Gadolinium Magnetic Resonance Imaging Research Articles

Arterial Topographic Anatomy Near the Femoral Head-Neck Perforation with Surgical Relevance.

Knowledge of the vascular supply of the femoral head is crucial for hip-preserving surgical procedures. The critical area for reshaping cam deformity is at the retinacular vessel penetration, an area with ill-defined topographic anatomy. We performed a cadaver study of the extension of the lateral retinaculum near the head-neck junction, distribution of the arterial vascular foramina, and initial intracapital course of these vessels. In 16 fresh proximal parts of the femur without head-neck deformities, the deep branch of the medial femoral circumflex artery was injected with gadolinium for magnetic resonance imaging (MRI) sequences to identify arterial structures. We found a mean number of 4.5 arterial foramina, showing a predominance from 10 to 12 o'clock. The retinaculum extended 20 mm from 1 to 10 o'clock. The surface distance from the cartilage border to the vascular foramina under the synovial fold was 6.5 mm, and the depth from the same cartilage border to the initial intraosseous vessel pathways was 5.3 mm. The data add further precision to the arterial topography at the retinacular foramina, an area that is crucial for the perfusion of the femoral head. It may overlap with the area of anterolateral cam deformity and plays a role in choosing the cuts for subcapital and intracapital osteotomies. The information is taken from normal hips and may not be directly applicable to the deformed hip. Nevertheless, it is a prerequisite for a surgeon to understand the normal anatomy and use those boundaries to prevent mistakes during intra-articular joint-preserving hip surgical procedures.

Electrical and Structural Substrate of Arrhythmogenic Right Ventricular Cardiomyopathy Determined Using Noninvasive Electrocardiographic Imaging and Late Gadolinium Magnetic Resonance Imaging.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a significant cause of sudden cardiac death in the young. Improved noninvasive assessment of ARVC and better understanding of the disease substrate are important for improving patient outcomes. We studied 20 genotyped ARVC patients with a broad spectrum of disease using electrocardiographic imaging (a method for noninvasive cardiac electrophysiology mapping) and advanced late gadolinium enhancement cardiac magnetic resonance scar imaging. Compared with 20 healthy controls, ARVC patients had longer ventricular activation duration (median, 52 versus 42 ms; P=0.007) and prolonged mean epicardial activation-recovery intervals (a surrogate for local action potential duration; median, 275 versus 241 ms; P=0.014). In these patients, we observed abnormal and varied epicardial activation breakthrough locations and regions of nonuniform conduction and fractionated electrograms. Nonuniform conduction and fractionated electrograms were present in the early concealed phase of ARVC. Electrophysiological abnormalities colocalized with late gadolinium enhancement scar, indicating a relationship with structural disease. Premature ventricular contractions were common in ARVC patients with variable initiation sites in both ventricles. Premature ventricular contraction rate increased with exercise, and within anatomic segments, it correlated with prolonged repolarization, electric markers of scar, and late gadolinium enhancement (all P<0.001). Electrocardiographic imaging reveals electrophysiological substrate properties that differ in ARVC patients compared with healthy controls. A novel mechanistic finding is the presence of repolarization abnormalities in regions where ventricular ectopy originates. The results suggest a potential role for electrocardiographic imaging and late gadolinium enhancement in early diagnosis and noninvasive follow-up of ARVC patients.

Gadolinium magnetic resonance imaging during pregnancy associated with adverse neonatal and post-neonatal outcomes

Gadolinium magnetic resonance imaging during pregnancy associated with adverse neonatal and post-neonatal outcomes

Assessment of endolymphatic hydrops and otolith function in patients with Ménière's disease.

