Characterization of cerebrovascular changes in Alzheimer's disease mice by photoacoustic imaging

The cerebral vasculature plays a significant role in the development of Alzheimer's disease(AD),however,the specific association between them remains unclear.In this paper,based on the benefits of photoacoustic imaging(PAI),including label-free,high-resolution,in vivo imaging of vessels,we investigated the structural changes of cerebral vascular in wild-type(WT)mice and AD mice at different ages,analyzed the characteristics of the vascular in different brain regions,and correlated vascular characteristics with cognitive behaviors.The results showed that vascular density and vascular branching index in the cortical and frontal regions of both WT and AD mice decreased with age.Meanwhile,vascular lacunarity increased with age,and the changes in vascular structure were more pronounced in AD mice.The trend of vascular dysfunction aligns with the worsening cognitive dysfunction as the disease progresses.Here,we utilized in vivo PAI to analyze the changes in vascular structure during the progression of AD,elucidating the spatial and temporal correlation with cognitive impairment,which will provide more intuitive data for the study of the correlation between cerebrovascular and the development of AD.

Visualizing the hepatic vascular architecture using superb microvascular imaging in patients with hepatitis C virus: A novel technique

AIM: To identify the hepatic vascular architecture of patients with hepatitis C virus (HCV) using superb microvascular imaging (SMI) and investigate the use of SMI in the evaluation of liver fibrosis.METHODS: SMI was performed in 100 HCV patients. SMI images were classified into five types according to the vascular pattern, and these patterns were compared with the fibrosis stage. Moreover, the images were analyzed to examine vascularity by integrating the number of SMI signals in the region of interest ROI [number of vascular trees (VT)]. The number of VT, fibrosis stage, serum parameters of liver function, and CD34 expression were investigated.RESULTS: There was a significant difference between SMI distribution pattern and fibrosis stage (P < 0.001). The mean VT values in each of the fibrosis stages were as follows: 26.69 ± 7.08 in F0, 27.72 ± 9.32 in F1, 36.74 ± 9.23 in F2, 37.36 ± 5.32 in F3, and 58.14 ± 14.08 in F4. The VT showed excellent diagnostic ability for F4 [area under the receiver operator characteristic (AUROC): 0.911]. The VT was significantly correlated with the CD34 labeling index (r = 0.617, P < 0.0001).CONCLUSION: SMI permitted the detailed delineation of the vascular architecture in chronic liver disease. SMI appears to be a reliable tool for noninvasively detecting significant fibrosis or cirrhosis in HCV patients.

Signal Alteration of Substantia Nigra on 3.0T Susceptibility-weighted Imaging in Parkinson's Disease and Vascular Parkinsonism

Recent researches have found that 7 Tesla SWI can detect the alteration of substantia nigra hyperintensity in Parkinson's disease(PD),multiple system atrophy(MSA),and progressive supranuclear palsy(PSP).The aim of this study was to investigate whether 3 Tesla SWI(3T SWI)can visualize anatomical alterations occurring in a hyperintense structure of the substantia nigra in PD and vascular parkinsonism(VP),and whether the evaluation of abnormal signal can be used as a factor in the differential diagnosis of PD and VP.Using 3 Tesla MRI,we evaluated 38 healthy subjects,33 patients with PD and 34 patients with VP.Two blinded readers independently assessed the images.We found that the dorsolateral nigral hyperintensity was absent in 31 of 33 patients with PD and 15 of 34 patients with VP.The dorsolateral nigral hyperintensity was present in 19 of 34 patients with VP and 35 of 38 healthy controls.Group comparisons of absence of dorsolateral nigral hyperintensity revealed significant differences between the patients with PD and those with VP(P<0.001).The sensitivity of SWI for PD was 93.9%and the specificity was 92.1%.Visual assessment of dorsolateral nigral hyperintensity on high-field SWI scans may serve as a new simple diagnostic imaging marker for PD.And our study results indicate that 3T SWI can be used as a tool to identify PD and VP.

