education Foundation, through grant number RSCH2004 to Harrison X. Bai.

Age-related fatty infiltration of lumbar paraspinal muscles: a normative reference database study in 516 Chinese females.

BACKGROUND: Fatty infiltration, as a result of aging, is an essential biomarker of muscle degeneration. This research aimed to investigate the age-dependent change of fatty degeneration in the paraspinal muscles of healthy Chinese women. This study also explores the effect of body size on fatty infiltration of paraspinal muscles. METHODS: Cross-sectional area of paraspinal muscles (CSAmuscle) and intermuscular adipose tissue (CSAIMAT) were measured at the L3 mid-vertebral level of 516 healthy females, who underwent abdomen quantitative computed tomography (QCT) scans. Subsequently, IMAT% [CSAIMAT / (CSAIMAT + CSAmuscle)] were calculated. The relationship between basic information and measurements was evaluated using Spearman correlations. Comparisons of QCT results among different BMI subgroups in different age groups were analyzed with the Kruskal-Wallis H test and LSD, post-hoc correction. Age-related changes were calculated after the adjustment of height and weight. RESULTS: The mean CSAIMAT of 20-29 years group (n=69) and 70-79 years group (n=25) were 3.00 cm2 and 11.06 cm2, respectively. While the mean CSAmuscle of 20-29 years group was 38.46 cm2 and 70-79 years group was 30.86 cm2. The mean IMAT% difference between 20-29 years group and 70-79 years group was -18.55%. Strong, positive non-linear associations were observed between ageing and CSAIMAT, along with IMAT% (r=0.656, P<0.01; r=0.714, P<0.01). However, CSAmuscle was shown to decrease with age in a weak, negative linear fashion (r=-0.265, P<0.01). Positive relationships between BMI and CSAIMAT, CSAmuscle, along with IMAT%, were found. Significant differences were observed between obesity and normal BMI subgroup for all variables in three age groups. CSAIMAT showed a larger age-related difference compared to CSAmuscle. CONCLUSIONS: Fatty infiltration in paraspinal muscles increased with age and BMI, while muscle loss may be associated with aging. The present study provided standardized reference data for the fatty degeneration of paraspinal muscles across the adult lifespan of Chinese females, which will play a critical role in future studies.

Prognostic value of magnetic resonance imaging performed during the subacute phase in adult patients with hypoxic-ischemic encephalopathy for long-term neurological outcomes.

OBJECTIVE: To investigate the value of a model based on brain magnetic resonance imaging (MRI) performed in the subacute phase (between the 1st and 30th day) in predicting long-term neurological outcomes of adult hypoxic-ischemic encephalopathy (HIE) patients. METHODS: Ninety-six adult HIE patients who underwent conventional MRI and diffusion-weighted imaging (DWI) during the subacute phase were retrospectively analyzed. Favorable (Cerebral Performance Categories (CPC) 1-2) and unfavorable outcome (CPC 3-5) groups were created based on patient neurological status approximately three months after the onset of hypoxic-ischemic events. A multivariate stepwise regression model was applied after univariate analysis of MRI findings, and then the overall MRI score, Alberta Stroke Program Early Computed Tomography Score (ASPECTS), Bilateral ASPECTS (Bi-ASPECTS), modified ASPECTS (mASPECTS) and Bi-ASPECTS combined with posterior circulation ASPECTS (PC-ASPECTS) were calculated based on MRI findings. Receiver operating characteristic (ROC) curves were used to assess prognostic accuracy. RESULTS: Both univariate and multivariate analyses showed the cerebral cortex and cerebellum, neostriatum, hippocampus, brainstem and postanoxic leukoencephalopathy were independent prognostic factors for unfavorable outcomes. The multivariate regression analysis resulted in an overall classification accuracy of 84.4%, a sensitivity of 84.2% (95% CI, 71.6-92.1%), and a specificity of 92.3% (95% CI, 78.0-98.0%) for unfavorable outcomes. The model had an areas under the ROC curves (AUC) of 0.944 (95% CI, 0.901-0.987); the MRI overall scores were 0.918 (95% CI, 0.866, 0.971), ASPECTS 0.839 (95% CI, 0.755, 0.923), Bi-ASPECTS 0.837 (95% CI, 0.753, 0.922), mASPECTS 0.851(95% CI, 0.771, 0.931) and Bi-ASPECTS+PC-ASPECTS 0.876 (95% CI, 0.806, 0.946). CONCLUSIONS: The multivariate model based on conventional MRI combined with DWI performed in the subacute phase could help predict the prognosis of adult HIE with high performance.

