Intravenous Administration Of gadolinium-DTPA Research Articles

Left atrial myxoma diagnosed and characterized by cardiac magnetic resonance imaging

A 71 year old man was referred for MRI investigation of the heart. He had a history of progressive dyspnea. Due to his echocardiographical findings and the known history of permanent atrial fibrillation, his cardiologist suspected atrial thrombi. MRI investigation of the heart showed a left atrial mass pedunculated at the atrial septum which showed signal enhancement after intravenous administration of gadolinium-DTPA. Left atrial myxoma was suspected. The patient underwent surgery with resection of the tumor and patch-occlusion of the atrial septum. Histology confirmed a polypoid cardial myxoma.

Inflammatory Abdominal Aortic Aneurysms: Diagnosis with Gadolinium Enhanced T1-Weighted Imaging

AIM: Inflammatory abdominal aortic aneurysms (IAAA) are a variant of abdominal aortic aneurysms, which are associated with an increased morbidity. The diagnosis of IAAA has traditionally been established with a combination of clinical and laboratory findings together with contrast enhanced CT. There is a high incidence of renal impairment in this group, and therefore contrast enhanced CT may be harmful.PATIENTS AND METHODS: Five patients with IAAA underwent T1-weighted spin echo and gradient echo gadolinium enhanced abdominal MRI. A total of eight examinations were performed, including three patients who underwent repeat MRI following steroid therapy.RESULTS: The inflammatory cuff was clearly identified following gadolinium administration in all eight examinations. The cuff enhanced homogeneously in all patients with no alteration in appearance following steroid therapy. The intravenous administration of gadolinium DTPA enabled clearer definition of locally involved structures.CONCLUSION: Gadolinium enhanced MRI readily demonstrates features of IAAA. In view of potential renal impairment in this patient group, we recommend this technique in preference to contrast enhanced CT in the initial investigation of inflammatory abdominal aortic aneurysms.Wallis, F. (2000). Clinical Radiology55, 136–139.

Virtual endoscopy of the upper urinary tract based on contrast-enhanced MR urography data sets

To investigate the feasibility of reconstructing a virtual endoscopy from MR imaging data sets of the upper urinary tract. The data obtained from 28 contrast-enhanced MR urographic examinations (5 normal; 23 pathologic) were post-processed to reconstruct a virtual ureterorenoscopy (VURS) using a threshold image segmentation. The visualization of the upper urinary tract was based on the acquisition of T1-weighted 3D gradient-echo sequences after intravenous administration of gadolinium-DTPA and a prior injection of low-dose furosemide. The employed MR urography technique created in all 28 cases a complete and strong contrast enhancement of the urinary tract. These 3D sequence data allowed the reconstruction of a VURS, even when the collecting system was not dilated. The best accuracy was provided by the MR urography sequences with the smallest voxel size. Moreover, the data acquisition based on a breath-hold technique has proved superior to that using a respiratory gating. Inside the renal pelvis, all calices could be assessed by turning the virtual endoscope in the appropriate direction. The visualization of the ureteral orifices in the bladder was also possible. All filling defects that were diagnosed by MR urography could be evaluated from the endoluminal view using the VURS. The exact characterization of the lesions based only on the assessment of the surface structure was difficult. A virtual endoscopy of the upper urinary tract can be successfully reconstructed using the data sets of high-resolution 3D MR urography sequences.

Struma Ovarii: MR Findings

The purpose of this study was to determine the MR appearance of struma ovarii correlating with the pathological features. MR findings of two patients with struma ovarii were retrospectively reviewed and compared with the pathological findings. Both tumors were complex masses composed of multiple cysts and solid components. The size and signal intensity of multiple cysts varied within the tumor. Hyperintense cystic areas on T1-weighted images were thought to correspond pathologically to hemorrhagic cysts and follicles containing viscous proteinaceous colloid. Solid components had as high a signal intensity as did uterine endometrium on T2-weighted images and as intermediate a signal intensity as did uterine muscle layer on T1-weighted images. After intravenous administration of gadolinium-DTPA, the solid components showed marked contrast enhancement. There was also ascitic fluid associated with adhesion and peritoneal thickening. The characteristic MR appearance of struma ovarii is thought to be a mixed mass composed of T2-hyperintense solid components with intense contrast enhancement and multiple T1-hyperintense cystic areas suggestive of hemorrhagic degeneration and viscous proteinaceous colloid.

