Post Gadolinium Research Articles

Hemorrhagic Cerebral Venous Infarction in a Patient with Atrial Fibrillation:

Venous sinus thrombosis is an uncommon cause of stroke. Magnetic resonance imaging and magnetic resonance venography are sensitive and specific non-invasive tools for the diagnosis. This is a report of patient who presented with atrial fibrillation and heart failure. The course of the disease was complicated by left-sided transverse sinus thrombosis leading to hemorrhagic stroke. There was normal looking transverse sinus upon contrast injection with gadolinium despite the lack of flow on magnetic resonance venography. It is postulate that this apparently normal transverse sinus appearance on post gadolinium T1-weighted imaging was a result of thrombus enhancement in the acute stage of the venous occlusion. This finding could mislead the diagnosis if it was read in isolation without the confirmation of the occlusion in magnetic resonance venography.

Hemorrhagic Cerebral Venous Infarction in a Patient with Atrial Fibrillation:

Venous sinus thrombosis is an uncommon cause of stroke. Magnetic resonance imaging and magnetic resonance venography are sensitive and specific non-invasive tools for the diagnosis. This is a report of patient who presented with atrial fibrillation and heart failure. The course of the disease was complicated by left-sided transverse sinus thrombosis leading to hemorrhagic stroke. There was normal looking transverse sinus upon contrast injection with gadolinium despite the lack of flow on magnetic resonance venography. It is postulate that this apparently normal transverse sinus appearance on post gadolinium T1-weighted imaging was a result of thrombus enhancement in the acute stage of the venous occlusion. This finding could mislead the diagnosis if it was read in isolation without the confirmation of the occlusion in magnetic resonance venography.

PWE-231 MRI is correlated to faecal calprotectin level in the evaluation of small bowel and colonic Crohn's disease

IntroductionCrohn's disease management requires knowledge of overall disease burden. A new MRI score of Crohn's disease activity was tested against reference standards of global activity—Harvey Bradshaw index (HBI) and faecal...

Paraspinal ganglioneuroma in the proband of a large family with mild cutaneous manifestations of NF1, carrying a deep NF1 intronic mutation

Supporting Information The following Supporting information is available for this article: Fig. S1. (a) Chest radiograph – there is a large right paraspinal soft tissue opacity at the base of the right hemithorax, not in the middle mediastinum, as it is not silhouetting the right heart border. (b) Magnetic resonance imaging – axial T2 and coronal inversion recovery (IR) sequences reveals a posterior mediastinal soft tissue mass along the lateral margin of the spinal column. Coronal T1 post gadolinium sequence shows the mass to heterogeneously enhance. Involvement of multiple right-sided neural foramen is well seen on this sequence as well as on the Sagittal T2 sequence. (c) A cluster of maturing ganglion cells within the Schwannian stromal background. Note the increased nuclear to cytoplasmic ratio and multinucleation within these cells compared to a mature ganglion cell. (d) A mature ganglion cell stained with synaptophysin. Note the positive staining within the borders of the intracytoplasmic secretory vesicles at the periphery of the cell. Table S1. Summary of reported individuals with neurofibromatosis type I and ganglioneuroma Table S2. Summary of the 10 deep intronic neurofibromatosis type I mutations with mRNA effect reported so far Additional Supporting information may be found in the online version of this article. 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.

Abstract 5561: Radiogenomic analysis indicates MR images are potentially predictive of EGFR mutation status in glioblastoma multiforme