Ménière's disease is associated with hydrops of the inner ear endolymphatic space, and histopathologically, the cochlea and vestibule are usually involved. We used gadolinium-enhanced magnetic resonance imaging and measured cervical and ocular vestibular evoked myogenic potentials and the gain in the utricular induced linear vestibulo-ocular reflex to test the hypothesis that vestibular hydrops in Ménière's disease patients is associated with otolith organ dysfunction. We evaluated 21 patients diagnosed with unilateral definitive Ménière's disease using gadolinium magnetic resonance imaging to detect endolymphatic hydrops in the cochlea and vestibule. Cervical and ocular vestibular evoked myogenic potentials and the gain in utricular induced linear vestibulo-ocular reflex during eccentric rotation were measured to assess otolith organ function. For eccentric rotation, patients were rotated while displaced from the axis of rotation, while linear acceleration stimulated the utricle and induced the vestibulo-ocular reflex. Magnetic resonance imaging revealed vestibular hydrops in 14 of 20 patients (70%). Among the 14 patients, ten (71%) had abnormal cervical and three (21%) had abnormal ocular vestibular evoked myogenic potentials. Four patients (4/21, 19%) had abnormal linear vestibulo-ocular reflexes, three of whom also had abnormal ocular vestibular evoked myogenic potentials. Overall, 16 of 17 patients had normal linear vestibulo-ocular reflexes and normal ocular vestibular evoked myogenic potentials. Vestibular endolymphatic hydrops in Ménière's disease patients caused otolith organ dysfunction, mainly in the saccule. The number of Ménière's disease patients with abnormal ocular vestibular evoked myogenic potentials was low (19%), and they also had abnormal utricular induced linear vestibulo-ocular reflexes.

Gadolinium agents for theragnosis of malignant tumors

Imaging agents are essential in diagnosing malignant tumors. Various elements are currently used as imaging agents in various chemical forms; gadolinium for magnetic resonance imaging (MRI), iodine for X-ray computed tomography (CT), and radioisotopes with short half-lives for positron emission tomography (PET). Among them, gadolinium is a special element which possesses outstanding theragnostic (e.g. diagnostic and therapeutic) properties for malignant tumors such as brain tumors, which are superior to all elements currently used clinically in various chemical forms. That is, gadolinium agents in nanoparticle or chelate forms can be used as MRI contrast agents or CT contrast agents to diagnose malignant tumors, and neutron capture therapy (NCT) agents to treat malignant tumors. Therefore, one gadolinium chemical in either chelate or nanoparticle forms could be used for theragnosis of malignant tumors. In this Opinion Article, researches conducted so far are briefly introduced, and outstanding theragnostic properties of gadolinium and what needs to happen before gadolinium agents can be applied to malignant tumor theragnosis, are discussed.

Association Between MRI Exposure During Pregnancy and Fetal and Childhood Outcomes.

Fetal safety of magnetic resonance imaging (MRI) during the first trimester of pregnancy or with gadolinium enhancement at any time of pregnancy is unknown. To evaluate the long-term safety after exposure to MRI in the first trimester of pregnancy or to gadolinium at any time during pregnancy. Universal health care databases in the province of Ontario, Canada, were used to identify all births of more than 20 weeks, from 2003-2015. Magnetic resonance imaging exposure in the first trimester of pregnancy, or gadolinium MRI exposure at any time in pregnancy. For first-trimester MRI exposure, the risk of stillbirth or neonatal death within 28 days of birth and any congenital anomaly, neoplasm, and hearing or vision loss was evaluated from birth to age 4 years. For gadolinium-enhanced MRI in pregnancy, connective tissue or skin disease resembling nephrogenic systemic fibrosis (NSF-like) and a broader set of rheumatological, inflammatory, or infiltrative skin conditions from birth were identified. Of 1 424 105 deliveries (48% girls; mean gestational age, 39 weeks), the overall rate of MRI was 3.97 per 1000 pregnancies. Comparing first-trimester MRI (n = 1737) to no MRI (n = 1 418 451), there were 19 stillbirths or deaths vs 9844 in the unexposed cohort (adjusted relative risk [RR], 1.68; 95% CI, 0.97 to 2.90) for an adjusted risk difference of 4.7 per 1000 person-years (95% CI, -1.6 to 11.0). The risk was also not significantly higher for congenital anomalies, neoplasm, or vision or hearing loss. Comparing gadolinium MRI (n = 397) with no MRI (n = 1 418 451), the hazard ratio for NSF-like outcomes was not statistically significant. The broader outcome of any rheumatological, inflammatory, or infiltrative skin condition occurred in 123 vs 384 180 births (adjusted HR, 1.36; 95% CI, 1.09 to 1.69) for an adjusted risk difference of 45.3 per 1000 person-years (95% CI, 11.3 to 86.8). Stillbirths and neonatal deaths occurred among 7 MRI-exposed vs 9844 unexposed pregnancies (adjusted RR, 3.70; 95% CI, 1.55 to 8.85) for an adjusted risk difference of 47.5 per 1000 pregnancies (95% CI, 9.7 to 138.2). Exposure to MRI during the first trimester of pregnancy compared with nonexposure was not associated with increased risk of harm to the fetus or in early childhood. Gadolinium MRI at any time during pregnancy was associated with an increased risk of a broad set of rheumatological, inflammatory, or infiltrative skin conditions and for stillbirth or neonatal death. The study may not have been able to detect rare adverse outcomes.