Functional magnetic resonance imaging of human renal allografts during the post-transplant period: Preliminary observations

Graft dysfunction is a common occurrence during the first weeks following renal transplantation. The current study was designed to evaluate the potential of renal magnetic resonance (MR) perfusion imaging to differentiate acute allograft rejection (AAR) from acute tubular necrosis (ATN) during the post-transplant period. Twenty-three consecutive patients with clinically suspected ATN and/or AAR and eight consecutive control patients (asymptomatic, serum creatinine concentration < 1.5 mg/dL) underwent MR perfusion imaging of the renal allograft within 64 days after transplantation. Histopathology was obtained in all cases with clinical suspicion of ATN or AAR. Sixty sequential fast gradient-recalled-echo MR images were acquired in each patient after intravenous administration of gadolinium-DTPA (0.1 mmol/kg). Histopathology revealed 6 patients with pure AAR, 4 patients with a combination of AAR and ATN, 12 patients with ATN and 1 patient with normal findings. Kidney graft recipients with normal renal function showed a moderate increase in signal intensity (SI) of the renal cortex and medulla after administration of contrast agent followed by an immediate and short decrease in SI of the medulla (biphasic medullary enhancement pattern). The increase in cortical SI of patients with AAR was significantly smaller (61 ± 4% increase above baseline) than that measured in normal allografts (136 ± 9% increase above baseline) (p < 0.05) and patients with ATN (129 ± 3% increase above baseline) (p < .05). Patients with ATN had a slightly delayed and diminished cortical enhancement and an uniphasic and lesser medullary enhancement pattern compared to that observed in normal allografts (p < 0.05). A close correlation (r = 0.72) was found between serum creatinine concentration levels and changes in SI. Thus, MR imaging results and histopathology were in agreement in 22 of 23 patients (96%). MR perfusion imaging of renal allografts can be used to noninvasively differentiate ATN from AAR during the post-transplant period, and may also be helpful in cases where covert AAR is superimposing ATN during a phase of anuria. Patients with ATN can be separated from normals in the majority of cases as reflected by an uniphasic medullary enhancement pattern.

Early postoperative gadolinium-DTPA-enhanced MR imaging after successful lumbar discectomy

A prospective study was undertaken to establish the normal spectrum of early gadolinium-enhanced magnetic resonance (MR) imaging findings in patients who had resolution of symptoms after lumbar discectomy. Thirty-four patients underwent MR examinations 6 weeks and 6 months after lumbar discectomy on a 1.5 T superconducting unit, including sagittal and axial spin-echo (SE) T1-weighted images before and after intravenous administration of gadolinium-DTPA, as well as sagittal turbo (or fast-) SE T2-weighted images. All patients showed soft tissue enhancement along the surgical track in the subcutaneous soft tissue lateral to the spinous process and in the epidural space. There was only minimal (45%) or no (55%) mass effect on the dural sac associated with epidural scar formation 6 months after surgery, but often the nerve root at the operative level was surrounded by this enhancing tissue. Facet joint enhancement was seen in most patients 6 weeks (63%) and 6 months (53%) after surgery. Intrathecal nerve root enhancement was observed in six patients, 6 weeks after surgery. Nine patients (20%) had residual mass effect on the neural elements with an enhancement pattern suggestive of a disc fragment. Enhancement of the intervertebral space was seen in 67% of patients 6 weeks after surgery and in 86% of patients after 6 months. It may be concluded that, despite the use of gadolinium-DTPA, MR studies obtained in the initial postoperative period are difficult to interpret, because of the normal sequence of changes. Consequently, the clinical picture still remains the major indicator for recurrent surgery.

Gadolinium-DTPA: value in MR imaging of extraspinal musculoskeletal infections

To determine if paramagnetic contrast agents can improve the detection, delineation, and characterization of extraspinal musculoskeletal infections (MSI) on magnetic resonance (MR) imaging, 42 patients with clinical suspicion of MSI underwent MR imaging before and after intravenous administration of gadolinium-DTPA. The lesions consisted of 27 proven infections and 15 noninfective conditions. Specificity and accuracy in identifying infective lesions averaged 80% and 84%, respectively, on precontrast studies and 80% and 89% on the enhanced examinations, with no statistically significant difference. Rim enhancement around abscess loculi was the only pathognomonic sign of infection seen in ten patients with chronic osteomyelitis and pyogenic or tuberculous infections. In 17 patients with acute osteomyelitis, brucellosis, or mycetoma, detection and delineation of the lesions were best on precontrast studies, while postcontrast examinations resulted in underestimation of the extent of abnormalities in all cases. We conclude that intravenous gadolinium-DTPA has limited usefulness in the MR evaluation of extraspinal MSI.

