Shen Shuai II recipe improves renal hypoxia to attenuate renal injury in 5/6 renal ablation/infarction rats and effect evaluation using blood oxygenation level-dependent functional magnetic resonance imaging.

Background: Renal hypoxia plays a key role in the progression of chronic kidney disease (CKD). Shen Shuai II Recipe (SSR) has shown good results in the treatment of CKD as a common herbal formula. This study aimed to explore the effect of SSR on renal hypoxia and injury in CKD rats. Methods: Twenty-five Wistar rats underwent 5/6 renal ablation/infarction (A/I) surgery were randomly divided into three groups: 5/6 (A/I), 5/6 (A/I) + losartan (LOS), and 5/6 (A/I) + SSR groups. Another eight normal rats were used as the Sham group. After 8-week corresponding interventions, blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) was performed to evaluate renal oxygenation in all rats, and biochemical indicators were used to measure kidney and liver function, hemoglobin, and proteinuria. The expression of fibrosis and hypoxia-related proteins was analyzed using immunoblotting examination. Results: Renal oxygenation, evaluated by BOLD-fMRI as cortical and medullary T2* values (COT2* and MET2*), was decreased in 5/6 (A/I) rats, but increased after SSR treatment. SSR also downregulated the expression of hypoxia-inducible factor-1α (HIF-1α) in 5/6 (A/I) kidneys. With the improvement of renal hypoxia, renal function and fibrosis were improved in 5/6 (A/I) rats, accompanied by reduced proteinuria. Furthermore, the COT2* and MET2* were significantly positively correlated with the levels of creatinine clearance rate (Ccr) and hemoglobin, but negatively associated with the levels of serum creatinine (SCr), blood urea nitrogen (BUN), serum cystatin C (CysC), serum uric acid (UA), 24-h urinary protein (24-h Upr), and urinary albumin:creatinine ratio (UACR). Conclusion: The degree of renal oxygenation reduction is correlated with the severity of renal injury in CKD. SSR can improve renal hypoxia to attenuate renal injury in 5/6 (A/I) rats of CKD.

Multi-b-value DWI to evaluate the synergistic antiproliferation and anti-heterogeneity effects of bufalin plus sorafenib in an orthotopic HCC model.

BACKGROUND: Multi-b-value diffusion-weighted imaging (DWI) with different postprocessing models allows for evaluating hepatocellular carcinoma (HCC) proliferation, spatial heterogeneity, and feasibility of treatment strategies. We assessed synergistic effects of bufalin+sorafenib in orthotopic HCC-LM3 xenograft nude mice by using intravoxel incoherent motion (IVIM), diffusion kurtosis imaging (DKI), a stretched exponential model (SEM), and a fractional-order calculus (FROC) model. METHODS: Twenty-four orthotopic HCC-LM3 xenograft mice were divided into bufalin+sorafenib, bufalin, sorafenib treatment groups, and a control group. Multi-b-value DWI was performed using a 3-T scanner after 3 weeks' treatment to obtain true diffusion coefficient Dt, pseudo-diffusion coefficient Dp, perfusion fraction f, mean diffusivity (MD), mean kurtosis (MK), distributed diffusion coefficient (DDC), heterogeneity index α, diffusion coefficient D, fractional order parameter ß, and microstructural quantity µ. Necrotic fraction (NF), standard deviation (SD) of hematoxylin-eosin staining, and microvessel density (MVD) of anti-CD31 staining were evaluated. Correlations of DWI parameters with histopathological results were analyzed, and measurements were compared among four groups. RESULTS: In the final 22 mice, f positively correlated with MVD (r = 0.679, p = 0.001). Significantly good correlations of MK (r = 0.677), α (r = -0.696), and ß (r= -0.639) with SD were observed (all p < 0.010). f, MK, MVD, and SD were much lower, while MD, α, ß, and NF were higher in bufalin plus sorafenib group than control group (all p < 0.050). CONCLUSION: Evaluated by IVIM, DKI, SEM, and FROC, bufalin+sorafenib was found to inhibit tumor proliferation and angiogenesis and reduce spatial heterogeneity in HCC-LM3 models. RELEVANCE STATEMENT: Multi-b-value DWI provides potential metrics for evaluating the efficacy of treatment in HCC. KEY POINTS: • Bufalin plus sorafenib combination may increase the effectiveness of HCC therapy. • Multi-b-value DWI depicted HCC proliferation, angiogenesis, and spatial heterogeneity. • Multi-b-value DWI may be a noninvasive method to assess HCC therapeutic efficacy.