Use of gadolinium in placental MRI to improve diagnostic performance for abnormally invasive placentas in patients at risk.

Abnormally invasive placentation (AIP) is a rare but life-threatening condition in which placental tissue surpasses its normal location and abnormally invades the myometrium and neighbouring structures. It is an important cause of excessive postpartum haemorrhage. Its incidence is increasing owing to the growing number of caesarean sections being performed. The diagnosis is reached by the presence of placental ultrasound (US) or magnetic resonance imaging (MRI) signs suggestive of this condition. When the accuracy for the detection of AIP using US and MRI was compared, similar results were obtained. Nevertheless, the performance of both imaging techniques for the detection of AIP is suboptimal. False-negative cases of AIP may represent an increase in maternal morbimortality, as some crucial interventions that are indicated in suspected AIP may not be performed. The indication of a scheduled caesarean delivery in a tertiary referral centre with a multidisciplinary team significantly improves outcomes. False-positives for AIP represent unnecessary maternal–fetal morbidity. For this reason, there is an real need to improve the diagnostic imaging accuracy for AIP. In this study, the authors tested the hypothesis that gadolinium contrast could improve the diagnostic performance of MRI for AIP. One of the main strengths of the study is its novelty, as gadolinium is not frequently used during pregnancy owing to safety concerns. Uncertainty surrounds the risk of possible fetal effects because gadolinium contrast is a water-soluble agent and can cross the placenta into the fetal circulation and amniotic fluid. The main concern is that the duration of fetal exposure is unknown because it can be swallowed from amniotic fluid re-entering the fetal circulation, which could potentially increase the risk of fetal harm. Nevertheless, studies have shown how no adverse perinatal or neonatal outcomes were detected in cases that received this agent during the first trimester (De Santis et al. Acta Obstet Gynecol Scand 2007;86(1):99–101) and how no teratogenic effects were detected in animals exposed to it during pregnancy. Its use during pregnancy has recently been accepted by the European Society of Radiology, the American College of Obstetrics and Gynecology (Committee Opinion No 656; Obstet Gynecol 2016;127(2):e.75–80) and the Society of Obstetricians and Gynaecologists of Canada (Patenaude et al. J Obstet Gynaecol Can 2014;36(4):349–63) when benefits clearly outweigh the possible risks, as may be the case for AIP. The results provided in this study show how the use of gadolinium significantly increased the diagnostic sensitivity and specificity (+12.5% for both), suggesting that the use of this contrast agent could constitute a new reliable way of improving the detection rate of AIP in patients at risk. This should be considered a great achievement that may be helpful particularly in cases of inconclusive MRI scans and that may potentially reduce the morbimortality associated with AIP. Nevertheless, we should keep in mind that technical advances and upcoming studies may show how other MRI contrast agents that do not cross the placenta, or the use of additional MRI sequences, could also help to increase the accuracy of the detection of AIP (Siauve et al. Am J Obstet Gynecol 2015;213:S103) from an expectedly safer and non-invasive perspective. None declared. Completed disclosure of interests form available to view online as supporting information. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Functional Magnetic Resonance Imaging in Acute Kidney Injury: Present Status.