Abstract Objective: To predict mutations of key genes in glioblastoma multiforme (GBM) from MR image features. Methods: We obtained mutational and MR image data from 35 patients in the Cancer Genome Atlas (TCGA) GBM database. T1-weighted axial images pre and post gadolinium contrast MRI were processed as follows: a board certified neuro-radiologist traced a region of interest (ROI) around the enhanced part of the largest lesion in the T1 post-contrast MRI and confirmed by comparing it with the T1 pre-contrast image. This ROI was then used to compute features that characterized the intensity of the enhanced lesion, the sharpness of lesion boundaries and the boundary shape. We used the resulting data set to build a linear regression model with regularization to predict the presence of a mutation in terms of image features. We focused on predicting mutations in EGFR because several drugs target it and because EGFR mutations are prevalent in the TCGA GBM data. We evaluated the performance of predicting EGFR mutations from MR imaging data using 5-fold cross validation (5F-CV) and the area under the ROC Curve (AUC). The optimal ROC operating point was defined as the point with the maximal sum of sensitivity and specificity when the cost of false positives and false negatives are considered equivalent. Results: We found that computationally-derived MR image features can predict the presence of EGFR mutations with an AUC of 0.80. The optimal operating point had a sensitivity and specificity of 83% and 93% respectively. The top ranked features in the image-based EGFR-predictor model suggest that EGFR-mutated tumors have blurrier edges than EGFR-wild-type tumors. Conclusion: Our preliminary radiogenomic analysis of GBM suggests MR images may be used to non-invasively determine the mutation status of EGFR, an important drug target in glioblastoma. The ability to determine important genomic aberrations based on image data suggests a increasingly important role for imaging in personalized medicine and warrants further investigation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5561. doi:1538-7445.AM2012-5561

Myocardial T1 measurement: comparison of modified Look-Locker inversion recovery (MOLLI) and TI scout in the Multi-ethnic Study of Atherosclerosis (MESA)

Summary Different cardiac MR acquisition sequences have been used to obtain myocardial T1 values. Among which available techniques, MOdified Look-Locker Inversionrecovery (MOLLI) and inversion-recovery TrueFisp (TI scout) sequences are widely used in research and clinical settings. We compared myocardial T1 values derived from both MOLLI and TI scout techniques in the post gadolinium delayed enhancement experiments in a large-scale multicenter study (Multi-Ethnic Study of Atherosclerosis, MESA). Our results indicated that myocardial T1 measurement using MOLLI is reproducible with TI scout. Background Different cardiac MR sequences have been used to obtain myocardial T1 values. The multipoint approach, as first described by Look and Locker (TI scout), has been widely used for estimation of the optimal TI in the assessment of myocardial delayed enhancement (DE). The other technique, MOdified Look-Locker Inversionrecovery (MOLLI) allows a rapid and highly reproducible T1 mapping of the heart with high levels of intra and inter-observer agreement. Even though each technique claims its own merit and reliability, the post-contrast myocardial T1 value is confounded by various factors that inhibit comparison of myocardial T1 between patients. In this work, we compared myocardial T1 values derived from both MOLLI and TI scout

Methotrexate-induced acute toxic leukoencephalopathy

Acute lymphoblastic leukemia (ALL) is one of the most common malignancies of childhood, which is treated with high doses of methotrexate (MTX), as it crosses the blood-brain barrier and can be administered intravenously and via intrathecal route to eradicate leukemic cells from central nervous system (CNS). Additionally, high doses of MTX not only prevent CNS recurrence but also hematologic relapses. Although, standard treatment protocol for ALL includes multimodality therapy, MTX is usually associated with neurotoxicity and affects periventricular deep white matter region. Methotrexate-induced 'acute toxic leukoencephalopathy' has varying clinical manifestations ranging from acute neurological deficit to seizures or encephalopathy. Diffusion weighted magnetic resonance imaging (DW-MRI) is widely available and routinely used in clinical practice to identify acute stroke and also to distinguish acute stroke from non-stroke like conditions. We report a local teenage Chinese girl who developed 2 discrete episodes of left upper and lower limb weakness with left facial nerve paresis after receiving the 2 nd and 3 rd cycle of high dose of intravenous and intrathecal methotrexate, without having cranial irradiation. After each episode of her neurological deficit, the DW-MRI scan showed focal restricted diffusion in right centrum semiovale. Her left sided focal neurological deficit and facial nerve paresis almost completely subsided on both these occasions within 3 days of symptom onset. Follow-up DW-MRI, after her neurological recovery, revealed almost complete resolution of previously noted restricted diffusion in right centrum semiovale, while the lesion was not evident on concurrent T2W (T2-weighted) and FLAIR (Fluid-Attenuated Inversion recovery) sequences, nor showed any post contrast enhancement on post gadolinium enhanced T1W (T1-weighted) sequences. No residual neurological deficit or intellectual impairment was identified on clinical follow up over a 2 year period.

