Multifractal analysis of white matter structural changes on 3D magnetic resonance imaging between normal aging and early Alzheimer's disease

Applications of multifractal analysis to white matter structure changes on magnetic resonance imaging（MRI） have recently received increasing attentions. Although some progresses have been made, there is no evident study on applying multifractal analysis to evaluate the white matter structural changes on MRI for Alzheimer＇s disease（AD） research. In this paper, to explore multifractal analysis of white matter structural changes on 3D MRI volumes between normal aging and early AD, we not only extend the traditional box-counting multifractal analysis（BCMA） into the 3D case, but also propose a modified integer ratio based BCMA（IRBCMA） algorithm to compensate for the rigid division rule in BCMA. We verify multifractal characteristics in 3D white matter MRI volumes. In addition to the previously well studied multifractal feature,△α, we also demonstrated △ f as an alternative and effective multifractal feature to distinguish NC from AD subjects.Both △α and △ f are found to have strong positive correlation with the clinical MMSE scores with statistical significance.Moreover, the proposed IRBCMA can be an alternative and more accurate algorithm for 3D volume analysis. Our findings highlight the potential usefulness of multifractal analysis, which may contribute to clarify some aspects of the etiology of AD through detection of structural changes in white matter.

Comprehending the therapeutic effects of stereotactic body radiation therapy for small hepatocellular carcinomas based on imagings

Surgical resection or radiofrequency ablation(RFA)is considered first-choice treatment for small hepatocellular carcinomas(HCCs).When a patient has a small HCC that is inoperable or unsuitable for RFA,what are alternative treatments?Some oncologists recommend transarterial chemoembolization(TACE),chemotherapy,molecular-targeted therapy,or immunotherapy.However,these treatments have minimally beneficial effects in small HCCs.Stereotactic body radiation therapy(SBRT)is a liver-directed radical therapy for small HCCs,with treatment outcomes similar to those for surgical resection or RFA,but many oncologists do not comprehend its efficacy or accept this therapy.We herein discuss 11 typical patients who received SBRT for various indications:refusal to undergo resection or RFA;surgical resection or RFA considered difficult or unfeasible;residual cancer after surgical resection or RFA or incomplete iodized oil retention after TACE;or tumor recurrence after resection or RFA.We describe each case,including the radiation field,tumor radiation dose,and response to SBRT in both the tumor and liver parenchyma.These clinical data should help readers understand this new therapeutic technique.We also conducted a literature review and found evidence to support survival benefit with SBRT,including good three-and five-year overall survival rates.The purpose of this article is to encourage readers to accept the concept that SBRT is a low-toxicity and effective therapeutic option for patients with small HCCs,which offers substantial local control and improved overall survival,especially for patients with a tumor that is unresectable or unsuitable for RFA,residual tumor after local therapy,or intrahepatic recurrent tumor.