Use Of Gadolinium Contrast Research Articles

Adenosine Triphosphate Stress Myocardial Strain in Ischemic Heart Disease: An Animal Study with Histological Validation

It is still challenging for cardiac magnetic resonance (CMR) to detect ischemic heart disease (IHD) without the use of gadolinium contrast. We aimed to evaluate the potential value of adenosine triphosphate (ATP) stress myocardial strain derived from feature tracking (FT) as a novel method for detecting IHD in a swine model. CMR cines, myocardial perfusion imaging at rest and during ATP stress, and late gadolinium enhancement were obtained in both control and IHD swine. Normal, remote, ischemic, and infarcted myocardium were analyzed. The diagnostic accuracy of myocardial strain for infarction and ischemia was assessed using coronary angiography and pathology as reference. Eleven IHD swine and five healthy control swine were enrolled in this study. Strain parameters, even at rest, were associated with myocardial ischemia and infarction(all p<0.05). The area under receiver operating characteristic curve(AUC) values of all strain parameters for detecting infarcted myocardium exceeded 0.900(all p<0.05). The AUC values for detecting ischemic myocardium were as follows: 0.906 and 0.847 for stress and rest radial strain, 0.763 and 0.716 for stress and rest circumferential strain, 0.758 and 0.663 for stress and rest longitudinal strain(all p<0.001). Heat maps demonstrated that all strain parameters showed mild to moderate correlations with the stress myocardial blood flow and myocardial perfusion reserve(all p<0.05). CMR-FT-derived ATP stress myocardial strain shows promise as a noninvasive method for detecting myocardial ischemia and infarction in an IHD swine model, with rest strain parameters offering potential as a needle-free diagnostic option.

Addition of gadolinium contrast to three-dimensional SSFP MR sequences improves the visibility of coronary artery anatomy in young children.

This study aims to compare the value of a gadolinium contrast-enhanced 1.5-T three-dimensional (3D) steady-state free precession (SSFP) sequence with that of a noncontrast 3D SSFP sequence for magnetic resonance coronary angiography in a pediatric population. Seventy-nine patients from 1 month to 18 years old participated in this study. A 3D SSFP coronary MRA at 1.5-T was applied before and after gadolinium-diethylenetriaminepentaaceticacid (DTPA) injection. The detection rates of coronary arteries and side branches were assessed by McNemar's χ2 test. The image quality, vessel length, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the coronary arteries were analyzed by the Wilcoxon signed-rank test. The intra- and interobserver agreements were evaluated with a weighted kappa test or an intraclass correlation efficient test. A contrast-enhanced scan detected more coronary arteries than a noncontrast-enhanced scan in patients under 2 years old (P < 0.05). The SSFP sequence with contrast media detected more coronary artery side branches in patients younger than 5 years (P < 0.05). The image quality of all the coronary arteries was better after the injection of gadolinium-DTPA in children younger than 2 years (P < 0.05) but not significantly improved in children older than 2 years (P > 0.05). The contrast-enhanced 3D SSFP protocol detected longer lengths for the left anterior descending coronary artery in children younger than 2 years and the left circumflex coronary artery (LCX) in children younger than 5 years (P < 0.05). SNR and CNR of all the coronary arteries in children younger than 5 years and the LCX and right coronary artery in children older than 5 years enhanced after the injection of gadolinium-DTPA (P < 0.05). The intra- and interobserver agreements were high (0.803-0.998) for image quality, length, SNR, and CNR of the coronary arteries in both pre- and postcontrast groups. The use of gadolinium contrast in combination with the 3D SSFP sequence is necessary for coronary imaging in children under 2 years of age and may be helpful in children between 2 and 5 years. Coronary artery visualization is not significantly improved in children older than 5 years.

PO-03-164 FEASIBILITY OF GADOLINIUM CONTRAST FLUOROSCOPY TO FACILITATE WATCHMAN FLX IMPLANTATION USING INTRACARDIAC ECHOCARDIOGRAPHY