Retinal astrocytic hamartomas in tuberous sclerosis complex

A3-month-old baby (born 36/40weeks)with antenatal diagnosis of tuberous sclerosis (TS) (having cardiac rhadomyomas and multiple subependymal nodules) was admitted with new onset infantile spasms. Electroencephalography revealed modified hypsarrhythmia. The spasms were managedwith Vigabatrin. Magnetic resonance imaging of the brain reveadled multiple subependymal and subcortical tubers scattered throughout both cerebral hemispheres in keeping with TS (Figs 1a and 1b). Two very tiny retinal masses, hypointense on T2-weighted images and moderately enhancing on post gadolinium T1-weighted images were noted within the left eye, suggestive of astrocytic hamartomas (Figs 2 and 3). Thesefindingswere further confirmed with orbital ultrasound that revealed welldefined retinal masses in left eye (Fig. 4). Ophthalmic examination under anesthesia confirmed multiple retinal astrocytic hamartomas in left eye. Her recent ophthalmic examination, at the age of 2 years demonstrated stable appearance of the retinal lesions. Retinal astrocytic hamartomas are known ocular manifestation of TS complex [1]. The largest reported

MRI identifies plantar plate pathology in the forefoot of patients with rheumatoid arthritis

Previous cadaveric studies have suggested that forefoot deformities at the metatarsophalangeal (MTP) joints in patients with rheumatoid arthritis (RA) might result from the failure of the ligamentous system and displacement of the plantar plates. This study aimed to examine the relationship between plantar plate pathology and the rheumatoid arthritis magnetic resonance imaging score (RAMRIS) of the lesser (second to fifth) MTP joints in patients with RA using high-resolution 3 T magnetic resonance imaging (MRI). In 24 patients with RA, the forefoot was imaged using 3 T MRI. Proton density fat-suppressed, T2-weighted fat-suppressed and T1-weighted post gadolinium sequences were acquired through 96 lesser MTP joints. Images were scored for synovitis, bone marrow oedema and bone erosion using the RAMRIS system and the plantar plates were assessed for pathology. Seventeen females and 7 males with a mean age of 55.5 years (range 37–71) and disease duration of 10.6 years (range 0.6–36) took part in the study. Plantar plate pathology was most frequently demonstrated on MRI at the fifth MTP joint. An association was demonstrated between plantar plate pathology and RAMRIS-reported synovitis, bone marrow oedema and bone erosion at the fourth and fifth MTP joints. In patients with RA, 3 T MRI demonstrates that plantar plate pathology at the lesser MTP joints is associated with features of disease severity. Plantar plate pathology is more common at the fourth and fifth MTP joints in subjects with RA in contrast to the predilection for the second MTP reported previously in subjects without RA.

Abstract 9402: Diffuse Myocardial Fibrosis Negatively Correlates with Exercise Capacity in Children with Subclinical Anthracycline Cardiotoxicity

Background The effectiveness of anthracycline chemotherapy in improving survival is limited by late cardiotoxicity. The aim of this study was to examine novel cardiac MRI and echocardiography measures to detect subclinical cardiotoxicity in childhood cancer survivors, and to determine its relationship to exercise capacity. Methods Thirty patients (15±3years, 50% male), 8±5 years after anthracycline therapy (cumulative dose 197±84 mg/m 2 ), underwent cardiac MRI, echocardiography and cardiopulmonary (cycle ergometer) exercise testing (VO 2peak ). Cardiac MRI assessed volumetric function, mass, and myocardial extra-cellular volume (ECV), a measure of diffuse fibrosis based on changes in blood and myocardial T1 values pre and post gadolinium. Tissue Doppler annular velocities (E’, A’) and peak circumferential and longitudinal strain, strain rate (SR) and torsion, from speckle tracking, were compared to 35 healthy controls (13±4 years). Data (mean ± SD) was analysed using Pearson's product-moment coefficient and unpaired t-tests (p<0.05). Results Patients were asymptomatic with normal LVEF (59±7%) but VO 2peak was 15% lower than age and gender determined healthy predicted values. Myocardial ECV was inversely correlated with mass/volume ratio (r = -0.5, p<0.01), and VO 2peak (r = -0.5, p<0.01), and lower VO 2peak correlated with increased cumulative dose (r = 0.4, p<0.05). Echocardiographic measures of systolic function were significantly reduced compared to controls (decreased circumferential and longitudinal strain, longitudinal SR and torsion, p<0.01). Diastolic dysfunction was evident with decreased circumferential and longitudinal diastolic SR and decreased annular velocities (p<0.01) relative to controls. There was no correlation between echocardiographic parameters and ECV or VO 2peak . Conclusion Diffuse myocardial fibrosis (increased ECV) is correlated with reduced mass/volume ratios and VO 2peak in children post anthracyline. While there were abnormalities of systolic and diastolic function, these metrics did not correlate with ECV or VO 2peak . Myocardial ECV provides a non-invasive early marker of ventricular remodelling that is related to exercise capacity which may be of prognostic value in childhood cancer survivors.