Evaluation of simultaneous-multislice diffusion-weighted imaging of liver at 3.0 T with different breathing schemes.

PURPOSE: To obtain the optimal simultaneous-multislice (SMS)-accelerated diffusion-weighted imaging (DWI) of the liver at 3.0 T MRI by systematically estimating the repeatability of apparent diffusion coefficient (ADC), signal-to-noise ratio (SNR) and image quality of different breathing schemes in comparison to standard DWI (STD) and other SMS sequences. METHODS: In this institutional review board-approved prospective study, hepatic DWIs (b = 50, 300, 600 s/mm2) were performed in 23 volunteers on 3.0 T MRI using SMS and STD with breath-hold (BH-SMS, BH-STD), free-breathing (FB-SMS, FB-STD) and respiratory-triggered (RT-SMS, RT-STD). Reduction of scan time with SMS-acceleration was calculated. ADC and SNR were measured in nine anatomic locations and image quality was assessed on all SMS and STD sequences. An optimal SMS-DWI was decided by systematically comparing the ADC repeatability, SNR and image quality among above DWIs. RESULTS: SMS-DWI reduced scan time significantly by comparison with corresponding STD-DWI (27 vs. 42 s for BH, 54 vs. 78 s for FB and 42 vs. 97 s for RT). In all DWIs, BH-SMS had the greatest intraobserver agreement (intraclass correlation coefficient (ICC): 0.920-0.944) and good interobserver agreement (ICC: 0.831-0.886) for ADC measurements, and had the best ADC repeatability (mean ADC absolute differences: 0.046-0.058 × 10-3mm2/s, limits of agreement (LOA): 0.010-0.013 × 10-3mm2/s) in nine locations. BH-SMS had the highest SNR in three representative sections except for RT-STD. There were no significant differences in image quality between BH-SMS and other DWI sequences (median BH-SMS: 4.75, other DWI: 4.5-5.0; P > 0.0.5). CONCLUSION: BH-SMS provides considerable scan time reduction with good image quality, sufficient SNR and highest ADC repeatability on 3.0 T MRI, which is thus recommended as the optimal hepatic DWI sequence for those subjects with adequate breath-holding capability.

[Magnetic Resonance Imaging Features and Their Pathological Mechanisms of Hashimoto's Encephalopathy].

Objective To analyze the routine and functional magnetic resonance imaging(MRI) features and their potential pathological mechanisms of Hashimoto's encephalopathy(HE). Methods The clinical data and routine and functional MRI images of 30 HE patients who were treated in our center from January 2010 to April 2017 were retrospectively reviewed. Among them,15 patients were examined with contrast-enhanced MRI,16 with diffusion-weighed imaging(DWI),8 with magnetic resonance angiography,2 with magnetic resonance spectroscopy,and 1 with both arterial spin labeled perfusion imaging and diffusion tensor imaging. Seven patients had consecutive clinical and imaging data. The distribution,MRI signals,and functional MRI features of HE were analyzed. Results Among 30 HE patients,routine MRI showed negative results in 8 cases and abnormal findings in 22 cases. Among 22 abnormal cases,9 were characterized by small cerebral vascular disease and 13 had non-specific abnormalities;of these 13 cases,12 had lesions mainly located at the supratentorial white matter,11 had multiple lesions,and 2 had lesions complicated with cerebellum atrophy. The lesions were focal or confluent,punctate or small patchy,showing abnormal signal intensity with iso-or hypo-intensity on T1-weighed imaging,hyper-intensity on both T2-weighed imaging and fluid-attenuated inversion recovery. Most of the lesions had no enhancement(12/15). Among 7 cases with abnormalities on DWI,hyper-intensity on DWI and hypo-intensity on apparent diffusion coefficient were seen in 3 sudden acute cases and hyper-intensity on DWI and increased apparent diffusion coefficient value in 4 sub-acute or slow onset cases. Three cases showed localized intracranial artery stenosis. In 2 cases,magnetic resonance spectroscopy revealed significant lower N-acetylaspartate peak,higher choline peak,and visible lactate peak or lipid peak. Of 7 cases with follow-up data,3 cases had no change,4 cases had changes including softening lesions(2/4),remitted and relapsed lesions(1/4),and rapid progression of brain atrophy with negative finding on the initial MRI(1/4). Conclusion Routine MRI combined with functional imaging can show the features of HE from different perspectives. Routine MRI shows multifocal or confluent lesions in the white matter,mostly without enhancement,while functional imaging may reveal pathological characteristics of different phases of acute or chronic ischemia and demyelinating changes of HE. Combined with clinical data,MRI can differentiate HE from other diseases based on routine and functional MRI appearances.