In patients with non-valvular atrial fibrillation, left atrial appendage closure (LAAC) is an alternative to oral anticoagulation for stroke-risk reduction. The standard imaging used during LAAC procedures is transesophageal echocardiography with iodinated contrast media. The recent worldwide supply chain shortage in April 2022 resulted in a global shortage of these contrast agents, limiting the ability to perform LAAC. Alternatives to iodinated contrast agents are needed to combat the impact of the contrast shortage on patient care. Limited published experience has shown effective use of IV gadolinium contrast for coronary angiography. We sought to validate the use of gadolinium contrast for LAAC in lieu of iodinated contrast agents. Thirty consecutive patients referred for LAAC underwent Watchman FLX implant with intracardiac echo (ICE) using gadolinium (Gadovist) for intra-procedural LAA angiography and device assessment prior to device release. Ultrasound imaging was performed with an 8 Fr. ICE catheter (AcuNav). Light sedation was used. Patients were managed with antithrombotic therapy for 12-weeks post implant with CT imaging at 4 months. Of the total cohort of 32 patients, two were excluded for creatinine clearance < 30 mL/min. The 30 remaining patients had successful closure of the LAA with no peri-device leaks (PDL) using an average of 11 mL (10-15) gadolinium contrast and ICE imaging. The workflow consisted of a pigtail angiogram of the LAA using 5 mL gadolinium with the remainder used through the Watchman delivery sheath post-deployment to visualize the tug test and assess for PDL. ICE verified Watchman FLX position at multiple angles. Procedure time was 42 min (30-59) with an average of 1.5 deployments per case (1-3). At 4 months, 26 (87%) had complete closure (20 by CT, 6 by TEE). Four patients had a PDL of 1.5 mm (1-3 mm) by CT. No device-related thrombus was noted. There were no complications noted during the first 4 months post implant. Gadolinium contrast may be used as an alternative to iodinated contrast agents for LAA angiography to facilitate Watchman FLX implantation with ICE with both efficacy and safety. Operators should have sufficient experience with Watchman FLX LAAC to minimize the need for multiple angiographic views and use ultrasound imaging to assess for PDL. Gadolinium contrast can be a valuable option during efforts to conserve IV iodinated contrast, but also for patients with iodinated contrast allergy.

Safety profile of Gadoterate meglumine on the renal function of patients with severe kidney disease

ObjectiveIntravenous administration of gadolinium-based contrast agents (GBCA) in patients with impaired renal function has been of concern to primary care physicians due to the potential worsening of renal dysfunction and nephrogenic systemic fibrosis (NSF). Our objective was to compare the potential change in estimated glomerular filtration rate (eGFR) in patients with known severe renal dysfunction (eGFR <30 ml/min), following Gadoterate meglumine (GM) administration with patients who do not receive contrast. MethodsAn IRB-approved retrospective analysis of all patients who underwent MRI examination at our institution, for any indication, between January 2016 and September 2020. Inclusion criteria: pre-MRI eGFR <30 ml/min within 24 h of MRI, follow-up eGFR between 48 and 96 h post-MRI, and absence of peritoneal or hemodialysis. The individuals who received GM (492 scans) were identified as cases, and those who did not receive contrast (1101 scans) were identified as controls for our study. Delta-eGFR response was calculated and covariate-adjusted, and propensity score analysis was performed. ResultsNo significant eGFR decrease was observed in patients who received GM compared to those who did not receive GM in our study. Also, no relationship between comorbidity, severity and contrast selection was observed. ConclusionThe use of Gadolinium contrast in MRI is often of critical importance for determining accurate anatomic relationships, differentiation of benign from malignant lesions, or determination of resolving vs. worsening disease. Though the risk of contrast administration can never be entirely ignored, especially in patients with low eGFR, our study indicates that safe administration of GM can be performed even in patients with severe kidney disease.

Native T1 heterogeneity for predicting reverse remodeling in patients with non-ischemic dilated cardiomyopathy.

