To determine the concurrence of activation in the primary motor cortex, induced by paradigms of active and passive movement of extremities, by using blood oxygen level-dependent functional magnetic ...resonance (MR) imaging.
The HIPAA-compliant study was approved by the institutional review board, and written informed consent was obtained from the participating volunteers. Functional MR imaging data were collected from 11 healthy volunteers (four women, seven men; age range, 24-42 years) during active and passive movements of hand, elbow, shoulder, ankle, knee, and hip. These data were then mapped onto three-dimensional anatomic images. Volumes of activation were determined by using cross-correlation analysis at a coefficient threshold of 0.4 (P < .01). Regions of interest were drawn in pre- and postcentral gyri based on anatomic criteria. The mean number of activated voxels in the pre- and postcentral gyri induced by active and passive movements was compared by using Wilcoxon analysis. Concurrence ratios and proportional ratios of activation between active and passive movements were calculated for each somatotopic location.
Primary motor cortex activation tended to increase with active compared with passive movements, although in the precentral gyrus, hand, elbow, and shoulder movements showed no statistically significant difference in mean number of activated voxels. In the postcentral gyrus, only the shoulder revealed a significant difference (P < .05). Concurrence ratios (activation volume overlap of two tasks/combined activation area of both tasks) ranged from 0.44 to 0.57. Proportional ratios (activation volume overlap of passive task with active task/total activation volume of passive task) ranged from 0.64 to 0.82.
Passive movement paradigms may be an alternative to or complement to active movement tasks in patient populations.
A left-handed patient with a grade II left frontal lobe astrocytoma had spontaneous seizures causing speech arrest and uncontrolled right upper extremity movements. Word-generation functional MR ...(fMR) imaging showed activity nearly exclusively in the right inferior frontal gyrus. The clinical history of the speech arrest and the intraoperative mapping proved left-hemisphere language dominance. Tumor involvement of the left inferior frontal gyrus caused uncoupling of the blood oxygenation level-dependent (BOLD) and neuronal response, leading to the erroneous fMR imaging appearance of right-hemisphere language dominance. Discrepancies between BOLD and intraoperative mapping in areas near lesions illustrate the complementary nature of these techniques.
Actinomycosis is an indolent, slowly progressive infection caused by gram-positive, anaerobic or microaerophilic bacteria. Hepatic involvement is rare and generally secondary to abdominal or thoracic ...actinomycosis. Hepatic actinomycosis in children may mimic a wide variety of diseases and thus make the diagnosis much more challenging. Here, we report a 5-year-old girl with apparently primary hepatic actinomycosis mimicking acute abdomen 2 weeks after varicella. The diagnosis was made by ultrasonic guided fine needle aspiration biopsy of a hypoechoic lesion of 3.5 cm diameter in the liver showing sulfur granules surrounded by neutrophils. Hepatic actinomycosis should be taken into account when evaluating acute abdomen symptoms in children.
Abstract Objective To compare the development of temporal bone in normal and atretic ears and to assess some radiological landmarks that could be important in the hearing restoration interventions in ...such patients. Material and methods Thirty-five patients with 40 atretic external ears were evaluated with temporal bone CT and compared to a control group of 40 normal ears retrospectively. Using comparable slice levels in all patients, the course and the caliper of the facial canal, the surface area of the incus and malleus, the level of mastoid aeration, the location and anteroposterior diameters of the jugular bulb and sigmoid sinus, the direction and the caliber of the tympanic bony part of the Eustachian tube, area of the middle ear cavity, distance from facial nerve to incudomalleolar joint, to the vestibule and to the jugular bulb were included in the assessment. Non-parametric and parametric statistical tests were used for comparison. Results In atretic ears middle ear sectional area was found to be smaller at the equivalent plane as compared to control subjects (mean area index: 19.3 mm2 versus 47.4 mm2 ). Mastoid aeration was low in general and the ossicles in the atretic ears were hypoplastic (mean ossicular sectional area: 8.3 mm2 versus 11 mm2 ). The distance from the jugular bulb to the facial nerve was significantly lower (mean: 6.2 mm versus 6.8 mm) ( p < 0.05) in the atretic ears. Facial canal caliber, distance from the facial canal to the incudomalleolar joint and distance from the facial canal to the vestibule in the atretic ears (means: 1.49, 2.93 and 1.82, respectively) did not show statistically significant difference from the control subjects (means: 1.44, 2.91 and 1.83, respectively) ( p > 0.05 for all). Conclusion External ear atresia is significantly associated with middle ear and mastoid abnormalities. The ossicles were underdeveloped which always have to be considered during reconstructive surgery. Radiologically, in the atretic ears anterior–posterior length of the temporal bone was more influenced as compared to superior–inferior portion, which justifies abnormal route of the facial nerve canal. However, there is no abnormality in the development of the facial nerve as the caliper is similar to the control subjects.
