Administration Of Gadolinium-diethylenetriamine Pentaacetic Acid Research Articles

Dexamethasone does not affect endolymphatic hydrops (EH) in patients with Meniere's disease within 24 h, and intratympanic administration of gadolinium plus dexamethasone simplifies high-quality imaging of EH using a novel protocol of 7 min

BackgroundIntratympanic administration of gadolinium chelate allows for a better visualization of endolymphatic hydrops (EH) using MRI than intravenous injection and was recently further improved to facilitate high-quality imaging of EH in 7 min. The aim of the present study was to simplify the intratympanic administration protocol by mixing gadolinium chelate with therapeutic dexamethasone and to evaluate the effects of this mixture on the visualization of EH in MRI. Materials and methodsIn an in vitro study, the potential impact of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) on the stability of dexamethasone was evaluated by analyzing dynamic changes in dexamethasone with high-performance liquid chromatography (HPLC) after mixing with Gd-DTPA. Ten patients with definite Meniere's disease (MD) were recruited to study the potential interference of dexamethasone on MRI visualization of EH, and 49 patients with MD were recruited to evaluate the effect of intratympanic injection of Gd-DTPA mixed with dexamethasone on MRI of EH using a 3T MR machine and a novel heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery reconstructed using a magnitude plus zero-filled interpolation (hT2FLAIR-MZFI) sequence. ResultsThe retention times and peak area of dexamethasone in HPLC were not modified by the addition of Gd-DTPA. EH grading in the cochlea and vestibule was not influenced in any ear by intratympanic injection of dexamethasone. Excellent inner ear images were obtained from all patients, and EHs with various grades were displayed. There were significant correlations between diagnosis and cochlear EH (p < 0.01, Spearman's Rho), between diagnosis and vestibular EH (p < 0.01, Spearman's Rho), and between cochlear and vestibular EH (p < 0.01, Spearman's Rho). The distribution of Gd-DTPA plus dexamethasone negatively correlated with the grade of vestibular EH. Injury of the endolymph-perilymph barrier was detected in one cochlea and three vestibules of 59 inner ears with MD. ConclusionsIntratympanic administration of Gd-DTPA plus dexamethasone yielded high-quality MRI images of EH in patients with MD using a novel 7-min protocol and simplified the clinical application. Intratympanic administration of Gd-DTPA plus dexamethasone might be used to test its therapeutic effect in future work. Level of evidence3.

Contrast-enhanced magnetic resonance (MR) T1 mapping with low-dose gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) is promising in identifying clear cell renal cell carcinoma histopathological grade and differentiating fat-poor angiomyolipoma.

This study aimed to identify clear cell renal cell carcinoma (ccRCC) histopathological grade and differentiate it from fat-poor angiomyolipoma (AML). This was achieved through contrast-enhanced magnetic resonance (MR) T1 mapping with intravenous low-dose gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). In total, 56 consecutive patients received MR scanning between January 2016 and December 2018 using the pre- and post- contrast-enhanced T1 mapping sequences with low-dose Gd-DTPA (0.036 mmol/kg). RCCs were pathologically proven in 40 patients after surgery and graded according to the International Society of Urological Pathology (ISUP) classification system. Ten AMLs were pathologically proven by surgery histopathology and six AMLs were diagnosed by magnetic resonance imaging (MRI). Patients were followed up for more than half a year. The mean T1 values of the renal lesion and ipsilateral normal renal parenchyma were measured before and after Gd-DTPA administration (T1p and T1e). The reduction of T1 value (T1d) and the ratio of its reduction (T1d %) were calculated and compared. In 40 ccRCCs, higher-grade [International Society of Urologic Pathology (ISUP) grade 3 and 4] and lower-grade (ISUP grade 1 and 2) ccRCCs were noted in 13 and 27 patients, respectively. The mean T1p was 1,514.8±139.4 ms and the mean T1d was 907.7±193.7 ms in the higher-grade ccRCCs, which were significantly higher than in the lower-grade ccRCCs (T1p =1,251.7±151.5 ms and T1d =648.5±218.2 ms, respectively; P<0.001). Fat-poor AMLs had higher T1p (1,677.3±104.8 ms) and T1e (865.6±251.5 ms) as compared to ccRCCs (P<0.001). Combined T1p + T1d showed the highest area under the curve (AUC) (0.912) in the differentiation of higher-grade ccRCCs from lower-grade ccRCCs (P=0.010). Combined T1p + T1e had the highest AUC (0.956) in the differentiation between ccRCCs and fat-poor AMLs (P=0.010). All T1 mapping metrics could discriminate between normal renal parenchyma and renal lesions (P<0.001). No significant difference was found in the T1p and T1e at different parts of the ipsilateral normal renal parenchyma. Interobserver agreement for quantitative longitudinal relaxation time in the T1 maps was excellent. Contrast-enhanced T1 mapping with low-dose Gd-DTPA may provide a more reliable and accurate approach in identifying ccRCCs histopathological grade and differentiating ccRCCs from fat-poor AMLs.