Acute kidney injury (AKI) is a common complication of hospitalization that is characterized by a sudden loss of renal excretory function and associated with the subsequent development of chronic kidney disease, poor prognosis, and increased mortality. Although the pathophysiology of renal functional impairment in the setting of AKI remains poorly understood, previous studies have identified changes in renal hemodynamics, perfusion, and oxygenation as key factors in the development and progression of AKI. The early assessment of these changes remains a challenge. Many established approaches are not applicable to humans because of their invasiveness. Functional renal magnetic resonance (MR) imaging offers an alternative assessment tool that could be used to evaluate renal morphology and function noninvasively and simultaneously. Thus, the purpose of this review is to illustrate the principle, application, and role of the techniques of functional renal MR imaging, including blood oxygen level-dependent imaging, arterial spin labeling, and diffusion-weighted MR imaging, in the management of AKI. The use of gadolinium in MR imaging may exacerbate renal impairment and cause nephrogenic systemic fibrosis. Therefore, dynamic contrast-enhanced MR imaging will not be discussed in this paper.

THE LARS AUGMENTED 4-TUNNEL HAMSTRING “HYBRID” ACLR GRAFT CONSTRUCTION ALLOWS ACCELERATED REHABILITATION WITHOUT KNEE LAXITY — CASE SERIES OF 111 PATIENTS AFTER 2 YEARS

Purpose: This prospective case series is designed to determine the 2-year clinical and radiological outcomes of patients undergoing an ACL reconstruction using the ligament augmentation reconstruction system (LARS) 133 prosthesis as an augmentation device for a 4-tunnel autologous hamstrings graft, in the context of accelerated rehabilitation. Methods: A total of 91 patients were assessed at 2 years post-operatively after undergoing an anterior cruciate ligament reconstruction (ACLR) with a doubled semitendinosis and LARS 133 prosthesis for the anteromedial bundle (AMB) and gracilis for the posterolateral bundle. Assessment included clinical review, KT-1000 arthrometry, IKDC, Tegner, Lysholm, Cincinnati and ACL QOL knee scoring, graft failure and re-operation rates. Tunnel positions and synovitis were assessed using gadolinium magnetic resonance imaging (MRI) scans and X-rays. Results: This technique in the context of accelerated rehabilitation is not associated with increased knee laxity and failure. There was no increase in knee laxity, with a mean side-to-side difference in KT-1000 arthrometer testing of 0.5[Formula: see text]mm ([Formula: see text]/[Formula: see text] 1.7). Two-year outcomes were satisfactory with 98% of all patients having an IKDC rating of A or B, and mean values of IKDC subjective 86.5 ([Formula: see text]/[Formula: see text] 11.6), Tegner 6.5 ([Formula: see text]/[Formula: see text] 2.0), Lysholm 87.1 ([Formula: see text]/[Formula: see text] 8.9), Cincinnati 378.8 ([Formula: see text]/[Formula: see text] 41.5) and ACL Quality of Life 81.5 ([Formula: see text]/[Formula: see text] 19.3). There was no evidence of synovitis and all tunnels were positioned satisfactorily. The graft failure rate was 1.1% and there was a re-operation rate of 15.4%. Conclusion: We conclude that LARS 133 augmentation of autologous hamstrings ACLR provides a graft construct allowing accelerated rehabilitation without increased knee laxity. It is not associated with significant synovitis within the first two years. Re-operation rates however are higher. The rates at which patients recover and return to life and sports activity following different ACLR graft types appears as a topic of future research interest.

