Functional magnetic resonance urography in infants: feasibility of a feed-and-sleep technique.

BACKGROUND: Functional magnetic resonance (MR) urography has been well established in the diagnostic workup of congenital anomalies of kidneys and urinary tract, though long acquisition time requires sedation or general anesthesia in infants. OBJECTIVE: To evaluate the success rate of an optimized functional MR urography protocol in infants carried out in natural sleep. MATERIALS AND METHODS: We retrospectively evaluated all functional MR urographies performed under general anesthesia or during natural sleep in infants younger than 1 year between 2010 and 2017 and rated image quality in both cohorts using a 3-point Likert scale. We tested the analyzability of functional sequences using a free available software. We also calculated examination time. Finally, we compared examinations in natural sleep and those with general anesthesia using independent t-test for continuous data and Mann-Whitney U test for categorical data. RESULTS: Functional MR urography could be performed successfully during natural sleep in 38 of 42 (90%) infants younger than 10 months. Four examinations were aborted before contrast medium was administrated. In the same period, 19 functional MR urographies were performed successfully under general anesthesia. Although image quality was significantly better in this group (P<0.0001), image quality was at least diagnostic in all finished examinations in natural sleep, and the functional analyzability was given in all completed examinations. There was a significant saving in examination time during natural sleep (P<0.001). CONCLUSION: Functional MR urography can be successfully performed in natural sleep in infants younger than 10 months.

A semiquantitative MRI-Score can predict loss of lung function in patients with cystic fibrosis: Preliminary results.

OBJECTIVES: To evaluate the applicability of a semiquantitative MRI scoring system (MR-CF-S) as a prognostic marker for clinical course of cystic fibrosis (CF) lung disease. METHODS: This observational study of a single-centre CF cohort included a group of 61 patients (mean age 12.9 ± 4.7 years) receiving morphological and functional pulmonary MRI, pulmonary function testing (PFT) and follow-up of 2 years. MRI was analysed by three raters using MR-CF-S. The inter-rater agreement, correlation of score categories with forced expiratory volume in 1 s (FEV1) at baseline, and the predictive value of clinical parameters, and score categories was assessed for the whole cohort and a subgroup of 40 patients with moderately impaired lung function. RESULTS: The inter-rater agreement of MR-CF-S was sufficient (mean intraclass correlation coefficient 0.92). MR-CF-S (-0.62; p < 0.05) and most of the categories significantly correlated with FEV1. Differences between patients with relevant loss of FEV1 (>3%/year) and normal course were only significant for MR-CF-S (p < 0.05) but not for clinical parameters. Centrilobular opacity (CO) was the most promising score category for prediction of a decline of FEV1 (area under curve: whole cohort 0.69; subgroup 0.86). CONCLUSIONS: MR-CF-S is promising to predict a loss of lung function. CO seems to be a particular finding in CF patients with an abnormal course. KEY POINTS: • Lung imaging is essential in the diagnostic work-up of CF patients • MRI serves as a powerful, radiation-free modality in paediatric CF patients • Observational single-centre study showed significant correlation of MR-CF score and FEV 1 • MR-CF score is promising in predicting a loss of lung function.

Contrast-Enhanced High-Pitch Computed Tomography in Pediatric Patients Without Electrocardiography Triggering and Sedation: Comparison of Cardiac Image Quality With Conventional Multidetector Computed Tomography.

OBJECTIVE: The aim of this study was to compare image quality of anatomical cardiac details without electrocardiography triggering, sedation, or heart rate-regulating drugs in contrast-enhanced pediatric chest computed tomography (CT), using high-pitch CT (HPCT) versus conventional pitch-mode technique (multidetector CT [MDCT]). METHODS: After written informed consent, 55 patients (median age, 11 years; range, 3-17 years) were prospectively included in this institutional review board-approved study. Patients underwent clinically indicated, contrast-enhanced MDCT or HPCT of the chest.Image quality was assessed evaluating morphological criteria on a 3-point scale (from 1, high, to 3, low detail) and summed up in a global score (from 4, best, to 12, poor image quality). Artifacts were analyzed correspondingly (from 3, low, to 9, severe artifacts). Effective dose and size-specific dose estimate were calculated for all scans. RESULTS: Cardiac image quality was higher in HPCT than in MDCT (7.1 [1.6] vs 8.8 [1.9], P < 0.001). Nevertheless, HPCT showed limitations in image quality, especially concerning the heart valves (2.5 [0.6] and 1.7 [0.5]) and coronary arteries (1.8 [0.6). Artifact score (3.4 [0.6 vs 5.1 [0.9, P < 0.001), effective dose (1.6 [1.3] vs 2.3 [1.6] mSv, P = 0.047), and size-specific dose estimate (2.5 [1.7] vs 4.1 [2.3] mGy, P = 0.002) were lower in HPCT compared with those in MDCT. CONCLUSIONS: In pediatric patients, contrast-enhanced HPCT of the chest provides high image quality without electrocardiography triggering or sedation, although image quality is somewhat limited for a detailed depiction of cardiac anatomy.

