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The impact of chronic cerebral hypoperfusion on resting-state blood oxygen level-dependent signal fluctuations remains unknown. We aimed to determine whether chronic ischemia induces changes in amplitude of low-frequency fluctuations (ALFF) and to investigate the correlation between ALFF and perfusion-weighted magnetic resonance imaging (PWI) parameters in patients with moyamoya disease (MMD). Thirty patients with pre- and postoperative resting-state functional magnetic resonance imaging and PWI were included, and thirty normal controls underwent resting-state functional magnetic resonance imaging. A decrease in preoperative frontal lobe ALFF was observed in patients with MMD. Postoperative frontal lobe ALFF showed moderate improvement but still remained lower than those in normal controls. The values of mean transit time and time-to-peak, but not cerebral blood volume and cerebral blood flow, correlated significantly with frontal lobe ALFF. Moreover, there were significant negative correlations between changes in frontal lobe PWI parameters and changes in frontal lobe ALFF on both operated side and contralateral side after the unilateral revascularization surgery. Our results demonstrate that reduced ALFF are closely related to the abnormal PWI parameters and vary with the alteration of cerebral perfusion in patients with MMD.

Magnetic resonance (MR) is currently used for diagnosis of osteosarcoma but not well even though contrast agents are administered. Here, we report a novel bone-targeted MR imaging contrast agent, Gd 2 -diethylenetriaminepentaacetate-bis(alendronate) (Gd 2 -DTPA-BA) for the diagnosis of osteosarcoma. It is the conjugate of a bone cell-seeking molecule (i.e., alendronate) and an MR imaging contrast agent (i.e., Gd-DTPA). Its physicochemical parameters were measured, including pK a , complex constant, and T 1 relaxivity. Its bone cell-seeking ability was evaluated by measuring its adsorption on hydroxyapatite. Hemolysis was investigated. MR imaging and biodistribution of Gd 2 -DTPA-BA and Gd-DTPA were studied on healthy and osteosarcoma-bearing nude mice. Gd 2 -DTPA-BA showed high adsorption on hydroxyapatite, the high MR relaxivity (r 1 ) of 7.613mM -1 s -1 (2.6 folds of Gd-DTPA), and no hemolysis. The MR contrast effect of Gd 2 -DTPA-BA was much higher than that of Gd-DTPA after intravenous injection to the mice. More importantly, the MR imaging of osteosarcoma was significantly improved by Gd 2 -DTPA-BA. The signal intensity of Gd 2 -DTPA-BA reached 120.3% at 50min, equal to three folds of Gd-DTPA. The bone targeting index (bone/blood) of Gd 2 -DTPA-BA in the osteosarcoma-bearing mice was very high to 130 at 180min. Furthermore, the contrast enhancement could also be found in the lung due to metastasis of osteosarcoma. Gd 2 -DTPA-BA plays a promising role in the diagnoses of osteosacomas, including the primary bone tumors and metastases., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Background: Magnetic resonance imaging (MRI) can be used to guide breast cancer surgery with breast conservation for large tumors with a substantially reduced size after neoadjuvant chemotherapy (NAC)., Purpose: To evaluate the value of dynamic contrast-enhanced MRI (DCE-MRI) for measuring residual tumor size and enhancement patterns following preoperative NAC., Material and Methods: Eighty-nine patients with breast cancer underwent breast DCE-MRI; 38 patients (39 lesions) were treated with NAC and examined for residual disease following therapy. Two patients were excluded because surgery had been performed >2 weeks after the final MR examination. Thus, we correlated the DCE-MRI results of 36 patients (37 lesions) with postoperative histopathological findings. Residual disease was confirmed by more enhancement compared to normal glandular tissue at the initial tumor site. Residual tumor size on DCE-MRI was compared with postoperative pathology findings. Tumor enhancement patterns on DCE-MRI were analyzed and correlated with pathological classification., Results: MRI revealed 34 cases of residual tumors, with two false positives and one false negative. Pathological and MR measurements were correlated (r = 0.793). The correlation of mass enhancement size (r = 0.87, n = 14) with pathology and DCE-MRI was higher than for non-mass-like enhancement (NME) (r = 0.735, n = 23). The distribution of pathologic classification was significantly different between different MRI enhancement patterns (P = 0.006). Mass enhancement had higher cellularity than NME., Conclusion: MRI is useful for evaluating residual carcinoma following NAC. Mass enhancement with higher cellularity after NAC can be evaluated more accurately, which is suitable for evaluating lumpectomy. However, other approaches are required for NME, which has lower cellularity., (© The Foundation Acta Radiologica 2015.)