Combination of three-gene immunohistochemical panel and magnetic resonance imaging-detected extramural vascular invasion to assess prognosis in non-advanced rectal cancer patients

AIM To identify a small, clinically applicable immunohistochemistry(IHC) panel that could be combined with magnetic resonance imaging(MRI)-detected extramural vascular invasion(EMVI) for assessment of prognosis concerning the non-advanced rectal cancer patients prior to operation.METHODS About 329 patients with pathologically confirmed rectal carcinoma(RC) were screened in this research, all of whom had been examined via an MRI and were treatment-na?ve from July 2011 to July 2014. The candidate proteins that were reported to be altered by RC were examined in tissues by IHC. All chosen samples were adopted from the fundamental cores of histopathologically confirmed carcinomas during the initial surgeries.RESULTS Of the three proteins that were tested, c-MYC, PCNA and TIMP1 were detected with relatively significant expression in tumors, 35.9%, 23.7% and 58.7% respectively. The expression of the three proteins were closely connected with prognosis(P = 0.032, 0.003, 0.021). The patients could be classified into different outcome groups according to an IHC panel(P < 0.01) via these three proteins. Taking into consideration known survival covariates, especially EMVI, the IHC panel served as an independent prognostic factor. The EMVI combined with the IHC panel could categorize patients into different prognostic groups with distinction(P < 0.01).CONCLUSION These studies argue that this three-protein panel of c-MYC, PCNA, coupled with TIMP1 combined with MRIdetected EMVI could offer extra prognostic details for preoperative treatment of RC.

Small intestinal vascular malformation bleeding:A case report with imaging findings

The small intestine is approximately 5-6 m long and occupies a large area in the abdominal cavity. These factors preclude the use of ordinary endoscopy and X-ray to thoroughly examine the small intestine for bleeding of vascular malformations. Thus,the diagnosis of intestinal bleeding is very difficult. A 47-year-old man presented at the hospital 5 mo ago with dark stool. Several angiomas were detected by oral approach enteroscopy,but no active bleeding was observed. Additionally,no lesions were detected by anal approach enteroscopy;however,gastrointestinal tract bleeding still occurred for an unknown reason. We performed an abdominal vascular enhanced computed tomography examination and detected ileal vascular malformations. Ileum angioma and vascular malformation were detected by a laparoscopic approach,and segmental resection was performed for both lesions,which were confirmed by pathological diagnosis. This report systemically emphasizes the imaging findings of small intestinal vascular malformation bleeding.

Retinal vascular morphological characteristics in diabetic retinopathy: an artificial intelligence study using a transfer learning system to analyze ultra-wide field images

AIM:To investigate the morphological characteristics of retinal vessels in patients with different severity of diabetic retinopathy(DR)and in patients with or without diabetic macular edema(DME).METHODS:The 239 eyes of DR patients and 100 eyes of healthy individuals were recruited for the study.The severity of DR patients was graded as mild,moderate and severe non-proliferative diabetic retinopathy(NPDR)according to the international clinical diabetic retinopathy(ICDR)disease severity scale classification,and retinal vascular morphology was quantitatively analyzed in ultra-wide field images using RU-net and transfer learning methods.The presence of DME was determined by optical coherence tomography(OCT),and differences in vascular morphological characteristics were compared between patients with and without DME.RESULTS:Retinal vessel segmentation using RU-net and transfer learning system had an accuracy of 99%and a Dice metric of 0.76.Compared with the healthy group,the DR group had smaller vessel angles(33.68±3.01 vs 37.78±1.60),smaller fractal dimension(Df)values(1.33±0.05 vs 1.41±0.03),less vessel density(1.12±0.44 vs 2.09±0.36)and fewer vascular branches(206.1±88.8 vs 396.5±91.3),all P<0.001.As the severity of DR increased,Df values decreased,P=0.031.No significant difference between the DME and non-DME groups were observed in vascular morphological characteristics.CONCLUSION:In this study,an artificial intelligence retinal vessel segmentation system is used with 99%accuracy,thus providing with relatively satisfactory performance in the evaluation of quantitative vascular morphology.DR patients have a tendency of vascular occlusion and dropout.The presence of DME does not compromise the integral retinal vascular pattern.