Optimization of delivering minimum Gd-DTPA at the posterior upper point on tympanic medial wall and hT2W-3D-FLAIR sequence for detecting endolymphatic hydrops

Objective: To optimize delivery of gadolinium-diethylenetriamine pentaacetic acid(Gd-DTPA) at the posterior upper point on tympanic medial wall and heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery (hT2W-3D-FLAIR) sequence, and to implement the technique of detecting endolymphatic hydrops using gadolinium-enhancement MRI. Methods: Thirteen patients with periphery vertigo, who visited Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Changhai Hospital during June and December of 2017, were enrolled in the study.0.10-0.20 ml of Gd-DTPA in various dilutions (10, 20, and 40-fold) were delivered at the posterior upper point on tympanic medial wall using a soft-tipped tympanic suction and drug-spraying needle through an artificially perforated tympanic membrane. Inner ear MRI was performed at 8, 24 h after Gd-DTPA administration using a 3T MR machine in combination with a 20-channel Tim 4G head/neck coil and the sequence of hT2W-3D-FLAIR to detect the gadolinium-enhancement signal within the inner ear and possible endolymphatic hydrops. The scanning time was either 8 min 35 s or 15 min 11 s. Results: Efficient inner ear uptake of Gd-DTPA was detected and induced high signal to noise ratio of MRI in patients receiving targeted delivery of 0.15-0.20 ml of 10-fold diluted contrast agent at the posterior upper point on tympanic medial wall. At 8 h after delivery, significant uptake was detected in the scala tympani and vestibuli of hook region and basal turn of the cochlea, and perilymhatic compartment of the vestibule. At 24 h after delivery, the distribution of Gd-DTPA became homogenous in each turn of the cochlea and perilymphatic compartment of the vestibule. However, obvious individual variance existed in the inner ear uptake when 0.10 ml of 40-fold diluted Gd-DTPA was delivered. Efficient inner ear uptake and high quality images that generated in patients receiving 0.10, 0.15, and 0.20 ml of 20-fold Gd-DTPA demonstrated endolymphatic hydrops with minor individual variance. There was insignificant difference in the enhancement signal of inner ear between 0.15 and 0.10 ml groups when Gd-DTPA was diluted at 20-fold except for the signal of semicircular canal of 0.15 ml group (190.00±53.95 vs 165.50±42.13, t=2.61, P<0.05). There was insignificant difference in the image quality between 8 min 35 s and 15 min 11 s canning time. Various degrees of endolymphatic hydrops were detected in 7 cochleae and 11 vestibule, and both simultaneous cochlear and vestibular endolymphatic hydrops were detected in 4 ears. Cochlear endolymphatic hydrops was detected in all the 3 patients with definite Meniere's disease, and 2 of them had combined cochlear and vestibular endolymphatic hydrops. Endolymphatic hydrops was not detected in patients with possible Meniere's disease nor with symptoms of superior semicircular canal dehiscence. Conclusion: Targeted delivery of 0.10 ml with 20-fold diluted Gd-DTPA (total dosage of 5 μmol) at the posterior upper point on tympanic medial wall in combination with 8 min 35 s scanning time hT2W-3D-FLAIR sequence for inner ear MRI in a 3T MR machine is a clinically practical method to detect endolymphatic hydrops, and reduce the requirement for MRI hardware.