Linking renal hypoxia and oxidative stress in chronic kidney disease: Based on clinical subjects and animal models.

This study aims to explore the relationships between renal function, hypoxia, and oxidative stress in chronic kidney disease (CKD). Seventy-six non-dialysis patients with CKD stages 1-5 and eight healthy subjects were included in the clinical research. They were divided into three groups: healthy subjects, CKD stages 1-3, and CKD stages 4-5. In the animal study, 16 rat models of CKD were established through 5/6 renal ablation/infarction (A/I) surgery, and 8 normal rats were split into 3 groups: Sham, CKD, and losartan groups. Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) was used to measure cortical and medullary T2* values (COT2* and MET2*) in all subjects and rats to evaluate renal oxygenation. Biochemical indicators were used to assess renal function and antioxidant capacity. Furthermore, the effects of losartan on renal fibrosis, hypoxia, and oxidative stress were examined using immunoblotting, colorimetric, and fluorometric assays. The results demonstrated significant positive associations between COT2* and MET2* with estimated glomerular filtration rate (eGFR). Patients with CKD stages 4-5 showed significantly lower serum superoxide dismutase (SOD) levels, which also had positive correlations with eGFR, COT2*, and MET2*. Furthermore, losartan treatment resulted in improved renal function and fibrosis, leading to increased levels of COT2*, MET2*, and SOD levels in 5/6 A/I rats. This was accompanied by reduced levels of hypoxia-inducible factor-1 alpha (HIF-1α) and malondialdehyde. Furthermore, losartan restored the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), and suppressed the expression of Kelch-like ECH-associated protein 1 (Keap1) in 5/6 A/I kidneys. The study indicates that decline in renal oxygenation and antioxidant capacity is associated with the severity of renal failure in CKD. Losartan can potentially alleviate renal hypoxia and oxidative stress in the treatment of CKD via Keap1-Nrf2/HO-1 pathway.

Magnetic susceptibility and R2*-based texture analysis for evaluating liver fibrosis in chronic liver disease.

PURPOSE: To explore potential feasibility of texture features in magnetic susceptibility and R2* maps for evaluating liver fibrosis. METHODS: Thirty-one patients (median age 46 years; 22 male) with chronic liver disease were prospectively recruited and underwent magnetic resonance imaging (MRI), blood tests, and liver biopsy. Susceptibility and R2* maps were obtained using a 3-dimensional volumetric interpolated breath-hold examination sequence with a 3T MRI scanner. Texture features, including histogram, gray-level co-occurrence matrix (GLCM), gray-level dependence matrix (GLDM), gray-level run length matrix (GLRLM), gray-level size zone matrix (GLSZM), and neighboring gray tone difference matrix (NGTDM) features, were extracted. Texture features and blood test results of non-significant (Ishak-F < 3) and significant fibrosis patients (Ishak-F ≥ 3) were compared, and correlations with Ishak-F stages were analyzed. Areas under the curve (AUCs) were calculated to determine the efficacy for evaluating liver fibrosis. RESULTS: Nine texture features of susceptibility maps and 19 features of R2* maps were significantly different between non-significant and significant fibrosis groups (all P < 0.05). Large dependence high gray-level emphasis (LDHGLE) of GLDM and long run high gray-level emphasis (LRHGLE) of GLRLM in R2* maps showed significantly negative and good correlations with Ishak-F stages (r = -0.616, P < 0.001; r = -0.637, P < 0.001). Busyness (NGTDM) in susceptibility maps, LDHGLE of GLDM and LRHGLE of GLRLM in R2* maps yield the highest AUCs (AUC = 0.786, P = 0.007; AUC = 0.807, P = 0.004; AUC = 0.819, P = 0.003). CONCLUSION: Texture characteristics of susceptibility and R2* maps revealed possible staging values for liver fibrosis. Susceptibility and R2*-based texture analysis may be a useful and noninvasive method for staging liver fibrosis.