Gadolinium-DTPA enhanced magnetic resonance imaging of bone cysts in patients with rheumatoid arthritis.

To examine the contents of intraosseous cysts in patients with rheumatoid arthritis (RA) through the signal intensity characteristics on gadolinium-DTPA (Gd-DTPA) enhanced magnetic resonance imaging. The hand or foot joints of nine patients with the cystic form of RA (where the initial radiological abnormality consisted of intraosseous cysts without erosions) were imaged before and after intravenous administration of Gd-DTPA. A 0.6 unit, T1 weighted spin echo and T2* weighted gradient echo were used to obtain images in at least two perpendicular planes. Most cysts showed a low signal intensity on the non-enhanced T1 weighted (spin echo) images and a high signal intensity on the T2* weighted (gradient echo) images, consistent with a fluid content. No cyst showed an enhancement of signal intensity on the T1 weighted images after intravenous administration of Gd-DTPA, whereas synovium hyperplasia at the site of bony erosions did show an increased signal intensity after Gd-DTPA. Magnetic resonance imaging detected more cysts (as small as 2 mm) than plain films, and the cysts were located truly intraosseously. In six patients no other joint abnormalities were identified by magnetic resonance imaging; the three other patients also showed, after Gd-DTPA administration, an enhanced synovium at the site of bony erosions. It is suggested that intraosseous bone cysts in patients with RA do not contain hyperaemic synovial proliferation. The bone cysts in patients with the cystic form of RA may be the only joint abnormality.

Bilateral lumbar intraspinal synovial cysts: Gd-enhanced MRI

We report a case of bilateral synovial cysts at L4–L5 level, examined by myelography, computed tomography (CT) and magnetic resonance imaging (MRI). On myelography, the lesions appeared as extradural masses. On CT, the lesions were cystic, with calcifiedd walls and were in close proximity to the facet joints. On MRI, the cystic nature of the lesions was confirmed. The wall appeared hypo-intense both on T1- and T2-weighted images (WI), and enhanced after intravenous administration of Gadolinium-DTPA (Gd-DTPA). This enhancement is thought to represent the peripheral fibrous capsule of the lesion and might be of importance both in the detection and the differential diagnosis of these lesions.

Subtraction gadolinium enhanced magnetic resonance for head and neck imaging.

The subtraction method of Des Plantes has been applied to gadolinium enhanced magnetic resonance imaging (GdMR). Using short acquisition times, T1 weighted spin echo pulse sequences are made immediately before and after the intravenous administration of gadolinium DTPA. To avoid moving the patient from the scanning tunnel the venipuncture is made into the dorsum of the foot. The needle is placed in the vein prior to putting the patient into the scanner and is irrigated with saline while the control series is obtained. 42 patients with naso-sinus or skull base tumours have been successfully investigated by this technique and satisfactory subtraction studies are now obtained on all patients other than the claustrophobic. Subtraction GdMR provides the best demonstration of the effects of gadolinium DTPA on the magnetic resonance signal for both normal and abnormal tissues. The signal recorded on the subtraction image is dependent on tissue blood supply and provides a more accurate record of tumour extent than that shown by unsubtracted GdMR scans.

MRI of intradural-extramedullary spinal neurinomas and meningiomas

The magnetic resonance images of 16 patients with intradural-extramedullary spinal tumors, consisting of 11 neurinomas and five meningiomas were reviewed The neurinomas appeared hypointense compared to the spinal cord on unenhanced T1-weighted images (T1WI) in nine of 11 patients, and hyperintense on T2-weighted images (T2WI) in nine of 11 patients. Neural foraminal extension was present in two cases. All 10 neurinomas were markedly enhanced; six of them exhibited ring-like enhancement on Gadolinium-DTPA (Gd-DTPA)-enhanced T1WI. The meningiomas appeared isointense on unenhanced T1WI in four of five patients and on T2WI in three of four patients. Three meningiomas showed moderate homogeneous contrast enhancement after the intravenous administration of Gd-DTPA. It is concluded that careful scrutiny of magnetic resonance images facilitates the differential diagnosis of spinal neurinomas and meningiomas.