Large enchondroma of the thoracic spine: a rare case report and review of the literature

BackgroundEnchondroma, a subtype of chondroma, originates from the medullary cavity of the bone and produces an expansile growth pattern. Enchondroma located in the spine is rare and a few cases of large thoracic enchondroma have been reported. The authors document a rare case of large enchondroma in the thoracic spine of a 49-year-old woman, and discuss its clinical, radiological and histopathological characteristics.Case presentationThe patient presented with rapidly progressive and severe pain on her upper back. Magnetic resonance imaging revealed an expansile lesion at the posterior elements of T3 that was hypointense on T1-weighted images and mixed iso- to hyperintense on T2-weighted images. Administration of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) resulted in heterogeneous enhancement. During surgery, a large tumor of 4.2cm × 4.7cm × 2.1cm was resected along with the lamina and spinous process. Histological examination revealed that the tumor consisted of mature hyaline cartilage with typical chondrocytes, indicating that it was an enchondroma.ConclusionsDespite its benign-growing nature, enchondroma should be examined closely for signs of enchondromatosis and enchondrosarcoma. Complete surgical resection is the treatment of choice for immediate relief of symptoms and avoidance of recurrence.

Complex imaging features of accidental cerebral intraventricular gadolinium administration

Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) is a contrast agent commonly used for enhancing MRI. In this paper, the authors report on 2 cases of postoperative inadvertent administration of Gd-DTPA directly into a ventriculostomy tubing side port that was mistaken for intravenous tubing. Both cases demonstrated a low signal on MRI throughout the ventricular system and dependent portions of the subarachnoid spaces, which was originally believed to be CSF with areas of T1 shortening in the nondependent portions of the subarachnoid spaces, and misinterpreted as basal leptomeningeal enhancement and meningitis. The authors propose that the appearance of profound T1 hypointensity within the ventricles and diffuse susceptibility artifact along the ependyma is pathognomonic of intraventricular Gd-DTPA and should be recognized.

Interstitial Fluid Pressure and Associated Lymph Node Metastasis Revealed in Tumors by Dynamic Contrast-Enhanced MRI

Elevated interstitial fluid pressure (IFP) in tumors can cause metastatic dissemination and treatment resistance, but its study poses a challenge because of a paucity of noninvasive imaging strategies. In this study, we address this issue by reporting the development of a noninvasive tool to assess tumor IFP and interstitial hypertension-induced lymph node metastasis. Using mouse xenograft models of several types of human cancer, we used gadolinium diethylene-triamine penta-acetic acid (Gd-DTPA) as a contrast agent for dynamic contrast-enhanced MRI (DCE-MRI). Immediately after Gd-DTPA administration, a high-signal-intensity rim was observed in the tumor periphery, which moved outward with time. Assuming the velocity of Gd-DTPA to be equal to the fluid flow velocity, we used a simple model of peritumoral interstitial fluid flow to calculate the fluid flow velocity at the tumor surface (v(0)) based on the rim movement. Significant positive correlations were found between v(0) and IFP in all tumor xenografts. Moreover, the primary tumors of metastasis-positive mice displayed higher IFP and v(0) than the primary tumors of metastasis-negative mice. Findings were confirmed in cervical cancer patients with pelvic lymph node metastases, where we found v(0) to be higher compared with patients without lymph node involvement (P < 0.00001). Together, these findings establish that Gd-DTPA-based DCE-MRI can noninvasively visualize tumor IFP, and they reveal the potential for v(0) determined by this method to serve as a novel general biomarker of tumor aggressiveness.

