Hyperintense Signals (hyperintense + signal)

Distribution by Scientific Domains


Selected Abstracts


Influence of the position of the foot on MRI signal in the deep digital flexor tendon and collateral ligaments of the distal interphalangeal joint in the standing horse

EQUINE VETERINARY JOURNAL, Issue 5 2009
M. SPRIET
Summary Reasons for performing study: Hyperintense signal is sometimes observed in ligaments and tendons of the equine foot on standing magnetic resonance examination without associated changes in size and shape. In such cases, the presence of a true lesion or an artifact should be considered. A change in position of a ligament or tendon relative to the magnetic field can induce increased signal intensity due to the magic angle effect. Objectives: To assess if positional rotation of the foot in the solar plane could be responsible for artifactual changes in signal intensity in the collateral ligaments of the distal interphalangeal joint and in the deep digital flexor tendon. Methods: Six isolated equine feet were imaged with a standing equine magnetic resonance system in 9 different positions with different degrees of rotation in the solar plane. Results: Rotation of the limb induced a linear hyperintense signal on all feet at the palmar aspect of one of the lobes of the deep digital flexor tendon and at the dorsal aspect of the other lobe. Changes in signal intensity in the collateral ligaments of the distal interphalangeal joint occurred with rotation of the limb only in those feet where mediolateral hoof imbalance was present. Conclusions: The position and conformation of the foot influence the signal intensity in the deep digital flexor tendon and in the collateral ligaments of the distal interphalangeal joint. Potential relevance: The significance of increased signal intensity in the deep digital flexor tendon and in the collateral ligaments of the distal interphalangeal joint should be interpreted with regard to the position and the conformation of the foot. [source]


Neuroimaging of Tuberculous Myelitis: Analysis of Ten Cases and Review of Literature

JOURNAL OF NEUROIMAGING, Issue 3 2006
Mohammad Wasay MD
ABSTRACT We retrospectively reviewed the clinical and neuroimaging features of 10 patients with tuberculous myelitis. The most common presenting symptoms were fever (70%) and paraplegia (60%). Bladder and bowel symptoms were present in 90% patients. On MRI, the involvement of the cervical/thoracic segment of the spinal cord was most commonly seen (90%). The most consistent finding was hyperintense signals on T2-weighted MRI. T1-weighted images showed isointense (n= 5) and hypointense (n= 4) signals in the spinal cord lesions. Post-contrast enhancement was present in 6 patients, epidural enhancement in 4 patients, and cord swelling in 2 patients. We reviewed more than 250 published cases with the diagnosis of tuberculous myelitis and radiculomyelitis with special attention to MRI findings. It is predominantly a disease of the thoracic spinal cord. Most spinal cord lesions appear as hyperintense on T2 and iso- or hypointense on T1-weighted images. MRI findings in patients with spinal cord tuberculosis have both diagnostic and prognostic significance. Cord atrophy or cavitation and the presence of syrinx on MRI may be associated with poor outcome. [source]


Increased asymmetric pulvinar magnetic resonance imaging signals in Creutzfeldt,Jakob disease with florid plaques following a cadaveric dura mater graft

NEUROPATHOLOGY, Issue 1 2006
Yoshinobu Wakisaka
A 9-year-old Japanese girl received a cadaveric dura mater graft during surgery following a head injury with brain contusion. She continued to do well, but when she became 19-years-old, she gradually showed a violent character and was treated in a psychiatric hospital. Another 6 years later, 200 months after the procedure, she developed a progressive gait ataxia, which subsequently led to her death within 10 months of onset. An autopsy showed she had CJD. This patient represents an atypical case of dura-associated CJD (dCJD) with unusual clinicopathological features including the late occurrence of myoclonus, an absence of periodic synchronous discharges in the electroencephalogram, and the presence of widespread florid plaques. However, our detection of an asymmetrical increase in the MRI-derived images of pulvinar nuclei has not been previously observed in other atypical cases of dCJD. Because atypical dCJD cases share several clinicopathological features with those of vCJD, and because asymmetrical hyperintense signals in the pulvinar have been observed in some neuropathologically confirmed vCJD cases, we had some difficulty in a differential diagnosis between atypical dCJD and vCJD. This is the first atypical dCJD case showing a pulvinar high signal compared with all other basal ganglia on MRI. [source]


Clinical diagnosis and differential diagnosis of CJD and vCJD,

APMIS, Issue 1 2002
Inga Zerr
The most widely distributed form of transmissible spongiform encephalopathy, sporadic Creutzfeldt-Jakob disease, typically affects patients in their sixties. Rapidly progressive dementia is usually followed by focal neurological signs and typically myoclonus. The disease duration in sporadic CJD is shorter than in variant CJD (6 months and 14 months, respectively). The clinical diagnosis in sporadic CJD is supported by the detection of periodic sharp and slow wave complexes in the electroencephalogram, hyperintense signals in basal ganglia on magnetic resonance imaging and elevated levels of neuronal proteins in the cerebrospinal fluid (such as 14-3-3). In contrast to the sporadic form, hyperintense signals in the posterior thalamus ("pulvinar sign") are seen in variant CJD. Following recent developments in diagnostic premortem techniques, clinical criteria for probable sporadic and probable variant CJD were established. Clinicopathological studies on sporadic CJD revealed different phenotypes which are characterized by neuropathological lesion profile, clinical syndrome, codon 129 genotype and type of proteinase K-resistant core of the prion protein. Alzheimer's disease and Lewy body dementia are the most frequent differential diagnoses in sporadic CJD in elderly patients, whereas chronic inflammatory disorders of the central nervous system have to be considered in younger patients. [source]