Comparison of contrast-enhanced fat-suppressed T1-3D-VIBE and T1-TSE MRI in evaluating anal fistula.

OBJECTIVE: To evaluate the accuracy of contrast-enhanced (CE) fat-suppressed three-dimensional (3D) T1-weighted imaging with volumetric interpolated breath-hold examination (FS-T1-3D-VIBE) and fat-suppressed T1-weighted turbo spin echo (FS-T1-TSE) sequence in characteristics of anal fistula. METHODS: One hundred and two patients underwent perianal CE-MRI examination on a 3T scanner including FS-T1-3D-VIBE and FS-T1-TSE sequences before surgery. The performance of each sequence was evaluated in terms of fistula classification, clarity of internal opening, number and position of internal openings including the distance between internal opening and anal verge, presence of secondary tracts and blind-ending sinus tracts. MRI findings were compared with surgical findings. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of fistula, gluteus maximus, and subcutaneous fat were compared between CE FS-T1-TSE and CE FS-T1-3D-VIBE. RESULTS: Compared with CE FS-T1-TSE, CE FS-T1-3D-VIBE displayed more accurate in secondary tract, lithotomy position of the internal opening and the distance between internal opening and anal verge (P < 0.05). CE FS-T1-3D-VIBE was found superior to CE FS-T1-TSE in the clarity of the internal openings and in the diagnostic accuracy of blind-ending sinus tracts and complex fistulas in Standard Practice Task Force classification (P < 0.05). CE FS-T1-3D-VIBE achieved higher SNRs and CNRs in fistula and gluteus maximus than CE FS-T1-TSE (P ≤ 0.001). CONCLUSION: CE-MRI of FS-T1-3D-VIBE might be a more valuable noninvasive technique than FS-T1-TSE to evaluate the anal fistula on evaluating the lithotomy position of internal opening, distance between internal opening and anal verge, clarity of internal opening, secondary tract, blind-ending sinus tract and classification of the complex fistula. The trial registration number for this prospective trial was Chi-TR1800020206 and the trial registration date was December 20, 2018.

An MRI-Based Radiomic Model for Individualized Prediction of Hepatocellular Carcinoma in Patients With Hepatitis B Virus-Related Cirrhosis.

Objective: To develop and validate a radiomic nomogram for individualized prediction of hepatocellular carcinoma (HCC) in HBV cirrhosis patients based on baseline magnetic resonance imaging examinations and clinical data. Methods: 364 patients with HBV cirrhosis from five hospitals were assigned to the training, internal validation, external validation-1 or external validation-2 cohort. All patients underwent baseline magnetic resonance image (MRI) scans and clinical follow-up within three-year time. Clinical risk factors and MRI-based features were extracted and analyzed. The radiomic signatures were built using the radiomics-score (Rad-score) that calculated for each patient as a linear weighted combination of selected MRI-based features. Prognostic performances of the clinical and radiomic nomograms were evaluated with Cox modeling in the training and validation cohorts. Results: Eighteen features were selected for inclusion in the Rad-score prognostic model. The radiomic signature from multi-sequence MRI yielded a concordance index (C-index) of 0.710, 0.681, 0.632 and 0.658 in the training, internal validation, external validation-1, external validation-2 cohorts, respectively. Sex and Child-Turcotte-Pugh (CTP) class were the most prognostic clinical risk factors in univariate Cox proportional hazards analyses. The radiomic combined nomogram that integrated the radiomic signature with the clinical factors yielded a C-index of 0.746, 0.710, and 0.641 in the training, internal validation, and external validation-1 cohorts, respectively, which was an improvement over either the clinical nomogram or radiomic signature alone. Conclusion: We developed an MRI-based radiomic combined nomogram with good discrimination ability for the individualized prediction of HCC in HBV cirrhosis patients within three-year time.

Magnetic resonance quantitative susceptibility mapping in the evaluation of hepatic fibrosis in chronic liver disease: a feasibility study.

