Ex vivo magnetic resonance imaging using hyaluronic acid fillers: Differences between monophasic and biphasic fillers.

BACKGROUND/PURPOSE: Hyaluronic acid (HA) is an anionic, non-sulfated glycosaminoglycan distributed throughout the human skin and injectable HA fillers are the most commonly used in aesthetic field. This study aimed to determine if differences in physical characteristics of HA products (monophasic or biphasic fillers) affect the patterns of magnetic resonance imaging (MRI). METHODS: Twenty biphasic fillers and nine monophasic fillers were obtained from a commercial source, and examined with a 3.0 Tesla MRI scanner. Visual assessments and measurements of signal intensity for region of interest (ROI) were performed. A non-parametric Wilcoxon rank sum test was used to compare the ROI values. RESULTS: Visual assessments by a radiologist did not show significant differences between the two types of fillers. While the signal intensity between the two types of filler did not differ significantly for T1-weighted images, the signal intensity of the biphasic filler was lower than that of the monophasic filler for T2-weighted images (P<.01). CONCLUSION: Monophasic and biphasic HA fillers exhibited different MRI properties. Our findings may provide better insights into the use of in vivo MRI to evaluate aesthetic, procedure-related complications.

The structural connectivity of the recurrent transient global amnesia.

BACKGROUND: One of recent interesting hypotheses of transient global amnesia (TGA) pathophysiology is the preexisting vulnerability of the memory network in patients with TGA. AIM OF THE STUDY: To verify the hypothesis that patients with recurrent amnestic attacks may have more disrupted structural connectivity than patients of a single TGA event, we compared the brain imaging of patients with repeated episodes of TGA with those who experienced a single attack. METHODS: Seven patients who were having recurrent TGA and 14 age- and sex-matched control subjects who had only a single episode of TGA participated in the study. Diffusion tensor images from both groups were assessed and analyzed using tract-based spatial statistics. RESULTS: The fractional anisotropy and mean diffusivity values were not reduced in any lesion within the memory pathway of recurrent patient group when compared with those of single event group. CONCLUSION: No disruptions in the structural connectivity of the memory pathway were observed in patients with recurrent TGA attacks, refuting the hypothesis that recurrent TGA patients present predisposing weakness of the memory network. The stability of structural connectivity suggests that repeated hippocampal lesions associated with TGA do not affect the microstructure of the brain.

Functional MRI as an Objective Measure of Olfaction Deficit in Patients with Traumatic Anosmia.

BACKGROUND AND PURPOSE: While posttraumatic anosmia is not uncommon, the olfactory function evaluation has strongly relied on subjective responses given by patients. We aimed to examine the utility of fMRI as an objective tool for diagnosing traumatic anosmia. MATERIALS AND METHODS: Sixteen patients (11 men and 5 women; mean age, 42.2 ± 10.4 years) with clinically diagnosed traumatic anosmia and 19 healthy control subjects (11 men and 8 women; mean age, 29.3 ± 8.5 years) underwent fMRI during olfactory stimulation with citral (a pleasant odor) or ß-mercaptoethanol (an unpleasant odor). All patients were subjected to a clinical olfactory functional assessment and nasal endoscopic exploration. Two-sample t tests were conducted with age as a covariate to examine group differences in brain activation responses to olfactory stimulation (false discovery rate-corrected P < .05). RESULTS: Compared with healthy control subjects, patients with traumatic anosmia had reduced activation in the bilateral primary and secondary olfactory cortices and the limbic system in response to ß-mercaptoethanol stimulation, whereas reduced activation was observed only in the left frontal subgyral region in response to citral stimulation. CONCLUSIONS: Brain activation was decreased in the bilateral primary and secondary olfactory cortices as well as the limbic system in response to olfactory stimulation in patients with traumatic anosmia compared with healthy control subjects. These preliminary results may shed light on the potential of fMRI for the diagnosis of traumatic anosmia.

Appropriate Minimal Dose of Gadobutrol for 3D Time-Resolved MRA of the Supra-Aortic Arteries: Comparison with Conventional Single-Phase High-Resolution 3D Contrast-Enhanced MRA.

