Cross-sectional imaging of the thyroid gland

Directed imaging is useful in assessing the thyroid gland. Nuclear scintigraphy reveals functional information about the thyroid gland, while cross-sectional imaging, including ultrasound, CT, and MR imaging provide important adjunctive anatomic information about the thyroid as well as about related structures in the neck, including the presence or absence of cervical and mediastinal lymphadenopathy, or extension of thyroid disease into adjacent soft tissues or the mediastinum. This article reviews the anatomy and physiology of the thyroid gland and addresses issues related to diseases affecting the thyroid gland, with an emphasis on neoplasms and the role of cross-sectional MR and CT imaging in the assessment of thyroid neoplasia.     

Serial magnetic resonance imaging in subacute sclerosing panencephalitis

Magnetic resonance (MR) imaging of a 17-year-old girl with subacute sclerosing panencephalitis (SSPE) was done several times to monitor the morphological changes and clinical course of the disease by comparison with computed tomographic (CT) scans. The MR image showed lesions that corresponded to the clinical symptoms in the early stages where no abnormalities appeared on the CT scans. The MR images delineated the extent of abnormal areas more clearly than the CT scans. However, the course of neurological manifestations did not always correspond to the MR findings. Serial MR imaging was useful in the detection and observation of the stages and clinical progress of SSPE.     

Serial Magnetic Resonance Imaging in Subacute Sclerosing Panencephalitis

Abstract: Magnetic resonance (MR) imaging of a 17-year-old girl with subacutesclerosing panencephalitis (SSPE) was done several times to monitor the morphological changes and clinical course of the disease by comparison with computed tomographic (CT) scans. The MR image showed lesions that corresponded to the clinical symptoms in the early stages where no abnormalities appeared on the CT scans. The MR images delineated the extentof abnormal areas more clearly than the CT scans. However, the course of neurological manifestations did not always correspond to the MR findings. Serial MR imaging was useful inthe detection and observation of the stages and clinical progress of SSPE.     

Cranial MR imaging in patients with von Recklinghausen's disease (neurofibromatosis type I)

MR imaging was performed for 24 patients with von Recklinghausen's disease. Twenty of the 24 patients showed abnormal findings in MR imaging. In many cases, the lesions were multifocal. In 14 patients small focal areas of increased signal on T2-weighted images were thought to represent heterotopias or hamartomas. Eight patients had optic tract gliomas. Three patients had parenchymal gliomas. In one patient, white matter showed high intensity on T2-weighted images representing delayed myelination. The rate of abnormal findings was higher for MR imaging than CT. MR imaging was found to be an excellent imaging method for known diseases and for detecting lesions in asymptomatic patients.     

Minimal thyroid ophthalmopathy

We studied six patients with the clinical, sonographic, CT, and biochemical profile of minimal euthyroid Graves' disease (MEGD). This syndrome was characterized clinically by small but obtrusive and measurable amounts of diplopia related to endocrine ophthalmopathy and the conspicuous absence of systemic or laboratory signs of thyrotoxicosis. Diagnostic emphasis will be given to certain manifestations of MEGD, namely the clinical patterns of ophthalmoparesis, the results of forced duction testing, orbital ultrasonography, and CT, as well as the need to obtain, in some cases, special antibody studies and the thyrotropin releasing hormone stimulation test.     

Imaging of topographic viral CNS infections

Infections caused by enteroviruses, rabies, adenoviruses, and Nipah and Hanta viruses are discussed. Several studies defined the pattern of MR imaging findings in these disease processes that reflect parenchymal infiltration with inflammatory cells, typically visualized as areas of low attenuation on CT, as well as of low T1 and high T2 signal intensity on MR imaging. Diffusion-weighted MR imaging has been shown to be superior to conventional magnetic resonance imaging for the detection of early signal abnormalities in encephalitis. Focal unilateral hyperperfusion as visualized by SPECT appears to be an indicator of severe inflammation of the brain tissue and was found to be an independent predictor of poor prognosis, whereas clinical outcome variables, CSF, or EEG findings are not.     

