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Pradip M Pattany

Publications and source records attributed to Pradip M Pattany.

7 recordsLinked to original sources
PubMed2004

The brachial plexus: normal anatomy, pathology, and MR imaging.

The brachial plexus is the most technically and anatomically challenging area of the peripheral nervous system for diagnostic imaging. Marked improvements in spatial and contrast resolution of plexus images have resulted from the use of phased-array technology and newer MR pulse sequence designs. This article presents case material incorporating these improvements and discusses the primary factors that continue to limit MR image quality, such as inhomogenous fat suppression, motion artifacts, and small vessels that mimic or obscure plexus components, and potential solutions and imaging alternatives. Brachial plexus anatomy and its appearance on multiplanar MR images are reviewed. The morphologic features and MR signal characteristics that have been found useful in distinguishing between normal and abnormal plexus components,and in detecting neuropathic lesions, are addressed in the context of clinical indications for plexus imaging as follows: mass involving the plexus, traumatic injury, entrapment syndrome, posttreatment evaluation, and miscellaneous conditions.

Animals↗
PubMed2003

MR angiography of the spine: update.

The role of MRA, as an adjunct to conventional MR imaging of the spine and spinal cord, is evolving. The older MRA methods that have been applied to spinal vascular imaging include 2D and 3D phase contrast techniques and a derivative of 3D time-of-flight techniques with data acquired for about several minutes after gadolinium contrast injection (standard 3D CE MRA). Newer 3D gradient-echo techniques, which allow the acquisition of each volume of data in tens of seconds as a contrast bolus traverses the region of interest (fast 3D CE MRA), offer the possibility of temporally resolving intradural arteries and veins. The appearance of normal and abnormal intradural vessels, primarily veins, on the standard 3D CE MRA method has been described for the thoracolumbar region. Normal intradural arteries have been more difficult to detect, although preliminary results with the fast 3D CE MRA method, are promising. Only by establishing the MRA appearance of normal arteries and veins, can one begin to define "abnormal" with greater confidence (presuming that the variability in the appearance of normal vessels is not so great as to preclude differentiation). In striving for this goal, MRA has already encountered competition from CT angiography. In the characterization of spinal vascular lesions, the value of MRA has been demonstrated most convincingly for dural AVF. This lesion is more accurately localized and more sensitively detected (by neuroradiolologists and others experienced in spine imaging) with combined MR imaging and standard 3D CE MRA than with MR imaging alone. Preliminary results suggest that sensitivity and specificity may be further improved if fast 3D CE MRA is combined with conventional MR imaging. Although less well documented, the value of MRA in characterizing other lesions, such as AVMs and vascular tumors, has been reported in recent publications. In the future, the role of MRA will depend on technical advances, such as parallel acquisition techniques and possibly implantable RF coils, which permit improved detection of, and differentiation between, intradural arteries and veins. With these improvements, MRA may play an expanded role in the characterization of spinal vascular abnormalities, encompassing trauma and degenerative spine disease and vascular malformations and tumors.

Contrast Media↗
PubMed2003

MR angiography of the spine and spinal cord.