Abstract 18396: Diffuse Myocardial Fibrosis Quantification by Cardiac MR is Strongly Associated with B-type Natriuretic Peptide (BNP) and Low Ejection Fraction: Implications for Paradigms of Myocardial Dysfunction

Background: While myocardial fibrosis has been proposed as the hallmark of pathologic remodeling, its role in myocardial dysfunction is not always recognized in paradigms of cardiac dysfunction. We hypothesized that myocardial fibrosis: 1) would correlate strongly to BNP, a nonspecific and quantitative metric of cardiac dysfunction and potent predictor of outcomes, even after adjustment for key metrics of cardiac changes; and 2) would be prevalent in the setting of cardiac dysfunction. Methods and Results: In 135 patients without myocardial infarction, amyloidosis or hypertrophic cardiomyopathy who were referred for contrast enhanced cardiac magnetic resonance, we quantified the extracellular volume fraction (Ve--a validated and quantitative metric of myocardial fibrosis):Ve = [λ · ρ · (1-hematocrit)] - Vpwhere ρ= specific density of myocardium (1.05), Vp is the myocardial plasma volume fraction (assumed to be a constant 4.5% reflecting capillary density), and λ=[ΔR1 myocardium ] / [ΔR1 bloodpool ] pre and post Gadolinium contrast (where R1=1/T1). T1 was measured with a modified ECG-gated Look-Locker IR-SSFP sequence validated against CuSO4 phantoms. BNP levels were log transformed given their skewed distribution. Elevated Ve was defined as >25%, (above the 99 th percentile in healthy volunteers). In linear regression models, Ve strongly related to ln BNP (unadjusted t value 8.4, p<0.0001, R2=0.35) even after adjusting for ejection fraction (EF), age, sex, diuretic use, myocardial mass index, and body mass index (adjusted t value 4.4, p<0.0001, R2=0.65). Similar data were obtained when circumferential or meridional wall stress was substituted for EF (not shown). In the 40% of patients with EF<50%, 71% had elevated Ve (chi square 24, p<0.0001). In the 45% of patients with BNP>100 pg/mL, 75% had elevated Ve (chi square 24, p<0.0001). Conclusions: Myocardial fibrosis is strongly and independently associated with cardiac dysfunction quantified by BNP levels. Myocardial fibrosis is highly prevalent in those with cardiac dysfunction defined by EF<50% or BNP>100 pg/mL. These data suggest an important role of myocardial fibrosis in human myocardial dysfunction. Paradigms of cardiac dysfunction should include the role of myocardial fibrosis.

WE‐G‐214‐02: Utility of 18F‐FDOPA PET for Radiotherapy Target Delineation in Glioma Patients