BACKGROUND AND PURPOSE: The development of nephrogenic systemic fibrosis and neural tissue deposition is gadolinium dose-dependent. The purpose of this study was to determine the appropriate minimal dose of gadobutrol with time-resolved MRA to assess supra-aortic arterial stenosis with contrast-enhanced MRA as a reference standard. MATERIALS AND METHODS: Four hundred sixty-two consecutive patients underwent both standard-dose contrast-enhanced MRA and low-dose time-resolved MRA and were classified into 3 groups; group A (a constant dose of 1 mL for time-resolved MRA), group B (2 mL), or group C (3 mL). All studies were independently evaluated by 2 radiologists for image quality by using a 5-point scale (from 0 = failure to 4 = excellent), grading of arterial stenosis (0 = normal, 1 = mild [<30%], 2 = moderate [30%-69%], 3 = severe to occlusion [≥70%]), and signal-to-noise ratio. RESULTS: The image quality of time-resolved MRA was similar to that of contrast-enhanced MRA in groups B and C, but it was inferior to contrast-enhanced MRA in group A. For the grading of arterial stenosis, there was an excellent correlation between contrast-enhanced MRA and time-resolved MRA (R = 0.957 for group A, R = 0.988 for group B, R = 0.991 for group C). The SNR of time-resolved MRA tended to be lower than that of contrast-enhanced MRA in groups A and B. However, SNR was higher for time-resolved MRA compared with contrast-enhanced MRA in group C. CONCLUSIONS: Low-dose time-resolved MRA is feasible in the evaluation of supra-aortic stenosis and could be used as an alternative to contrast-enhanced MRA for a diagnostic technique in high-risk populations.

Fluorouracil therapy in patients with carcinoma of the large bowel: a pharmacokinetic comparison of various rates and routes of administration.

The pharmacokinetics of fluorouracil after oral, intravenous and rectal administration were compared in 12 patients with colorectal cancers. Oral administration of 10 to 15 mg/kg gave variable plasma levels (0 to 10.5 microgram/ml) and bioavailability (0 to 74%; mean 28%). Bioavailability increased markedly with increases in dose, suggesting saturation of the 'first pass' hepatic metabolism of the drug. Differences in bioavailability could not be related to standard liver function tests or the presence of metastatic deposits in the liver. Plasma levels were not detectable after rectal administration in the 4 patients studied and were very low (0 to 8 microgram/ml) during high dose (20 to 30 mg/kg/24h) slow intravenous infusion in 6 patients. These findings indicate that different dose schedules and routes of administration produce markedly different plasma levels. They suggest that the rate of degradation of fluorouracil by the liver is quite variable and may become saturated with increasing dose. For these reasons monitoring of plasma levels of the drug in individual patients may be useful.

Intracranial dermoid cyst ruptured into the membranous labyrinth causing sudden sensorineural hearing loss: CT and MR imaging findings.

A ruptured dermoid cyst is rare and can present with various symptoms. We report imaging findings of an intracranial dermoid cyst that ruptured into the endolymphatic sac, causing sudden sensorineural hearing loss.

Detailed MR imaging anatomy of the cisternal segments of the glossopharyngeal, vagus, and spinal accessory nerves in the posterior fossa: the use of 3D balanced fast-field echo MR imaging.

BACKGROUND AND PURPOSE: The cisternal segments of the lower cranial nerves (CNs) adjacent to the jugular foramen (JF) are difficult to identify reliably by routine MR imaging. We performed a 3D balanced fast-field echo imaging technique (3D-bFFE) to obtain detailed anatomy of the cisternal segments of CNs IX, X, and XI. MATERIALS AND METHODS: 3D-bFFE was used to image the cisternal segments of the lower CNs in 20 healthy volunteers. As an anatomic landmark, CSF recesses adjacent to the JF were divided into 3 parts: the recess for the cochlear aqueduct, the recess for CN IX, and the recess for the CN X/XI complex. MR images were evaluated to identify the cisternal segment of each cranial nerve in relation to these anatomic landmarks. RESULTS: The mean angles of the recess for the cochlear aqueduct for CN IX and CN X/XI to the posterior petrous bone were 41.6 +/- 2.5 degrees , 69.7 +/- 3.1 degrees , and 76.0 +/- 3.4 degrees , respectively (P < .01). The mean length of the recess for the cochlear aqueduct for CN IX and the CN X/XI complex was 5.91 +/- 0.19, 5.08 +/- 0.11, and 4.76 +/- 0.13 cm, respectively (P < .01). 3D-bFFE adequately depicted the cisternal segments of CN IX on 38 sides (95%) and the CN X/XI complex on 39 sides (97.5%). CONCLUSIONS: The cisternal segments of CN IX, CN X, and CN XI are well identified by using 3D-bFFE, especially by determining the angles of the CSF recesses adjacent to the JF.