Synergistic enhancement of iron oxide nanoparticle and gadolinium for dual-contrast MRI

PurposeThe use of MR contrast agents allows accurate diagnosis by exerting an influence on the longitudinal (T1) or transverse (T2) relaxation time of the surrounding tissue. In this study, we combined the use of iron oxide (IO) particles and nonspecific extracellular gadolinium chelate (Gd) in order to further improve the sensitivity and specificity of lesion detection. ProceduresWith a 7-Tesla scanner, pre-contrasted, IO-enhanced and dual contrast agent enhanced MRIs were performed in phantom, normal animals, and animal models of lymph node tumor metastases and orthotopic brain tumor. For the dual-contrast (DC) MRI, we focused on the evaluation of T2 weighted DC MRI with IO administered first, then followed by the injection of a bolus of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA). ResultsBased on the C/N ratios and MRI relaxometry, the synergistic effect of coordinated administration of Gd-DTPA and IO was observed and confirmed in phantom, normal liver and tumor models. At 30min after administration of Feridex, Gd-DTPA further decreased T2 relaxation in liver immediately after the injection. Additional administration of Gd-DTPA also immediately increased the signal contrast between tumor and brain parenchyma and maximized the C/N ratio to −4.12±0.71. Dual contrast MRI also enhanced the delineation of tumor borders and small lesions. ConclusionsDC-MRI will be helpful to improve diagnostic accuracy and decrease the threshold size for lesion detection.

Effects of Contrast Agent and Outer Volume Saturation Bands on Water Suppression and Shimming of Hepatic Single-Volume Proton MR Spectroscopy at 3.0T

Purpose. To determine whether administration of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) and whether placement of the outer volume saturation bands significantly affect shimming and water suppression on hepatic MR spectroscopic prescanning. Method. Region of interest (ROI) of 2 cm × 2 cm × 2 cm was carefully positioned in the region of the middle portion of the right hepatic lobe. 32 patients were examined before and after administration of Gd-DTPA with and without outer-volume saturation bands. Linewidths (Full-Width Half-Maximum (FWHM)) and water suppression were obtained. A paired t-test for comparison of means was used. Results. (1) The group with the outer volume saturation bands demonstrated slightly better water suppression effect than the group without outer volume saturation bands before administration. (2) The group with the outer volume saturation bands demonstrated better water suppression effect than the group without outer volume saturation bands after administration. (3) Both shimming and water suppression effectswere decreased on enhanced MR spectroscopic prescanning (all P < 0.05). Conclusions. Placement of the outer volume saturation bands is helpful to improve water suppression both before and after contrast agent administration. Gd-DTPA exerts a slightly adverse effect (a statistically significant but clinically unimportant) on magnetic resonance spectroscopic prescanning at 3T.

Lactate MRSI and DCE MRI as surrogate markers of prostate tumor aggressiveness

Longitudinal studies of lactate MRSI and dynamic contrast-enhanced MRI were performed at 4.7 T in two prostate tumor models grown in rats, Dunning R3327-AT (AT) and Dunning R3327-H (H), to determine the potential of lactate and the perfusion/permeability parameter Ak(ep) as markers of tumor aggressiveness. Subcutaneous AT (n = 12) and H (n = 6) tumors were studied at different volumes between 100 and 2900 mm(3) (Groups 1-5). Lactate concentration was determined using selective multiple quantum coherence MRSI with the phantom substitution method. Tumor enhancement after the administration of gadolinium diethylenetriaminepenta-acetic acid was analyzed using the Brix-Hoffmann model and the Ak(ep) parameter was used as a measure of tumor perfusion/permeability. Lactate was not detected in the smallest AT tumors (Group 1; 100-270 mm(3) ). In larger AT tumors, the lactate concentration increased from 2.8 ± 1.0 mm (Group 2; 290-700 mm(3)) to 8.4 ± 2.9 mm (Group 3; 1000-1340 mm(3)) and 8.2 ± 2.2 mm (Group 4; 1380-1750 mm(3) ), and then decreased to 5.0 ± 1.7 mm (Group 5; 1900-2500 mm(3)), and was consistently higher in the tumor core than in the rim. Lactate was not detected in any of the H tumors. The mean tumor Ak(ep) values decreased with increasing volume in both tumor types, but were significantly higher in H tumors. In AT tumors, the Ak(ep) values were significantly higher in the rim than in the core. Histological hypoxic and necrotic fractions in AT tumors increased with volume from 0% in Group 1 to about 20% and 30%, respectively, in Group 5. Minimal amounts of hypoxia and necrosis were found in H tumors of all sizes. Thus, the presence of lactate and heterogeneous perfusion/permeability are signatures of aggressive, metabolically deprived tumors.

