Previous Lumbar Spine Surgery Decreases the Therapeutic Efficacy of Dorsal Root Ganglion Pulsed Radiofrequency in Patients with Chronic Lumbosacral Radicular Pain.

Chronic lumbosacral radicular pain (CLRP) as a possible adverse consequence of lumbar spine surgery represents a serious medical challenge. Pulsed radiofrequency of dorsal root ganglion (PRF-DRG) treatment is known to be effective in alleviating CLRP. This retrospective study compares the efficacy of a single CT-guided PRF-DRG procedure in the treatment of unilateral CLRP between patients without (non-PSS) and with (PSS) previous lumbar spine surgery. Non-PSS and PSS groups included 30 and 20 patients, respectively. Outcomes (pain intensity and disability) were evaluated by means of the visual analog scale (VAS) and Oswestry disability index (ODI) immediately after the procedure (VAS), as well as three and six months after the procedure, respectively. Non-PSS group showed a significant (p ˂ 0.001) decrease of VAS (median) at all follow-up intervals (from 6 to 4; 4; 4.5 points, respectively). The PSS group showed a significant yet transient VAS (median) decrease (from 6 to 5 points) immediately after the procedure only (p < 0.001). The decrease of VAS was more pronounced in the non-PSS group after three and six months (p = 0.0054 and 0.011, respectively) in intergroup comparison. A relative decrease of VAS ≥ 50% during follow-up was achieved in 40%; 43.3%; 26.7% (non-PSS), and 25%; 5%; 0% (PSS) of patients. ODI (median) significantly decreased in the non-PSS group (from 21.5 to 18 points) at three and six months (p = 0.014 and 0.021, respectively). In conclusion, previous lumbar spine surgery decreases the therapeutic efficacy of PRF-DRG procedure in CLRP patients.

Worm-like appearance of Listeria monocytogenes brain abscess: presentation of three cases.

Brain abscess caused by Listeria monocytogenes (LM) is a rare, yet serious condition with high mortality if not recognized and treated timely. We present a series of three cases of LM brain abscesses and describe their characteristic radiological appearances which can be considered very typical. LM abscesses frequently present as markedly irregular formations, revealing characteristic worm-like tubular pattern of chaotic curvilinear arrangement. Knowledge of this imaging pattern can be very helpful in early recognition of LM abscesses whose initial differential diagnosis can often be misleading initially.

Radiological markers of idiopathic normal pressure hydrocephalus: Relative comparison of their diagnostic performance.

PURPOSE: Numerous radiological measures have been proposed as imaging biomarkers of idiopathic normal pressure hydrocephalus (iNPH), however, the number of studies systematically comparing their diagnostic values remains limited. The study objective was to compare the diagnostic performance of fifteen cross-sectional imaging iNPH biomarkers. MATERIALS AND METHODS: Eighty subjects were prospectively enrolled in the study: 35 subjects with clinically confirmed iNPH and 45 matched healthy controls (HC). Values of linear, angular and index measurements including three newly proposed biomarkers were obtained from 3T brain MRI studies by two independent readers. Diagnostic performance of biomarkers was studied by using receiver operating characteristic (ROC) analysis and t-statistic. RESULTS: All biomarkers studied were able to reliably differentiate iNPH subjects from HC (p < .001) except for cella media-to-temporal horn ratio. Z-Evans index, vertical cella media and vertical frontal horn diameters showed the highest discriminatory power between iNPH and HC groups (area under curve >0.99). Simple linear measurements of vertical (0.99) or horizontal (0.95) frontal horn diameters showed results comparable to calculated ratios, i.e. z-Evans (0.99) and Evans (0.96) indexes, respectively. CONCLUSION: The best diagnostic performance among fifteen radiological iNPH biomarkers was found in linear measurements referring to caudocranial alterations of the ventricular geometry, outweighing those referring to laterolateral ventricular enlargement (as e.g. commonly used Evans index). Simple linear measurements of vertical or horizontal frontal horn diameters showed comparable results to calculated, more time-consuming z-Evans or Evans indexes, respectively.