Investigating the relationship between intracranial atherosclerotic plaque remodelling and diabetes using high-resolution vessel wall imaging

BACKGROUND Intracranial atherosclerosis,a leading cause of stroke,involves arterial plaque formation.This study explores the link between plaque remodelling patterns and diabetes using high-resolution vessel wall imaging(HR-VWI).AIM To investigate the factors of intracranial atherosclerotic remodelling patterns and the relationship between intracranial atherosclerotic remodelling and diabetes mellitus using HR-VWI.METHODS Ninety-four patients diagnosed with middle cerebral artery or basilar artery INTRODUCTION Intracranial atherosclerotic disease is one of the main causes of ischaemic stroke in the world,accounting for approx-imately 10%of transient ischaemic attacks and 30%-50%of ischaemic strokes[1].It is the most common factor among Asian people[2].The adaptive changes in the structure and function of blood vessels that can adapt to changes in the internal and external environment are called vascular remodelling,which is a common and important pathological mechanism in atherosclerotic diseases,and the remodelling mode of atherosclerotic plaques is closely related to the occurrence of stroke.Positive remodelling(PR)is an outwards compensatory remodelling where the arterial wall grows outwards in an attempt to maintain a constant lumen diameter.For a long time,it was believed that the degree of stenosis can accurately reflect the risk of ischaemic stroke[3-5].Previous studies have revealed that lesions without significant luminal stenosis can also lead to acute events[6,7],as summarized in a recent meta-analysis study in which approximately 50%of acute/subacute ischaemic events were due to this type of lesion[6].Research[8,9]has pointed out that the PR of plaques is more dangerous and more likely to cause acute ischaemic stroke.Previous studies[10-13]have found that there are specific vascular remodelling phenomena in the coronary and carotid arteries of diabetic patients.However,due to the deep location and small lumen of intracranial arteries and limitations of imaging techniques,the relationship between intracranial arterial remodelling and diabetes is still unclear.In recent years,with the development of magnetic resonance technology and the emergence of high-resolution(HR)vascular wall imaging,a clear and multidimensional display of the intracranial vascular wall has been achieved.Therefore,in this study,HR wall imaging(HR-VWI)was used to display the remodelling characteristics of bilateral middle cerebral arteries and basilar arteries and to explore the factors of intracranial vascular remodelling and its relationship with diabetes.

Deep tissue near-infrared imaging for vascular network analysis

Subcutaneous vein network plays important roles to maintain microcirculation that is related to some diagnostic aspects.Despite developments of optical imaging technologies,still the difficulties about deep skin vascular imaging have been continued.On the other hand,since hemoglobin con-centration of human blood has key role in the veins imaging by optical manner,the used wavelength in vascular imaging,must be chosen considering absorption of hemoglobin.In this research,we constructed a near infrared(NIR)light source because of lower absorption of hemoglobin in this optical region.To obtain vascular image,reflectance geometry was used.Next,from recorded images,vascular network analysis,such as calculation of width of vascular of interest and complexity of selected region were implemented.By comparing with other modalities,we observed that proposed imaging system has great advantages including nonionized radiation,moderate penetration depth of 0.5-3 mm and diameter of 1 mm,cost-effective and algorit hmic simplicity for analysis.