BACKGROUND: Noninvasive methods for the early diagnosis and staging of hepatic fibrosis are needed. The present study aimed to investigate the alteration of magnetic susceptibility in the liver of patients with various fibrosis stages and to evaluate the feasibility of using susceptibility to stage hepatic fibrosis. METHODS: A total of 30 consecutive patients with chronic liver diseases (CLDs) underwent magnetic resonance imaging (MRI) and liver biopsy evaluation of hepatic fibrosis, necroinflammatory activity, iron load, and steatosis. Quantitative susceptibility mapping (QSM), R2* and proton density fat fraction (PDFF) images were postprocessed from the same gradient-echo data for quantitative tissue characterization using region of interest (ROI) analysis. The differences for MRI measurements between cohorts of non-significant (Ishak-F <3) and significant fibrosis (Ishak-F ≥3) and the correlation of MRI measurements with fibrosis stages and necroinflammatory activity grades were tested. Receiver operating characteristic (ROC) analysis was also performed. RESULTS: There was a significant difference in liver susceptibility between the cohorts of significant and non-significant fibrosis (Z=-2.880, P=0.004). A moderate negative correlation between the stages of liver fibrosis and liver susceptibility was observed (r=-0.471, P=0.015). Liver magnetic susceptibility differentiated non-significant from significant hepatic fibrosis with an area under the receiver operating curve (AUC) of 0.836 (P=0.004). A highly sensitive diagnostic performance with an AUC of 0.933 was obtained using magnetic susceptibility and PDFF together (P<0.001). CONCLUSIONS: A noninvasive liver QSM-based evaluation promises an accurate assessment of significant fibrosis in patients with CLDs.

Dynamic changes of inflammation and apoptosis in cerebral ischemia­reperfusion injury in mice investigated by ferumoxytol­enhanced magnetic resonance imaging.

The inflammatory response and apoptosis are key factors in cerebral ischemia­reperfusion injury. The severity of the inflammatory reaction and apoptosis has an important impact on the prognosis of stroke. The ultrasmall superparamagnetic iron oxide particle has provided an effective magnetic resonance molecular imaging method for dynamic observation of the cell infiltration process in vivo. The aims of the present study were to investigate the inflammatory response of cerebral ischemia­reperfusion injury in mice using ferumoxytol­enhanced magnetic resonance imaging, and to observe the dynamic changes of inflammatory response and apoptosis. In the present study a C57BL/6n mouse cerebral ischemia­reperfusion model was established by blocking the right middle cerebral artery with an occluding suture. Subsequently, the mice were injected with ferumoxytol via the tail vein, and magnetic resonance scanning was performed at corresponding time points to observe the signal changes. Furthermore, blood samples were used to measure the level of serum inflammatory factors, and histological staining was performed to assess the number of iron­swallowing microglial cells and apoptotic cells. The present results suggested that there was no significant difference in the serum inflammatory factors tumor necrosis factor­α and interleukin 1ß between the middle cerebral artery occlusion (MCAO) and MCAO + ferumoxytol groups injected with ferumoxytol and physiological saline. The lowest signal ratio in the negative enhancement region was decreased 24 h after reperfusion in mice injected with ferumoxytol. The proportion of iron­swallowing microglial cells and TUNEL­positive cells were the highest at 24 h after reperfusion, and decreased gradually at 48 and 72 h after reperfusion. Therefore, the present results indicated that ferumoxytol injection of 18 mg Fe/kg does not affect the inflammatory response in the acute phase of cerebral ischemia and reperfusion. Ferumoxytol­enhanced magnetic resonance imaging can be used as an effective means to monitor the inflammatory response in the acute phase of cerebral ischemia­reperfusion injury. Furthermore, it was found that activation of the inflammatory response and apoptosis in the acute stage of cerebral ischemia­reperfusion injury is consistent.

Evaluation of intratumoral heterogeneity by using diffusion kurtosis imaging and stretched exponential diffusion-weighted imaging in an orthotopic hepatocellular carcinoma xenograft model.