Purpose: To evaluate the impact of adding 18F‐FDOPA‐PET, an amino acid tracer, to standard of care MRI for radiotherapy target volume delineation for gliomas. Methods: 6 patients with newly diagnosed brain tumors were given 5.0 mCi +/− 10% of 3,4‐dihydroxy‐6‐[18F]‐fluoro‐L‐phenylalanine (18F‐FDOPA), and underwent a 10‐minute PET/CT acquisition. Overall pathology confirmed WHO grade 3 astrocytoma (n=3), grade 3 oligoastrocytoma (n=1), and glioblastoma (n=2). T1‐weighted post gadolinium (T1‐gad) and T2‐weighted/FLAIR MRI sequences were rigidly aligned to the 18F‐FDOPA‐PET/CT. Three experienced radiation oncologists contoured the T2/FLAIR abnormality, T1‐gad enhancement, and areas of 18F‐FDOPA uptake separately. An experienced nuclear medicine physician contoured 18F‐FDOPA uptake, which was considered as the gold standard for positive disease on PET imaging. Intersection, union, and exclusion boolean operators were performed to determine discordance and concordance between MRI and 18F‐FDOPA‐PET, along with interobserver variability defining 18F‐FDOPA‐PET volume. In addition, uniform expansions of the T1‐gad contours were performed in increments of 0.5 cm until 100% of the 18F‐FDOPA‐PET volume was covered. Results: 18F‐FDOPA‐PET uptake was observed in all patients, with interobserver delineation variability between radiation oncologists (RadOnc1‐RadOnc3) and the gold standard ranging from 47% less to 191% more volume. On average 9.5% (0.3%–29.1%) of the 18F‐FDOPA‐PET gold standard volume extended beyond the RadOnc T2/FLAIR volumes. Half of the cases had no enhancement, and of the remainder on average 77.8% (61.3%–93.1%) of the 18F‐FDOPA‐PET volume extended outside the T1‐gad enhancement. An average expansion of 2.0cm (1.0cm–5.0cm) beyond the T1‐gad contours was necessary to cover 100% of the 18F‐FDOPA‐PET volume. Conclusions: This work introduces the potential utilization of 18F‐FDOPA‐PET for identifying positive disease not visible with conventional MRI and the potential to customize radiotherapy target volumes to the active disease. Future studies will correlate pathology with concordant and discordant regions, and compare biopsy confirmed results with automatic segmentation techniques for 18F‐FDOPA‐PET.Funding has been provided by Brains Together for a Cure

Fat-saturated post gadolinium T1 imaging of the brain in multiple sclerosis

Magnetic resonance imaging (MRI) is of vital importance in the diagnosis and follow-up of patients with multiple sclerosis (MS). Imaging sequences better demonstrating enhancing lesions can help in detecting active MS plaques. To evaluate the role of fat-saturated gadolinium-enhanced T1-weighted (T1W) images of the brain in MS and to assess the benefit of performing this additional sequence in the detection of enhancing lesions. In a prospective study over a six-month period, 70 consecutive patients with clinically diagnosed MS were enrolled. These constituted 14 male and 56 female patients between the ages of 21 and 44 years. All the patients underwent brain MRIs on a 1.5 Tesla Magnet. Gadolinium-enhanced T1 images with and without fat saturation were compared and results were recorded and analyzed using a conspicuity score and McNemar test. There were a total of 157 lesions detected in 70 patients on post-contrast T1W fat-saturated images compared with 139 lesions seen on the post-contrast T1W fast spin-echo (FSE) images. This was because 18 of the lesions (11.5%) were only seen on the fat-saturated images. In addition, 15 lesions were more conspicuous on the fat saturation sequence (9.5%). The total conspicuity score obtained, including all the lesions, was 2.24 +/-0.60 (SD). Using the two-tailed McNemar test for quantitative analysis, the P value obtained was <0.0001. T1W fat-saturated gadolinium-enhanced images show better lesion enhancement than T1W images without fat saturation.

1894 DIFFUSION-WEIGHTED MAGNETIC RESONANCE IMAGING REFLECTS PATHOLOGIC PHENOTYPES OF BLADDER CANCER

underwent radical cystectomy and extended pelvic/iliac lymph node dissection for bladder cancer by a single surgeon. Of the 230 patients, 122 with biopsy-proven bladder cancer underwent a pre-operative MRI of the pelvis on a 1.5 Tesla magnet utilizing coronal single shot T2, axial fast spin echo T1, three plane fast spin echo T2, fat suppressed gradient echo T1 before and during dynamic phase of gadolinium enhancement. Pre and post gadolinium fat suppressed gradient echo T1 in the axial plane were also obtained for each patient. Two radiologists evaluated all of the MR images and blindly assigned a clinical stage that was compared with the pathologic stage obtained from radical cystectomy and extended pelvic/iliac lymphadenectomy. Nodes measuring more than 1 cm by MRI were considered positive. RESULTS: A logistic regression was performed in order to determine if radiologist T-stage assessment was predictive of T-stage pathology. T-stage pathology was classified into two groups: (1) T0–T2 and (2) T3–T4. 74% of cases were correctly classified ( 2 23.29, p .001), however, only one radiologist’s T-stage rating was predictive of T-stage pathology grouping ( .989, p .003). Over-staging and under-staging were each observed at similar frequency (29% and 35% respectively). Chi-squared tests of independence were employed to measure the association between the radiologists’ nodal stage assessment and pathological results. Although radiologists’ N-stage assessment was associated with N-stage pathology (p 0.001), the sensitivity to diagnose nodal metastasis was only 40.7%. CONCLUSIONS: This series represents one of the largest cohort of bladder cancer patients pre-operatively staged with dynamic gadolinium enhanced MRI. Tumor staging of bladder cancer using MRI may be more accurate than traditional CT scans, but still lacks significant predictive power. MRI remains limited in its ability to accurately stage nodal involvement most likely secondary to presence of micrometastatic disease. Better imaging techniques are needed for preoperative staging of invasive bladder cancer.

