Injection Of Gadolinium-based Contrast Material Research Articles

Dynamic contrast-enhanced magnetic resonance lymphangiography in pediatric patients with central lymphatic system disorders.

Central conducting lymphatics (CCLs) disorders represent a broad spectrum of clinical entities ranging from self-limiting traumatic leaks treated by conservative strategies, to complex lymphatic circulation abnormalities that are progressive and unresponsive to currently available treatments. Dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) performed by intranodal injection of gadolinium-based contrast material is a recently developed technique which allows a minimally invasive evaluation of the CCL abnormalities providing a dynamic assessment of lymph flow and its pathways. In our institution, DCMRL is performed after bilateral cannulation of inguinal lymph nodes, using a MR protocol which includes volumetric 3D T2-SPACE (sampling perfection with application-optimized contrasts using different flip-angle evolution) and free-breathing respiratory navigated sequence and TWIST (time-resolved angiography with Interleaved stochastic trajectories) MR angiography sequence, during intranodal injection of paramagnetic contrast medium. Although DCMRL applications in clinical practice are still improving, a minimally invasive assessment of lymphatic pathways is particularly important both in pediatric patients with primitive lymphatic system disorders and in children with complex congenital heart disease associated with CCL impairment.

Active Cardiac Sarcoidosis Imitating Cardiac Metastases.

A 54-year-old woman diagnosed with sarcoidosis based on mediastinal lymph node biopsy underwent conventional contrast material–enhanced chest CT examination without electrocardiographic synchronization to evaluate pulmonary sarcoidosis. Past medical history included prior left total mastectomy for breast cancer (Fig 1, A). CT results demonstrated multiple hypoattenuating masses involving the septum, free walls of both ventricles, and right atrium (Fig 1, B, C). Cardiac metastases were a potential diagnosis; however, the cardiac lesions were similar in appearance to lymph nodes noted in the hilum and mediastinum. Subsequent late gadolinium enhancement MRI results showed abnormal foci of delayed enhancement in both ventricles and the right atrium, corresponding to the lesions on chest CT (Fig 1, D). Fluorine 18 fluorodeoxyglucose PET results showed abnormal uptake in these areas (maximum standardized uptake value, 12.0) (Fig 1, E). Finally, results of endomyocardial biopsy from the right ventricle revealed a granuloma with lymphocytes, demonstrating active sarcoidosis (Fig 1, F). Open in a separate window A, Contrast-enhanced CT image obtained with a delay time of 90 seconds after contrast medium injection at a slice thickness of 5 mm shows hilar and mediastinal lymphadenopathy (arrows). Note the prior left total mastectomy (arrowheads). B and C, Contrast-enhanced CT images demonstrate hypoattenuating foci in the septum, both ventricles, and right atrium (arrows). D, A four-chamber view of late enhancement MRI acquired 10 minutes after injection of gadolinium-based contrast material reveals delayed gadolinium enhancement in the septum, both ventricles, and right atrium (arrows). E, Abnormal fluorine 18 fluorodeoxyglucose (18F-FDG) uptake is observed in the septum, both ventricles, and right atrium on the 18F-FDG PET image (arrows). F, Endomyocardial biopsy specimen obtained from the right ventricle demonstrates granulomas with giant cells. (CD68 immunohistochemical staining; magnification rate, ×400.)

High-Signal Bladder Urine at T1-Weighted MR Imaging Performed 1-7 Days After a Prior Gadolinium-Enhanced MRI: Prevalence and Correlation with Renal Function.

Objective:To determine the prevalence of high-signal bladder urine at T 1 weighted MRI performed 1–7 days after injection of gadolinium-based contrast material and to assess for correlation with altered renal function.Methods:The study group consisted of 267 patients who underwent MRI that included the bladder 1–7 days after a prior gadolinium-enhanced MRI. A control group consisted of 200 patients who underwent pelvic MRI and had not received gadolinium-based contrast material within the prior month. One reader recorded the relative T 1 weighted signal intensity of bladder urine and calculated the estimated glomerular filtration rate (eGFR) for each patient. A positive scan was defined as one with bladder urine T 1 weighted signal higher than that of muscle.Results:25 (9%) of 267 study group scans were positive; this included 68% ( n = 19) of scans obtained 12–24 h after gadolinium-based contrast material administration, 21% ( n = 3) after 25–36 h, 7% ( n = 2) after 37–48 h, and 3% ( n = 1) after 49–72 h. No positive scan occurred after 72 h or in the control group. Mean eGFR in positive scans obtained more than 36 h after gadolinium-based contrast material administration was significantly lower than in negative scans in the same timeframe (37 vs 76 ml/min, respectively; p = 0.01).Conclusion:High T 1 weighted signal in bladder urine occasionally is present on MRI performed up to 3 days after gadolinium-based contrast material administration, presumably reflecting residual excreted gadolinium-based contrast material. When visible more than 36 hours after gadolinium-based contrast material administration, such increased signal is associated with low eGFR.Advances in knowledge:Increased signal is occasionally present in bladder urine at MRI performed up to 3 days after gadolinium-based contrast material administration. When higher signal is visible more than 36 hours after contrast administration, it is associated with decreased eGFR.

Small (<2-cm) Upper-Tract Urothelial Carcinoma: Evaluation with Gadolinium-enhanced Three-dimensional Spoiled Gradient-Recalled Echo MR Urography

To retrospectively evaluate the detection of small (<2-cm) urothelial tumors by using gadolinium-enhanced three-dimensional (3D) spoiled gradient-recalled echo (GRE) magnetic resonance (MR) urography. This HIPAA-compliant study received institutional review board approval. All patients included had previously consented to the use of their medical records for research purposes. Eleven of 110 patients (10 men, one woman; mean age, 73.5 years) who underwent MR urography were ultimately identified to have 23 upper-tract urothelial carcinomas smaller than 2 cm or carcinoma in situ. Breath-hold coronal T2-weighted single-shot fast spin-echo and breath-hold coronal 3D T1-weighted spoiled GRE images with fat suppression during nephrographic and excretory phases after intravenous injection of gadolinium-based contrast material were obtained in all patients with a 1.5-T imager. Two radiologists reviewed the MR images in consensus for the presence of tumors. Lesion detectability was compared between each sequence by using the McNemar test. Of 23 tumors, 17 (74%) were detected by using at least one sequence, eight (35%) were detected with T2-weighted imaging, 15 (65%) were detected on nephrographic phase images, and 15 (65%) were detected on excretory phase images. Two lesions each were detected only on either nephrographic or excretory phase images. Detectability was significantly higher on nephrographic and excretory phase images compared with T2-weighted images (P < .05). Gadolinium-enhanced 3D spoiled GRE MR urography helped detect 74% of small urothelial carcinomas. Nephrographic and excretory phase images are essential for helping detect small urothelial carcinomas.

Slow Spin Exchange Explains the Effects of Diuresis on Gadolinium Enhancement in MR Imaging in the Kidney, not in Other Organs

Katzberg et al (1) described the increased intensity of the T1-weighted signal at magnetic resonance (MR) imaging of the kidneys and other abdominal organs after injection of gadolinium-based contrast material. They showed that this effect was greatly enhanced in patients who also received furosemide prior to imaging. Pointing to the confinement of gadolinium in extracellular space and to the furosemide-induced transport of water from intra- to extracellular space, the authors attributed the additional increase in signal intensity to slow spin exchange between the two spatial compartments. In other words, they assumed that the signal intensity of intracellular space does not change in the presence of extracellular gadolinium, because the intracellular T1 remains constant.