[Bilateral loss of the horizontal vestibulo-ocular reflex in Wernicke encephalopathy - a specific and early clinical sign]. / Bilateralt bortfall av horisontell vestibulo-okulär reflex - Ett tidigt och specifikt kliniskt tecken vid Wernickes encefalopati.

Wernicke encephalopathy is a condition in which thiamine deficiency causes cognitive dysfunction, ataxia and eye motor abnormalities. The condition is potentially reversible if treated with high doses of intravenous thiamine (vitamin B1). The video head impulse test, in which the vestibulo-ocular reflex is tested, can reveal an early specific sign of selective dysfunction in the medial vestibular nuclei by demonstrating selective dysfunction of the horisontal vestibulo-ocular reflex. We present two cases with clinical and neuroradiological findings consistent with Wernicke encephalopathy where such oculomotor findings were detected.

Iterative reconstruction of pulmonary MDCT angiography: effects on image quality, effective dose and estimated organ dose to the breast.

AIMS: To compare the image characteristics, effective dose and estimated organ dose to the female breast in pulmonary MDCT angiography (MDCTA), reconstructed with either standard filtered back projection (FBP), or iterative reconstruction in image space (IRIS). METHODS: Pulmonary MDCTA performed in 116 females (age 18 - 77 years; body mass index 15 - 48) was reconstructed with FBP (n=52) or IRIS (n=64). Scans were acquired on a 128-row MDCT system using automatic tube current modulation, 100 kV tube voltage, and a quality reference mAs value of 120 (FBP) and 80 (IRIS). Dose was calculated from CT dose index (CTDIvol) and dose length product (DLP) values utilising ImPACT software. Image noise was measured within the pulmonary artery. Qualitative visual assessment of the scans was performed (1=negligible noise, 5=noise obscuring diagnostic information). RESULTS: The average CTDIvol yielded 4.33 mGy for FBP and 3.54 mGy for IRIS, respectively (18.2% decrease). The average effective scan dose was 2.73±0.57 mSv (FBP) and 2.29±0.68 mSv (IRIS), respectively (16.1% decrease). The estimated average organ dose to the breast decreased from 5.1±1.1 mGy (FBP) to 4.2±1.2 mGy (IRIS, 17.6% decrease). No non-diagnostic scans (score 5) were encountered in either group. Significant improvement in image noise levels (P<0.01) and subjective image quality (P<0.02) were noted in IRIS group. CONCLUSION: Pulmonary MDCTA utilizing a 100 kV technique, automatic tube current modulation, and iterative image reconstruction offers robust results in routine conditions among an unselected female population, with breast doses being comparable to two-view digital mammography. Moreover, iterative reconstruction offers improvements in both image noise and visual perception of the scans, thus suggesting a potential for further dose reduction.

Reduction of effective dose and organ dose to the eye lens in head MDCT using iterative image reconstruction and automatic tube current modulation.

AIMS: To compare the effective and eye lens radiation dose in helical MDCT brain examinations using automatic tube current modulation in conjunction with either standard filtered back projection (FBP) technique or iterative reconstruction in image space (IRIS). METHODS: Of 400 adult brain MDCT examinations, 200 were performed using FBP and 200 using IRIS with the following parameters: tube voltage 120 kV, rotation period 1 second, pitch factor 0.55, automatic tube current modulation in both transverse and longitudinal planes with reference mAs 300 (FBP) and 200 (IRIS). Doses were calculated from CT dose index and dose length product values utilising ImPACT software; the organ dose to the lens was derived from the actual tube current-time product value applied to the lens. Image quality was assessed by two independent readers blinded to the type of image reconstruction technique. RESULTS: The average effective scan dose was 1.47±0.26 mSv (FBP) and 0.98±0.15 mSv (IRIS), respectively (33.3% decrease). The average organ dose to the eye lens decreased from 40.0±3.3 mGy (FBP) to 26.6±2.0 mGy (IRIS, 33.5% decrease). No significant change in diagnostic image quality was noted between IRIS and FBP scans (P=0.17). CONCLUSION: Iterative reconstruction of cerebral MDCT examinations enables reduction of both effective and organ eye lens dose by one third without signficant loss of image quality.