Case report. Tuberculous cervical lymphadenitis mimicking metastatic lymph nodes from papillary thyroid carcinoma.

We report two unusual cases of tuberculous lymphadenitis mimicking metastatic lymph nodes from papillary thyroid carcinoma (PTC). Pre-operative ultrasonography of the cervical nodes suggested a metastasis with cystic necrosis and calcification in PTC patients, but permanent pathology revealed tuberculosis lymphadenitis after neck dissection. In cases suspicious for metastatic cervical nodes in patients with PTC, fine-needle aspiration cytology may be indicated for the differential diagnosis of tuberculosis lymphadenitis, especially in those who have experienced tuberculosis in the past.

Diffusion tensor imaging and fiber tractography in Parry-Romberg syndrome.

We report a case of Parry-Romberg syndrome in a 32-year-old woman presenting with intermittent headache and mild sensory disturbance. MR imaging revealed minimal asymmetric atrophy of the right hemisphere with a few nonspecific white matter hyperintensities. Diffusion tensor imaging and fiber tractography, however, demonstrated clear fiber derangement, especially in the sensory tract of the right cerebral white matter.

Subthalamic lesion on MR imaging in a patient with nonketotic hyperglycemia-induced hemiballism.

SUMMARY: Hemiballism with corresponding striatal T1 hyperintensity on MR imaging has occasionally been reported in patients with nonketotic hyperglycemia. However, the subthalamic nucleus lesion, which is believed to be pathogenetically related to hemiballism, is rarely documented in a living patient with nonketotic hyperglycemia. We describe a patient with nonketotic hyperglycemia-induced hemiballism, whose responsible lesion (ie, the subthalamus) was demonstrated by MR imaging.

Atrophy measurement of the anterior commissure and substantia innominata with 3T high-resolution MR imaging: does the measurement differ for patients with frontotemporal lobar degeneration and Alzheimer disease and for healthy subjects?

BACKGROUND AND PURPOSE: The anterior commissure (AC) and substantia innominata (SI) can be clearly demonstrated at 3T high-resolution MR imaging. Our aim was to investigate if atrophy of the AC and SI on 3T MR imaging differs among patients with frontotemporal lobar degeneration (FTLD) and Alzheimer dementia (AD) and healthy subjects. MATERIALS AND METHODS: Seven consecutive patients with FTLD, 20 patients with AD, and 16 age-matched control subjects were enrolled. MR imaging was performed at 3T. The AC thickness as well as the SI thickness was measured on a thin-section coronal T2-weighted image, and the AC area was measured on a sagittal T1-weighted image. The measurement differences among the participants were analyzed with the Kruskal-Wallis test. A correlation of the measurement with the Mini-Mental State Examination (MMSE) score was obtained with the Spearman rank correlation test. RESULTS: Thinning of the AC was significantly more prominent in FTLD than in AD (P < .001). Although the right SI thickness was significantly decreased in patients with AD as compared with control subjects (P < .05), there was no significant difference, with a substantial overlap of the average SI thickness among the 3 groups. The thickness and the area of the AC were positively correlated with the MMSE score (rho = 0.612, P < .001, and rho = 0.659, P < .001, respectively). In contrast, the average SI thickness showed a weak positive correlation with the MMSE score (rho = 0.325, P < .05). CONCLUSION: Measurement of AC atrophy with 3T MR imaging may provide additional diagnostic clues for FTLD and AD. Conversely, SI atrophy measurement does not provide an additional benefit in the evaluation of FTLD and AD, owing to a considerable overlap in the average thickness of bilateral SI.

Peripheral ossifying fibroma in the oral cavity: CT and MR findings.

We report a case of peripheral ossifying fibroma arising from the anterior oral cavity in a 12-year-old boy. CT and MR scans showed a large exophytic soft tissue mass overlying the anterior hard palate and maxillary alveolar ridge. The tumour revealed peripheral calcification without adjacent bone changes.

White matter abnormalities in drug-naïve patients with obsessive-compulsive disorder: a diffusion tensor study before and after citalopram treatment.