Comparison between Gd-DTPA-enhanced MRI and USPIO-enhanced MRI in diagnosing benign and metastatic cervical lymph nodes in rabbit models

To compare the diagnostic value of gadolinium diethylenetriaminepenta-acetic acid (Gd-DTPA)-enhanced MRI with ultrasmall superparamagnetic iron oxide (USPIO)-enhanced MRI in differentiating reactive hyperplastic lymph nodes from metastatic lymph nodes in rabbit models. Reactive hyperplastic cervical lymph node model was established in 18 rabbits as hyperplasia group, and tumor-bearing lymph node model was established in another 18 rabbits as tumor group. For Gd-DTPA-enhanced MRI, T1WI and T2WI were performed on 9 animals of each model, and T1WI was acquired 80 seconds after administration of Gd-DTPA. For USPIO-enhanced MRI, T1WI, T2WI and T2*WI were performed on another 9 animals of each model before and 24 hours after administration of USPIO. MRI images were analyzed and correlated with surgical specimens and pathological results. In the tumor group, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of Gd-DTPA-enhanced MRI were 62.5%, 91.3%, 88.2%, 70.0% and 76.6%, respectively. The corresponding values of USPIO-enhanced MRI were 95.0%, 90.9%, 90.5%, 95.2% and 92.9%, respectively. The sensitivity and accuracy of USPIO-enhanced MRI differ significantly from those of Gd-DTPA-enhanced MRI. In the hyperplasia group, the accuracy of Gd-DTPA-enhanced MRI was 74.2%, while 87.1% for USPIO-enhanced MRI. USPIO-enhanced MRI has higher accuracy in diagnosing metastatic lymph nodes than Gd-DTPA-enhanced MRI.

Effects of Contrast Agent on Water Suppression and Shimming of Kidney Single-Volume Proton MR Spectroscopy at 3.0T

The aim of this study was to determine whether the administration of gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA) significantly affects shimming and water suppression on kidney magnetic resonance spectroscopic prescanning and whether the impact of shimming and water suppression is changed with time after intravenous administration on a 3.0-T system. Forty patients (two patients were excluded from analysis because of motion) were examined before and after the administration of Gd-DTPA (the interval between the right and left kidneys was approximately 40 seconds). Regions of interest were carefully positioned in the region of the corresponding location of both kidneys separately. Line widths (full width at half maximum) and water suppression were obtained. A paired t test for comparison of means was used. In addition, repeat measurements with a shorter time interval (obtained 120-130 seconds after the injection) and a longer time interval (obtained 150-160 seconds after the injection) were performed in five patients in the same regions of interest of the right kidney. Sequential ¹H magnetic resonance spectroscopic prescanning in the same region of interest was performed in one patient. The left kidney had slightly better shimming and water suppression effects than the right kidney after contrast agent administration (all P values < .01). The limiting resolution of both shimming and water suppression effects was decreased on enhanced images in both kidneys (all P values < .01). The longer time interval group had better shimming and water suppression effects than the shorter time interval group (all P values < .01). After the administration of Gd-DTPA in one patient, sequential values of shimming and water suppression in the right and left kidneys, respectively, were 13 Hz and 97% and 12 Hz and 97% prior to the examination, 34 Hz and 86% and 30 Hz and 88% at 5 minutes, 32 Hz and 89% and 27 Hz and 90% at 10 minutes, 28 Hz and 91% and 24 Hz and 91% at 15 minutes, and 24 Hz and 92% and 20 Hz and 92% at 25 minutes. Gd-DTPA exerts adverse effects on water suppression and shimming, both of which show a trend of becoming well gradually with time extension after the injection of Gd-DTPA. This phenomenon limits the diagnostic use of kidney magnetic resonance spectroscopy performed immediately after contrast-enhanced magnetic resonance imaging.