MRI-based preplanning using CT and MRI data fusion in patients with cervical cancer treated with 3D-based brachytherapy: feasibility and accuracy study.

PURPOSE: Magnetic resonance imaging (MRI)-assisted radiation treatment planning enables enhanced target contouring. The purpose of this study is to analyze the feasibility and accuracy of computed tomography (CT) and MRI data fusion for MRI-based treatment planning in an institution where an MRI scanner is not available in the radiotherapy department. METHODS AND MATERIALS: The registration inaccuracy of applicators and soft tissue was assessed in 42 applications with CT/MRI data fusion. The absolute positional difference of the center of the applicators was measured in four different planes from the top of the tandem to the cervix. Any inaccuracy of registration of soft tissue in relation to the position of applicators was determined and dose-volume parameters for MRI preplans and for CT/MRI fusion plans with or without target and organs at risk (OAR) adaptation were evaluated. RESULTS: We performed 6,132 measurements in 42 CT/MRI image fusions. Median absolute difference of the center of tandem on CT and MRI was 1.1 mm. Median distance between the center of the right ovoid on CT and MRI was 1.7 and 1.9 mm in the laterolateral and anteroposterior direction, respectively. Corresponding values for the left ovoid were 1.6 and 1.8 mm. Rotation of applicators was 3.1°. Median absolute difference in position of applicators in relation to soft tissue was 1.93, 1.50, 1.05, and 0.84 mm in the respective transverse planes, and 1.17, 1.28, 1.27, and 1.17 mm in selected angular directions. The dosimetric parameters for organs at risk on CT/MRI fusion plans without OAR adaptation were significantly impaired whereas the target coverage was not influenced. Planning without target adaptation led to overdosing of the target volume, especially high-risk clinical target volume--D90 88.2 vs. 83.1 (p < 0.05). CONCLUSIONS: MRI-based preplanning with consecutive CT/MRI data fusion can be safe and feasible, with an acceptable inaccuracy of soft tissue registration.

Comparison of duplex ultrasonography and magnetic resonance imaging in the detection of significant renal artery stenosis.

OBJECTIVE: The aim of our study was to evaluate duplex ultrasonography (DUS) and magnetic resonance angiography (MRA) in detection of haemodynamically significant renal artery stenosis (RAS). METHODS: The study included patients with high clinical suspicion of renovascular hypertension (RVH). The imaging of renal arteries was performed by DUS, MRA and digital subtraction angiography (DSA). Significant RAS was defined as maximum systolic velocity > or =180 cm/sec (DUS) or as 60% reduction of the endoluminal arterial diameter (MRA, DSA). The results of DUS and MRA were assessed in respect to the results of DSA. RESULTS: Arterial supply of 186 kidneys in 94 patients was evaluated. DSA revealed significant RAS in 61 kidneys evaluated. DUS was not able to examine arterial supply in 18 kidneys of 13 patients. In the detection of significant RAS, DUS was characterized by sensitivity and specificity of 85% and 84%. MRA achieved satisfactory imaging quality in all but one kidney evaluated. The sensitivity and specificity of MRA in the detection of significant RAS was 93% and 93%, respectively. CONCLUSION: In patients with high clinical probability of RVH, MRA proved to be more reliable and superior in both sensitivity and specificity to DUS in the detection of significant RAS.

Prevention of allergy in infants of allergic mothers by probiotic Escherichia coli.