A recent study has shown that the heterogeneity of native T1 mapping may be a new prognostic factor for patients with non-ischemic dilated cardiomyopathy (NIDCM). This study aimed to investigate the predictive value of native T1 heterogeneity of the left ventricular (LV) myocardium, as assessed by pixel-wise histogram analysis, for predicting left ventricular reverse remodeling (LVRR) by medical therapy in patients with NIDCM. A total of one hundred and thirteen NIDCM patients (mean age: 63 ± 12years; 91 males and 22 females; mean LV ejection fraction (EF): 37 ± 10%) were retrospectively analyzed. T1 mapping images were acquired using a modified look-locker inversion recovery (MOLLI) sequence. We performed histogram analysis of native T1 mapping of LV myocardium, mean (T1-mean) and standard deviation (T1-STD) of native T1 time from each pixel were calculated. Extracellular volume fraction (ECV) was also evaluated. LVRR was defined as LVEF increased ≥ 10% points and decrease in LV end-diastolic volume ≥ 10% at 12months from initiation of medical therapy. Cutoff value of T1-mean and T1-STD was set as median value of each parameter. Sixty (53%) NIDCM patients reached LVRR. Area under the receiver-operating characteristics curve for predicting LVRR was 0.763 (95% confidence interval (CI) 0.679-0.847) for %LGE, 0.757 (95% CI 0.663-0.850) for T1-mean, 0.724 (95% CI 0.625-0.823) for T1-STD, 0.800 (95% CI 0.717-0.882) for ECV, respectively. Proportion of LVRR was significantly lower in NIDCM patients with high T1-mean and high T1-STD (12%) compared to NIDCM with high T1-mean and low T1-STD (65%) (p < 0.001). Adding T1-STD to T1-mean improved AUC from 0.757 to 0.806, comparable to AUC of ECV. Combination of T1-mean and T1-STD, a parameter of heterogeneity of native T1 of the LV myocardium, may be a useful for prediction of LVRR by medical therapy without use of gadolinium contrast for patients with NIDCM.

Recent advances in magnetic resonance imaging for peripheral artery disease.

The global burden of peripheral artery disease (PAD) is significant. This has led to numerous recent advances in magnetic resonance imaging (MRI) techniques in PAD. Older techniques such as time of flight MRI or phase contrast MRI are burdened by long acquisition times and significant issues with artifacts. In addition, the most used MRI modality, contrast-enhanced MR angiography (CE-MRA) is limited by the use of gadolinium contrast and its potential toxicity. Novel MRI techniques such as arterial spin labeling (ASL), blood-oxygen-level dependent imaging (BOLD), and first-pass perfusion gadolinium enhancement are advancing the field by providing skeletal muscle perfusion/oxygenation data while maintaining excellent spatial and temporal resolution. Perfusion data can be critical to providing objective clinical data of a visualized stenosis. In addition, there are a number of new MRI sequences assessing plaque composition and lesion severity in the absence of contrast. These approaches used in combination can provide useful clinical and prognostic data and provide critical endpoints in PAD research.

Myocardial Strain Using Cardiac MR Feature Tracking and Speckle Tracking Echocardiography in Duchenne Muscular Dystrophy Patients.

Duchenne muscular dystrophy (DMD) is an inherited X-linked disorder with an incidence of 1 in 3500 male births, and cardiomyopathy is becoming the leading cause of death. While Cardiac MRI (CMR) and late gadolinium enhancement (LGE) are important tools in recognizing myocardial involvement, myocardial strain imaging may demonstrate early changes and allow patients to avoid gadolinium contrast. We performed CMR feature tracking (FT) and echo-based speckle tracking (STE) strain measures on DMD patients and age/sex matched controls who had received a CMR with contrast and transthoracic echocardiogram. Data were collected for longitudinal strain in the apical four-chamber view and circumferential strain in the mid-papillary parasternal short axis. Segmental wall analysis was performed and compared with the presence of LGE. Data were analyzed using student's t tests or one-way ANOVA adjusting for multiple comparisons. We measured 24 subjects with DMD and 8 controls. Thirteen of 24 DMD subjects were LGE positive only in the lateral segments in short-axis views. Average circumferential strain (CS) measured by FT was significantly decreased in DMD compared to controls (- 18.8 ± 6.1 vs. - 25.5 ± 3.2; p < 0.001) and showed significant differences in the anterolateral, inferolateral, and inferior segments. Average CS by STE trended towards significance (p = 0.06) but showed significance in only the inferior segment. FT showed significant differences in the inferolateral segment between LGE positive (- 15.5 ± 9.0) and LGE negative (- 18.2 ± 8.3) in DMD subjects compared to controls (- 28.6 ± 7.3; p ≤ 0.04). FT also showed significant differences between anteroseptal and inferolateral segments within LGE-positive (p < 0.003) and LGE-negative (p < 0.03) DMD subjects while STE did not. There were no significant differences in longitudinal strain measures. CMR-FT-derived myocardial strain was able to demonstrate differences between subjects with DMD and controls not detected by STE. FT was also able to demonstrate differences in LGE-positive and LGE-negative segments within patients with DMD. FT may be able to predict LGE-positive segments in DMD without the use of gadolinium contrast.