Correlation study between facet joint cartilage and intervertebral discs in early lumbar vertebral degeneration using T2, T2* and T1ρ mapping.

Recent advancements in magnetic resonance imaging have allowed for the early detection of biochemical changes in intervertebral discs and articular cartilage. Here, we assessed the feasibility of axial T2, T2* and T1ρ mapping of the lumbar facet joints (LFJs) to determine correlations between cartilage and intervertebral discs (IVDs) in early lumbar vertebral degeneration. We recruited 22 volunteers and examined 202 LFJs and 101 IVDs with morphological (sagittal and axial FSE T2-weighted imaging) and axial biochemical (T2, T2* and T1ρ mapping) sequences using a 3.0T MRI scanner. IVDs were graded using the Pfirrmann system. Mapping values of LFJs were recorded according to the degeneration grades of IVDs at the same level. The feasibility of T2, T2* and T1ρ in IVDs and LFJs were analyzed by comparing these mapping values across subjects with different rates of degeneration using Kruskal-Wallis tests. A Pearson's correlation analysis was used to compare T2, T2* and T1ρ values of discs and LFJs. We found excellent reproducibility in the T2, T2* and T1ρ values for the nucleus pulposus (NP), anterior and posterior annulus fibrosus (PAF), and LFJ cartilage (intraclass correlation coefficients 0.806-0.955). T2, T2* and T1ρ mapping (all P<0.01) had good Pfirrmann grade performances in the NP with IVD degeneration. LFJ T2* values were significantly different between grades I and IV (PL = 0.032, PR = 0.026), as were T1ρ values between grades II and III (PL = 0.002, PR = 0.006) and grades III and IV (PL = 0.006, PR = 0.001). Correlations were moderately negative for T1ρ values between LFJ cartilage and NP (rL = -0.574, rR = -0.551), and between LFJ cartilage and PAF (rL = -0.551, rR = -0.499). T1ρ values of LFJ cartilage was weakly correlated with T2 (r = 0.007) and T2* (r = -0.158) values. Overall, we show that axial T1ρ effectively assesses early LFJ cartilage degeneration. Using T1ρ analysis, we propose a link between LFJ degeneration and IVD NP or PAF changes.

Feasibility study for evaluating early lumbar facet joint degeneration using axial T1 ρ, T2 , and T2* mapping in cartilage.

PURPOSE: To assess the feasibility of axial T2 , T2*, and T1 ρ mapping of lumbar facet joint (LFJ) cartilage for evaluation of early degeneration. MATERIALS AND METHODS: We examined a total of 176 LFJs from 21 volunteers using axial T2 , T2*, and T1 ρ mapping with a 3.0T magnetic resonance imaging (MRI) scanner. All LFJs were measured and grouped according to the presence of low back pain (LBP), the Weishaupt grading system, and the Pfirrmann grade of the adjacent intervertebral disk (IVD). T2 , T2*, and T1 ρ values were analyzed and compared among the different groups. RESULTS: Low interobserver agreement was found in the Weishaupt grading of LFJs (κ = 0.161). The T1 ρ values of LFJs were significantly different between adjacent two Pfirrmann grade of disks (grade I 50.15 ± 3.63 msec / grade II 53.27 ± 3.80 msec, P = 0.002; grade II 53.27 ± 3.80 msec / grade III 58.40 ± 4.17 msec, P < 0.01), and in different Weishaupt grades of LFJs (P = 0.000). T2* values were only found significantly different between Pfirrmann grade I and III of disks (P = 0.048). There was no significant difference in T2 values of LFJs whatever in Pfirrmann (P = 0.556) or Weishaupt grades (P = 0.694). No significant difference was found in T2 , T2*, and T1 ρ values between volunteers with LBP and without LBP (PT2 = 0.783, PT2*=0.311, PT1 ρ = 0.259). CONCLUSION: Axial T1 ρ could be an effective and sensitive method to assess for early degenerative changes in LFJ cartilage. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:468-475.