BACKGROUND: The objective is to study the effect of after-birth oral colonization by a probiotic Escherichia coli strain in infants of allergic mothers to reduce occurrence of allergy later in life. METHODS: In a controlled clinical trial, 158 infants were randomly divided into groups of (i) 56 colonized infants of allergic mothers, (ii) 57 control infants of allergic mothers, and (iii) 45 control infants of healthy mothers. Incidence rates of bacterial pathogens in stool and levels of anti-E. coli immunoglobulins and some cytokines in serum were determined, and secretory IgA was monitored in stool filtrates and maternal milk. Clinical check-ups of infants aged 4 days, 3 and 6 months, 2, 3 and 5 years were carried out and clinical symptoms of allergy were monitored. One milliliter of the probiotic E. coli strain was administered to infants of allergic mothers at first within 48 h after birth and subsequently 3 times a week over a period of 4 weeks. Control infants of allergic and healthy mothers were monitored in these intervals as well. RESULTS: Presence of the E. coli strain was monitored in stool samples throughout the study. At the conclusion of the study, allergy symptoms were found in 14 infants of control allergic mothers, 7 infants of healthy mothers, and in 2 colonized infants of allergic mothers. Colonization affected levels of several cytokines and specific anti-E. coli antibodies. CONCLUSIONS: After birth, targeted colonization of the intestine by a probiotic E. coli strain can be an effective means of allergy prevention in infants of allergic mothers.

Contrast-enhanced MR angiography utilizing parallel acquisition techniques in renal artery stenosis detection.

Significant renal artery stenosis (RAS) is a potentially curable cause of renovascular hypertension and/or renal impairment. It is caused by either atherosclerosis or fibromuscular dysplasia. Correct and timely diagnosis remains a diagnostic challenge. MR angiography (MRA) as a minimally invasive method seems to be suitable for RAS detection, however, its diagnostic value widely differs in the literature (sensitivity 62-100% and specificity 75-100%). The aim of our prospective study was to compare the diagnostic value of contrast-enhanced MRA utilizing parallel acquisition techniques in the detection of significant RAS with digital subtraction angiography (DSA). A total of 78 hypertensive subjects with suspected renal artery stenosis were examined on a 1.5 Tesla MR system using a body array coil. Bolus tracking was used to monitor the arrival of contrast agent to the abdominal aorta. The MRA sequence parameters were as follows: TR 3.7 ms; TE 1.2 ms; flip angle 25 degrees; acquisition time 18s; voxel size 1.1 mm x1.0 mm x 1.1 mm; centric k-space sampling; parallel acquisition technique with acceleration factor of 2 (GRAPPA). Renal artery stenosis of 60% and more was considered hemodynamically significant. The results of MRA were compared to digital subtraction angiography serving as a standard of reference. Sensitivity and specificity of MRA in the detection of hemodynamically significant renal artery stenosis were 90% and 96%, respectively. Prevalence of RAS was 39% in our study population. Contrast-enhanced MRA with high spatial resolution offers sufficient sensitivity and specificity for screening of RAS.

Comparison of magnetic resonance imaging and cardiac catheterization in patients with suspected severe aortic stenosis.

OBJECTIVE: Magnetic resonance imaging (MRI) is a novel technique used in the assessment of aortic stenosis. The aim of the study was to compare MRI and cardiac catheterization (CAT) that is still considered to be a "golden standard" in this indication. METHODS: Thirty-four patients referred to CAT for the evaluation of aortic stenosis were enrolled into the study. CAT was performed according to the standardized protocol. Cardiac output was measured by thermodilution and mean aortic gradient was determined using simultaneous blood pressure measurement in aorta and left ventricle. MRI was performed within the period of 3 weeks after CAT. True FISP sequence with retrospective ECG gating was used for the imaging of the aortic valve orifice. Planimetry of the aortic valve area (AVA) was performed at the time of maximal opening of the valve during systole. RESULTS: MRI enabled the measurement of AVA in all patients enrolled. Mean AVA defined by CAT and MRI were 0,97 (+/- 0,41) cm2 and 1,38 (+/- 0,55) cm2, respectively. The correlation between the evaluated methods was statistically significant (p=0,003), but not very strong (r=0,43). The comparison of both methods in the identification of the severe aortic stenosis was characterized by kappa value of 0,331. CONCLUSION: Our study shows low agreement between cardiac catheterization and magnetic resonance imaging in the assessment of aortic stenosis. However, MRI might have a role in the diagnostic algorithm in patients with suspected severe aortic stenosis and moderate mean aortic gradient or concomitant valvular insufficiency.