Clinico-morphological correlations based on MRI in syringomyelia. Study of 22 cases

Twenty-two patients with syringomyelia were investigated clinically and by MR imaging using clearly defined clinical and radiologic protocols. Intramedullary cavities were identified by MR images in 20 cases and by CT scanning after intrathecal injection of Metrizamide in two cases. In all but one case, when the clinical picture was purely motor, concordance was established between clinical findings and morphologic type of intramedullary cavity. Syringomyelic syndromes should now be defined not only on the basis of clinical data but on clinicoradiologic features. The examination of choice is MR imaging, because of its reliability and safety and because it allows tridimensional analysis of cavities and associated malformations. Results of MR imaging exploration suggest a possible improved physiopathologic approach to the disease and more effective therapeutic procedures.     

Magnetic Resonance Imaging Of The Central Nervous System

Magnetic resonance (MR) is a powerful new imaging modality which has recently become competitive with X-ray computed tomography (CT) for imaging of the central nervous system (CNS). The advantages of MR include lack of ionizing radiation and the necessity to use iodinated contrast. MR is able to image directly in the transaxial, coronal, and sagittal planes. With appropriate pulsing sequences, MR is more sensitive than CT in the detection of early disease associated with increased water content. Included in this category are multiple sclerosis, early infarcts, small tumours, and inflammatory lesions. MR is superior to CT in the posterior fossa due to beam hardening artifacts in the latter modality. In the cord, MR is useful in the evaluation of syringomyelia, spinal dysraphism, and intramedullary tumours.

Due to its increased sensitivity in the detection of early disease, MR should generally be used as the initial screening procedure in the evaluationof possible intracranial disease. Current limita-tionsof MR include longer single slice imaging times, thicker slices, inability to use contrast agents to define blood/brain barrier breakdown, and the inabilityto image calcification and cortical bone. Patients on cardiac monitors or on respirators and those with intracranial aneurysm clips and cardiac pacemakers are currently excluded from MR imaging.     

Magnetic resonance imaging of the central nervous system

Magnetic resonance (MR) is a powerful new imaging modality which has recently become competitive with X-ray computed tomography (CT) for imaging of the central nervous system (CNS). The advantages of MR include lack of ionizing radiation and the necessity to use iodinated contrast. MR is able to image directly in the transaxial, coronal, and sagittal planes. With appropriate pulsing sequences, MR is more sensitive than CT in the detection of early disease associated with increased water content. Included in this category are multiple sclerosis, early infarcts, small tumours, and inflammatory lesions. MR is superior to CT in the posterior fossa due to beam hardening artifacts in the latter modality. In the cord, MR is useful in the evaluation of syringomyelia, spinal dysraphism, and intramedullary tumours. Due to its increased sensitivity in the detection of early disease, MR should generally be used as the initial screening procedure in the evaluation of possible intracranial disease. Current limitations of MR include longer single slice imaging times, thicker slices, inability to use contrast agents to define blood/brain barrier breakdown, and the inability to image calcification and cortical bone. Patients on cardiac monitors or on respirators and those with intracranial aneurysm clips and cardiac pacemakers are currently excluded from MR imaging.     

Computed tomography, magnetic resonance imaging and pathological correlations in a case of Binswanger's disease

The results of 3 computed tomography (CT) examinations carried out over a 7 year period and of a post-mortem magnetic resonance (MR) study showed aspects of a white matter disease in a hypertensive patient suffering from vascular dementia. Histopathology revealed the primary cause of dementia to be a white matter degeneration sparing the U fibers. Rarefaction of both the myelin sheaths and the axons was present together with severe thickening of the medullary arteries. These findings support the existence of Binswanger's disease (BD) as a distinct variety of arteriosclerotic dementia. CT and MR imaging are valuable aids for diagnosis. However, since there are many other causes of CT and MR demonstrated diffuse white matter degeneration in the elderly, a conclusive diagnosis of BD requires pathological confirmation.     

Subacute sclerosing panencephalitis : CT and MR imaging in a rapidly progressive case

We report the findings on CT and MR imaging in a patient with rapidly progressive subacute sclerosing panencephalitis (SSPE), which correlated with the clinical progression of the disease. In view of the rapid neurological deterioration and CSF pleocytosis, a brain biopsy was done and this confirmed the diagnosis.     

