[MRI-based follow-up study of spinal tuberculosis in children].

OBJECTIVE: To investigate the value of MRI follow-up in pediatric patients with spinal tuberculosis. METHODS: From February 2004 to April 2013, MRI imaging data in 21 children with spinal tuberculosis by pathologically and clinically proven were retrospectively analysed. There were 11 males and 10 males, with an average age of 9.4 years old ranging from 2 to 14 years old. Eighteen patients were received conservative treatment, 3 patients were treated by surgical operation. The course of disease ranged from 2 months to 3 years. All cases underwent two or more MRI examinations for follow-up. MRI findings of the first and second examination were comparatively analyzed,including signal changes of vertebral body and intervertebral, paraspinal abscess and the change of kyphosis angle. RESULTS: In the 21 cases with tuberculosis, 85 vertebral bodies were affected in total, including 10.6%(9/85), 49.4%(42/85) and 40%(34/85) vertebral bodies separately in the cervical,thoracic, lumbosacral spine. Follow-up MRI showed vertebral body shape and signal had no obvious change during or after treatment, 15 cases with vertebral bodies changed flat or cuneate, 10 cases with disc involvement,and intervertebral space became narrowing at different level. Among 13 patients with kyphosis angle greater than 0°, 7 were located on thoracic, 2, 3, 1 were on thoracolumbar, lumbar and cervical spine, respectively. Among 18 cases with conservative treatment,kyphosis angle were 0° on the first and the follow up MRI of 8 patients. One case of mild (<10°) kyphosis,follow-up MRI during therapy showed the angle slightly increased; 5 cases with moderate (10° to 30°), follow-up MRI during therapy showed no obvious change; 4 cases with severe (>30°), follow-up MRI during and after therapy showed kyphosis increased in varying degrees. CONCLUSION: Follow-up MRI can make a big difference in the spinal tuberculosis of children; it can clearly show the change of the vertebral body and intervertebral space, paraspinal abscess and the kyphosis angle after the treatment,which can provide reference for clinical treatment and estimating prognosis.

[Relationship between gestational age and apparent diffusion coefficient values in different regions of fetal brain from middle to late trimester].

OBJECTIVE: To analyze the relationship between gestational age and apparent diffusion coefficient (ADC) values in different regions of fetal brain from middle to late trimester. METHODS: DW images performed in 70 singleton non-sedated fetuses with questionably abnormal results on sonography and normal fetal MR imaging results were retrospectively reviewed. The median gestational age was 32.4 weeks (range, 24-38).With the formula of ADC = ln (S600/S0)/(B0-B600), the mean ADC values were obtained for fetal parietal white matter (WM), frontal WM, temporal WM, occipital WM, pons, cerebellum, basal ganglia and thalamus. The relationship of mean ADC values in different regions with gestational age was analyzed with linear regression. RESULTS: The mean ADC values were 1.77 ± 0.32 mm(2)/s (SD) in fetal parietal white matter (WM), 1.71 ± 0.32 mm(2)/s in occipital WM, 1.31 ± 0.18 mm(2)/s in thalamus, 1.34 ± 0.15 mm(2)/s in basal ganglia. And the mean ADC values in cerebellum, pons, frontal WM and temporal WM were 1.17 ± 0.16, 1.41 ± 0.18, 1.87 ± 0.18 and 1.74 ± 0.19 mm(2)/s respectively. A significant negative correlation between ADC values and gestational age was found for parietal WM, occipital WM, pons, cerebellum, basal ganglia and thalamus (P < 0.05). Frontal WM ADC (P > 0.05) and temporal WM ADC (P = 0.05) did not significantly change with gestational age whereas only a downward trend was present. The correlation coefficient (r) and coefficient of regression (b) were 0.420 and -0.045 in parietal WM; 0.470 and -0.052 in occipital WM; 0.370 and -0.027 in cerebellum; 0.027 and -0.020 in pons; 0.320 and -0.027 in thalamus; 0.300 and -0.021 in basal ganglia. The mean ADC values peaked in frontal WM and lowest in pons. The mean ADC values in white matter were higher than those in deep gray nuclei, cerebellum and pons.With the development of fetal brain,ADC values declined the fastest in cerebellum and occipital WM, followed by basal ganglia and thalamus. CONCLUSION: Regional differences in non-sedated fetal brain ADC values and their evolutions with gestational age are likely to reflect variations in brain maturation.