Adenoma of the Ciliary Pigment Epithelium with Diffuse Iris Pigment Dispersion

To the Editor: Adenoma of the ciliary pigment epithelium (CPE) is an exceedingly rare tumor that is difficult to clinically differentiate from malignant melanoma.[1] Herein, we report a case of an adenoma of the CPE in Chinese women and discuss the clinical features of this unusual tumor. A 57-year-old woman complaining of obviously visual deterioration vision in her right eye for 1-year presented to Beijing Tongren Hospital in December 2013. There was no previous history of ocular trauma or intraocular inflammation. On examination, the visual acuity was 0.2 in the right eye and 1.2 in the left eye. Intraocular pressure readings were 23.8 mmHg and 14.6 mmHg in the right and left eyes, respectively. Slit-lamp examination revealed diffuse fine pigmentosus keratic precipitates on the posterior corneal surface and diffuse pigment dispersion on the iris in the right eye. There was no visible iris neovascularization and iridodonesis. After mydriasis, a dark brown mass occupied the superotemporal posterior chamber, and a segmental cataract was present with amber color [Figure 1a]. The left eye was entirely normal. Bilateral fundus was normal by indirect ophthalmoscopy. Figure 1 (a) A dark brown mass and a segmental cataract with amber color; (b) Ultrasonography showed an acoustically solid, abruptly elevated, and hillock-shaped mass; (c) Ultrasound biomicroscopy demonstrated a moderately irregular acoustically solid and the ... Ultrasonography (US) showed an acoustically solid, abruptly elevated, hillock-shaped mass, measuring 9.6 mm × 7.6 mm (basal) × 5.4 mm (apical thickness) [Figure 1b]; ultrasound biomicroscopy demonstrated a moderately irregular acoustically solid in 10:30–13:30 o’clock meridians in the ciliary body, measuring 9.89 mm × 6.96 mm × 4.57 mm. The lesion had invaded the structure of chamber angle and the root of the iris [Figure 1c]; magnetic resonance imaging (MRI) showed that the mass was hyperintense in T1-weighted images and hypointense in T2-weighted images to the brain [Figure 1d]. The tumor showed enhancement after gadolinium. The patient underwent local resection of the tumor in the form of iridocyclectomy. Histopathologically, the tumor showed heavy pigmentation and nests of pigmented epithelial cells forming gland-like structures that were separated by vascularized fibrous connective tissue [Figure 1e]. They contained numerous characteristic round or oval clear vacuoles, encompassed by cells whose cytoplasm was replete with large, spherical melanosomes [Figure 1f]. No mitoses were seen. The tumor was diagnosed as adenoma of the pigmented ciliary epithelium. The CPE as a stretch from the retina pigment epithelium can sometimes undergo reactive proliferation and migration. However, true tumors of the pigment epithelia of the ciliay body are extremely rare.[1] A patient with an adenoma of the CPE may be asymptomatic, or impairment of visual acuity due to secondary cataract or subluxation of the lens may develop.[2] Angle closure was responsible for secondary glaucoma. Dinakaran et al.[3] reported that smaller tumors of adenoma of the CPE invaded the angle, and larger lesions caused extensive pigment dispersion although noninvasively. The tumor size in our patient was larger than the reported. It not only invaded the angle but also caused extensive pigment dispersion. Diffuse iris pigment dispersion and the dark pigmentation let us to be thought it could be a benign tumor, a necrotic melanocytoma or an adenoma of the pigment epithelium. In general, adenoma of the CPE shows medium to high internal reflectivity and acoustic solidity with an abruptly elevated in US and displays hypointense in T2-weighted images to the brain and enhancement after gadolinium in MRI.[4] Adenoma of the CPE appears deeper color than melanoma. It lacks the surrounding pigmented base or collar-button configuration that is usually seen in melanomas. Prominent tumor blood vessels, frequently noted in melanoma, are rarely seen in adenoma of the CPE.[1] In addition, acoustic hollowness are more often seen with melanomas since rapid growth forming cystoids in the tumor. Ciliary body melanocytoma is also a deeply pigmented solid mass and more likely to display pigment dispersion and secondary glaucoma due to undergo central necrosis. However, it arises from the uveal stroma with a rough or corrugated surface and no contrast enhancement in MRI with gadolinium. In some cases, the clinical differentiation adenoma of the CPE may be impossible. Histopathology is still the only standardization for a diagnosis. Tumors that arise from the CPE are usually characterized by prominent clear vacuoles and density of melanin granules.[5] Recognition of the characteristic features of adenoma of the CPE should facilitate the diagnosis of this unusual tumor. This benign tumor should be observed periodically, and local tumor resection should be considered if there is progressive growth or secondary glaucoma. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Efficient labeling in vitro with non-ionic gadolinium magnetic resonance imaging contrast agent and fluorescent transfection agent in bone marrow stromal cells of neonatal rats.