Effect of breast milk of healthy and allergic mothers on in vitro stimulation of cord blood lymphocytes.

Maternal milk has beneficial effects on the development and function of the newborn's immune system. Whether the milk of allergic mother has the same effects as the milk of healthy mothers is not yet quite clear. To contribute to the characterization of its immunomodulatory action, we tested the effect of milk of healthy and allergic mothers on the proliferation and immunoglobulin formation in cultures of cord blood mononuclear leucocytes (CBML) of newborns of healthy and allergic mothers. CBML proliferation was tested by (3)H-thymidine incorporation, IgM, IgG and IgA production by reverse ELISPOT. CBML response was examined in unstimulated cultures and after stimulation with polyclonal activators in the presence or absence of colostrum or milk. The cells of children of allergic mothers have a significantly higher proliferative activity than those of children of healthy mothers. Maternal colostrum/milk in high doses markedly suppresses cell proliferation after stimulation with polyclonal activators, whereas lower milk doses in the cultures have no such effect and exert a rather stimulatory action. Immunoglobulin production by cord blood lymphocytes is also different in the two groups of children. Low basal immunoglobulin formation is increased after stimulation with a strong polyclonal activator of B cells--Bacillus firmus, CBML of children of allergic mothers produce more IgA than those of children of healthy mothers. The stimulated production of all immunoglobulin classes in cells of children of healthy mothers is still enhanced by colostrum/milk. Children of allergic mothers show a markedly increased production of only IgM and IgA. The effect of healthy and allergic colostrum and milk on cell proliferation and immunoglobulin production is similar. The lymphocytes of children of allergic mothers differ from the lymphocytes of children of healthy mothers in their proliferative activity and the ability to form immunoglobulin already at birth.

Focal nodular hyperplasia: spoke-wheel arterial pattern and other signs on dynamic contrast-enhanced ultrasonography.

OBJECTIVE: To evaluate the prevalence of spoke-wheel pattern and typical symptoms of focal nodular hyperplasia (FNH) by means of dynamic contrast-enhanced ultrasonography (CEUS) in relation to lesion size. METHODS: Twenty-eight patients were included in the trial, in whom, based on the CEUS, we raised suspicion of hypervascularized liver lesion; there were 30 lesions altogether. The final diagnosis of FNH was verified by means of CT, MRI or lesion biopsy. Majority of patients (26) were females, compared to 2 male, with average age of 33.3 years. Average lesion size was 45.6 mm. Besides the ultrasound examination, we used also "blood pool" ultrasound contrast agent of second generation, sulphur hexafluoride (BR1); we evaluated enhancement of the lesion until the late stage-within 5 min from application. RESULTS: In lesions larger than 3 cm (n=20), stellate vascular enhancement was found in 19 cases (95.0%) early in arterial phase. As for lesions smaller than 3 cm (n=10), spoke-wheel pattern was observed only in 3 cases (30%) and lesions smaller than 2 cm practically did not show this phenomenon at all (n=1; 17%). Generally, symptom of spoke-wheel pattern was observed in 22 cases, i.e. in 73.3%. In total, central scar was present in 63.3% (n=19) of cases. In lesions larger than 3 cm, it was present in 85.0% (n=17), in lesions smaller than 3 cm in 20% (n=2). CONCLUSION: Contrast-enhanced ultrasonography can be the final diagnostic method for FNH larger than 3 cm which has typical spoke-wheel vessel structure on CEUS. If this phenomenon is not present and the central scar is not visible, specific diagnosis of FNH cannot be based solely on CEUS findings.

Dynamic and delayed contrast enhancement in upper abdominal MRI studies: comparison of gadoxetic acid and gadobutrol.

