Topical contrast-enhanced CT and MR dacryocystography: imaging the lacrimal drainage apparatus of healthy volunteers.

OBJECTIVE: The purpose of this study was to evaluate the feasibility of administering topical contrast material during helical CT dacryocystography and topical saline solution during MR dacryocystography to reveal the lacrimal drainage apparatus. SUBJECTS AND METHODS: Fourteen healthy volunteers underwent helical CT dacryocystography, MR dacryocystography, or both. Eight of the 14 subjects underwent both techniques; three subjects underwent MR dacryocystography, and three subjects underwent CT dacryocystography. Images were evaluated by two radiologists for degree of visualization of components of the lacrimal drainage apparatus. Each volunteer was questioned about the relative discomfort of contrast material and saline solution administration. RESULTS: The lacrimal drainage system was seen on both CT dacryocystography and MR dacryocystography. CT dacryocystography allowed two-dimensional and three-dimensional reconstructions on which adjacent bone anatomy could be seen. The MR dacryocystography two-dimensional reconstructions and maximum intensity projections also showed the drainage apparatus. However, smaller drainage structures were more consistently seen on CT dacryocystography than on MR dacryocystography. Saline solution was more comfortable than contrast material. CONCLUSION: CT dacryocystography and MR dacryocystography reproducibly and non-invasively revealed the lacrimal drainage apparatus and allowed a better physiologic examination than cannulation dacryocystography. MR dacryocystography can be performed without administration of ionizing radiation or contrast material, but this technique cannot show adjacent bone anatomy and less consistently showed the smaller drainage structures than CT dacryocystography

FLAIR and HASTE imaging in neurologic diseases.

The need to develop faster imaging techniques has led to the implementation of fast spin-echo imaging, EPI, and hybrid imaging techniques. This article discusses two of these faster imaging techniques, fast fluid-attenuated inversion-recovery (FLAIR) imaging and half-Fourier acquisition single-shot turbo spin-echo (HASTE) imaging, and their potential clinical application in neurologic diseases. FLAIR imaging, in particular, has demonstrated considerable promise for the evaluation of intracranial pathology. HASTE imaging can be used for rapid imaging of the brain or spine in those patients who are claustrophobic or who have difficulty remaining still, but it does not yet have a primary role in clinical neuroradiology

Effects of contrast dose, delayed imaging, and magnetization transfer saturation on gadolinium-enhanced MR imaging of brain lesions.

This paper discusses the types of paramagnetic agents available for clinical brain imaging and reviews investigations that have sought to optimize the use of these agents by varying the administered dose, delaying the imaging time after contrast administration, and altering image contrast by using magnetization transfer saturation pulses

Feasibility of sequential high-dose chemotherapy and peripheral blood stem cell support for pediatric central nervous system malignancies.

BACKGROUND: The outlook for many brain tumors remains poor. Increased dose intensity has been correlated with response rate and survival in many solid tumors. PATIENTS AND METHODS: Ten children with recurrent or newly diagnosed brain tumors were treated with four sequential courses of high-dose single agent chemotherapy with peripheral blood stem cell (PBSC) support. PBSC harvesting was undertaken prior to chemotherapy and following the first course of chemotherapy (3.6 g/m2 etoposide). Each course of chemotherapy consisted of a single drug followed 48 hours later by PBSC reinfusion. Three patients were treated on Regimen A: etoposide, carboplatinum 1.95 g/m2, cyclophosphamide 5 g/m2, and thiotepa 300 mg/m2; three patients were treated on Regimen A\u27 with carmustine 600 mg/m2 replacing cyclophosphamide; four patients received Regimen B: etoposide, carboplatinum 1.95g/m2, cyclophosphamide 7 g/m2, and thiotepa 900 mg/m2. RESULTS: No course of chemotherapy was complicated by \u3e14 days of neutropenia. Platelet recovery was more prolonged, particularly in patients who had previously received craniospinal irradiation. Non-hematologic toxicity was severe with three toxic deaths including two patients who developed hemolytic-uremic syndrome and respiratory failure. Two of three patients with primitive neuroectodermal tumors had a partial response; no responses were observed in patients with high-grade gliomas. CONCLUSIONS: Administration of multiple courses of high-dose chemotherapy with PBSC support is feasible in this patient population and successfully mitigates hematologic toxicity. Non-hematologic toxicity becomes prohibitive as chemotherapy doses are escalated

Brain: gadolinium-enhanced fast fluid-attenuated inversion-recovery MR imaging.

PURPOSE: To determine the clinical utility of gadolinium-enhanced fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) imaging of the brain by comparing results with those at gadolinium-enhanced T1-weighted MR imaging with magnetization transfer (MT) saturation. MATERIALS AND METHODS: In 105 consecutive patients referred for gadolinium-enhanced brain imaging, FLAIR and T1-weighted MR imaging with MT saturation were performed before and after administration of gadopentetate dimeglumine (0.1 mmol per kilogram of body weight). Pre- and postcontrast images were evaluated to determine the presence of abnormal contrast enhancement and whether enhancement was more conspicuous with the FLAIR or T1-weighted sequences. RESULTS: Thirty-nine studies showed intracranial contrast enhancement. Postcontrast T1-weighted images with MT saturation showed superior enhancement in 14 studies, whereas postcontrast fast FLAIR images showed superior enhancement in 15 studies. Four cases demonstrated approximately equal contrast enhancement with both sequences. Six cases showed some areas of enhancement better with T1-weighted imaging with MT saturation and other areas better with postcontrast fast FLAIR imaging. Superficial enhancement was typically better seen with postcontrast fast FLAIR imaging. CONCLUSION: Fast FLAIR images have noticeable T1 contrast making gadolinium-induced enhancement visible. Gadolinium enhancement in lesions that are hyperintense on precontrast FLAIR images, such as intraparenchymal tumors, may be better seen on T1-weighted images than on postcontrast fast FLAIR images. However, postcontrast fast FLAIR images may be useful for detecting superficial abnormalities, such as meningeal disease, because they do not demonstrate contrast enhancement of vessels with slow flow as do T1-weighted images

Solitary plasmacytoma of the mastoid bone presenting as coalescent mastoiditis.

Acute mastoiditis is a complication of acute otitis media that produces air cell opacification and coalescence on computed tomographic (CT) imaging. This appearance, however, is nonspecific and may be seen in patients with infection and tumor. Magnetic resonance imaging (MRI) can aid in differentiating the two on the basis of differences in tissue signal characteristics and by showing the presence or absence of an associated soft-tissue mass. In this report, we demonstrate the utility of MRI as a complementary imaging modality to CT in the diagnosis of a solitary plasmacytoma of the temporal bone that was initially thought to be coalescent mastoiditis