Imaging in Juvenile Spondyloarthritis.

This review aims to provide an update on the use of imaging in the assessment of juvenile spondyloarthritis (JSpA) disease manifestations. Recent studies have demonstrated superior reliability and specificity of MRI for assessment of sacroiliac joint inflammation compared with radiography. The use of gadolinium contrast may not add incremental value to the assessment of inflammatory sacroiliitis. Sacroiliitis is common at diagnosis of spondyloarthritis. Inflammatory changes of the lumbar spine are not uncommon, and changes over time in the sacroiliac and apophyseal joints may not be concordant. Ultrasonography (US) in turn has been recognized as an excellent imaging technique to visualize the peripheral manifestations of JSpA. US does not only add important information to the clinical assessment but also helps to understand the complexity of the enthesis. Recognition of specific aspects in children is important though. The standardization of image acquisition as well as the establishment of the evidence base are underway. MRI and ultrasonography are recognized as increasingly important tools in the diagnosis and management of juvenile spondyloarthritis.

Adenosine Stress and Rest T1 Mapping Can Differentiate Between Ischemic, Infarcted, Remote, and Normal Myocardium Without the Need for Gadolinium Contrast Agents

ObjectivesThe aim of this study was to evaluate the potential of T1 mapping at rest and during adenosine stress as a novel method for ischemia detection without the use of gadolinium contrast. BackgroundIn chronic coronary artery disease (CAD), accurate detection of ischemia is important because targeted revascularization improves clinical outcomes. Myocardial blood volume (MBV) may be a more comprehensive marker of ischemia than myocardial blood flow. T1 mapping using cardiac magnetic resonance (CMR) is highly sensitive to changes in myocardial water content, including MBV. We propose that T1 mapping at rest and during adenosine vasodilatory stress can detect MBV changes in normal and diseased myocardium in CAD. MethodsTwenty normal controls (10 at 1.5-T; 10 at 3.0-T) and 10 CAD patients (1.5-T) underwent conventional CMR to assess for left ventricular function (cine), infarction (late gadolinium enhancement [LGE]) and ischemia (myocardial perfusion reserve index [MPRI] on first-pass perfusion imaging during adenosine stress). These were compared to novel pre-contrast stress/rest T1 mapping using the Shortened Modified Look-Locker Inversion recovery technique, which is heart rate independent. T1 values were derived for normal myocardium in controls and for infarcted, ischemic, and remote myocardium in CAD patients. ResultsNormal myocardium in controls (normal wall motion, MPRI, no LGE) showed normal resting T1 (954 ± 19 ms at 1.5-T; 1,189 ± 34 ms at 3.0-T) and significant positive T1 reactivity during adenosine stress compared to baseline (6.2 ± 0.5% at 1.5-T; 6.3 ± 1.1% at 3.0-T; all p < 0.0001). Infarcted myocardium showed the highest resting T1 of all tissue classes (1,442 ± 84 ms), without significant T1 reactivity (0.2 ± 1.5%). Ischemic myocardium showed elevated resting T1 compared to normal (987 ± 17 ms; p < 0.001) without significant T1 reactivity (0.2 ± 0.8%). Remote myocardium, although having comparable resting T1 to normal (955 ± 17 ms; p = 0.92), showed blunted T1 reactivity (3.9 ± 0.6%; p < 0.001). ConclusionsT1 mapping at rest and during adenosine stress can differentiate between normal, infarcted, ischemic, and remote myocardium with distinctive T1 profiles. Stress/rest T1 mapping holds promise for ischemia detection without the need for gadolinium contrast.

Impact of low signal intensity assessed by cine magnetic resonance imaging on detection of poorly viable myocardium in patients with prior myocardial infarction.

Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been established as a modality to detect myocardial infarction (MI). However, the use of gadolinium contrast is limited in patients with advanced renal dysfunction. Although the signal intensity (SI) of infarct area assessed by cine MRI is low in some patients with prior MI, the prevalence and clinical significance of low SI has not been evaluated. The aim of this study was to evaluate how low SI assessed by cine MRI may relate to the myocardial viability in patients with prior MI. Fifty patients with prior MI underwent both cine MRI and LGE-MRI. The left ventricle was divided into 17 segments. The presence of low SI and the wall motion score (WMS) of each segment were assessed by cine MRI. The transmural extent of infarction was evaluated by LGE-MRI. LGE was detected in 329 of all 850 segments (39%). The low SI assessed by cine MRI was detected in 105 of 329 segments with LGE (32%). All segments with low SI had LGE. Of all 329 segments with LGE, the segments with low SI showed greater transmural extent of infarction (78 [72 - 84] % versus 53 [38 - 72] %, P < 0.01), thinner wall (4.0[3.1 - 4.8] mm versus 6.5 [5.2 - 8.1] mm, P < 0.01), and higher WMS (4.0 [4.0 - 4.0] versus 2.0 [2.0 - 3.0], P < 0.01). The low SI assessed by cine MRI may be effective for detecting poorly viable myocardium in patients with prior MI.