The neuroimaging of neurodegenerative and vascular disease in the secondary prevention of cognitive decline

Structural brain changes indicative of dementia occur up to 20 years before the onset of clinical symptoms. Efforts to modify the disease process after the onset of cognitive symptoms have been unsuccessful in recent years. Thus, future trials must begin during the preclinical phases of the disease before symptom onset. Age related cognitive decline is often the result of two coexisting brain pathologies: Alzheimer's disease(amyloid, tau, and neurodegeneration) and vascular disease. This review article highlights some of the common neuroimaging techniques used to visualize the accumulation of neurodegenerative and vascular pathologies during the preclinical stages of dementia such as structural magnetic resonance imaging, positron emission tomography, and white matter hyperintensities. We also describe some emerging neuroimaging techniques such as arterial spin labeling, diffusion tensor imaging, and quantitative susceptibility mapping. Recent literature suggests that structural imaging may be the most sensitive and cost-effective marker to detect cognitive decline, while molecular positron emission tomography is primarily useful for detecting disease specific pathology later in the disease process. Currently, the presence of vascular disease on magnetic resonance imaging provides a potential target for optimizing vascular risk reduction strategies, and the presence of vascular disease may be useful when combined with molecular and metabolic markers of neurodegeneration for identifying the risk of cognitive impairment.

Value of superb micro-vascular imaging in predicting ischemic stroke in patients with carotid atherosclerotic plaques

BACKGROUND Unstable carotid atherosclerotic plaques are prone to cause ischemic stroke.Contrast-enhanced ultrasound(CEUS) is the primary method of assessing plaque stability, but CEUS cannot be a method for screening for unstable plaque. The emergence of superb micro-vascular imaging(SMI) offers the possibility of clinically screening for unstable plaque AIM To investigate the value of SMI in predicting ischemic stroke in patients with carotid atherosclerotic plaques.METHODS Patients with carotid atherosclerotic plaques(luminal stenosis of 50%-70%) were enrolled into the present study. All patients received conservative medication.The patient's clinical baseline data, serological data, CEUS and SMI data were analyzed. All patients underwent a 3-year follow-up. The follow-up endpoint was the occurrence of ischemic stroke and patients were divided into stroke group and non-stroke group according to whether the prognosis occurred or not.Subsequently, the difference in clinical data was compared, the correlation of SMI and CEUS was analyzed, and multiple Cox regression and receiver operating characteristic curve were applied to investigate the value of SMI and CEUS in predicting cerebral arterial thrombosis in three years.RESULTS In this study, 43 patients were enrolled in the stroke group and 82 patients were enrolled in the non-stroke group. Cox regression revealed that SMI level(P =0.013) and enhancement intensity(P = 0.032) were the independent factors influencing ischemic stroke. There was a positive correlation between SMI level and enhancement intensity(r = 0.737, P = 0.000). The area under curve of SMI level predicting ischemic stroke was 0.878. The best diagnostic point was ≥ level Ⅱ, and its sensitivity and specificity was 86.05% and 79.27%. The area under curve of enhancement intensity predicting ischemic stroke was 0.890. The best diagnostic point was 9.92 db, and its sensitivity and specificity was 88.37% and89.02%. As the SMI level gradually increased, the incidence of ischemic stroke increased gradually(X^2 = 108.931, P = 0.000).CONCLUSION SMI can be used as a non-invasive method of screening for unstable plaques and may help prevent ischemic stroke.

Evaluation of Ventricular-vascular Coupling in Patients with Type 2 Diabetes Mellitus Using 2-Dimensional Speckle Tracking Imaging

The elastic and functional coupling of heart and vessels makes the stroke work （SW） of the heart optimal. Speckle tracking imaging （STI） can evaluate the myocardial strain and function. We studied ventricular-vascular coupling in 80 diabetic patients with different systolic function using STI. The patients were divided into two groups according to ejection fraction （EF）： the diabetes mel- litus with normal EF （DMN） group and the diabetes mellitus with abnormal EF （DMA） group. Forty-two volunteers served as control group. The relative wall thickness （RWT）, left ventricular mass index （LVMI）, stroke volume （SV）, SW, rate-pressure product （RPP）, systemic vascular resis- tance index （SVRI）, left ventricular end-systolic elastance （Ees）, effective arterial elasticity （Ea） and ventricular-vascular coupling index （VVI） were measured and calculated by conventional echocardi- ography. The longitudinal strain （LS） at basement （LSBA）, papillary muscle （LSvM） and cardiac apex （LSAv） was assessed with STI. It was found： （A） compared with control group, in DMN and DMA groups, LSBA, LSvM and LSAp decreased, and they were lower in DMA group. （B） VVI, RPP and SVRI increased, and they were higher in DMN group; Ees decreased, and it was lower in DMA group. （C） LSBA, LSpM, and LSAv had negative correlation with VVI. LSAp, RWT, LVMI and SW were independent predictors for VVI. The area under the receiver operating characteristic （ROC） curves was used for identification of DMA and DMN with LSBA, LSpM, and LSAp, and the area under the ROC of LSAp was the largest. This study supports that myocardial LS could reflect the ventricu- lar-vascular coupling. Different segments had an order to “respond to” the state of the coupling, and the cardiac apex might be the earliest.