OBJECTIVES: This review has three objectives: 1) to describe spinal vascular anatomy, focusing on thoracolumbar intradural vessels detectable by both magnetic resonance angiography (MRA) and digital subtraction x-ray angiography (DSA), 2) to compare the MRA techniques that have been used to detect the major intradural vessels, and 3) to illustrate the clinical application of these MRA techniques, especially their efficacy in characterizing spinal dural arteriovenous fistulae (AVF). METHODS: MRA is an adjunct to conventional magnetic resonance imaging. MRA is usually implemented as a three-dimensional (3D) contrast-enhanced (CE) gradient-echo technique, with two approaches to data acquisition: 1) "standard" 3D CE MRA, requiring approximately 10 minutes per 3D volume, and 2) "fast" (bolus/dynamic) 3D CE MRA, requiring approximately 0.5 to 2 minutes per 3D volume depending on k-space sampling schemes. Vessels are displayed on targeted maximum intensity projection images. RESULTS: Normal intradural vessels detected on standard CE MRA are primarily veins (medullary and median), whereas both arteries and veins are detected on fast CE MRA. Identification of arteries (artery of Adamkiewicz, anterior spinal artery) is limited, and their differentiation from veins can be incomplete. Intradural vessels in patients with dural fistulae have abnormal features on MRI (length of flow voids and postcontrast serpentine enhancement) and standard 3D CE MRA (length, tortuosity, and qualitative size of dominant perimedullary vessel), which differ significantly from those of normal vessels. Standard MRA added to a conventional MRI study significantly (P=0.016) increased the rate of detection of the spinal level of a dural fistula. The correct level +/- one vertebral segment was identified in 73% of true-positive patients. CONCLUSIONS: Application of spinal MRA requires knowledge of vascular anatomy, specifically the major intradural vessels, and careful implementation of 3D CE MRA techniques. The standard technique allows for more effective noninvasive screening for vascular lesions, particularly dural AVF, than magnetic resonance imaging alone. Preliminary results indicate that the fast technique may further improve characterization of normal and abnormal intradural vessels, especially if continued technical advances yield greater temporal resolution while maintaining adequate spatial resolution.

Arterial Occlusive Diseases↗
PubMed2003

Proton MR spectroscopy of gliomatosis cerebri: case report of elevated myoinositol with normal choline levels.

A 69-year-old woman presented with clinical and imaging findings suspicious for gliomatosis cerebri, later confirmed by biopsy (moderately cellular, infiltrating glioma). Single voxel proton MR spectroscopy (TE 20 and TE 135) and spectroscopic imaging (TE 135) performed at admission showed normal choline, decreased N-acetyl, and elevated myo-inositol levels relative to creatine. The primary conclusion is that in suspected cases of gliomatosis cerebri, myo-inositol/creatine and myo-inositol/N-acetyl should be determined because they may provide evidence of tumor, even though choline/creatine is normal. A corollary to this conclusion is that choline/creatine may be misleading if used to demarcate infiltrating glioma from edema.

Aged↗
PubMed2002

Effects of physiologic human brain motion on proton spectroscopy: quantitative analysis and correction with cardiac gating.

SUMMARY: Proton MR spectroscopy is a powerful noninvasive method that enables measurement of certain brain metabolites in healthy subjects and patients with diseases. A major difficulty with clinical and research applications of in vivo proton MR spectroscopy is the variability of metabolite concentrations, especially in regions with substantial physiologic motion. In our preliminary evaluation, we tested the hypothesis that physiologic brain motion leads to lower mean metabolite concentrations and higher SDs for the measured metabolite concentrations.

Adult↗
PubMedDate not supplied

Proton magnetic resonance spectroscopy of the thalamus in patients with chronic neuropathic pain after spinal cord injury.

BACKGROUND AND PURPOSE: Spinal cord injury (SCI) results in a number of consequences; one of the most difficult to manage is chronic neuropathic pain. Thus, defining the potential neural and biochemical changes associated with chronic pain after SCI is important because this may lead to development of new treatment strategies. Prior studies have looked at the thalamus, because it is a major sensory relay station. The purpose of our study was to define alterations in metabolites due to injury-induced functional changes in thalamic nuclei by using single-voxel stimulated echo acquisition mode MR spectroscopy. METHODS: Twenty-six men were recruited: 16 patients with SCI and paraplegia (seven with pain, nine without pain) and 10 healthy control subjects. Pain was evaluated in an interview, which included the collection of information concerning the location, quality, and intensity of pain, carefully identifing the dysesthetic neuropathic pain often seen in SCI. Localized single-voxel (8-cm(3) volume) proton spectra were acquired from the left and right thalami. RESULTS: The concentration of N-acetyl (NA) was negatively correlated with pain intensity (r = -0.678), and the t test showed that NA was significantly different between patients with pain and patients without pain (P =.006). Myo-inositol was positively correlated with pain intensity (r = 0.520); difference between patients with pain and those without pain was almost significant (P =.06). CONCLUSION: The observed differences in metabolites in SCI patients with and pain and in those without pain suggest anatomic, functional, and biochemical changes in the thalamic region.

Adult↗