The utility of three-dimensional dynamic contrast-enhanced magnetic resonance imaging in delineating vessel-rich regions: a case report of an aneurysmal bone cyst of the mandible

Aneurysmal bone cysts (ABCs) are classified as bone-related lesions based on the 2005 World Health Organization histological classification of odontogenic tumors. Most ABCs are diagnosed using a combination of conventional radiography, computed tomography, magnetic resonance imaging (MRI), and digital subtraction angiography. ABCs should be differentiated from true cysts or other pseudocysts because their treatment is different. Additionally, unlike other cysts, ABCs pose a hemorrhagic risk in surgery; thus, preoperative evaluation of intralesional blood flow is required. Here we report a case of a mandibular ABC in a 39-year-old woman and focus on its dynamic contrast-enhanced MRI (DCE-MRI) features. On DCE-MRI, the lesion was divided into two areas according to the enhancement pattern: the blood-pooling and blood-flow areas. The series of DCE-MR images of the blood-pooling area showed marked enhancement of the margin, but no enhancement in the inner part of the cavity. Additionally, the time-signal intensity curve (TIC) demonstrated no change in the signal intensity (SI) until approximately 15 min after gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) administration. In contrast, the series of DCE-MR images of the blood-flow area exhibited marked enhancement in the cyst cavity in the early phase. The TIC showed a rapid increase in SI in the early phase, followed by a rapid decrease until 150 s, and finally a gradual decrease until approximately 15 min after Gd-DTPA administration. Thus, in the current patient, preoperative DCE-MRI clearly delineated the vessel-rich area within the lesion.

Prevalence of Myocardial Scar in Patients With Cryptogenic Cerebral Ischemic Events and Patent Foramen Ovale

This study sought to evaluate the prevalence of subclinical myocardial infarctions with cardiovascular magnetic resonance imaging (CMRI) in patients with patent foramen ovale (PFO) after cryptogenic cerebral ischemic events. A thrombotic mass passing a PFO may embolize in cerebral but also in coronary arteries, resulting in both cerebral and myocardial ischemic events. CMRI with late gadolinium enhancement (LGE) analysis is the most sensitive imaging technique to detect small myocardial infarctions. PFO patients (n = 74) with a first cryptogenic cerebral ischemic event without a clinical history for myocardial infarction underwent CMRI and coronary angiography. Right and left ventricular volumes and ejection fractions were measured by CMRI. LGE imaging was performed after administration of gadolinium-diethylenetriaminepentaacetic acid. The presence of atrial septal aneurysm (ASA) was evaluated by transesophageal echocardiography. LGE was detected in 8 of 74 (10.8%) patients. LGE pattern was transmural or subendocardial. Patients with LGE and those without did not differ in cardiovascular risk factors, type of ischemic event, presence of ASA, right and left ventricular volumes, and ejection fractions. LGE volume was small and comprised only 7.9 +/- 2.4% of left ventricular muscle mass. Coronary artery disease was ruled out in 7 of 8 patients with LGE. There was a trend towards a larger PFO size in patients with LGE compared with patients without LGE (13.2 +/- 4.1 mm vs. 16.0 +/- 2.8 mm, p = 0.06). Subclinical myocardial infarctions determined in CMRI were observed in 10.8% of patients with PFO after a first cryptogenic cerebral ischemic event. Our results strengthen the pathophysiologic role of a PFO with paradoxical embolism in patients with cryptogenic cerebral ischemic events.

Single breath‐hold assessment of ventricular volumes using 32‐channel coil technology and an extracellular contrast agent