Although studies have been undertaken on gadolinium labeling-based molecular imaging in magnetic resonance imaging (MRI), the use of non-ionic gadolinium in the tracking of stem cells remains uncommon. To investigate the efficiency in tracking of stem cells with non-ionic gadolinium as an MRI contrast agent, a rhodamine-conjugated fluorescent reagent was used to label bone marrow stromal cells (BMSCs) of neonatal rats in vitro, and MRI scanning was undertaken. The fluorescent-conjugated cell uptake reagents were able to deliver gadodiamide into BMSCs, and cell uptake was verified using flow cytometry. In addition, the labeled stem cells with paramagnetic contrast medium remained detectable by an MRI monitor for a minimum of 28 days. The present study suggested that this method can be applied efficiently and safely for the labeling and tracking of bone marrow stromal cells in neonatal rats.

Development of virus-like particles for diagnostic and prophylactic biomedical applications.

As ordered nanoscale architectures, viruses and virus-like particles (VLPs) remain unsurpassed by synthetic strategies to produce uniform and symmetric nanoparticles. Maintaining or mimicking the symmetry of pathogenic viruses, VLPs offer a ready platform for facilitating recognition, uptake, and processing by the immune system. An emerging understanding of how viruses interact with the immune system offers a means of precisely designing nanoparticles for biomedical use, both with respect to the structure of the particle as well as their ability to stimulate the immune system. Here we discuss recent advances by our group toward two parallel and complementary applications of VLPs, derived primarily from plants, bacteriophage, and nonviral sources, in biomedicine: diagnostic imaging and rational vaccine design. First we discuss advances in increasing VLP payloads of gadolinium magnetic resonance imaging (MRI) contrast agent as well as controlling the characteristics of individual gadolinium containing molecules to increase efficacy. In order to better understand the in vivo potential of VLP constructs, we then discuss the interface of protein-cages and the immune system beginning with the nonspecific innate immune system stimulation and continuing into the use of nonpathogenic VLPs as scaffolds for specific antigen presentation and control of the immune response.

Leptomeningeal metastasis from solid tumors: a diagnostic and therapeutic challenge.

Leptomeningeal metastasis (LM) is a severe complication in the natural history of malignancies that occurs in 4-15% of patients (pts) with solid tumors. Clinical presentation, cerebrospinal fluid cytology (CSF), and gadolinium magnetic resonance imaging (gdMRI) of the brain and spine are the methods routinely used to diagnose LM. Treatment encompasses involved-field radiotherapy of bulky or symptomatic disease sites and chemotherapy; however, no standard therapy has been established yet. We collected and reviewed retrospectively the clinical, pathological, radiological findings as well as the outcomes of 50 consecutive patients with LM from solid tumors to determine whether the diagnostic modalities and therapeutic procedures affected the outcomes. The results of this study confirm the role of gdMRI in the diagnosis of LM in clinical practice and suggest that an aggressive treatment may improve survival in patients with this debilitating and increasingly frequent neurological complication.

EU-wide monitoring survey on emerging polar organic contaminants in wastewater treatment plant effluents