[Normal pneumatization time of paranasal sinuses in 799 children: evaluation with magnetic resonance imaging].

OBJECTIVE: To evaluate the onset of initial pneumatization of paranasal sinuses with magnetic resonance imaging (MRI) and provides references in the diagnosis and treatment of pediatric paranasal sinuses disease. METHODS: The MRI images of paranasal sinuses were retrospectively reviewed for 799 children of 0 month to 15 years old and the first pneumatization time of paranasal sinuses were analyzed. RESULTS: The ethmoidal sinuses was the first pneumatized in 100% (46/46) of newborn children. And 45.7% (21/46) of maxillary sinuses showed pneumatization during the first month of life and 97.8% (45/46) were pneumatized at 7 - 12 months. The pneumatized sphenoid sinuses was first identified as early as 4 months. And 86% (43/50) were pneumatized from 1 to 2 years old. Frontal sinuses was the last pneumatized paranasal sinuses. And 8% (4/50) of frontal sinuses were pneumatized at 1 - 2 years old and 97.8% (42/43) showed pneumatization at 14 - 15 years old. CONCLUSION: MRI may be used to observe the pneumatization of paranasal sinuses. The initial pneumatization time of paranasal sinuses is earlier than previously described.

[Neurologic complications in children with enterovirus 71-infected hand-foot-mouth disease : clinical features, MRI findings and follow-up study].

OBJECTIVE: To explore the clinical and magnetic resonance imaging (MRI) characteristics and the follow-up outcomes of neurologic complications in children with enterovirus 71-infected hand-foot-mouth disease. METHODS: The clinical and MRI manifestations and follow-up outcomes in 35 children, at Second Affiliated Hospital, Wenzhou Medical College from August 2008 to November 2010, hospitalized with neurologic complications of enterovirus 71-infected hand-foot-mouth disease were retrospectively analyzed. RESULTS: Six children with aseptic meningitis presented the clinical symptoms and signs of meningitis. Five of them showed subdural effusion and ventriculomegaly, or both on MRI. At follow-ups, neurologic sequel could not be found. Among 24 cases with brainstem encephalitis, there were myoclonic jerks and tremor, ataxia, or both (grade I disease, n = 12), myoclonus and cranial-nerve involvement (grade II disease, n = 4), and cardiopulmonary failure after brain-stem infection (grade III disease, n = 8). In patients with brainstem encephalitis, lesions were predominantly located at the posterior portions of medulla and pons with hypointensity on T1WI and hyperintensity on T2WI. Cerebellar dentate nucleus, caudate nucleus and lenticular nucleus could also be involved. At follow-ups, the patients with mild symptoms had no neurologic sequel and the lesions within brain stem became small or vanished in most cases. While in the majority of serious patients, neurologic sequel could be found and the lesions located at brain stem became encephalomalacia. Fourteen cases with acute flaccid paralysis presented acute limb myasthenia with tendon reflex and muscular tension decreased. On spinal MRI, the lesions predominantly involved anterior horn regions of spinal cord with hypointensity on T1WI and hyperintensity on T2WI. Most patients improved their muscle strength and most lesions of spinal cord became smaller or vanished during follow-ups. CONCLUSION: MRI is the most effective modality of diagnosis and follow-up for neurologic complications in children with enterovirus 71-infected hand-foot-mouth disease. On MRI, the lesions mainly involve the anterior horn of spinal cord, medulla oblongata and pons. At follow-ups, most patients have no neurologic sequel and the visualized lesions will be absorbed after active treatment.