BACKGROUND: To investigate the value of diffusion kurtosis imaging (DKI) and diffusion-weighted imaging (DWI) with a stretched exponential model (SEM) in the evaluation of tumor heterogeneity in an orthotopic hepatocellular carcinoma (HCC) xenograft model. METHODS: Thirty orthotopic HCC xenograft nude mice models were established and randomly divided into two groups, the sorafenib induction group (n=15) and control group (n=15). Every mouse in each group underwent MRI with DKI and SEM on a 1.5T MR scanner at 7, 14, and 21 days after sorafenib intervention. DKI and SEM parameters including mean kurtosis (MK), mean diffusivity (MD), α, and distributed diffusion coefficient (DDC) were measured, calculated, and compared between the two groups and among different time points. Sequential correlations between histopathological results including necrotic fraction (NF), micro-vessel density (MVD), Ki-67 index, standard deviation (SD), and kurtosis from hematoxylin-eosin staining, and DKI and SEM parameters were analyzed. RESULTS: MK, MD, and DDC of HCC in the sorafenib induction group were significantly higher than those in the control group at each time point (P<0.05), while α was significantly lower (P<0.05). Significantly positive correlations were found between MK and NF (r=0.693, P=0.010), SD (r =0.785, P=0.003), kurtosis (r=0.779, P=0.003), between MD and NF (r=0.794, P=0.003), SD (r=0.629, P=0.020), kurtosis (r=0.645, P=0.018), and between DDC and NF (r=0.800, P=0.003), SD (r=0.636, P=0.020), kurtosis (r=0.664, P=0.016), and significantly negative correlations were observed between α and NF (r=-0.704, P=0.009), SD (r=-0.754, P=0.003), and kurtosis (r=-0.792, P=0.003) in the sorafenib induction group. CONCLUSIONS: DKI and SEM parameters may be potentially useful for evaluating intratumoral heterogeneity in HCC.

A GPC3-specific aptamer-mediated magnetic resonance probe for hepatocellular carcinoma.

PURPOSE: To construct and test a hepatocellular carcinoma (HCC)-targeted magnetic resonance probe based on a glypican-3 (GPC3)-specific aptamer (AP613-1) with ultrasmall superpara-magnetic iron oxide (USPIO). METHODS: Oleic acid-coated USPIO nanoparticles were modified with amino polyethylene glycol on the surface. Amino groups of the USPIO nanoparticles were reacted with the carboxyl group of 5' carboxyl-modified AP613-1, forming an aptamer-mediated USPIO (Apt-USPIO) probe. The material characterization of this probe including transmission electron microscopy (TEM), zeta potential, dynamic laser scattering, and magnetic behavior was carried out. The targeting efficiency and magnetic resonance imaging (MRI) performance of Apt-USPIO were evaluated both in vitro and in vivo with USPIO alone as a control. The cytotoxicity and bio-compatibility of Apt-USPIO and USPIO were analyzed by cell counting kit-8 tests in vitro and animal experiments in vivo. RESULTS: TEM imaging revealed that the Apt-USPIO nanoparticles were spherical in shape and well dispersed. Specific uptake of Apt-USPIO in Huh-7 cells could be observed using the Prussian blue staining test; however, no uptake of USPIO could be found. In vitro phantom T2-weighted MRI showed a significant decrease of the signal intensity in Apt-USPIO-incubated Huh-7 cells compared to USPIO-incubated Huh-7 cells. In vivo T2-weighted MRI showed significantly negative enhancement in the Huh-7 tumors enhanced with Apt-USPIO, whereas no enhancement was found with USPIO alone. Excellent biocompatibility of Apt-USPIO and USPIO was also demonstrated. CONCLUSION: In this study, a molecular MRI probe which was highly specific to GPC3 on HCC was successfully prepared. Our results validated the targeted imaging effect of this Apt-USPIO probe in vivo for GPC3-expressing HCCs in xenograft mice.

In vivo fluorescence imaging of hepatocellular carcinoma using a novel GPC3-specific aptamer probe.