Two patients with intestinal failure requiring home parenteral nutrition, a NOD2 mutation and tuberculous lymphadenitis.

BACKGROUND: Mutations in the NOD2 gene are a significant risk factor to acquire intestinal failure requiring home parenteral nutrition. Tuberculous lymphadenitis is the main manifestation of extrapulmonary tuberculosis. Defects in the innate immunity, including NOD2 mutations, may increase the risk for acquiring infections caused by M. tuberculosis. An association of intestinal failure, mutations in the NOD2 gene and tuberculous lymphadenitis has not been described before. CASE PRESENTATION: We report of two patients with intestinal failure secondary to mesenteric ischemia. Both patients presented with fever and weight loss while receiving long term home parenteral nutrition. Both of them were found to have mutations in the NOD2 gene. Catheter related infections were ruled out. FDG-PET-CT scans initially obtained in search for another infectious focus that would explain the symptoms unexpectedly showed high FDG uptake in mediastinal lymph nodes. Direct or indirect evidence proved or was highly suggestive for tuberculous lymphadenitis. Intravenous tuberculostatic therapy was started and led to a reversal of symptoms and to resolution of the lesions by FDG-PET-CT. CONCLUSION: Mutations in the NOD2 gene may put patients both at an increased risk for acquiring M. tuberculosis infections as well as at an increased risk of intestinal failure after extensive intestinal resection. Thus we suggest to specifically include reactivated and opportunistic infections in the differential diagnosis of suspected catheter related infection in patients with intestinal failure who carry mutations in their NOD2 gene.

Comparison between high-resolution CT and MRI using a very short echo time in patients with cystic fibrosis with extra focus on mosaic attenuation.

BACKGROUND: It would be beneficial to establish pulmonary MRI as a complementary approach to CT for direct visualization of mosaic perfusion, bullae, and emphysema in patients with cystic fibrosis. OBJECTIVES: The purpose of this study was to compare both modalities, CT and MRI, using the Helbich-Bhalla score with a special focus on reliable detection of a mosaic pattern. METHODS: Out of 51 patients examined by MRI on a 1.5-Tesla system during a period of 2 years, 19 patients were scheduled for additional low-dose CT in a clinical context. The MRI protocol comprised a gradient echo (GRE) sequence with a very short echo time (TE = 0.8 ms) in inspiration and expiration, a 3-D GRE sequence in breath hold, and a fast spin echo sequence with respiration and ECG triggering. MDCT was carried out in inspiration and adapted to body weight using 100 or 120 kV, 30-60 mA, 1- and 3-mm slice thicknesses, as well as low and high kernels. Additionally incremental slices in 3 positions were recorded in expiration for distinct detection of air trapping. CT and MRI analyses were performed by two radiologic readers in consensus unaware of the clinical parameters. The Helbich-Bhalla score of both examinations was correlated. Mean difference and accordance were assessed in each category. RESULTS: There was a strong correlation between CT and MRI (R = 0.87, p < 0.01). The mean Helbich-Bhalla score for CT was 12.2 (range 1-18) and for MRI it was 11.7 (range 2-19). The mean difference was 0.5 points. Besides this strong correlation for findings (bronchiectasis, mucus plugging, peribronchial thickening, and consolidation) with a prolonged T2 TE in MRI, we could also state a qualitative agreement of 95-100% in the categories with short T2 and low signal intensity in MRI as emphysema, bullae, and mosaic perfusion. CONCLUSIONS: These results suggest that in our patient group none of the relevant findings were missed by MR imaging and reading.

Differing Pulmonary Structural Abnormalities Detected on Pulmonary MR Imaging in Cystic Fibrosis Patients with Varying Pancreatic Function.

PURPOSE: In cystic fibrosis (CF) the phenotypic expression of complaints varies widely. Genotypes with sufficient pancreatic function (PS) exhibit milder lung disease compared to CF patients with insufficient pancreatic function (PI). The purpose of this study was to evaluate structural lung disease (SLD) in CF patients with differing pancreatic status but similar results on pulmonary function testing using a pulmonary magnetic resonance imaging score (MR-CF score). MATERIALS AND METHODS: In this retrospective study, 20 patients in our single-center CF database were included: 10 with PS (mean age 12.5 years; six male; BMI 17.4 kg/m2; FeV1 102 %) were matched by gender, age and lung function with 10 PI patients. Experienced observers semi-quantitatively assessed SLD for each lung lobe. The established MR-CF score measures the extent and the severity of bronchiectasis and bronchial wall thickening, mucus plugging, centrilobular opacity, consolidation, sacculation, and air trapping. The total score and sub-score values were compared to the pancreatic status. RESULTS: Patients with CF-PS had overall statistically significant lower MR-CF scores (p = 0.024), and therefore milder SLD, compared to CF-PI. The differences were most significant for bronchiectasis (p = 0.0042) and air trapping (p = 0.0304). SLD was more severe in the upper lobes in all patients. However, differences between CF-PS and CF-PI patients were present in both the upper and lower lung areas (p = 0.0247 and p = 0.0196, respectively). CONCLUSION: Our results demonstrated that CF patients with impaired pancreatic function show more severe lung pathology detected by MRI, especially bronchiectasis and air trapping. KEY POINTS: · Pulmonary MRI offers morphological and functional details without using ionizing radiation. · CF patients with pancreatic insufficiency show more severe pulmonary structural impairment. · Bronchiectasis and air trapping are the most common structural lung changes with predominance in the upper lung lobes.. CITATION FORMAT: · Kraus MS, Teufel M, Esser M et al. Differing Pulmonary Structural Abnormalities Detected on Pulmonary MR Imaging in Cystic Fibrosis Patients with Varying Pancreatic Function. Fortschr Röntgenstr 2020; 192: 567 - 575.