Reperfusion injury components and manifestations determined by cardiovascular MR and MDCT imaging

Advances in magnetic resonance(MR) and computed tomography(CT) imaging have improved visualization of acute and scar infarct.Over the past decade,there have been and continues to be many significant technical advancements in cardiac MR and multi-detector computed tomography(MDCT) technologies.The strength of MR imaging relies on a variety of pulse sequences and the ability to noninvasively provide information on myocardial structure,function and perfusion in a single imaging session.The recent technical developments may also allow CT technologies to rise to the forefront for evaluating clinical ischemic heart disease.Components of reperfusion injury including myocardial edema,hemorrhage,calcium deposition and microvascular obstruction(MO) have been demonstrated using MR and CT technologies.MR imaging can be used serially and noninvasively in assessing acute and chronic consequences of reperfusion injury because there is no radiation exposure or administration of radioactive materials.MDCT is better suited for assessing coronary artery stenosis and as an alternative technique for as-sessing viability in patients where MR imaging is contraindicated.Changes in left ventricular(LV) volumes and function measured on cine MR are directly related to infarct size measured on delayed contrast enhanced images.Recent MR studies found that transmural infarct,MO and peri-infarct zone are excellent predictors of poor post-infarct recovery and mortality.Recent MR studies provided ample evidence that growth factor genes and stem cells delivered locally have beneficial effects on myocardial viability,perfusion and function.The significance of deposited calcium in acute infarct detected on MDCT requires further studies.Cardiac MR and MDCT imaging have the potential for assessing reperfusion injury components and manifestations.

Advances in multimodal magnetic resonance imaging of vascular mild cognitive impairment

Vascular mild cognitive impairment(VaMCI)represents the early stage of symptoms of vascular cognitive impairment(VCI).There are many intervention factors in this period.If the active treatment can delay the further development of the disease and even reduce the risk of transforming into vascular dementia(VaD).As a widely used imaging method,multi-mode magnetic resonance imaging can evaluate the brain structure and function of patients with VaMCI noninvasively and explore the relationship between brain structure,function and cognitive function change.It is beneficial to provide an idea for early diagnosis of VaMCI and to further understand the neuropathologic mechanism of its occurrence,which has broad application prospects.In this paper,the research status and new methods of VaMCI are reviewed by using multi-mode magnetic resonance imaging in recent years.

Current Status of Intra-Vascular Imaging during Coronary Interventions

Most important interventional application of IVUS is plaque assessment, vessel sizing and stent implantation guidance. Image guided PCI is associated with decreased incidence of stent thrombosis and MACE rate as evident in recently published meta-analysis of IVUS guided PCI studies. Many imaging studies have shown very clearly under-expansion, edge-dissection, tissue-prolapse, mal apposition, and geographical miss are associated with adverse events following DES implantation, and IVI guides in optimization of stent implantation by identifying and rectifying these predictors of DES outcomes.