OBJECTIVE: To prospectively compare contrast properties of extracelullar (gadobutrol) and hepatospecific (gadoxetic acid) contrast agents in upper abdominal MRI studies. MATERIALS AND METHODS: Standardized (0.1 ml/kg) dose of gadobutrol (56 subjects) and gadoxetic acid (51 subjects) was administered intravenously by MRI-compatible injector at 2 ml/s, followed by 20 ml saline flush. MR signal intensity changes (SIC) between precontrast scans and arterial phase, portal venous phase, equilibrium, and delayed scans at 10 and 20 min were measured in abdominal aorta, portal vein, common bile duct, liver, and spleen. Mean SIC values for gadobutrol and gadoxetic acid were compared by a two-sample t-test with p-value <0.05 considered significant. RESULTS: In abdominal aorta, the mean SIC in the arterial phase did not significantly differ between gadobutrol (330%) and gadoxetic acid (295%). In portal vein, the mean SIC in the portal venous phase significantly differed between gadobutrol (267%) and gadoxetic acid (176%). Liver parenchyma enhancement was significantly higher for gadobutrol than for gadoxetic acid in both arterial phase (28 versus 13%) and portal venous phase (81 versus 46%). On the contrary, gadobutrol reached significantly lower mean SIC in the liver on delayed scans at 10 min (47 versus 59%) and 20 min (40 versus 67%), as well as in common bile duct at 10 min (54 versus 133%) and 20 min (57 versus 457%), respectively. In the spleen, mean SIC for gadobutrol was significantly higher at all phases. CONCLUSION: Gadobutrol showed superior enhancement of upper abdominal structures in the dynamic phases whereas gadoxetic acid showed better enhancement of the hepatobiliary structures on delayed scans.

Clinical use of magnetic resonance imaging for the diagnosis of acute myocardial infarction in the survivors of cardiac arrest.

The ventricular arrhythmias with underlying coronary artery disease are a leading cause of sudden cardiac death (SCD). While the SCD survivors with proven AMI are considered to be at low risk of SCD recurrence, those without the evidence of AMI represent a high risk group that benefits from implantable cardioverter defibrillator. Therefore, the evaluation of SCD survivors for the presence of acute myocardial infarction (AMI) as a triggering factor of cardiac arrest is essential. In SCD survivors, the use of the standard diagnostic criteria of AMI may be difficult, as both serum cardiac biomarkers and electrocardiogram can be influenced by previous cardiac arrest. A novel technique that may be used for the diagnosis of AMI is magnetic resonance imaging (MRI). We report its use in four patients after cardiopulmonary resuscitation where the diagnosis of AMI could not be definitely established or excluded by means of other diagnostic procedures.

Contrast-enhanced magnetic resonance and thallium scintigraphy in the detection of myocardial viability: a prospective comparative study.

The aim of the present study was to prospectively compare contrast-enhanced magnetic resonance imaging (CE-MRI) with single-photon emission tomography using (201)Thallium chloride (SPECT Tl) in the detection of myocardial viability. Patients with chronic coronary artery disease and systolic dysfunction defined by an ejection fraction (EF)

Liver, meconium, haemorrhage: the value of T1-weighted images in fetal MRI.

BACKGROUND: Ultrafast T2-weighted (T2-W) MRI sequences are currently considered a routine technique for fetal MR imaging. Limited experience exists with fetal T1-weighted (T1-W) imaging techniques. OBJECTIVE: To determine MRI patterns of some fetal abdominal or haemorrhagic disorders with particular respect to the diagnostic value of T1-W images. MATERIALS AND METHODS: In addition to standard T2-W single-shot sequences, T1-W single-shot and/or multislice sequences were employed in 25 MR examinations performed in 23 fetuses between 20 and 36 weeks of gestation for more detailed assessment of liver, meconium-filled digestive tract, haemorrhage, or further characterization of a fetal abdominal mass. Diagnostic value and presence of motion artefacts on T1-W images was recorded in each case. RESULTS: T1-W images enabled superior delineation of fetal liver and large intestine. They provided additional diagnostic information in 9 (39%) of 23 fetuses. One false-positive and one false-negative MRI diagnosis of malrotation anomaly were encountered. Use of single-shot T1-W sequences reduced the occurrence of motion artefacts in 64%. CONCLUSION: Our results suggest that the specific signal properties of methaemoglobin, meconium and liver are sufficiently important for T1-W sequences to become a routine part of fetal MRI protocols when dealing with digestive tract anomalies, diaphragmatic and abdominal wall defects, intraabdominal masses, and fetal haemorrhage.