Fe5 C2 NPs exhibit a high contrast in magnetic resonance imaging (MRI), superior photoacoustic tomography improvements, and efficient photothermal therapy (PTT) due to their unique core/shell structure, with a magnetic core and carbon shell. By conjugating a new class of affinity proteins (ZHER2:342), they can target to tumor cells with low cytotoxicity, and kill them through laser irritation. It is also possible to ablate tumors under guidance by MRI and PTT without noticeable side effects., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Purpose: To investigate the long-term time course of the contrast effects after the intravenous injection of gadofluorine M or gadofluorine P in mice., Materials and Methods: Magnetic resonance images were acquired longitudinally after intravenous injection of 0.1 μmol Gd/g gadofluorine M into BALB/c mice. The contrast effects were also assessed in C57BL/6J mice injected with gadofluorine M, BALB/c mice injected with gadofluorine P, and BALB/c mice injected with a double dose of gadopentetate dimeglumine., Results: The injection of gadofluorine M into BALB/c mice caused prolonged contrast effects in the blood and other organs. The liver enhancement was especially long-lasting and still evident 6 days after injection. Strain-related differences in contrast kinetics of gadofluorine M were not observed between BALB/c mice and C57BL/6J mice. In comparison with gadofluorine M, clearances from the blood, liver, and kidney were more rapid and contrast enhancement in the spleen was generally lower for gadofluorine P. The enhancement in the gallbladder cavity, indicating biliary excretion, was evident only after gadofluorine P injection. Blood enhancement at 10 min was much weaker for gadopentetate dimeglumine., Conclusion: Both gadofluorine M and gadofluorine P appear to be applicable to blood pool imaging and liver imaging in mice.

Rationale and Objectives: We aimed to determine the capability of magnetic resonance (MR) lymphography using gadofluorine M and to demonstrate normal lymph drainage from the mammary glands in mice., Materials and Methods: Three mice were intradermally injected with gadofluorine M near the papilla of the right fifth mammary gland, and subsequently underwent serial MR imaging to determine the appropriate method for assessment of the lymphatic pathway. MR lymphography was performed in 10 mice for the five right mammary glands to assess lymph drainage from each gland., Results: After intradermal injection near the right fifth papilla, high signal intensities representing lymph drainage were clearly demonstrated in the right inguinal and right proper axillary lymph nodes in all mice. The contrast between the lymph node and adjacent muscles was highest 10 minutes after injection and was still evident at 30 minutes. The lymph pathways from the five right mammary glands were successfully revealed, and no contralateral lymph nodes received lymph flow. Although variations in lymph drainage patterns from the first and second mammary glands existed among mice, injection in the third, fourth, and fifth glands gave consistent results. Lymphatics from the third gland drained exclusively into the proper axillary lymph node, and those from the fourth and fifth glands drained into the inguinal and proper axillary nodes., Conclusion: MR lymphography with gadofluorine M allows noninvasive visualization of lymph drainage from the mammary glands in healthy mice., (Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate the utility of interstitial MR lymphography with gadopentetate dimeglumine (Gd-DTPA) or gadoxetate disodium (Gd-EOB-DTPA) in mice., Materials and Methods: We performed MR lymphography after the subcutaneous injection of Gd-DTPA or Gd-EOB-DTPA (0.1, 0.5, or 2.0 μmol per mouse) into the right footpad in six healthy mice, and the time courses of contrast enhancement were assessed. Additionally, the lymphatic pathways from two distinct sites were assessed in tandem by interstitial MR lymphography studies., Results: Subcutaneous injection of Gd-DTPA or Gd-EOB-DTPA caused lymph node enhancement immediately after injection, followed by a rapid decline. Dose dependency was shown for the lymph node enhancement, and a high-dose injection caused prominent visualization of the veins. Lymph node enhancement did not differ significantly between Gd-DTPA and Gd-EOB-DTPA or between Gd-EOB-DTPA premixed and not premixed with bovine serum albumin. The tandem assessment of two lymphatic pathways was feasible, and image fusion aided detailed comparison., Conclusion: Interstitial MR lymphography with Gd-DTPA or Gd-EOB-DTPA allowed clear visualization of the lymphatic pathway in healthy mice, and no significant difference was found between the two agents. Their rapid kinetics limits the imaging timing window, however, facilitates repeated assessment in a single imaging session., (Copyright © 2011 Wiley-Liss, Inc.)