Radiation/paclitaxel treatment of p53-abnormal non-small cell lung cancer xenograft tumor and associated mechanism.

BACKGROUND: Mutations in key tumor suppressor genes such as tumor protein 53 (TP53) and phosphatase and tensin homolog deleted on chromosome ten (PTEN) are the main genetic alterations in cancers. TP53 mutations have been found in most patients with non-small cell lung cancer (NSCLC), whereas PTEN mutations are rarely found in lung cancer, though most NSCLCs lack PTEN protein synthesis. However, the signaling involved in radio- and chemotherapy of NSCLC with wild-type PTEN and nonfunctional p53 is not clearly understood. METHODS: In this study, we established a xenograft tumor model with H358 NSCLC cells expressing wild-type PTEN, but nonfunctional p53. Protein expression and phosphorylation of PTEN and its downstream signal molecules in NSCLC tissues were detected by Western blot. RESULTS: We demonstrated that radiation and paclitaxel alone inhibited tumor growth, but a combined therapy of radiation and paclitaxel was more effective in inhibiting NSCLC tumor growth. Interestingly, both radiation and paclitaxel significantly increased PTEN protein expression and phosphorylation. Further identification of the affected PTEN downstream molecules showed that Akt phosphorylation at Ser(473) and Thr(308) residues was significantly decreased, whereas Bax and cleaved caspase-3 levels were significantly increased in tumor tissues treated with both radiation and paclitaxel. The combined treatment was more effective than either treatment alone in regulating the studied molecules. We also found that paclitaxel, but not radiation, inhibited phosphoinositide 3-kinase (PI3K) activity. CONCLUSIONS: Our study suggested that a PTEN-PI3K-Akt-Bax signaling cascade is involved in the therapeutic effect of combined radiation/paclitaxel treatment in NSCLC without p53 expression. Our study also suggested that PTEN is an ideal target in tumors with wild-type PTEN and a lack of functional p53.

The mechanism involved in the loss of PTEN expression in NSCLC tumor cells.

Loss of PTEN expression is observed in most non-small cell lung cancers (NSCLC). However, the mechanism by which PTEN expression is regulated in NSCLC has not been fully elucidated. In this study, we investigated the role of DNA methyltransferases (Dnmts), microRNA-29b (miR-29b), and anti-miR-29b inhibitor in PTEN promoter methylation and PTEN gene expression in H358 NSCLC cells in vitro and in vivo. PTEN mRNA was measured by RT-PCR. PTEN and Dnmts protein levels were measured by Western blot. miR-29b expression was detected by Northern blot. A xenograft H358 tumor mouse model was established by subcutaneously inoculating H358 cells into the right hind limbs of nude mice. We found that radiation induced cell apoptosis and hypomethylation in PTEN promoter, PTEN and miR-29b expression, and downregulation of Dnmt1, 3a and 3b expression in H358 tumor cells. The effect of radiation on gene expression and apoptosis was blocked by anti-miR-29b inhibitor. In the xenograft H358 tumor model, anti-miR-29b inhibitor reversed radiation-induced tumor growth delay, PTEN reexpression and downregulation of Dnmts expression. Our study suggested that miR-29b is an upstream molecule of PTEN. miR-29b regulates PTEN gene expression through downregulating Dnmts expression and subsequently induces hypomethylation in PTEN promoter. Targeting therapy could be established in NSCLC by upregulating miR-29b expression.

[Clinical features and imaging findings of intravenous leiomyomatosis].