Intravenous leiomyomatosis is a seldom neoplasia characterized by invasion of venous channels by a benign smooth muscle tumor originating either from a uterine myoma or from vessel wall. Extension to ...the heart may cause mechanical obstruction and is frequently misdiagnosed as a right-atrial myxoma. We present a case of recurrent intravenous leiomyomatosis with previous hysterectomy because of uterine leiomyoma which have different magnetic resonance characteristics than that of the former reports.
Takayasu arteritis is a rare type of chronic, granulomatous vasculitis, characterized by inflammation of blood vessels of large caliber, such as the aorta, and its branches. Clinical presentation ...varies, depending on the severity of symptoms. Onset may be gradual, however at times, presentation may be acute, and life threatening. Herein, we present the case of a 29-year-old female, 3 months post-op, following a right carotid artery stenting procedure. The patient presented with nonspecific symptoms of malaise, arthralgia, and blurry vision. Clinical presentation and imaging findings were consistent with Takayasu's Arteritis.
A 20-year-old male with craniomandibular deformity and almost total visual loss of the right eye due to bilateral optic atrophy underwent cerebral nonenhanced computed tomography (NECT) examinations. ...He had multiple sphenoidal-temporoparietal meningiomas, with adjacent hyperostoses and distant calvarial hyperdense lesions, as well as sclerotic expansion of right mandibular condyle. History, clinical and imaging findings were suggestive of associated fibrous dysplasia (FD), which explained the visual loss due to optic nerve compression through sphenoidal optic foramens. Cranial and mandibular FD and concurrent multiple globoid meningiomas in this case may suggest a mutual influence, which may explain the etiopathogenesis of FD lesions and/or bone hyperdensities adjacent or distant to meningiomas.
There is a relative lack of definitive information about the contrast-enhancement characteristics of lesions in posterior reversible encephalopathy syndrome (PRES).
Evaluation of contrast-enhanced ...MRI findings in PRES with a special emphasis on pathophysiology of post-gadolinium behavior of these lesions.
Contrast-enhanced 1.5
T MRI findings and relevant clinical data of the patients were retrospectively reviewed on 13 cases (six males, seven females; age range: 22–78; mean age 47). Although fluid attenuated inversion recovery (FLAIR) and diffusion-weighted MR images were considered for identification of the entity, primarily post-contrast T1-weighted MR images were searched for traces of enhancement in the lesions.
No definitely enhancing lesion was identified in the MR images obtained in 6–48
h after onset of symptoms (mostly headaches, seizures and cortical visual field deficits) in this series. Severity of disease indicated by small hemorrhages, confluence of lesions or progression to cytotoxic edema did not seem to alter this result. Typical lesion characteristics were consistent with vasogenic edema on FLAIR and diffusion MR images. Acute elevation of blood pressure on chronic hypertensive background was responsible in four, eclampsia in three, uremia with blood pressure fluctuations in three, and cyclosporine-toxicity in three cases.
Although occasional enhancing brain lesions have been reported in the literature on PRES, contrast-enhancement of lesions may be a factor of scan timing and underlying etiology. Prospective studies with larger series on PRES are required for better evaluation of contrast-enhancement in MRI with respect to scan timing, which in turn may help understand its pathophysiology better.
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