Vascular invasion in hepatocellular carcinoma: is there a correlation with MRI?

Hepatocellular carcinoma (HCC) is one of the commonest malignancies worldwide. Prognosis is predicted by size at diagnosis, vascular invasion and tumour proliferation markers. This study investigates if MRI features of histologically proven HCCs correlate with vascular invasion. Between 2006 and 2008, 18 consecutive patients, with a total of 27 HCCs, had comprehensive MRI studies performed at our institution within a median of 36 days of histology sampling. Each lesion was evaluated independently on MRI by 3 radiologists (blinded to both the radiology and histopathology reports) using a 5-point confidence scale for 23 specific imaging features. The mean of the rating scores across readers was calculated to determine interobserver consistency. The most consistent features were then used to examine the value of features in predicting vascular invasion, using a χ(2 )test for trend, having eliminated those features without sufficient variability. 22 of the 23 imaging features showed sufficient variability across lesions. None of these significantly correlated with the presence of vascular invasion, although a trend was identified with the presence of washout in the portal venous phase on MRI and the median size of lesions, which was greater with vascular invasion. This study suggests that no single MRI feature accurately predicts the presence of vascular invasion in HCCs, although a trend was seen with the presence of washout in the portal venous phase post gadolinium. Larger prospective studies are required to investigate this further.

Cardiac magnetic resonance left ventricular quantitative analysis post gadolinium: reliable and reproducible?

Background Cardiovascular magnetic resonance (CMR) imaging is widely accepted as the gold standard in the assessment of LV volume and function. To date this assumption has been based on analysis of unenhanced gradient echo cine imaging. In certain clinical scenarios the use of gadolinium contrast is required for the evaluation of myocardial perfusion and late contrast enhancement. By performing an LV cine stack between the perfusion and late enhancement sequences the total scan duration can be reduced. However, it is possible that post contrast image acquisition alters endocardial and epicardial border detection and therefore affects the results of ventricular functional analysis (Fig. 1).

Cardiovascular effects of intravenous gadolinium administration to anaesthetized dogs undergoing magnetic resonance imaging

ObjectiveTo assess changes in heart rate and arterial blood pressure following intravenous (IV) gadolinium–based contrast media administration to sevoflurane–anaesthetized dogs undergoing magnetic resonance imaging (MRI). Study designProspective clinical study. AnimalsFifty client–owned dogs (31 male, 19 female; aged 6–156 months; weighing 4.2–45.4 kg; ASA 2–3). MethodsHeart rate and oscillometric blood pressures (systolic, mean and diastolic) were recorded at 10 minutes, 5 minutes and immediately pre–administration of IV gadolinium contrast medium (time 0), then at 1, 2, 3, 5 and 10 minutes post–gadolinium administration. Repeated measures anova was used to compare cardiovascular variables pre and post–gadolinium administration. Significance was set at p < 0.05. ResultsThere were no significant changes in cardiovascular variables following the IV administration of gadolinium. Conclusions and clinical relevanceAdministration IV of gadolinium–based contrast media was not associated with adverse cardiovascular effects in these sevoflurane–anaesthetized dogs undergoing MRI.