To evaluate the feasibility of a single breath-hold 3D cine balanced steady-state free precession (b-SSFP) sequence after gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA) injection for volumetric cardiac assessment. Fifteen adult patients routinely referred for cardiac magnetic resonance imaging (MRI) underwent quantitative ventricular volumetry on a clinical 1.5T MR-scanner using a 32-channel cardiac coil. A stack of 2D cine b-SSFP slices covering the ventricles was used as reference, followed by a single breath-hold 3D cine balanced SSFP protocol acquired before and after administration of Gd-DTPA. The acquisition was accelerated using SENSE in both phase encoding directions. Volumetric and contrast-to-noise data for each technique were assessed and compared. The 3D cine protocol was accomplished within one breath-hold (mean acquisition time 20 sec; spatial resolution 2.1 x 2.1 x 10 mm; temporal resolution 51 msec). The contrast-to-noise ratio between blood and myocardium was 234 determined for the multiple 2D cine data, and could be increased for the 3D acquisition from 136 (3D precontrast) to 203 (3D postcontrast) after injecting Gd-DTPA. In addition the endocardial definition was significantly improved in postcontrast 3D cine b-SSFP. There was no significant difference for left and right ventricular volumes between standard 2D and 3D postcontrast cine b-SSFP. However, Bland-Altman plots showed greater bias and scatter when comparing 2D with 3D cine b-SSFP without contrast. 3D cine b-SSFP imaging of the heart using 32 channel coil technology and spatial undersampling allows reliable volumetric assessment within a single breath-hold after application of Gd-DTPA.

MR Imaging of the Cochlear Modiolus after Intratympanic Administration of Gd-DTPA

We evaluated whether enhancement of the cochlear modiolus could be visualized 24 hours after intratympanic injection of gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA) using a 3-dimensional real inversion recovery sequence combined with a 32-channel head coil at 3 tesla. Intratympanic injection of Gd-DTPA has been reported for visualizing endolymphatic hydrops in Meniere's disease, and its use has shown communication between the cochlear perilymph and cerebrospinal fluid in the internal auditory canal. Although the cochlear modiolus has been considered the route for this communication, this has not been confirmed through direct visualization of its enhancement. We qualitatively and quantitatively evaluated the presence of contrast enhancement in the modiolus in 19 patients with clinically suspected endolymphatic hydrops or hearing loss who underwent imaging as described above. The contrast ratio (CR) between the cochlear modiolus and cerebellar white matter on the injected side was 1.09+/-1.23, and that on the non-injected side was -0.48+/-0.38 (P<0.01). In all subjects, the CR value was larger on the injected than non-injected side, and enhancement of the cochlear modiolus was also recognized visually. Intratympanic Gd-DTPA can be administered to visualize enhancement of the cochlear modiolus and may thereby reveal its functional anatomy.

Area at Risk and Viability after Myocardial Ischemia and Reperfusion Can Be Determined by Contrast-Enhanced Cardiac Magnetic Resonance Imaging

Background/Aims: Clinical differentiation between infarcted and viable myocardium in the ischemic area at risk is controversial. We investigated the potential of contrast-enhanced cardiac magnetic resonance imaging (ceCMRI) in determining the area at risk 24 h after ischemia. Methods: Myocardial ischemia was induced by percutaneous coronary intervention of the left anterior descending coronary artery in pigs. Coronary occlusion time was 30 min in group A, which caused little myocardial infarction and 45 min in group B, which led to irreversible damage. 24 h after reperfusion ceCMRI was performed at 2 and 15 min after administration of gadolinium-diethylenetriamine pentaacetic acid. The area at risk was determined by intravenous injection of Evans blue and myocardial viability by triphenyltetrazolium-chloride staining. Results: The signal-intense areas at 2 and 15 min after contrast administration matched the area at risk in groups A and B. Nonviable myocardium in group A was overestimated (14–15%) while good agreement was present in group B. Conclusion: The area at risk of reperfused ischemic myocardium can be determined by ceCMRI 24 h after coronary recanalization. This type of information might have relevant clinical implications in the treatment and stratification of patients with acute coronary syndrome in particular after surgical interventions.