OBJECTIVE: The aim was to investigate the white matter abnormalities of drug-naïve patients with obsessive-compulsive disorder (OCD) using diffusion tensor-imaging and the white matter changes in the patients after pharmacotherapy. METHOD: Thirteen drug-naïve OCD patients and 13 age- and sex-matched healthy comparison subjects were examined using diffusion tensor-imaging and structural magnetic resonance imaging. Measurements were made in OCD patients before and after 12 weeks of citalopram treatment. RESULTS: Compared with controls, the drug-naïve OCD patients showed significant increases in fractional anisotropy (FA) in the corpus callosum, the internal capsule and white matter in the area superolateral to the right caudate. The increases in FA were mostly no longer observed in patients after 12 weeks of treatment compared with controls. CONCLUSION: Our findings suggest that white matter alterations are associated with the pathophysiology of OCD, and the abnormalities may be partly reversible with pharmacotherapy.

Crystallographic orientation contrast associated with Ga+ ion channelling for Fe and Cu in focused ion beam method.

In this study, Cu and Fe single crystals are used to examine the change in secondary electron intensity associated with Ga(+) ion channelling in a focused ion beam (FIB) system. The single crystals having three different orientations are tilted with respect to the beam incidence and the resulting variation in the secondary electron intensity is measured through the variation in brightness of the crystals. It is shown that intensity minima appear at the beam directions normal to the lower indices of the crystal orientations. The appearance of the intensity minima including the magnitude of the minima is consistent with the prediction based on the event of ion channelling in the crystal and is affected by the crystal structure. The effect of background on the intensity minima is discussed in this study. It is suggested that the presence of the intensity minima may be used to identify a crystal orientation including a crystal structure.

Comparison of intravenous and oral high-dose methotrexate in treatment of solid tumours.

An outpatient regimen of oral high-dose methotrexate was studied in 14 patients with solid tumours over 12 months. Detailed pharmacokinetic analysis in five patients showed high oral bioavailability (mean +/- SE of mean 87.6 +/- 1.5%), indicating that with this regimen oral methotrexate was well absorbed and the first-pass effect low. Oral administration resulted in peak plasma methotrexate concentrations of 8.4 +/- 0.5 mumol/l (382 +/- 23 microgram/100 ml) and was almost as effective as intravenous administration, which achieved peak concentrations of 9.9 +/- 0.4 mumol/l (450 +/- 18 microgram/100 ml). In all 14 patients the clinical response to oral treatment was comparable to that reported to intravenous administration of high-dose methotrexate used in combination with other cytotoxic drugs. The disease-free interval in cases of adult sarcoma was 7.4 +/- 1.3 months and the relapse rate 29%. Out of four patients with small-cell carcinoma, two showed an objective response to oral treatment. We suggest that oral high-dose methotrexate given in divided doses is a rational alternative to expensive intravenous high-dose methotrexate regimens, but further clinical evaluation is necessary.

Management of the hypercalcaemia of malignancy by peritoneal dialysis.

A case is reported which illustrates the use of peritoneal dialysis in the treatment of hypercalcaemia due to metastatic carcinoma of the breast. Control of hypercalcaemia was rapid and sustained. Removal of calcium did not completely explain the results observed. The possibility is discussed that treatment temporarily suppressed tumour growth or removed some dialysable hypercalcaemic or tumour growth factor.

High-dose methotrexate therapy.

Eighty-six adults with malignant disease were given high doses of methotrexate with folinic acid rescue, with acceptable toxicity. Protocal violations in two cases led to death. The results of therapy in some diagnostic groups are encouraging.

Agenesis of internal carotid artery associated with congenital anterior hypopituitarism.

We report a rare case of unilateral agenesis of the internal carotid artery in association with congenital anterior hypopituitarism. The collateral circulation is supplied by a transsellar intercavernous anastomotic vessel connecting the internal carotid arteries. These abnormalities are well depicted on MRI and MRA. The agenesis of the internal carotid artery may explain the pathogenesis of some of congenital anterior hypopituitarism.

Treatment of advanced bladder cancer using cis-platinum.

Cis-platinum (120 mg/m2) was given to 14 patients with locally inoperable or metastatic transitional cell carcinoma of the bladder. Five patients (35%) showed a response, two complete (14%), and three partial (21%). Nine patients (65%) had no response. The median duration of survival was 3.5 months for non-responders; 6.5 months for partial responders; and 25 months for complete responders. The side effects and implications of treatment using this agent are discussed.