In the year 2010, effluents from 90 European wastewater treatment plants (WWTPs) were analyzed for 156 polar organic chemical contaminants. The analyses were complemented by effect-based monitoring approaches aiming at estrogenicity and dioxin-like toxicity analyzed by in vitro reporter gene bioassays, and yeast and diatom culture acute toxicity optical bioassays. Analyses of organic substances were performed by solid-phase extraction (SPE) or liquid–liquid extraction (LLE) followed by liquid chromatography tandem mass spectrometry (LC-MS-MS) or gas chromatography high-resolution mass spectrometry (GC-HRMS). Target microcontaminants were pharmaceuticals and personal care products (PPCPs), veterinary (antibiotic) drugs, perfluoroalkyl substances (PFASs), organophosphate ester flame retardants, pesticides (and some metabolites), industrial chemicals such as benzotriazoles (corrosion inhibitors), iodinated x-ray contrast agents, and gadolinium magnetic resonance imaging agents; in addition biological endpoints were measured. The obtained results show the presence of 125 substances (80% of the target compounds) in European wastewater effluents, in concentrations ranging from low nanograms to milligrams per liter. These results allow for an estimation to be made of a European median level for the chemicals investigated in WWTP effluents. The most relevant compounds in the effluent waters with the highest median concentration levels were the artificial sweeteners acesulfame and sucralose, benzotriazoles (corrosion inhibitors), several organophosphate ester flame retardants and plasticizers (e.g. tris(2-chloroisopropyl)phosphate; TCPP), pharmaceutical compounds such as carbamazepine, tramadol, telmisartan, venlafaxine, irbesartan, fluconazole, oxazepam, fexofenadine, diclofenac, citalopram, codeine, bisoprolol, eprosartan, the antibiotics trimethoprim, ciprofloxacine, sulfamethoxazole, and clindamycine, the insect repellent N,N′-diethyltoluamide (DEET), the pesticides MCPA and mecoprop, perfluoroalkyl substances (such as PFOS and PFOA), caffeine, and gadolinium.

Identification of early and distinct glioblastoma response patterns treated by boron neutron capture therapy not predicted by standard radiographic assessment using functional diffusion map

BackgroundRadiologic response of brain tumors is traditionally assessed according to the Macdonald criteria 10 weeks from the start of therapy. Because glioblastoma (GB) responds in days rather than weeks after boron neutron capture therapy (BNCT) that is a form of tumor-selective particle radiation, it is inconvenient to use the Macdonald criteria to assess the therapeutic efficacy of BNCT by gadolinium-magnetic resonance imaging (Gd-MRI). Our study assessed the utility of functional diffusion map (fDM) for evaluating response patterns in GB treated by BNCT.MethodsThe fDM is an image assessment using time-dependent changes of apparent diffusion coefficient (ADC) in tumors on a voxel-by-voxel approach. Other than time-dependent changes of ADC, fDM can automatically assess minimum/maximum ADC, Response Evaluation Criteria In Solid Tumors (RECIST), and the volume of enhanced lesions on Gd-MRI over time. We assessed 17 GB patients treated by BNCT using fDM. Additionally, in order to verify our results, we performed a histopathological examination using F98 rat glioma models.ResultsOnly the volume of tumor with decreased ADC by fDM at 2 days after BNCT was a good predictor for GB patients treated by BNCT (P value = 0.022 by log-rank test and 0.033 by wilcoxon test). In a histopathological examination, brain sections of F98 rat glioma models treated by BNCT showed cell swelling of both the nuclei and the cytoplasm compared with untreated rat glioma models.ConclusionsThe fDM could identify response patterns in BNCT-treated GB earlier than a standard radiographic assessment. Early detection of treatment failure can allow a change or supplementation before tumor progression and might lead to an improvement of GB patients’ prognosis.

Impact of molecular imaging in preclinical cancer research.

Impact of molecular imaging in preclinical cancer research.

MRI gadolinium enhancement precedes neuroradiological findings in acute necrotizing encephalopathy

We report a 2-year-old Japanese boy with acute necrotizing encephalopathy (ANE) triggered by human herpes virus-6, who presented insightful magnetic resonance imaging (MRI) findings. He was admitted due to impaired consciousness and a convulsion, 2days after the onset of an upper respiratory infection. At admission, cranial MRI showed marked gadolinium enhancement at the bilateral thalami, brainstem and periventricular white matter without abnormal findings in noncontrast MRI sequences. On the following day, noncontrast computed tomography demonstrated homogeneous low-density lesions in the bilateral thalami and severe diffuse brain edema. The patient progressively deteriorated and died on the 18th day of admission. The pathogenesis of ANE remains mostly unknown, but it has been suggested that hypercytokinemia may play a major role. Overproduced cytokines cause vascular endothelial damage and alter the permeability of the vessel wall in the multiple organs, including the brain. The MRI findings in our case demonstrate that blood–brain barrier permeability was altered prior to the appearance of typical neuroradiological findings. This suggests that alteration of blood–brain barrier permeability is the first step in the development of the brain lesions in ANE, and supports the proposed mechanism whereby hypercytokinemia causes necrotic brain lesions. This is the first report demonstrating MRI gadolinium enhancement antecedent to typical neuroradiological findings in ANE.