Binswanger's encephalopathy: a review

Summary Binswanger's encephalopathy is reviewed in respect to history, computed tomography, magnetic resonance imaging, epidemiology, pathology, clinical picture, laboratory findings, differential diagnosis, and treatment. The various viewpoints on the pathogenesis of the process are discussed, in particular the role of ischemia, vascular disease, high blood pressure, lacunar infarction, hypoxia, edema, and hydrocephalus. The white matter hypomyelination of congophilic angiopathy and Alzheimer's disease should provide clues. A unifying hypothesis has not been attained.Abbreviations AD Alzheimer's disease - BE Binswanger's encephalopathy - BP blood pressure - CA congophilic angiopathy - CSF cerebrospinal fluid - CT computed tomography - EEG electroencephalography - HU Hounsfield units - ISL incidental subcortical lesions - LD low density - MR magnetic resonance imaging - NPH normal pressure hydrocephalus - PV periventricular - PVH periventricular hyperintensity in MR, including capping and rimming - PVLD periventricular low density in CT - PVWM periventricular white matter - TIA transient ischemic attack - UBOs unidentified bright objects - U fibers arcuate fibers - WM white matter - WMHF white matter hyperintense foci in MR - WMLD white matter low density     

MR imaging in the detection of diffuse axonal injury with mild traumatic brain injury

PURPOSE: To evaluate the occurrence and distribution of mild traumatic brain injury (MTBI) caused by diffuse axonal injury (DAI) using magnetic resonance (MR) imaging and to attempt to correlate MR findings with post-concussion symptoms (PCS). PATIENTS AND METHODS: Forty MTBI patients (mean age: 32.5 years) with normal cranial computed tomography (CT) findings were examined with standard MR protocol including T(1)-weighted, T(2)-weighted, fluid attenuated inversion recovery (FLAIR), gradient echo (GRE) and diffusion-weighted (DW) sequences. MR imaging was performed within 24 hours of injury. The lesions were classified as DAI based on their location and morphologic appearance. RESULTS: In MR imaging of five (12.5%) of the patients, the lesions compatible with DAI were observed. Four patients (10%) had the foci of low signal intensity compatible with hemorrhagic shear injury on the GRE sequence, and five (12.5%) patients had high signal intensity on FLAIR and DW sequence. CONCLUSION: MR imaging can be helpful in revealing DAI lesions in patients with normal CT scan findings after MTBI. FLAIR, GRE and DW sequences are superior to conventional spin-echo images in detecting DAI lesions.     

Benign odontogenic tumors of the mandible and maxilla

Benign odontogenic tumors are characterized by imaging findings of expansile growth and well-defined margins with smooth borders, and their appearance is very similar to that of odontogenic and nonodontogenic cysts. From the viewpoint of diagnostic imaging of odontogenic tumors, teeth are designed differently according to their origin from the apex or crown. Therefore, for differential diagnosis, it is necessary to select diagnostic methods that make it possible to evaluate these findings in detail. Intraoral and panoramic radiography are highly effective in examining the relationship between teeth and lesions, especially the vertical relationship. When a lesion is suspected in the mandible or maxilla on CT, MR imaging, or nuclear medicine, these procedures must be performed as supplementary imaging techniques. CT demonstrates well the degree of bone resorption, osteosclerosis, cortical bone swelling, destruction, and calcification. MR imaging is effective in differentiating between tumors and cysts, evaluating the infiltration of malignant tumors in the jawbone and surrounding soft tissue, and detecting bone marrow changes of the jaw. Differentiation between tumors and cysts must be achieved by contrast-enhanced studies. Combining plain radiography with advanced imaging techniques, including CT and MR imaging, can improve the accuracy of diagnosing odontogenic tumors.     

Adults and children with headache: evidence-based diagnostic evaluation

Headache represents one of the most common complaints in the outpatient and emergency room setting [1]. Most causes of headache are benign and do not require emergent imaging or intervention. The authors' review of the diagnostic tests does not offer absolute indications for neuroimaging because most of the evidence is based on studies that are not randomized controlled trials. Imaging guidelines for adults and children, however, have emerged based on the available level 2 and 3 literature. CT imaging remains the initial test of choice for new-onset headache in adults and headache suggestive of SAH. Most of the available literature also recommends performing lumbar puncture when CT is equivocal in ruling out SAH [1]. The sensitivity of MR imaging appears to be less than CT for SAH [1]. Newer MR imaging techniques need to be tested and developed to determine if they have higher sensitivity than CT or lumbar puncture in the detection of SAH. In adults with suspected brain metastatic disease, contrast-enhanced MR imaging is the imaging study of choice [38,39]. Contrast-enhanced MR imaging is the examination of choice for brain metastatic lesions less than 2 cm [39]. CT angiography and MR angiography have sensitivities greater than 85% for brain aneurysms larger than 5 mm [43]. If clinically warranted, aneurysms smaller than 5 mm may require digitally subtracted angiography because of the low sensitivity of MR and CT angiography. In children, the choice of diagnostic test strategy depends on the risk group. In high-risk patients, MR imaging is the test of choice whereas in low-risk patients, close clinical observation with periodic reassessment is the best strategy [44]. Clinical diagnosis will always play a key role in the evaluation of headache disorders; however, for the small subset of patients who present with headache secondary to an intracranial space-occupying lesion, bleeding, or SAH, making the diagnosis is crucial to decreasing morbidity and mortality. CT, MR imaging, and lumbar puncture play important roles in the assessment of headache disorders, but their future roles will continue to evolve as the technology becomes more sophisticated and robust, and physicians become more expert with their use [1].     