BACKGROUND: Glypican-3 (GPC3) is highly expressed in most of the hepatocellular carcinomas (HCCs), even in small HCCs. It may be used as a potential biomarker for early detection of HCC. The aptamer is a promising targeting agent with unique advantages over antibody. This study was to introduce a novel GPC3 specific aptamer (AP613-1), to verify its specific binding property in vitro, and to evaluate its targeting efficiency in vivo by performing near-infrared (NIR) fluorescence imaging on an HCC xenograft model. METHODS: AP613-1 was generated from the systematic evolution of ligands by exponential enrichment. Flow cytometry and aptamer-based immunofluorescence imaging were performed to verify the binding affinity of AP613-1 to GPC3 in vitro. NIR Fluorescence images of nude mice with unilateral (n=12) and bilateral (n=4) subcutaneous xenograft tumors were obtained. Correlation between the tumor fluorescence intensities in vivo and ex vivo was analyzed. RESULTS: AP613-1 could specifically bind to GPC3 in vitro. In vivo and ex vivo tumors, fluorescence intensities were in excellent correlation (P<0.001, r=0.968). The fluorescence intensity is significantly higher in tumors given Alexa Fluor 750 (AF750) labeled AP613-1 than in those given AF750 labeled initial ssDNA library both in vivo (P<0.001) and ex vivo (P=0.022). In the mice with bilateral subcutaneous tumors injected with AF750 labeled AP613-1, Huh-7 tumors showed significantly higher fluorescence intensities than A549 tumors both in vivo (P=0.016) and ex vivo (P=0.004). CONCLUSIONS: AP613-1 displays a specific binding affinity to GPC3 positive HCC. Fluorescently labeled AP613-1 could be used as an imaging probe to subcutaneous HCC in xenograft models.

Use of Ultrasmall Superparamagnetic Iron Oxide Enhanced Susceptibility Weighted Imaging and Mean Vessel Density Imaging to Monitor Antiangiogenic Effects of Sorafenib on Experimental Hepatocellular Carcinoma.

We investigated effectiveness of ultrasmall superparamagnetic iron oxide enhanced susceptibility weighted imaging (USPIO-enhanced SWI) and mean vessel density imaging (Q) in monitoring antiangiogenic effects of Sorafenib on orthotopic hepatocellular carcinoma (HCC). Thirty-five HCC xenografts were established. USPIO-enhanced SWI and Q were performed on a 1.5 T MR scanner at baseline, 7, 14, and 21 days after Sorafenib treatment. Intratumoral susceptibility signal intensity (ITSS) and Q were serially measured and compared between the treated (n = 15) and control groups (n = 15). Both ITSS and Q were significantly lower in the treated group at each time point (P < 0.05). Measurements in the treated group showed that ITSS persisted at 7 days (P = 0.669) and increased at 14 and 21 days (P < 0.05), while Q significantly declined at 7 days (P = 0.028) and gradually increased at 14 and 21 days. In the treated group, significant correlation was found between Q and histologic microvessel density (MVD) (r = 0.753, P < 0.001), and ITSS correlated well with MVD (r = 0.742, P = 0.002) after excluding the data from baseline. This study demonstrated that USPIO-enhanced SWI and Q could provide novel biomarkers for evaluating antiangiogenic effects of Sorafenib on HCC.

Assessment of thoracic vasculature in patients with central bronchogenic carcinoma by unenhanced magnetic resonance angiography: comparison between 2D free-breathing TrueFISP, 2D breath-hold TrueFISP and 3D respiratory-triggered SPACE.