Communication between cochlear perilymph and cerebrospinal fluid through the cochlear modiolus visualized after intratympanic administration of Gd-DTPA

Intratympanic injection of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) has been reported as a procedure to visualize endolymphatic hydrops of Meniere's disease. We frequently noted that cerebrospinal fluid (CSF) in the internal auditory canal (IAC) was also enhanced after this procedure. The purpose of this study was to evaluate how frequently this occurs and to investigate the specific features of patients who lack this communication. A total of 25 patients with clinically suspected endolymphatic hydrops underwent the procedure. After 24 h, three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and 3D constructive interference in steady state (3D-CISS) were performed. The presence of contrast enhancement in the CSF space of the fundus of the IAC was evaluated. The contrast ratio between CSF of the IAC fundus and cerebellar white matter on the injected side was 1.49 +/- 0.65, and that of the noninjected side was 0.32 +/- 0.16 (P < 0.01). Enhancement of the CSF space in the IAC fundus was seen in all but two subjects: one had enlarged endolymphatic duct and sac syndrome (EEDS), and the other had cochlear nerve agenesis. In these two patients, the cochlear modiolus seemed to be normal. Intratympanic Gd-DTPA administration can reveal permeability of the modiolus and might facilitate evaluation of functional abnormalities of the modiolus not detected by conventional imaging tests.

A periosteal chondroma in the lumbar spinal canal

✓ Periosteal chondromas located in the spine are rare. The authors document a case of periosteal chondroma in the lumbar spinal canal of a 77-year-old man. The patient had severe pain in his right leg and used a wheelchair because of weakness in both legs. Magnetic resonance imaging revealed a round tumor that was hypo- or isointense on T1-weighted images and uniformly hyperintense on T2-weighted images. Administration of gadolinium-diethylenetriamine pentaacetic acid resulted in margin enhancement on T1-weighted images. During the operation, a round tumor 1.5 cm in diameter was found on the surface of the anterior wall of the L-3 lamina. Histological examination revealed that the tumor consisted of chondroid tissue with typical chondrocytes, indicating that it was a periosteal chondroma.

A periosteal chondroma in the lumbar spinal canal

Periosteal chondromas located in the spine are rare. The authors document a case of periosteal chondroma in the lumbar spinal canal of a 77-year-old man. The patient had severe pain in his right leg and used a wheelchair because of weakness in both legs. Magnetic resonance imaging revealed a round tumor that was hypo- or isointense on T1-weighted images and uniformly hyperintense on T2-weighted images. Administration of gadolinium-diethylenetriamine pentaacetic acid resulted in margin enhancement on T1-weighted images. During the operation, a round tumor 1.5 cm in diameter was found on the surface of the anterior wall of the L-3 lamina. Histological examination revealed that the tumor consisted of chondroid tissue with typical chondrocytes, indicating that it was a periosteal chondroma.

Correlation of emmprin expression in vascular endothelial cells with blood-brain-barrier function: a study using magnetic resonance imaging enhanced by Gd-DTPA and immunohistochemistry in brain tumors.

In a previous study, we demonstrated that the expression levels in tumor cells of emmprin (CD147) correlated with the grade of astrocytic tumors. Also, we found that emmprin was expressed in vascular endothelial cells of the non-neoplastic brain and hypothesized that emmprin expression could be associated with normal blood-brain-barrier (BBB) function of vascular endothelial cells. In this study, this possibility was examined in non-neoplastic brain, glioma and metastatic carcinoma tissues by comparing emmprin immunohistochemistry with gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) enhancement of magnetic resonance imaging (MRI), which is a clinical indicator of the BBB function. This study included 10 cases of non-neoplastic brain tissues, 7 of metastatic carcinoma, 7 of diffuse astrocytoma, 4 of anaplastic astrocytoma and 13 of glioblastoma multiforme. In all the cases, MRI with administration of Gd-DTPA was performed. The lesions were resected using the microdissection method with the help of ultrasonography and a neuronavigator. The tissues from Gd-DTPA-enhanced or non-enhanced areas were processed into frozen sections and subjected to immunohistochemistry with anti-emmprin antibody. The expression of emmprin in brain vascular endothelial cells inversely correlated with Gd-DTPA-enhancement of MRI: emmprin was positive in tissues not enhanced by Gd-DTPA and was negative in DTPA-enhanced tissues. Since BBB function presumably remains unimpaired in regions in which MR images are not Gd-DTPA-enhanced, emmprin expression appears to be associated with unimpaired BBB function. This is the first report to demonstrate a possible correlation between emmprin expression and BBB function in humans.