Abstract 11232: Assessment of Diffuse Myocardial Fibrosis With Native T1 Values on Cardiovascular Magnetic Resonance and Its Relationship With Myocardial Function in Asymptomatic Aortic Stenosis Patients

Introduction: Aortic stenosis (AS) typically provokes diffuse myocardial fibrosis (DMF). Methods to evaluate DMF using cardiovascular magnetic resonance (CMR) are yet to be made easier and validated for wide clinical use. Hypothesis: To test whether T1 mapping, without the use of gadolinium contrast, may be useful for assessment of DMF and whether it correlates with subclinical myocardial dysfunction in asymptomatic AS patients. Methods: 80 asymptomatic patients with moderate or severe AS and normal LVEF and 15 sex-matched control subjects were prospectively enrolled. Patients underwent 2D-echocardiography, speckle tracking imaging and CMR in a 3.0T scanner including mapping of T1 relaxation time with modified Look-Locker Inversion-recovery (MOLLI) sequence. Patients were divided into three groups according to the native T1 value. Results: Native T1 values correlated well with the degree of DMF on intraoperative myocardial biopsy specimens (r=0.777, p-value&lt;0.001) and differed significantly between AS and control subjects (1208±45 vs. 1169±21(msec), p-value&lt;0.001). LV volumes and mass were significantly different between the tertiles (80.8±10.3 vs. 93.4±23.1 vs. 121.5±37.9(mL/m2), 78.0±18.3 vs. 93.4±29.7 vs. 121.1±44.3(g/m2) for LV end-diastolic volume index and LV mass index, all p-value&lt;0.001) as well as the degree of AS severity (0.55±0.14 vs. 0.46±0.12 vs. 0.45±0.13(cm2/m2), p-value=0.008 for indexed aortic valve area on echocardiography). Native T1 significantly correlated with global longitudinal strain by 2D-speckle trackle imaging (r=0.598, p-value&lt;0.001), e’ velocity (r=-0.437, p-value&lt;0.001) and indexed left atrial volume (r=0.475, p-value&lt;0.001). Conclusion: Native T1 value using MOLLI sequence in asymptomatic AS patients enables noninvasive, simple quantification of DMF and correlates well with subclinical LV systolic and diastolic dysfunction.

Assessment of myocardial viability in low signal intensity areas on cine MRI comparison with late gadolinium enhancement imaging in patients with prior myocardial infarction

Background Delayed-enhancement magnetic resonance imaging (DEMRI) is highly effective for the diagnosis of myocardial infarction in both the acute and chronic phases, which is characterized as hyperenhancement after gadolinium injection. The use of gadolinium contrast, however, is limited in patients with advanced renal dysfunction and dialysis. On cine MRI, the signal intensity (SI) of noninfarcted area is equal to that of skeletal muscle and liver in normal subjects. It is well known that the SI of infarcted area is not uniform in patients with prior myocardial infarction. The significance of low SI in infarcted area on cine MRI has not been evaluated. The purpose of this study was to assess the myocardial viability of the area with low SI on cine MRI as compared with DEMRI in patients with prior myocardial infarction. Methods Fifty patients with prior myocardial infarction underwent both cine MRI and DE-MRI to assess the myocardial function and viability. The left ventricle was divided into 17 segments, resulted in a total of 850 segments. On cine MRI, the presence of low SI area and wall motion score (WMS) of each segments were assessed. On DE-MRI, the presence of late gadolinium enhancement (LGE) area, the thickness of LGE area and outer non-enhanced area, and the transmural extension of infarction were evaluated. Results The low SI area on cine MRI was documented in 2.1±2.7 segments per patient and 105 of all 850 segments (12.4%). In DE-MRI, the LGE was detected in 6.6±3.7 segments per patient and 329 of all 850 segments (38.7%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy to predict the myocardial necrosis by the presence of low SI area on cine MRI were 32%, 100%, 100%, 70% and 74%, respectively. Of 329 segments with LGE on DE-MRI, the segments with low SI showed thinner LGE area (3.0±1.0mm versus 3.3±1.3mm, p=0.037), thinner outer non-LGE area (1.1±1.0mm versus 3.3±2.0mm, p<0.001), greater transmural extent (76±14% versus 53±21%, p<0.001), and lower WMS (3.8±10.5 versus 1.5±0.8, p<0.001) than the segment without low SI. Conclusions Although the sensitivity is relatively low, the presence of low SI area on cine MRI is as igh of prior myocardial infarction. The area with low SI has poor viability. Funding None.