Background: The features of intracranial arteries in patients with Moyamoya disease (MMD) have been widely investigated. However, the MR characteristics of extracranial internal carotid artery (EICA) and their effect on outcomes of revascularization treatment are not fully understood. Purpose: To investigate the characteristics of EICA and their relationship with outcomes of revascularization treatment in adult patients with MMD based on higher‐resolution MRI (HRMRI). Study Type: Prospective interventional outcomes. Subjects: Two hundred eighty‐eight consecutive patients with MMD (mean age: 43.7 ± 11.2 years; 140 male). Field Strength/Sequence: Turbo inversion recovery magnitude T1‐weighted imaging and turbo spin echo (TSE) T2‐weighted imaging, three‐dimensional time‐of‐flight MR angiography, T2‐fluid attenuated inversion recovery, and 3D T1‐SPACE vessel wall imaging at 3.0 T. Assessment: The HRMRI characteristics of EICA were determined. The relationship between the characteristics of EICA (proximal stenosis, diffuse wall thickening, carotid plaques, and luminal thrombosis) and stroke outcomes of revascularization treatment in patients with MMD was analyzed. The discriminative ability of EICA characteristics in combination with intracranial carotid artery features (involvement of vessel segments, bilateral involvement, and Suzuki stage) to determine stroke outcomes was compared with that of intracranial artery features alone during a mean 8.0 months follow‐up period. Statistical Tests: Cox proportional hazards models and Kaplan–Meier curves to calculate the hazard ratios (HRs) for stroke with 95% confidence intervals (CIs). Area under the receiver operating characteristic curve (AUC) for assessing discriminative performance. A P value <0.05 was considered statistically significant. Results: During a mean 8.0 ± 2.2 months follow‐up, of the 288 participants, 137 had proximal stenosis (47.6%), 106 had diffuse wall thickening (36.8%), 60 had carotid plaques (20.8%), and 27 had luminal thrombosis (9.4%) of EICA. Of these features, proximal stenosis (HR = 2.86; 95% CI = 1.13–7.29) and diffuse wall thickening (HR = 2.62; 95% CI = 1.16–5.94) of EICA were significantly associated with stroke after surgery, before and after adjusting for confounding factors. In discriminating the stroke outcomes after surgery, combining characteristics of EICA with features of intracranial arteries resulted in a significant incremental improvement (DeLong test, P < 0.05) in the AUC over that obtained with features of intracranial arteries alone (AUC: 0.73 vs. 0.60–0.64). Conclusion: Proximal stenosis and diffuse wall thickening of EICA were significantly associated with stroke outcomes after surgery in patients with MMD. Our findings suggest that understanding the characteristics of EICA has added value for intracranial vessels in predicting future events after surgery in patients with MMD. Evidence Level: 2 Technical Efficacy: Stage 4 [ABSTRACT FROM AUTHOR]

Background: Little is known about the association between stroke and imaging and clinical features in conservatively treated patients with moyamoya disease (MMD). Purpose: To investigate independent risk factors for stroke in conservatively treated patients with MMD during a long‐term follow‐up. Study Type: Prospective study. Subjects: One hundred sixty conservatively managed patients with MMD (median age 46 years, 89 male). Field Strength/Sequence: Time of flight, turbo inversion recovery magnitude T1WI, turbo spin echo (TSE) T2WI, echo‐planar imaging DWI, T2‐fluid attenuated inversion recovery, dynamic susceptibility contrast‐magnetic resonance imaging, and pre‐ and post‐contrast 3D TSE T1WI sequences at 3.0 Tesla. Assessment: Patients were assessed at baseline and followed yearly. Ischemic and hemorrhagic stroke incidence rates were determined. Multiple demographic, clinical (modified Rankin score [mRS]), and cerebral imaging (cerebral blood volume [CBV] and concentric enhancement of arterial wall) factors at baseline were considered as potential predictors of stroke during the follow‐up period. Statistical Tests: Univariable and multivariable Cox proportional hazards models to calculate the hazard ratios (HRs) and corresponding 95% confidence interval (CI) for stroke. Cumulative risk of stroke was estimated by the Kaplan–Meier product‐limit method. A P value <0.05 was considered statistically significant. Results: The median follow‐up duration was 47 months. During the follow‐up period, 18 (11.25%) patients experienced stroke events (13 [8.13%] ischemic, 5 [3.12%] hemorrhagic). Univariable analysis showed that 11 factors were significantly associated with stroke. After adjustment for clinical characteristics, multivariable analysis showed that mRS score ≥3 (HR, 1.99; 95% CI, 1.26–3.14), decreased CBV (HR, 5.31; 95% CI, 2.32–12.13), and concentric enhancement of the arterial wall (HR, 4.16; 95% CI, 1.55–11.15) were significantly associated with stroke. Data Conclusion: Decreased CBV, mRS score ≥ 3, and concentric enhancement of the arterial wall were significantly associated with increased incidence of stroke in conservatively treated MMD. Evidence Level: 2 Technical Efficacy: Stage 4 [ABSTRACT FROM AUTHOR]

Rationale and Objectives: To explore the differential diagnosis of benign and malignant papillary neoplasms on MRI with non-mass enhancement. A total of 48 patients with surgically confirmed papillary neoplasms showing non-mass enhancement were included. Clinical findings, mammography and MRI features were retrospectively analyzed, and lesions were described according to the breast imaging report and data system (BI-RADS). Multivariate analysis of variance was used to compare the clinical and imaging features of benign and malignant lesions. Fifty-three papillary neoplasms were shown on MR images with non-mass enhancement, including 33 intraductal papilloma and 20 papillary carcinomas (9 intraductal papillary carcinoma, 6 solid papillary carcinomas, and 5 invasive papillary carcinoma). Mammography showed amorphous calcification in 20% (6/30), of which 4 were in papilloma and 2 were in papillary carcinoma. On MRI, papilloma mostly showed linear distribution in 54.55% (18/33), clumped enhancement in 36.36% (12/33). Papillary carcinoma showed segmental distribution in 50% (10/20), clustered ring enhancement in 75% (15/20). ANOVA showed age (p = 0.025), clinical symptoms (p < 0.001), apparent diffusion coefficient (ADC) value (p = 0.026), distribution pattern (p = 0.029) and internal enhancement pattern (p < 0.001) were statistically significant between benign and malignant of papillary neoplasms. Multivariate analysis of variance suggested that the internal enhancement pattern was the only statistically significant factor (p = 0.010). Papillary carcinoma on MRI with non-mass enhancement mostly showed internal clustered ring enhancement, while papilloma mostly showed internal clumped enhancement; additional mammography is of limited diagnostic value, and suspected calcification occurs mostly in papilloma. [ABSTRACT FROM AUTHOR]

Objective: To retrospectively analyze CT and MR imaging features of the brain in patients with hydrogen sulfide poisoning based on clinical symptom grading and to investigate their correlations with clinical symptoms and patients' prognosis.Methods: A retrospective analysis was performed of CT and MR imaging data of the brain in 40 patients with hydrogen sulfide poisoning in our hospital. There were four main imaging manifestations. Patients were clinically graded according to the central nervous system symptom scores of the Poisoning Severity Score (PSS) and staged according to the gas inhalation time segment. Based on clinical symptom grading, the frequencies and proportions of four imaging signs that occurred in each group were counted, their development trends were analyzed, and the correlations of imaging features with clinical grading and prognosis were calculated.Results: Forty patients were divided into minor, moderate and severe clinical grades and classified into four stages. In patients with minor and moderate clinical grading, only one patient suffered from generalized brain edema at stage 1, with a good prognosis. Patients with severe clinical grade showed the highest probability of presenting with the four imaging signs. The imaging signs were correlated with the severe clinical grade and a poor prognosis (P = 0.000, R = 0.828; P = 0.000, R = 0.858).Conclusion: In patients with the severe clinical grade, generalized brain edema and symmetrical hypodensity/abnormal signals in the bilateral basal ganglia and around the lateral ventricles were the main findings and were shown to persist. The presence of imaging signs can assist in the clinically effective evaluation of clinical symptom grade. [ABSTRACT FROM AUTHOR]