Prediction of colorectal tumor grade and invasion depth through narrow-band imaging scoring

AIM To determine the usefulness of assigning narrow-band imaging(NBI) scores for predicting tumor grade and invasion depth in colorectal tumors.METHODS A total of 161 colorectal lesions were analyzed from138 patients who underwent endoscopic or surgical resection after conventional colonoscopy and magnifying endoscopy with NBI. The relationships between the surface and vascular patterns of the lesions, as visualized with NBI, and the tumor grade and depth of submucosa(SM) invasion were determined histopathologically.Scores were assigned to distinct features of the surface microstructures of tubular and papillary-type lesions.Using a multivariate analysis, a model was developed for predicting the tumor grade and depth of invasion based on NBI-finding scores.RESULTS NBI findings that correlated with a high tumor grade were associated with the "regular/irregular"(P < 0.0001)surface patterns and the "avascular area" pattern(P =0.0600). The vascular patterns of "disrupted vessels"(P = 0.0714) and "thick vessels"(P = 0.0133) but none of the surface patterns were associated with a depth of invasion of ≥ 1000 μm. In our model, a total NBIfinding score ≥ 1 was indicative of a high tumor grade(sensitivity: 0.97; specificity: 0.24), and a total NBIfinding score ≥ 9(sensitivity: 0.56; specificity: 1.0) was predictive of a SM invasion depth ≥ 1000 μm. Scores less than these cutoff values signified adenomas and a SM invasion depth < 1000 μm, respectively. Associations were also noted between selected NBI findings and tumor tissue architecture and histopathology.CONCLUSION Our multivariate statistical model for predicting tumor grades and invasion depths from NBI-finding scores may help standardize the diagnosis of colorectal lesions and inform therapeutic strategies.

The functions and applications of A7R in anti-angiogenic therapy, imaging and drug delivery systems

Vascular endothelial growth factor receptor 2(VEGFR-2)and neuropilin-1(NRP-1)are two prominent antiangiogenic targets.They are highly expressed on vascular endothelial cells and some tumor cells.Therefore,targeting VEGFR-2 and NRP-1 may be a potential antiangiogenic and antitumor strategy.A7R,a peptide with sequence of Ala-Thr-Trp-Leu-Pro-Pro-Arg that was found by phage display of peptide libraries,can preferentially target VEGFR-2 and NRP-1 and destroy the binding between vascular endothelial growth factor 165(VEGF165)and VEGFR-2 or NRP-1.This peptide is a new potent inhibitor of tumor angiogenesis and a targeting ligand for cancer therapy.This review describes the discovery,function and mechanism of the action of A7R,and further introduces the applications of A7R in antitumor angiogenic treatments,tumor angiogenesis imaging and targeted drug delivery systems.In this review,strategies to deliver different drugs by A7R-modified liposomes and nanoparticles are highlighted.A7R,a new dual targeting ligand of VEGFR-2 and NRP-1,is expected to have efficient therapeutic or targeting roles in tumor drug delivery.

What can imaging tell us about cognitive impairment and dementia?

Dementia is a contemporary global health issue with far reaching consequences, not only for affected individuals and their families, but for national and global socio-economic conditions. The hallmark feature of dementia is that of irreversible cognitive decline, usually affecting memory, and impaired activities of daily living. Advances in healthcare worldwide have facilitated longer life spans, increasing the risks of developing cognitive decline and dementia in late life. Dementia remains a clinical diagnosis. The role of structural and molecular neuroimaging in patients with dementia is primarily supportive role rather than diagnostic, American and European guidelines recommending imaging to exclude treatable causes of dementia, such as tumor, hydrocephalus or intracranial haemorrhage, but also to distinguish between different dementia subtypes, the commonest of which is Alzheimer&#x02019;s disease. However, this depends on the availability of these imaging techniques at individual centres. Advanced magnetic resonance imaging (MRI) techniques, such as functional connectivity MRI, diffusion tensor imaging and magnetic resonance spectroscopy, and molecular imaging techniques, such as 18F fluoro-deoxy glucose positron emission tomography (PET), amyloid PET, tau PET, are currently within the realm of dementia research but are available for clinical use. Increasingly the research focus is on earlier identification of at risk preclinical individuals, for example due to family history. Intervention at the preclinical stages before irreversible brain damage occurs is currently the best hope of reducing the impact of dementia.