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).

A change in pituitary magnetic resonance imaging protocol detects ACTH‐secreting tumours in patients with previously negative results

While detection of pituitary tumours with magnetic resonance imaging (MRI) may reduce diagnostic costs and improve surgical outcomes for patients with Cushing's disease, the optimal T1-weighted spin-echo (SE) MRI protocol remains unknown. We hypothesized that specific MR scanning parameters influence detection of corticotropinomas. Between December 1997 and November 2004, 21 of 84 consecutive patients with Cushing's disease had a falsely negative initial pituitary MRI study and a lesion identified subsequently at the National Institutes of Health Clinical Center. This study retrospectively reviewed and compared technical parameters used for the two pituitary T1-weighted SE MRIs in 18 patients with available scans. Repetition time (TR)/echo times (TE), field of view (FOV), matrix size, magnetic field strength, slice thickness, use of gadolinium contrast and the time interval between studies were recorded. The MRI interscan interval was 5.4 +/- 1.1 months. All scans used gadolinium, matrix sizes were similar and nearly all had 3-mm thick slices. Parameters that differed between the NIH- and externally performed scans were: TR (400 ms vs. 492 +/- 19 ms, P = 0.0002); TE (10.3 +/- 0.5 vs. 17.2 +/- 1.2 ms, P = 0.0003); FOV (12 x 12 cm vs.17 +/- 0.6 x 18 +/- 0.7 cm, P < 0.0001). Immunohistochemistry of tumours resected at transsphenoidal surgery confirmed all to be corticotropinomas. Not all 'T1-weighted SE' scans are equally accurate. MRI technique, particularly FOV and TR/TE value, influences results. We recommend that endocrinologists consider pituitary MRI parameters when interpreting the results.

MRI screening of the cerebellopontine angle and inner ear with fast spin-echo T2 technique.

In patients with unilateral hearing loss and dizziness it is important to rule out a cerebellopontine angle process. This is often done by audiological and otoneurological investigations. However, in many cases we must rely on the imaging of the temporal bone and the cerebello-brainstem area. The paper has presented the three dimensional (3D) Fast Spin-Echo (FSE) T2 weighted, 0.7 mm thick MR images, which in addition to being quick, does not require the use of expensive contrast material. Between September 1996 and November 1997, 152 patients with unilateral hearing loss and/or balance disorders were investigated. In normal cases the 7th and 8th nerves could be followed accurately from the brainstem to the internal auditory meatus. The found tumors were hypointense compared to the cerebrospinal fluid and could be outlined with reasonable accuracy even without gadolinium contrast. The inner ear had high signal, like cerebrospinal fluid. The patency of the cochlea could be estimated accurately. Thus, 3D FSE T2 weighted images can reliably differentiate between patients with and without pathologies of the cerebellopontine angle. The use of gadolinium contrast could be avoided in most of the cases, but contrast is necessary for differential diagnostic purposes in patients with alterations in the cerebellopontine angle or in doubtful cases.

Molecular Breast Imaging as a Cost Effective Diagnostic Tool for Breast Cancer.

