High signal in the adenohypophysis on T1-weighted images presumably due to manganese deposits in patients on long-term parenteral nutrition

Hypermanganesaemia is reported in patients on long-term parenteral nutrition. Deposition of manganese, giving high signal on T1-weighted images, may involve the basal ganglia. MRI in nine patients (mean age 51 years, range 31-75 years) on long-term parenteral nutrition (mean duration 30 months, range 6-126 months), demonstrated high signal in the anterior pituitary gland on T1-weighted sagittal and coronal images. The gland appeared normal on T2-weighted images. Signal intensity in the basal ganglia on T1-weighted images was increased in all patients. Endocrine assessment showed no significant abnormality. Neurological examination showed a mild parkinsonian movement disorder in one patient. Hypermanganaesemia was present in all nine (1.3-2.8 micromol/l, mean 1.87 micromol/l). The high signal in the anterior pituitary gland was probably related to deposition of paramagnetic substances, especially manganese.     

Hyperintense basal ganglia on T1-weighted MR images in a patient with central nervous system lupus and chorea

We describe a patient with central nervous system lupus and choreatic movements in whom both basal ganglia showed high signal intensity on T1-weighted MR images, while the signal on T2-weighted images remained low. Within 8 months after onset, the choreatic movements had disappeared, with a corresponding decrease in the hyperintense T1 signal. The emergence of the choreatic movement disorder in this patient might have been related to the T1 hyperintensity of the basal ganglia, which, in turn, might have resulted from a vascular insult associated with central nervous system lupus.     

18F]fluorodeoxyglucose uptake in neonatal acute lung injury measured by positron emission tomography

PURPOSE: Our goal was to investigate the role of serial dynamic contrast-enhanced SPGR MRI in the nonsurgical follow-up of patients with temporomandibular joint (TMJ) pain. METHOD: Ten patients (10 joints) with internal derangement of the TMJ were imaged with T1-weighted SE and serial postgadolinium SPGR MR pulse sequences. RESULTS: On T1-weighted images prior to treatment, the disk position was normal in one joint and anteriorly displaced without reduction in nine joints. After treatment, the disk remained normally positioned in one joint, was anteriorly displaced without reduction in eight joints, and was anteriorly displaced with reduction in one joint. The dynamic study after treatment showed a decrease in contrast enhancement of the posterior disk attachment in 7 of 10 joints. These seven patients had resolution or reduction in joint pain. CONCLUSION: These results suggest an association between a decrease in contrast enhancement of the posterior disk attachment and resolution or reduction in joint pain. This association was much stronger than the association between the clinical findings and the anatomy of the disk.     

Postoperative sella: evaluation with fast spin echo T2-weighted high-resolution imaging

OBJECTIVE: The purpose of this study was to investigate the magnetic resonance features of the postoperative sella with fast spin echo (FSE) T2-weighted high-resolution imaging and to evaluate the benefits of the sequence using a follow-up magnetic resonance imaging protocol after transsphenoidal surgery. METHODS: Coronal spin echo (SE) T1-weighted and FSE T2-weighted images were prospectively obtained in 24 patients after surgery for pituitary adenomas. We observed the signals and the contour of normal structures, fluid collection, implanted materials, and mass lesions, including granulation tissue and adenoma. RESULTS: The pituitary gland was delineated in 51 of 59 FSE T2-weighted images, 90.2% of which presented clear boundaries. Whereas the gland was detected in 49 of 58 SE T1-weighted images, only 20.4% showed the boundaries. A mass lesion was identified in each of 12 patients with good resolution on FSE T2-weighted images. SE T1-weighted images detected mass lesions in 7 of 12 patients without distinctive boundaries. Contrast enhancement had little advantage in clarifying the boundaries between normal and abnormal structures. For the detection of mass lesions in the sella, the kappa values for interobserver agreement were 0.8 for FSE T2-weighted images and 0.25 for SE T1-weighted images. CONCLUSION: FSE T2-weighted imaging is a reliable method with which to assess the sella with sufficient resolution after transsphenoidal surgery. The combination of unenhanced SE T1-weighted and FSE T2-weighted images may reduce the use of contrast material after pituitary surgery.     