Cytokine levels in healthy and allergic mothers and their children during the first year of life.

To assess the regulatory changes of immune system in children genetically pre-disposed to allergic diseases and in their mothers, we tested cytokines IL-4, IL-5, IL-6, IL-10, IL-13, IFN-gamma and TGF-beta in 21 healthy and 21 allergic mothers (serum at the time of delivery, colostrum and milk throughout the suckling period) and their children (cord blood, venous blood and stool filtrates) up to 1 yr of age. Samples were taken at the time of delivery, 4 days post-partum and then after 3, 6 and 12 months. Significant differences between the healthy and the allergic group were found in the levels of IL-4, IL-10, IL-13 and IFN-gamma. The levels of IL-4 in the allergic group were generally higher; the levels in the sera of children of allergic mothers during the post-natal life decreased, reaching levels typical for the healthy group at 1 yr of age. Allergic mothers exhibited markedly higher IL-10 levels in the serum at the time of delivery and in milk 3 months after delivery than healthy mothers while after 6 months the IL-10 levels in all samples from the allergic group were very low. Children from allergic group had lower intestinal content of IL-13 in comparison with the healthy counterparts. At 1 yr of age, the levels of IFN-gamma in sera and stool of children from the allergic group sharply increased. TGF-beta levels in the sera of both groups were high, while in the milk they were relatively low and substantially lower that in the children's stool. TGF-beta of mammary secretions is therefore unlikely to exert a decisive regulatory influence on the children's immunity. Long-term clinical monitoring of the children will be performed to evaluate the potential prognostic significance of these changes for the future development of allergies.

Vascular compression of rostral medulla oblongata: prospective MR imaging study in hypertensive and normotensive subjects.

PURPOSE: To prospectively evaluate prevalence of neurovascular contacts (NVCs) at the rostral medulla oblongata in normotensive and hypertensive subjects. MATERIALS AND METHODS: Forty-three patients with severe essential hypertension and 45 normotensive subjects were matched for age, sex, and body mass index. Magnetic resonance (MR) imaging included transverse and coronal T2-weighted turbo spin-echo (section thickness, 3.0 mm), transverse three-dimensional (3D) time-of-flight MR angiographic (section thickness, 0.8 mm), and 3D constructive interference in steady state (CISS) (section thickness, 1.0 mm) sequences. All MR images were reviewed by two radiologists who were blinded to the hypertensive status of subjects. Presence and degree of NVC at rostral medulla and left/right rostral ventrolateral medulla (RVLM) were evaluated together with conspicuity of anatomic structures on MR images. Differences in prevalence of NVC among normotensive and hypertensive subjects were tested for statistical significance (P <.05) by using nonparametric tests. RESULTS: Among hypertensive patients, 34 (79%) of 43 showed NVC of rostral medulla at any location, and 14 (33%) of 43 had NVC at the left RVLM. In controls (normotensive subjects), 35 (78%) of 45 showed NVC of rostral medulla, and 17 (38%) of 45 had NVC at left RVLM. Prevalence of NVC was not significantly different between both groups at any location of rostral medulla. Compared with T2-weighted turbo spin-echo and 3D time-of-flight MR imaging sequences, 3D CISS offered better contrast resolution of neural and vascular structures and superior delineation of outer vascular contours. CONCLUSION: Vascular compression of the rostral medulla oblongata is a frequent finding in both hypertensive and normotensive subjects. Results of this study do not support NVC at left RVLM as an etiologic factor in essential hypertension.