Abstract Introduction: Molecular breast imaging (MBI), also referred to as breast specific gamma imaging (BSGI), utilizes nuclear medicine imaging with technetium 99-sestamibi to demonstrate metabolic activity of breast tissue. A focused gamma camera is used to assist in detecting lesions concerning for malignancy based on abnormal radiotracer uptake. MBI is performed with the patient in a sitting position and requires less breast compression than mammography. MBI is safe for patients with implanted metallic devices and renal disease. Facility charge for MBI is approximately $600 vs. $2500 for magnetic resonance imaging (MRI).Methods: IRB approval was obtained prior to study initiation. Forty four (44) patients underwent MBI with technetium 99-sestamibi after mammography and or ultrasound detected abnormalities for which biopsy was recommended.Results: Forty four (44) women ranging in age from 28 to 82 (median age 52) were found to have abnormal mammogram and or ultrasound findings requiring image guided biopsy. Prior to biopsy, MBI was performed. Fifteen MBI's were interpreted as demonstrating areas concerning for malignancy. Nine of the 44 patients (20.5%) demonstrated malignancy on biopsy pathology. Eight of these nine patients had positive MBI findings concerning for malignancy (88.9%). The patient whose MBI did not demonstrate findings consistent with malignancy had two sites of DCIS. The positive predictive value of these results was 53.3% and the negative predictive value was 96.55%.Conclusions: MBI shows promise in evaluating patients with abnormal mammogram or ultrasound findings. MBI is available at a much lower cost than MRI ($600 vs. $2500), which would have resulted in savings of $83,600 in this study alone. MBI can be used in patients for whom MRI is not an option such as claustrophobic patients, patients with renal disease limiting use of gadolinium contrast and patients who for other reasons such as body habitus and implanted metallic devices are not candidates for MRI. Further studies evaluating MBI are warranted to determine what role it may play in providing additional diagnostic data about patients with abnormal mammograms or ultrasounds. The role of MBI in settings where breast MRI is not available, is not technically feasible or is not an option due to cost also warrants further evaluation. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5014.

Identification of breast calcification using magnetic resonance imaging

MRI phase and magnitude images provide information about local magnetic field variation (DeltaB0), which can consequently be used to understand tissue properties. Often, phase information is discarded. However, corrected phase images are able to produce contrast as a result of magnetic susceptibility differences and local field inhomogeneities due to the presence of diamagnetic and paramagnetic substances. Three-dimensional (3D) susceptibility weighted imaging (SWI) can be used to probe changes in MRI phase evolution and, subsequently, result in an alternate form of contrast between tissues. For example, SWI has been useful in the assessment of negative phase induced DeltaB0 modulation due to the presence of paramagnetic substances such as iron. Very little, however, has been done to assess positive phase induced contrast changes resulting from the presence of diamagnetic substances such as precipitated calcium. As ductal carcinoma in situ, which is the precursor of invasive ductal cancer, is often associated with breast microcalcification, the authors proposed using SWI as a possible visualization technique. In this study, breast phantoms containing calcifications (0.4-1.5 mm) were imaged using mammography, computed tomography (CT), and SWI. Corrected phase and magnitude images acquired using SWI allowed identification and correlation of all calcifications seen on CT. As the approach is a 3D technique, it could potentially allow for more accurate localization and biopsy and maybe even reduce the use of gadolinium contrast. Furthermore, the approach may be beneficial to women with dense breast tissue where the ability to detect microcalcification with mammography is reduced.

Differentiation of adenomyomas from leiomyomas and normal myometrium on pelvic MR imaging- the role of Gadolinium enhancement