Effectiveness of slow-release lanreotide, a long-acting somatostatin analogue, in the treatment of acromegaly

We report the use of MRI in the diagnosis, follow-up and therapeutic management of three cases of intralabyrinthine Schwannoma. The diagnosis was based on the history and initial and follow-up MRI findings. The main feature suggesting the diagnosis was a nodular intralabyrinthine mass of low signal intensity on T2-weighted images, and high or isointense signal on T1-weighted images (relative to cerebrospinal fluid), which showed contrast enhancement. Follow-up imaging showed growth of the tumour in one patient. One patient underwent surgery for severe tinnitus. To detect these lesions, MRI should be focussed on the inner ear, using thin-section T2-weighted and T1-weighted images before and after contrast medium. MRI allowed informed surgical planning.     

Innervation of the lumbar facet joints. Origins and functions

STUDY DESIGN: The levels of dorsal root ganglia and paravertebral sympathetic ganglia innervating the lumbar facet joint were investigated in rats using the retrograde transport method. The pathways and functions of the nerve fibers supplying the lumbar facet joint were determined immunohistochemically. OBJECTIVES: To study lumbar facet pain in relation to its innervation. SUMMARY OF BACKGROUND DATA: The lumbar facet joints have been reported to be innervated segmentally. Little is known, however, about the origins and functions of the nerve fibers. METHODS: Cholera toxin B subunit, a neural tracer, was placed in the L5-L6 facet joint, and the bilateral dorsal root ganglia and paravertebral sympathetic ganglia were examined immunohistochemically. The serial sections of lumbar vertebrae of newborn rats and the sections of the facet joint capsules, dorsal root ganglia, and paravertebral sympathetic ganglia of adult rats were investigated immunohistochemically. The pathways of the nerve fibers supplying the facet joint were reconstituted. RESULTS: Labeled neurons existed in ipsilateral dorsal root ganglia from L1 to L5 and in paravertebral sympathetic ganglia from T12 to L6. The dorsal ramus of the spinal nerve and rami communicantes were connected to each other by calcitonin gene-related peptide immunoreactive fibers and dopamine beta-hydroxylase immunoreactive fibers. CONCLUSIONS: The L5-L6 facet joint was innervated by ipsilateral dorsal root ganglia and paravertebral sympathetic ganglia, segmentally and nonsegmentally. Some of the sensory fibers from the facet joint may pass through the paravertebral sympathetic trunk, reaching L1 and/or L2 dorsal root ganglia. Inguinal and/or anterior thigh pain with lower lumbar facet joint lesions may be explained as referred pain.     

Amyloid arthropathy of the hip joint: MR demonstration of presumed amyloid lesions in 152 patients with long-term hemodialysis

The aim of this study was to determine the spectrum of MR findings of presumed amyloid arthropathy of the hip joints in patients on long-term hemodialysis. We prospectively performed T1- and T2-weighted spin-echo imaging on 152 consecutive patients on hemodialysis. The duration of hemodialysis ranged from 5 months to 24 years, 2 months (mean: 8 years, 8 months). The frequency, location, and signal intensity of bone lesions were assessed. In 12 cases with contrast-enhanced MR examination, enhancement pattern of bone lesions, synovial lesions, and intra-articular lesions were characterized. Bone lesions presumed to be amyloid deposits were identified in 60 patients (39%). Magnetic resonance imaging revealed that amyloid lesions were more extensive than anticipated by plain radiographs. All bone lesions showed decreased signal intensity on T1-weighted images. On T2-weighted images, bone lesions showed increased signal intensity in 32 patients (54%), decreased signal intensity in 11 patients (18%), and both increased and decreased signal intensity in 17 patients (28%). Following intravenous injection of gadolinium-based contrast, all bone lesions showed moderate enhancement. Synovial thickening could not be identified on T1- and T2-weighted images. However, contrast-enhanced images showed thickened synovial membrane, which could be differentiated from joint fluid. Intra-articular nodules showed decreased or intermediate signal intensity on T1-weighted images and decreased signal intensity on T2-weighted images; the intra-articular nodules were contiguous with subchondral bone lesions. Magnetic resonance imaging is useful for evaluating the distribution and extent of amyloidosis of the hip joints in patients undergoing long-term hemodialysis.     