OBJECTIVE: To explore the clinical features and imaging findings of intravenous leiomyomatosis (IVL). METHOD: The clinical features and imaging findings of 9 patients with pathologically confirmed IVL were retrospectively analyzed. RESULTS: Out of these 9 patients, there were 5 first-episode patients and 4 recurrent patients. Five patients had a history of uterine leiomyoma.Inferior vena cava (IVC) were involved in all 9 patients. The tumor extended through IVC into right heart chamber in 7 patients, among whom tumor were initially arisen from pelvic vessels in 6 patients. The first-episode symptoms included chest tightness and shortness of breath (n=4), edema of low extremity (n=2), abdominal distention (n=2), and menorrhagia (n=1). Tumors in pelvis/venous system and right heart cavity appeared as hypoechoic mass under ultrasound examinations, and hypodense mass with mottled enhancement were observed on contrasted CT. Tumors appeared to be isointense to muscles on T1-weighted images and slightly hyperintense on T2-weighted images. CONCLUSIONS: IVL has certain clinical history and lesion locations. Combined imaging examinations are helpful in the early diagnosis, surgery planning, and follow-up of IVL.

Tissue Doppler imaging study of right ventricular myocardial systolic activation in subjects with pulmonary arterial hypertension.

BACKGROUND: Tissue Doppler imaging (TDI) has provided an objective means to quantify global and regional left ventricular (LV) and right ventricular (RV) function with improved accuracy and greater reproducibility than conventional echocardiography. This study was conducted to assess RV myocardial systolic activation by TDI in subjects with pulmonary arterial hypertension (PAH). METHODS: A total of 30 patients with PAH and 30 healthy volunteers, all comparable in age and sex, underwent standard Doppler echo and TDI. Using pulsed Doppler echocardiography combined with TDI, the following regional parameters were evaluated in three different myocardial segments (RV basal lateral wall, basal septal, and LV basal lateral) on apical 4-chamber view: systolic (Sm), early- and late-diastolic (Em and Am) peak velocities. RV myocardial systolic activation delay was defined as the difference in time to peak TDI systolic velocities between the RV basal lateral wall and basal septal. In addition, RV end-diastolic and end-systolic areas were measured to calculate RV fractional area change from the same apical 4-chamber view. RESULTS: Compared with the control group, patients with PAH showed increased RA and RV end-diastolic diameter (RA: (4.5 +/- 1.2) cm vs (3.0 +/- 0.8) cm, P < 0.05 and RV: (4.8 +/- 1.9) cm vs (3.4 +/- 0.5) cm, P < 0.05) and reduced RV fractional area change; (35 +/- 14)% vs (56 +/- 9)%, P < 0.05. These PAH patients showed lower myocardial peak velocities and a significant activation delay compared with controls (P < 0.05). Moreover, a strong correlation between RV myocardial systolic activation delay and RV fractional area change was shown in patients with pulmonary arterial hypertension (r = -0.82). CONCLUSIONS: In PAH, RV myocardial systolic activation was markedly delayed, which was directly related to the RV fractional area change. RV myocardial systolic activation delay assessed by TDI could offer a unique approach to predict RV dysfunction.

[Application of real-time tissue elastography in diagnosis of breast cancer].

OBJECTIVE: To investigate the clinical value of real-time tissue elastography (RTE) in the diagnosis of breast cancer. METHODS: One hundred and twenty patients with breast lumps (135 lesions) were examined with B-mode imaging, color Doppler flowing imaging (CDFI) and RTE. The elastogram was graded using 5-score evaluating method. The postoperative pathological diagnosis was used as gold standard, and the sensitivity, specificity and accuracy of RTE and two-dimensional ultrasonography combined with RTE in diagnosis of breast cancer were calculated. RESULT: When the score >4 was set for cut-off criteria of malignancy, the sensitivity, specificity and accuracy of RTE was 85.45%, 83.75% and 84.4%, respectively. While two-dimensional ultrasonography combined with RTE was used, the sensitivity, specificity and accuracy increased up to 100%, 95% and 97%, respectively. CONCLUSION: RTE combined with two-dimensional ultrasonography can improve the validity in the diagnosis of malignant breast lesions.