Imaging in renal trauma

Renal injuries are classified,based on the American Association for the Surgery of Trauma classification,in to five grades of injury.Several imaging modalities have been available for assessing the grade of renal injury,each with their usefulness and limitations.Currently,plain radiographs and intravenous urography have no role in the evaluation of patients with suspected renal injury.Ultrasonography(USG) has a limited role in evaluating patients with suspected retroperitoneal injury;however,it plays an important role during follow up in patients with urinoma formation.USG helps to monitor the size of a urinoma and also for the drainage procedure.The role of selective renal arteriography is mainly limited to an interventional purpose rather than for diagnostic utility.Retrograde pyelography is useful in assessing ureteral and renal pelvis integrity in suspected ureteropelvic junction injury and for an interventional purpose,like placing a stent across the site of ureteric injury.Magnetic resonance imaging has no role in acute renal injuries.Multidetector computed tomography is the modality of choice in the evaluation of renal injuries.It is also useful in evaluating traumatic injuries to kidneys with preexisting abnormalities and can help to define the extent of penetrating injuries in patients with stab wounds in the flank region.The combination of imaging findings along with clinical information is important in the management of the individual patient.This article will describe a spectrum of renal injuries encountered in a trauma setting.

Theranostic applications:Non-ionizing cellular and molecular imaging through innovative nanosystems for early diagnosis and therapy

Modern medicine is expanding the possibilities of receiving "personalized" diagnosis and therapies,providing minimal invasiveness,technological solutions based on non-ionizing radiation,early detection of pathologies with the main objectives of being operator independent and with low cost to society.Our research activities aim to strongly contribute to these trends by improving the capabilities of current diagnostic imaging systems,which are of key importance in possibly providing both optimal diagnosis and therapies to patients.In medical diagnostics,cellular imaging aims to develop new methods and technologies for the detection of specific metabolic processes in living organisms,in order to accurately identify and discriminate normal from pathological tissues.In fact,most diseases have a "molecular basis" that detected through these new diagnostic methodologies can provide enormous benefits to medicine.Nowadays,this possibility is mainly related to the use of Positron Emission Tomography,with an exposure to ionizing radiation for patients and operators and with extremely high medical diagnosticscosts.The future possible development of non-ionizing cellular imaging based on techniques such as Nuclear Magnetic Resonance or Ultrasound,would represent an important step towards modern and personalized therapies.During the last decade,the field of nanotechnology has made important progress and a wide range of organic and inorganic nanomaterials are now available with an incredible number of further combinations with other compounds for cellular targeting.The availability of these new advanced nanosystems allows new scenarios in diagnostic methodologies which are potentially capable of providing morphological and functional information together with metabolic and cellular indications.

Expectations from imaging for pre-transplant evaluation of living donor liver transplantation

Living donor liver transplant(LDLT)is a major surgi-cal undertaking.Detailed pre-operative assessment of the vascular and biliary anatomy is crucial for safe and successful harvesting of the graft and transplantation.Computed tomography(CT)and magnetic resonance imaging(MRI)are currently the imaging modalities of choice in pre-operative evaluation.These cross-sec-tional imaging techniques can reveal the vascular and biliary anatomy,assess the hepatic parenchyma and perform volumetric analysis.Knowledge of the broad indications and contraindications to qualify as a recipi-ent for LDLT is essential for the radiologist reporting scans in a pre-transplant patient.Similarly,awareness of the various anatomical variations and pathological states in the donor is essential for the radiologist to generate a meaningful report of his/her observations.CT and MRI have largely replaced invasive techniques such as catheter angiography,percutaneous cholan-giography and endoscopic retrograde cholangiopan-creatography.In order to generate a meaningful report based on these pre-operative imaging scans,it is also mandatory for the radiologist to be aware of the sur-geon’s perspective.We intend to provide a brief over-view of the common surgical concepts of LDLT and give a detailed description of the minimum that a radiologist is expected to seek and report in CT and MR scans per-formed for LDLT related evaluation.