MR imaging in solvent-induced chronic toxic encephalopathy

PURPOSE: To use MR to examine patients with CNS symptoms indicating +chronic intoxication. MATERIAL AND METHODS: Thirty-two subjects exposed to industrial solvents for 5 to 28 years and 40 age-matched, healthy controls were examined. RESULTS: All patients showed decreased signal in the basal ganglia on T2-weighted images. In 11 of the patients the white matter showed diffuse hyperintensity with loss of the grey-white matter discrimination and with distinct periventricular hyperintensities in 5 of the patients. The controls had no pathological changes in the brain. CONCLUSION: Although the relatively small number of patients may obscure the significance, findings observed on T2-weighted images were patchy periventricular hyperintensities and hypointensities in the basal ganglia. Fast spin-echo is a good technique with fast acquisition of images with true spin-echo contrast features.     

Lymphoepithelioma-like carcinoma of the ureter

We reported a case of the biliary cystadenoma of the liver. The cystic mass had lobulation and septation and showed marked hyperintensity on T1-weighted images and hypointensity on T2-weighted images; MR findings were very unusual for cystadenoma. The content of the cystic mass was jelly-like, thick mucinous fluid without intracystic hemorrhage. We concluded that these unusual signal intensities of the cyst were due to hyperproteinous mucinous fluid.     

Use of fluorescent in situ hybridization to detect aneuploidy in cervical dysplasia

An 8 year old girl with acute disseminated encephalomyelitis (ADEM) is described. Elevated serum antibody titers suggested recent Mycoplasma pneumoniae infection. T2-weighted image of magnetic resonance imaging (MRI) disclosed multiple lesions of high signal intensity in bilateral basal ganglia and thalami as well as in the white matter. Postcontrast T1-weighted image revealed an enhanced lesion in the deep white matter. She showed rapid clinical improvement in response to corticosteroid therapy. The lesions had disappeared completely on MRI performed 10 weeks after the onset. ADEM is believed to be a demyelinating disorder of probable autoimmune etiology. MRI findings in this case may support the hypothesis that the primary pathological event is vascular injury and demyelination occurs only as a secondary phenomenon.     

Intriguing gastrointestinal properties of bismuth: a folk remedy brought into the realm of clinical and investigative medicine

An 8-year-old girl showed symptoms of encephalitis during acute Epstein-Barr virus (EBV) infection. The diagnosis of EB virus infection was made by changes in the titres of EB virus-specific antibody. Cranial MRI demonstrated abnormal low and high signal intensities in the striatal body (putamen and caudate nucleus) on T1-weighted and T2-weighted images, respectively, during the acute phase. These abnormal findings had almost completely resolved 1 month later. EBV infection should be considered when lesions are localised to the basal ganglia.     

Parallel implementations of individual-based models in biology: bulletin- and non-bulletin-board approaches

Low-field magnetic resonance imaging (MRI) was performed on the stifle joints of four normal adult mongrel dogs using a 0.064 Tesla scanner. Markers were placed on each stifle joint to serve as reference points for comparing gross sections with the images. A T1-weighted sequence was used to image one stifle joint on each dog in the sagittal plane and the other stifle joint in the dorsal plane. The dogs were euthanized immediately following MRI and the stifle joints frozen intact. Each stifle joint was then embedded in paraffin, again frozen, and sectioned using the markers as reference points. On T1-weighted images, synovial fluid had low signal intensity (dark) compared to the infrapatellar fat pad which had a high signal intensity (bright). Articular cartilage was visualized as an intermediate bright signal and was separated from trabecular bone by a dark line representing subchondral bone. Menisci, fibrous joint capsule, and ligamentous structures appeared dark. In the true sagittal plane, the entire caudal cruciate ligament was often seen within one image slice. The patella was visualized as an intermediate bright signal (trabecular bone) surrounded by a low intensity signal (cortical bone). The trochlea and the intercondylar notch were difficult areas to analyze due to signal volume averaging of the curved surface of these areas and the presence of several types of tissues.     