BACKGROUND: Preoperative assessment of the integrity of major thoracic vessels in central bronchogenic carcinoma is vital for tumor staging and treatment planning. Contrast-enhanced CT is currently the first choice of modality for this purpose in clinical practice with limitations including exposure to ionizing radiation and the use of iodinated contrast material. MRI has been increasingly employed for the staging of lung cancer. More recently, unenhanced magnetic resonance angiography (MRA) which is totally non-invasive and contrast-free has been reported able to show thoracic vessels. This study was to compare image qualities of three unenhanced-MRAs and to evaluate accuracy of them in assessing thoracic vessel invasion by using contrast-enhanced CT as a reference standard. METHODS: A total of 30 patients with central bronchogenic carcinoma confirmed by pathology were examined by CT and unenhanced MRA including 2D free-breathing (FB)-TrueFISP, breath-holding (BH)-TrueFISP and 3D respiratory-triggered (RT)-SPACE. Image qualities of pulmonary arteries and veins, thoracic aorta and vena cava were scored for each MRA sequence. Vessel to lung tissue signal contrast-to-noise ratio (CNR), vessel to tumor signal contrast ratio (VTR), and tumor to background signal contrast ratio (TBR) were calculated. On each method, vessel invasion was evaluated according to types of morphological relationships between the tumor and major vessels. RESULTS: The three MRAs showed no significant difference in CNR (P=0.518) while TrueFISP MRAs were better than SPACE in terms of VTR (P=0.000) and image quality (P=0.002). Excellent consistency with CT was found for all three MRAs in assessment of the morphological relationships between tumors and major vessels (FB-TrueFISP: kappa =0.821; BH-TrueFISP: kappa =0.862; RT-SPACE: kappa =0.811). CONCLUSIONS: Both TrueFISP and SPACE allow satisfactory visualization of major mediastinal and hilar vessels and are comparable to MDCT in assessment of vessel invasion in patients with central lung cancer. TrueFISP sequences are better than SPACE in regard to image quality and VTR.

Evaluation of antiangiogenic and antiproliferative effects of sorafenib by sequential histology and intravoxel incoherent motion diffusion-weighted imaging in an orthotopic hepatocellular carcinoma xenograft model.

PURPOSE: To investigate the effectiveness of intravoxel incoherent motion (IVIM) in the assessment of the therapeutic efficacy of sorafenib in an orthotopic hepatocellular carcinoma (HCC) xenograft model. MATERIALS AND METHODS: Thirty-five HCC nude mouse models were established. IVIM was performed on a 1.5T MR scanner at baseline (n = 5) and serially at 7, 14, and 21 days after sorafenib treatment. The apparent diffusion coefficient (ADCtotal ), true diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) at these timepoints were measured and compared between the treated (n = 15) and control group (n = 15). Differences in measurements among different timepoints were evaluated. Correlations between IVIM parameters and histologic features including necrotic fraction (NF) and microvessel density (MVD) were analyzed. RESULTS: Compared to the control group, ADCtotal and D were significantly higher at each timepoint (P = 0.009), while f significantly decreased at 7 days (P = 0.009) and increased at 21 days (P = 0.028) in the treated group. Serial measurements in the treated group showed that both ADCtotal and D increased significantly at 7, 14, and 21 days compared to baseline (P < 0.05), while f significantly declined at 7 days (P = 0.016) and increased at 21 days (P = 0.009). Significant correlations were found between ADCtotal and NF (r = 0.811, P < 0.001), D and NF (r = 0.838, P < 0.001), and between f and NF (r = 0.528, P = 0.017) in the treated group. CONCLUSION: IVIM may provide useful biomarkers for evaluating the therapeutic effects of sorafenib on HCC. LEVEL OF EVIDENCE: 1 J. Magn. Reson. Imaging 2017;45:270-280.

Hyaluronic acid-modified manganese-chelated dendrimer-entrapped gold nanoparticles for the targeted CT/MR dual-mode imaging of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common malignant tumor of the liver. The early and effective diagnosis has always been desired. Herein, we present the preparation and characterization of hyaluronic acid (HA)-modified, multifunctional nanoparticles (NPs) targeting CD44 receptor-expressing cancer cells for computed tomography (CT)/magnetic resonance (MR) dual-mode imaging. We first modified amine-terminated generation 5 poly(amidoamine) dendrimers (G5.NH2) with an Mn chelator, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), fluorescein isothiocyanate (FI), and HA. Then, gold nanoparticles (AuNPs) were entrapped within the above raw product, denoted as G5.NH2-FI-DOTA-HA. The designed multifunctional NPs were formed after further Mn chelation and purification and were denoted as {(Au0)100G5.NH2-FI-DOTA(Mn)-HA}. These NPs were characterized via several different techniques. We found that the {(Au0)100G5.NH2-FI-DOTA(Mn)-HA} NPs exhibited good water dispersibility, stability under different conditions, and cytocompatibility within a given concentration range. Because both AuNPs and Mn were present in the product, {(Au0)100G5.NH2-FI-DOTA(Mn)-HA} displayed a high X-ray attenuation intensity and favorable r1 relaxivity, which are advantageous properties for targeted CT/MR dual-mode imaging. This approach was used to image HCC cells in vitro and orthotopically transplanted HCC tumors in a unique in vivo model through the CD44 receptor-mediated endocytosis pathway. This work introduces a novel strategy for preparing multifunctional NPs via dendrimer nanotechnology.