Magnetic resonance imaging of guinea pig cochlea after vasopressin-induced or surgically induced endolymphatic hydrops

Objective To investigate the ability to detect the in vivo cochlear changes associated with vasopressin-induced and surgically induced endolymphatic hydrops using MRI at 3 tesla (T). Study Design Prospective, animal model. Setting Animal laboratory. Subjects and Methods In group 1, five guinea pigs underwent post–gadolinium temporal bone MRI before and after seven and 14 days of chronic systemic administration of vasopressin by osmotic pump. In group 2, five guinea pigs underwent temporal bone MRI eight weeks after unilateral surgical ablation of the endolymphatic sac. Three-tesla high-resolution T1-weighted sequences were acquired pre- and postcontrast administration. Region of interest signal intensities of the perilymph and endolymph were analyzed manually. Quantitative evaluation of hydrops was measured histologically. Results Gadolinium preferentially concentrated in the perilymph, allowing for distinction of cochlear compartments on 3.0-T MRI. The T1-weighted contrast MRI of vasopressin-induced hydropic cochlea showed significant increases in signal intensity of the endolymph and perilymph. Surgically induced unilateral hydropic cochlea also showed increased signal intensity, compared with the control cochlea of the same animal, but less of an increase than the vasopressin group. The histological degree of hydrops induced in the vasopressin group was comparable to previous studies. Conclusions In vivo postcontrast MRI of the inner ear demonstrated cochlear changes associated with chronic systemic administration of vasopressin and surgical ablation of the endolymphatic sac. Understanding the MRI appearance of endolymphatic hydrops induced by various methods contributes to the future use of MRI as a possible tool in the diagnosis and treatment of Ménière's disease.

Prevalence of late gadolinium enhancement in magnetic resonance imaging of patients with left ventricular non-compaction cardiomyopathy

Methods 14 patients (11 male, average age 37 years) with positive Jenni-criterion for LVNC in echocardiography underwent cMRI (Siemens Sonata 1.5 T). Cine TruFISP, TSE T1(pre and post contrast Early Gadolinium Enhancement ratio (EGEr) according to Friedrich et al. 1998) and T2wheighted images (Edema Ratio (ER myocardial signal intensity (SI)/scelettal muscle (SI)) were acquired as well as additional late gadolinium enhancement images (LGE) after administration of 0.2 mmol gadodiamide per kg body weight. LGE was deemed as either beeing present or not.

Assessment Of Cardiac Inflammation And Injury Following Prolonged Exercise Using Cardiovascular Magnetic Resonance (CMR) Imaging

PURPOSE: Myocardial inflammation may be a potential mechanism for the release of troponin and NTproBNP following a Marathon. CMR has not been previously used to detect and quantify myocardial inflammation and fibrosis pre- and post-Marathon. METHODS: CMR was performed in 18 athletes 24hrs pre and 6 hours post a Marathon run. Each scan was performed on a 1.5T Siemens Avanto scanner using a 4 channel body array coil. Myocardial structure and function was assessed using breath hold SSFP cine imaging in long and short axis views. The presence of myocardial inflammation and oedema was assessed using STIR imaging and a 3-4 minute spin echo sequence immediately post 0.1mmol intravenous gadolinium-DTPA to assess relative gadolinium enhancement. Inversion recovery segmented-FLASH imaging with TI adjusted to null normal myocardium to highlight regions of fibrosis was used to image delayed enhancement. Each participant had bloods drawn for TnI, NT-proBNP, and CRP at baseline, immediately post and 6 hours after the run. Each CMR scan was analyzed for wall thickness per segment, volumes and function, myocardial oedema. Delayed enhancement images were analysed using Medis software. RESULTS: Biventricular volumes, stroke volume, ejection fraction, and mass were unchanged pre and 6 hrs post marathon. The majority of subjects were found to have a rise in BTproBNP levels immediately and 6 hours after the race as well as elevations in TnI above the level of cut off for myocardial infarction (P=0.001). There were no focal regions of visual signal increase on the STIR images in any of the 18 subjects. Global myocardial oedema was predefined using a cut off ratio of 1.9 comparing SI of myocardium to skeletal muscle on STIR imaging, and a relative 45% increase in the SI myocardium/skeletal muscle immediately post intravenous gadolinium on relative gadolinium enhancement imaging (rGE). No subject reached these cut off values. None had any visual myocardial fibrosis on late enhancement imaging or using automated software. CONCLUSIONS: Serum markers of myocardial cell damage post ultra endurance exercise are not associated with CMR detectable levels of myocardial oedema, inflammation or scarring, suggesting lower degrees of myocardial damage than in patients with acute myocardial infarction, inspite of similar levels of troponin elevation.