Cerebral perfusion impairment in a patient with toluene abuse

We report the case of a 17-yr-old man diagnosed as a toluene abuser. He had an 8-mo history of toluene inhalation exposure and was admitted to this hospital with symptoms of auditory and visual hallucination. Magnetic resonance imaging (MRI) revealed no structural abnormalities both on T1- and T2-weighted images, whereas SPECT using 99mTc-ethyl cysteinate dimer (ECD) showed multifocally decreased perfusion in the cerebral cortex, basal ganglia and thalami. Our case indicates that SPECT detects early central nervous system injury from toluene inhalation even when neurological examination and neuroanatomic imaging such as MRI are normal.     

Malignant lesions of the liver identified on T1- but not T2-weighted MR images at 1.5 T

The authors reviewed their 2 1/2-year experience with a magnetic resonance (MR) imaging protocol for a 1.5-T MR imager that included T2-weighted fat-suppressed spin-echo, T1-weighted breath-hold gradient-echo, and serial dynamic gadolinium-enhanced T1-weighted gradient-echo imaging to identify histologic types of malignant liver lesions more apparent on T1- than on T2-weighted images. MR images of 212 consecutive patients with malignant liver lesions were reviewed. T2-weighted, T1-weighted, and dynamic contrast-enhanced T1-weighted images were examined separately in a blinded fashion. Seven patients demonstrated liver lesions (lymphoma [two patients] and carcinoid, hepatocellular carcinoma, colon adenocarcinoma, transitional cell carcinoma, and melanoma [one patient each]) on T1-weighted images that were inconspicuous on T2-weighted images. In all cases, the lesions were most conspicuous on T1-weighted images obtained immediately after administration of contrast agent. Histologic confirmation was present for all seven patients. The consistent feature among these lesions was that they were hypovascular, due either to a fibrous stroma or to dense monoclonal cellularity. These results suggest that in some patients with hypovascular primary neoplasms, the lesions may be identified only on T1-weighted images, and that immediate postcontrast T1-weighted images are of particular value in demonstrating lesions.     

Plasma volume expansion with oral fluids in hypohydrated men at rest and during exercise

A case of malignant fibrous histiocytoma (MFH) in a 29-year-old man was reported. CT scans revealed an iso density mass which was homogeneously enhanced by contrast medium. MRI demonstrated that the right frontal tumor showed slight low signal intensity in T1-weighted image, and iso signal intensity in T2-weighted image. Gadolinium-enhanced T1-weighted image showed a homogeneously enhanced multinodular tumor. Right carotid angiogram revealed a tumor stain fed by the precentral artery. On operation, en-bloc resection was performed successfully. Postoperatively, local irradiation of 60Gy was performed. Microscopically, fibroblast-like cells arranged in storiform pattern were observed, and bizarre multinucleated giant cells were also observed. Ki-67 labelling index was 54%. We considered the tumor was a MFH and arose from an intracerebral mesenchymal tissue. We reviewed some literature and briefly discussed clinicopathological features and therapy of intracranial MFH.     