OBJECTIVE: The objective of this study was to assess the usefulness of Gadolinium contrast enhancement in differentiating adenomyomas from leiomyomas and normal myometrium.DESIGN: We identified all pelvic MR scans performed at Washington University 2003-2007 fulfilling the following criteria: use of Gadolinium contrast and concomitant presence of at least one adenomyoma, at least one leiomyoma, and at least one area of normal myometrium, as independently reported by two senior radiologists.MATERIALS AND METHODS: On all pelvic MR scans that met inclusion criteria, the signal intensity (SI) of myometrial, adenomyomatous and leiomyomatous tissue were measured before and after Gadolinium enhancement. All signal intensities were calculated relative to the pre-Gadolinium signal intensity. The heterogeneity of each tissue was then graded by 2 independent radiologists on a scale of 1-4, in reference to myometrium. Mean heterogeneity scores for each group were calculated and compared with unpaired t-tests.RESULTS: Myometrial tissue enhanced by factors of 2.1, 3.6 and 3.6 after Gadolinium administration at sequence 1, 2 and 3 (95% Confidence Interval < 0.27). There was significantly less Gadolinium enhancement in adenomyomas, which enhanced by 1.4, 2.4 and 2.5 (95% CI < 0.21). A wide variation was observed in the Gadolinium enhancement of leiomyomas, which enhanced by 1.9, 2.8 and 3.2 (95% CI > 0.53).Table 1Vascularity of adenomyomas and leiomyomas relative to myometrium on contrast MR scanTimepointPre-GadoliniumPost 1Post 2Post 3Normal myometrium12.0573.6223.646Adenomyoma0.9411.3622.3942.492Leiomyoma0.9931.8772.8473.19095% Confidence Interval: <0.27 for Normal myometrium; <0.21 for Adenomyoma; >0.53 for Leiomyoma. Open table in a new tab CONCLUSIONS: Whereas leiomyomas revealed a wide variation in their enhancement patterns, adenomyomas demonstrated less enhancement relative to normal myometrium on Gadolinium enhanced MR imaging. Adenomyomas are more homogenous and enhance less than leiomyomas. These findings may be important in differentiating adenomyomas from leiomyomas and thereby assist in pre-operative planning. OBJECTIVE: The objective of this study was to assess the usefulness of Gadolinium contrast enhancement in differentiating adenomyomas from leiomyomas and normal myometrium. DESIGN: We identified all pelvic MR scans performed at Washington University 2003-2007 fulfilling the following criteria: use of Gadolinium contrast and concomitant presence of at least one adenomyoma, at least one leiomyoma, and at least one area of normal myometrium, as independently reported by two senior radiologists. MATERIALS AND METHODS: On all pelvic MR scans that met inclusion criteria, the signal intensity (SI) of myometrial, adenomyomatous and leiomyomatous tissue were measured before and after Gadolinium enhancement. All signal intensities were calculated relative to the pre-Gadolinium signal intensity. The heterogeneity of each tissue was then graded by 2 independent radiologists on a scale of 1-4, in reference to myometrium. Mean heterogeneity scores for each group were calculated and compared with unpaired t-tests. RESULTS: Myometrial tissue enhanced by factors of 2.1, 3.6 and 3.6 after Gadolinium administration at sequence 1, 2 and 3 (95% Confidence Interval < 0.27). There was significantly less Gadolinium enhancement in adenomyomas, which enhanced by 1.4, 2.4 and 2.5 (95% CI < 0.21). A wide variation was observed in the Gadolinium enhancement of leiomyomas, which enhanced by 1.9, 2.8 and 3.2 (95% CI > 0.53). 95% Confidence Interval: <0.27 for Normal myometrium; <0.21 for Adenomyoma; >0.53 for Leiomyoma. CONCLUSIONS: Whereas leiomyomas revealed a wide variation in their enhancement patterns, adenomyomas demonstrated less enhancement relative to normal myometrium on Gadolinium enhanced MR imaging. Adenomyomas are more homogenous and enhance less than leiomyomas. These findings may be important in differentiating adenomyomas from leiomyomas and thereby assist in pre-operative planning.

Chronic Pachymeningitis Presenting as Asymmetric Sensorineural Hearing Loss

The objective of this study was to characterize the auditory dysfunction associated with chronic pachymeningitis (inflammation of the dura mater). We conducted a university-based retrospective review. Three patients were identified who were diagnosed with chronic pachymeningitis after being referred for asymmetric sensorineural hearing loss. All patients were found to have other neurologic symptoms and signs during careful neurotologic evaluation. Two varieties of chronic pachymeningitis exist: a hypertrophic mass lesion and a linear dural thickening. Although the hypertrophic variety could be easily detectable by noncontrast magnetic resonance imaging (MRI), the linear form is only visible with the use of gadolinium enhancement. Chronic pachymeningitis is a rare form of sensorineural hearing loss that could portend an underlying disease of greater concern. Extensive evaluation is needed to exclude identifiable causes of chronic pachymeningitis, including infectious, neoplastic, and autoimmune diseases. The clinician should be aware that the evaluation of a patient with asymmetric sensorineural hearing loss involves more than simply ruling out an acoustic neuroma. Fast-spin echo MRI techniques without the use of gadolinium contrast could miss a number of potentially treatable diseases such as chronic pachymeningitis. Patients with asymmetric sensorineural hearing loss should be carefully evaluated for other neurologic findings, and imaging with enhanced MRI is recommended.

Contrast enhanced body magnetic resonance angiography.

The use of gadolinium contrast for body MRA is reviewed. Considerations for timing of the bolus of contrast are discussed. The utility of this technique is illustrated through clinical examples. Contrast enhanced MRA is rapidly replacing conventional angiography for many applications.