Contrast-enhanced susceptibility weighted imaging with ultrasmall superparamagnetic iron oxide improves the detection of tumor vascularity in a hepatocellular carcinoma nude mouse model.

PURPOSE: To evaluate the effectiveness of contrast-enhanced susceptibility-weighted imaging with ultrasmall superparamagnetic iron oxide (USPIO-enhanced SWI) in the assessment of intratumoral vascularity in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Orthotopic xenograft HCC nude mouse models were established first and magnetic resonance imaging (MRI) examinations were performed on a 1.5T MR scanner 28 days later. Three groups of mice, 10 in each, were imaged using unenhanced and USPIO-enhanced SWI at doses of 4, 8, and 12 mg Fe/kg. Intratumoral susceptibility signal intensity (ITSS) was scored. ITSS-to-tumor contrast-to-noise ratio (ITSST-CNR) was measured. These measurements were compared between unenhanced and USPIO-enhanced SWI at each dose and differences in the measurements between different dose groups were estimated. Correlation between ITSS and tumor microvessel density (MVD) was analyzed. RESULTS: Compared with unenhanced SWI, significantly higher ITSS was identified on USPIO-enhanced SWI at doses of 8 mg Fe/kg (Z = -2.000, P = 0.046) and 12 mg Fe/kg (Z = -2.333, P = 0.020). Significantly higher ITSST-CNR was found on USPIO-enhanced SWI than that on unenhanced SWI (P < 0.05). Significantly higher ITSST-CNR at a dose of 8 mg Fe/kg was observed than that at 4 mg Fe/kg (Z = -3.326, P = 0.001). Positive correlation between ITSS on USPIO-enhanced SWI at a dose of 8 mg Fe/kg and tumor MVD was demonstrated (r = 0.817, P = 0.004). CONCLUSION: USPIO-enhanced SWI at a dose of 8 mg Fe/kg greatly improves the detection of intratumoral vascularity in a xenograft HCC model. J. Magn. Reson. Imaging 2016;44:288-295.

Reduction of radiation dose in the spiral CT scan of the lumbar spine by the combined use of body mass index (BMI) and automatic exposure control (AEC).

OBJECTIVE: The aim of this study was to investigate the significance of the combined use of BMI and AEC in reducing the radiation dose of CT volume scans of the lumbar spine. METHODS: A prospective study was performed to continuously collect data from 50 patients (age range from 19 to 60 years, male versus female 20/30) whose BMIs were less than 25 kg/m^{2} (group A) and 50 patients (age range from 21 to 82 years, male versus female 24/26) whose BMIs were equal to or more than 25 kg/m^{2} (group B). The 50 patients in each group were randomly divided into 5 subgroups with each subgroup having lower radiation dose from subgroup 1 to 5. All the patients were performed lumbar spiral CT scans (GE LightSpeed VCT 64-slice scanner) and the scan parameters were different in different subgroups. Volume CT dose index (CTDIvol) was recorded. The qualities of the images were graded. The one-way ANOVA and Kruskal-Wallis test were done. RESULTS: Both in group A and B, there were significant differences in CTDIvol among the 5 subgroups (P< 0.001). The quality of the images in the 5 subgroups of group A didn't show statistical difference. The standard deviation (SD) and signal to noise ratio (SNR) values of the L4-5 psoas major muscles in subgroup 5 of group B was statistical different from the other 4 subgroups (P< 0.01). CONCLUSION: Use of BMI combined with AEC reduces radiation dosage, without compromising the image quality. For patients in group A and group B, parameters of subgroup 5 and subgroup 4 may respectively be applied for lower dose CT scanning.