Pathology and imaging of the lacrimal drainage system

The lacrimal drainage apparatus drains tears from the eye. The system is susceptible to a multitude of pathologic findings, including obstruction, infection, inflammation, and neoplasms. The diagnosis of several of these processes is aided by the use of radiologic studies. In conjunction with dacryocystography, cross-sectional modalities, such as CT and MR imaging have improved the ability of diagnostic imaging to characterize the obstructive nature and soft tissue or osseous changes of various disease processes.     

Serial magnetic resonance imaging studies in a case of late onset globoid cell leukodystrophy.

The late onset type of globoid cell leukodystrophy (GLD) is a rare disorder and only three magnetic resonance imaging (MR) studies have been reported for this disease. We report a sporadic case of late onset GLD. The illness started at the age of 3 years and 8 months with spastic gait. He became bedridden at the age of 4 years and 7 months. The diagnosis was made by deficient activity of galactosylceramidase in lymphocytes, and the biochemical and morphological examinations of the biopsied sural nerve were also conducted. Computed tomography (CT) and MR study revealed that the degenerative change of the white matter was initially recognized in the occipital and parietal lobes and then extended forward. Literature of the CT or MR findings of GLD is also reviewed.     

Hemorrhagic stroke

Neuroimaging by CT or MR imaging is necessary for the identification of hemorrhagic stroke and provides information about its cause. The appearance of intracranial hematoma (ICH) on CT and MR imaging evolves over time and must be understood to facilitate accurate diagnosis. The cause of ICH varies by location. New evidence suggests that MR imaging alone may be adequate to identify hemorrhagic stroke in the acute setting, and that MR imaging is superior to CT for identification of chronic microbleeds and hemorrhagic conversion of infarction.     

MR imaging of salivary glands

Diagnostic imaging of salivary glands has been revolutionized with the advent of cross-sectional imaging modalities like CT and MR imaging. In the era before CT, imaging of the salivary glands was relatively unrewarding and was used uncommonly by ear-nose-throat surgeons. Early diagnostic tests like plain films and sialography evaluated dilated parotid ducts and calculus disease within ducts or glands. Full evaluation of salivary glands, especially deep lobes of parotid gland and masses of minor salivary glands, was not possible by these methods, however. Imaging of the parotid glands has developed significantly since that time. CT and MR imaging greatly compliment physical and endoscopic examinations (and previous favorites like sialography) by direct visualization of previously blind areas of the salivary glands and extension of the disease process in surrounding tissue planes.     

A case report of Lhermitte-Duclos disease with systematic AVMs]

We report a case of Lhermitte-Duclos disease (LDD) with huge AVMs of left extremities. The patient is a 46-year-old woman, who was identified heart failure due to AVMs at 13 years old and underwent amputation of left arm and several embolizations for AVM of left leg. Following a loss of consciousness, she was admitted to our hospital at 46 years old. CT scan showed a low-density area in the vermis of cerebellum. MR imaging showed a tumor with characteristic parallel linear striation. She was treated with partial resection of tumor. Pathological findings were dysplastic gangliocytoma. She was diagnosed LDD by MR imaging and pathological findings. Some reports describe an association between LDD and Cowden disease. On the other hand, there are reports of an association between Cowden disease and AVM. However, to our knowledge, there is no report of an association between LDD and AVM. Although this case didn't be revealed an association with Cowden disease, we believe that this case is a very interesting one henceforth suggesting the association between LDD, Cowden disease, and AVM.