Taquicardia ventricular dependiente de cicatriz en ausencia de cardiopatía aparente: utilidad de la cardiorresonancia

A 43-year-old man with no history of cardiac disease was referred to our hospital for the study of an episode of a haemodynamically unstable regular monomorphic wide QRS complex tachycardia. The cardiac magnetic resonance imaging (MRI) showed the presence of sub-epicardial fibrosis in the mid-anterolateral segment of the left ventricle. Scar dependent ventricular tachycardia (VT), even in the absence of cardiac disease, and idiopathic VT are different conditions. Delayed gadolinium MRI could be useful in the differential diagnosis between them.

A clinically challenging diagnosis of adenoma of the retinal pigment epithelium presenting with clinical features of choroidal hemangioma

BackgroundAdenoma of the retinal pigment epithelium (RPE) is a rare intraocular tumor that can simulate other pigmented tumors such as choroidal melanoma. We report a case of non-pigmented adenoma of the RPE initially diagnosed as choroidal hemangioma.Case reportA 42-year-old woman presented to Kurume University Hospital in November 1992 with an orange-yellow tumor nasal to the optic disc in the left fundus. The tumor was 9.0 × 9.0 mm in diameter, 6.0 mm thick, and was characterized by high intensity on T1-weighted magnetic resonance imaging (MRI), low intensity on T2-weighted MRI, and enhancement on gadolinium MRI. Fluorescein angiography revealed early hypofluorescence and late hyperfluorescence of the tumor and retinal feeder vessels. By April 1996, exudate had developed around the tumor margins. The patient was treated with external beam radiation therapy (20 Gy) in July 1996, but the tumor did not diminish in size. Subsequently, she developed extensive loss of vision due to total retinal detachment. Accordingly, her left eye was enucleated in June 2005 because of severe ocular pain due to absolute glaucoma. Histopathological examination indicated that the tumor was contiguous with the normal surrounding RPE and was composed of cords and tubules of mostly non-pigmented spindle-shaped cells with round to oval nuclei and a small amount of cytoplasm containing melanin granules. The tumor cells were immunoreactive for vimentin, S-100 protein, and cytokeratin 18. The final diagnosis was adenoma of the RPE.ConclusionAdenoma of the retinal pigment epithelium may be associated with incompetent vessels leading to serous retinal detachment and extensive visual loss, and may exhibit clinical characteristics similar to choroidal hemangioma.

Improving T1 and T2 magnetic resonance imaging contrast agents through the conjugation of an esteramide dendrimer to high‐water‐coordination Gd(III) hydroxypyridinone complexes

Commercial gadolinium magnetic resonance imaging (MRI) contrast agents are limited by low relaxivity (r₁) and coordination to only a single water molecule (q = 1). Consequently, gram quantities of these agents must be injected to obtain sufficient diagnostic contrast. In this study, MRI contrast agents for T(1) and T₂ relaxivity were synthesized using hydroxypyridinone and terephthalamide chelators with mesityl and 1,4,7-triazacyclononane capping moieties. When covalently conjugated to a highly biocompatible esteramide dendrimer, T₂ relaxation rates up to 52 mm(-1) s(-1) and T₁ relaxation rates up to 31 mm(-1) s(-1) per gadolinium were observed under clinically relevant conditions. These values are believed to be brought about by using a dendritic macromolecule to decrease the molecular tumbling time of the small molecule complexes. These agents also show high aqueous solubility and low toxicity in vitro. In this study we report six new compounds: three discrete complexes and three dendrimer conjugates.