Ｇｄ‐ＤＴＰＡ（ガドペンテト酸ジメグルミン）による顎内障のＭＲＩ診断

Magnetic resonance (MR) imaging was performed in five internal derangement of temporomandibular joint (TMJ) patients, before and after intravenous administration of gadolinium-DTPA (Gd-DTPA) as a contrast agent. MR imaging was performed with a O.5 tesla unit (VISTA MR; PICKER INTERNATIONAL) using a surface coil. We obtained multiple 5 mm sagital images with open and closed jaw positions. Precontrast proton density images were obtained with a repetition time (TR) of 1, 000 msec and an echo time (TE) of 40 msec (TR/TE=1, 000/40). Gd-DTPA was administered intravenously in a dose of 0.2 ml per kilogram of body weight. After the injection, postcontrast Ti weighted images (500/20) or postcontrast proton density images (1, 000/40) were obtained.In the postcontrast Ti weighted images, the soft tissue surrounding the articular disk was enhanced and it provided helpful information for assessing the disk position. On the other hand, there was no effect of the contrast agent in the postcontrast proton density images. None of the patients experienced allergic reactions or other side effects. Gd-DTPA appeared to be a safe and effective contrast agent for MR imaging with Ti weighted images. However, compared with our usual imaging of the TMJ, the imaging did not indicate greater MR sensitivity for detecting the articular disk by means of Gd-DTPA enhancement.

Gadolinium-DTPA in rheumatoid arthritis and related diseases: first results with dynamic magnetic resonance imaging.

Thirty-four joints (19 knees, 15 wrists) of 31 patients suffering from rheumatoid arthritis and related disorders were examined prior to and following intravenous administration of Gadolinium-DTPA (0.1 mmol/kg body weight). T1-weighted spin-echo sequences and the gradient-echo technique FLASH were applied. FLASH scanning was used for the registration of the time-dependent changes of signal intensity following Gd-DTPA. Synovial proliferations exhibited a rapid and marked increase of signal intensity whereas fatty tissue, bone marrow, muscle and synovial effusion demonstrated only minor changes, causing enhanced contrast between synovial pannus and joint effusion or other neighbouring structures. Within the synovial pannus, ratios (absolute signal increase) of 131.3 +/- 53.4% and 122.9 +/- 51.1% were found in T1-weighted spin-echo and in FLASH sequences respectively. The average signal increase gradient of pannus (108.2 +/- 70.6%/min) was significantly (p less than 0.001) different from muscle (13.4 +/- 7.8%/min), fatty tissue (10.2 +/- 8.4%/min), bone marrow (5.5 +/- 7.1%/min), and joint effusion (14.7 +/- 7.8%/min).

Efficient use of flash sequences in the staging of bone and soft tissue tumors

Delineation of neoplasms from normal tissue is possible using Flash sequences. These sequences prove useful in preoperative staging of bone tumours and soft tissue tumours. However, contrast between neoplastic and surrounding normal tissue is lower than in optimal selected spin-echo sequences. Flash-90 sequence is superior to Flash-10 sequence in the demonstration of intraosseous extension of predominantly sclerotic, calcified and purely fibrous tumours. In contrast, Flash-10 sequence proves superior for the demarcation of osteolytic tumours with minimal fibrous tissue content. Delineation of extraosseous tumour masses against muscle can best be achieved using Flash-90 sequence after intravenous administration of Gadolinium-DTPA. Flash-90 sequence enables sharp demarcation of extraosseous masses of bone tumours against surrounding fat, whereas Flash-10 sequence proves useful in the delineation of non-lipomatous soft tissue tumours against normal fat.

Brain tumors: MR imaging with gadolinium-DTPA.

Magnetic resonance (MR) imaging was performed on 40 patients with intracranial tumors, before and after intravenous administration of gadolinium-DTPA (Gd-DTPA). Precontrast studies included a comprehensive protocol of spin-echo sequences. Tumors were visualized on precontrast images either directly or indirectly by anatomic distortion caused by the mass. However, differentiation of the tumor from adjacent tissues was possible in only 17 of 40 cases. Delineation of the tumor was best on precontrast, T2-weighted images. After administration of Gd-DTPA (0.1 mmol/kg), increased signal intensity from the tumor was observed in all patients. The localized increase in signal intensity in the tumor considerably improved the tumor delineation in 36 of 40 patients. Whereas most of the meningiomas, neuromas, and adenomas could be delineated prior to administration of contrast material if appropriate pulse sequences were applied, glioblastomas and intracranial metastases required Gd-DTPA administration for diagnostically sufficient tumor display.