Smart drug delivery systems (SDDSs) for cancer treatment are of considerable interest in the field of theranostics. However, developing SDDSs with early diagnostic capability, enhanced drug delivery and efficient biodegradability still remains a scientific challenge. Herein, we report near-infrared light and tumor microenvironment (TME), dual responsive as well as size-switchable nanocapsules. These nanocapsules are made of a PLGA-polymer matrix coated with Fe/FeO core-shell nanocrystals and co-loaded with chemotherapy drug and photothermal agent. Smartly engineered nanocapsules can not only shrink and decompose into small-sized nanodrugs upon drug release but also can regulate the TME to overproduce reactive oxygen species for enhanced synergistic therapy in tumors. In vivo experiments demonstrate that these nanocapsules can target to tumor sites through fluorescence/magnetic resonance imaging and offer remarkable therapeutic results. Our synthetic strategy provides a platform for next generation smart nanocapsules with enhanced permeability and retention effect, multimodal anticancer theranostics, and biodegradability. Nanoparticles that can change shape have attracted attention for improved circulation and tumor penetration. Here, the authors report on a size changeable nanoparticle that responds to near-infrared light and can be used for photothermal therapy, photodynamic therapy, and drug delivery applications. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles(NPs) are characterized by a rich variety of properties. Because of their excellent physical and chemical properties, they have come to the fore in biomedicine and other fields. The magnetic NPs were extensively studied in magnetic separation of cells, targeted drug delivery, tumor hyperthermia, chemo-photothermal therapy, magnetic resonance imaging (MRI) and other biomedical fields. Magnetic NPs are increasingly used in magnetic resonance imaging (MRI) based on their inherent magnetic targeting, superparamagnetic enzyme-like catalytic properties and nanoscale size. Poly(lactic-co-glycolic acid) (PLGA) is a promising biodegradable material approved by FDA and EU for drug delivery. Currently, PLGA-based magnetic nano-drug delivery systems have attracted the attention of researchers. Herein, we achieved the effective encapsulation of sized-controlled polyethylene glycol-3,4-dihydroxy benzyl-amine-coated superparamagnetic iron oxide nanoparticles (SPIO NPs) and euphorbiasteroid into PLGA nanospheres via a modified multiple emulsion solvent evaporation method (W 1 /O 2 /W 2). NPs with narrow size distribution and acceptable magnetic properties were developed that are very useful for applications involving cancer therapy and MRI. Furthermore, SPIO-PLGA NPs enhanced the MRI T 2 relaxation properties of tumor sites.The prepared SPIO NPs and magnetic PLGA nanospheres can be promising magnetic drug delivery systems for tumor theranostics. This study has successfully constructed a tumor-targeting and magnetic-targeting smart nanocarrier with enhanced permeability and retention, multimodal anti-cancer therapeutics and biodegradability, which could be a hopeful candidate for anti-tumor therapy in the future. [Display omitted] • For the first time, the lipid-soluble drug EFL 1 and the water-soluble magnetic nanomaterials are co-loaded into the PLGA. • Based on the research idea of "theranostics" realize targeted treatment under the dual guidance of magnetism and biology. [ABSTRACT FROM AUTHOR]