Vertebral pseudarthrosis in the osteoporotic spine

STUDY DESIGN: Radiologic and operative findings of intravertebral cleft in the osteoporotic spine were investigated and the pathomechanism discussed. OBJECTIVES: To clarify the pathologic features of the intravertebral cleft. SUMMARY OF BACKGROUND DATA: Intravertebral "vacuum" cleft is one of the common radiographic findings in the osteoporotic spine. It is thought that the cleft is a rare lesion of an ununited fracture, or pseudarthrosis. Evidential findings of the disease, however, have never been reported. METHODS: Simple bone grafting was performed in five cases (average age, 76.8 years) of thoracolumbar intravertebral cleft in osteoporotic spine in patients who had been suffering from prolonged pain of the back or leg. Preoperative radiologic evaluation using flexion-extension radiograph and magnetic resonance imaging was performed in all patients. At operation, the cleft and the components of the structure were macroscopically and microscopically observed. The fluid content in the cleft was biochemically analyzed. RESULTS: In all patients, preoperative flexion-extension radiographs showed intravertebral instability at the location of the clefts that indicated gas density in three cases and water density in two cases. Magnetic resonance imaging showed that, for the most part, the cleft was low intensity on the T1-weighted image and high intensity on the T2-weighted scans, regardless of the radiographic findings. At operation, abnormal movement was observed at the cleft of the affected body, which was covered with hypertrophic membrane. The serous fluid within the cleft was aspirated before the excision of soft tissue. The thick membrane was excised and showed that the cleft was lined by smooth fibrocartilaginous tissue and the great degree of motion between the fracture ends that is consistent with the pathologic appearance of pseudarthrosis. CONCLUSIONS: The unstable cleft in the affected vertebral body of the osteoporotic spine with magnetic resonance findings of low intensity on the T1-weighted scans and high intensity on the T2-weighted scans suggests that the cleft is a false joint lined by fibrocartilaginous tissue with notable movement consistent with pseudarthrosis.     

Suprasellar granular cell tumor

A case of a suprasellar granular cell tumor, approximately 1.5 cm in diameter, in a 68-year-old woman is described. Diagnosis was established postoperatively by histopathological examination of the tumor tissue. The preoperative computed tomographic scan revealed a slightly hyperdense suprasellar mass with strong contrast enhancement. There was no evidence of calcification. The T1-weighted image on magnetic resonance imaging scan showed an isointense tumor with non-homogeneous enhancement after intravenous gadolinium diethylene-triamine-pentaacetic acid. In the proton-weighted image, the suprasellar mass presented a non-homogeneously enhanced signal. A non-homogeneous signal reduction was seen in the T2-weighted image.     

Segmental hyperintensity on T1-weighted MRI of the liver: indication of segmental cholestasis

The purpose of this study was to determine the relationship between segmental hyperintensity of the liver on T1-weighted images and segmental cholestasis in patients with obstructive jaundice. T1-weighted and T2-weighted MR images were obtained of 73 patients with obstructive jaundice caused by various diseases. Fat-suppressed T1-weighted images were also obtained of 10 patients. Eleven patients with segmental intrahepatic bile duct dilatation (cholestasis) showed segmental hyperintensity on T1-weighted images and/or fat-suppressed T1-weighted images and no signal intensity difference on T2-weighted images. Sixty-two patients with widespread intrahepatic bile duct dilatation showed no intensity difference on T1-weighted and T2-weighted images (P < .01). Segmental hyperintensity on T1-weighted images was correlated with intrahepatic cholestasis.     

Troubling issues with research publications

Germinomas occurring in the thalamus and basal ganglia sometimes cause atrophy of the cerebral hemisphere on the affected side. The authors present the case of a 12-year-old girl with a germinoma that developed in the basal frontal lobe and cerebral basal ganglia. Magnetic resonance imaging showed atrophy not only of the cerebrum but also of the brainstem. A T2-weighted image revealed an area of high intensity that proved to be wallerian degeneration extending from the corona radiata and internal capsule to the brainstem. The authors suggest that this pathological change may be involved in the development of the symptoms and hemiatrophy associated with germinomas in this region of the brain.     

Prevention of osteoporosis in women treated for hereditary breast and ovarian carcinoma: a need that is overlooked

An extremely rare case of ecchordosis physaliphora is presented in which the authors focus especially on its radiological characteristics. The patient complained of a headache with no other neurological abnormalities. A thorough radiological examination revealed a small intradural prepontine mass with no bone destruction of the clivus. Magnetic resonance imaging was very useful in visualizing this mass as a low signal intensity lesion on T1-weighted images and as a high signal intensity lesion on T2-weighted images without any contrast enhancing effects. At surgery, a cystic gelatinous nodule was found ventral to the pons; the nodule was connected to the dorsal wall of the clivus via a delicate stalk. Histological studies proved that this was an ecchordosis physaliphora. Review of the literature demonstrates that the reported cases of ecchordoses have many common radiological features that would suggest the diagnosis of this rare disease.