Late enhancement using multidetector row computer tomography: a feasibility study with low dose 80 kV protocol.

AIMS: Detecting stenoses of coronary arteries with multidetector row computer tomography (MDCT) is a well feasible non-invasive method. However, there is still the problem of deciding whether a stenosis is hemodynamically relevant or not. Objective of the present study was to validate the feasibility of a low dose protocol for MDCT using 80 kV for detecting late enhancement. METHODS AND RESULTS: Using a Alderson-Rando Phantom evaluation of the effective dose of this LE protocol was performed. Ten patients (six male, four female, mean age 61) with known coronary artery disease and scheduled for a conventional coronary angiogram in our facility were subsequently recruited. All patients underwent CT-angiography (CTA) 1 day prior to magnetic resonance imaging. Five minutes after the application of 100ml contrast agent for the CTA scan, a low dose late enhancement scan (80 kV, 400 mA s maximum, ECG pulsed scan, 64 mm x 0.6mm collimation, 0.33 s tube rotation) was performed. Phantom dose measurements showed an effective dose for this protocol of 1.19 mSv (male) and 1.61 mSv (female). Fifty-six percent (5/9) of the patients showed a late enhancement on the MRI scan. Three transmural late enhancements and all four negative findings were correctly identified by CT. This represents a sensitivity of 78% (3/5), specificity of 100% (3/3), NPV of 100% (4/4) and a PPV of 97%. CONCLUSION: We were able to show that the low dose protocol is feasible and, furthermore, preliminary results look promising.

Radiation Dose Optimization in Pediatric Chest CT: Major Indicators of Dose Exposure in 1695 CT Scans over Seven Years.

PURPOSE: To analyze possible influencing factors on radiation exposure in pediatric chest CT using different approaches for radiation dose optimization and to determine major indicators for dose development. MATERIALS AND METHODS: In this retrospective study at a clinic with maximum care facilities including pediatric radiology, 1695 chest CT examinations in 768 patients (median age: 10 years; range: 2 days to 17.9 years) were analyzed. Volume CT dose indices, effective dose, size-specific dose estimate, automatic dose modulation (AEC), and high-pitch protocols (pitch ≥ 3.0) were evaluated by univariate analysis. The image quality of low-dose examinations was compared to higher dose protocols by non-inferiority testing. RESULTS: Median dose-specific values annually decreased by an average of 12 %. High-pitch mode (n = 414) resulted in lower dose parameters (p < 0.001). In unenhanced CT, AEC delivered higher dose values compared to scans with fixed parameters (p < 0.001). In contrast-enhanced CT, the use of AEC yielded a significantly lower radiation dose only in patients older than 16 years (p = 0.04). In the age group 6 to 15 years, the values were higher (p < 0.001). The diagnostic image quality of low-dose scans was non-inferior to high-dose scans (2.18 vs. 2.14). CONCLUSION: Radiation dose of chest CT was reduced without loss of image quality in the last decade. High-pitch scanning was an independent factor in this context. Dose reduction by AEC was limited and only relevant for patients over 16 years. KEY POINTS: · The radiation dose of pediatric chest CT was reduced in the last decade.. · High-pitch scanning is an independent factor of dose optimization.. · Dose reduction by AEC is limited and only relevant for older children.. CITATION FORMAT: · Esser M, Hess S, Teufel M et al. Radiation Dose Optimization in Pediatric Chest CT: Major Indicators of Dose Exposure in 1695 CT Scans over Seven Years. Fortschr Röntgenstr 2018; 190: 1131 - 1140.

Mid-term results and quantitative comparison of postoperative shoulder function in traumatic and non-traumatic rotator cuff tears.

INTRODUCTION: The objective of this study was to compare the postoperative range of motion (ROM) and patient satisfaction after surgical reconstruction of traumatic and non-traumatic rotator cuff tears. MATERIALS AND METHODS: The cases of 46 consecutive patients who underwent the same standardised surgical reconstruction and postoperative rehabilitation protocol between 1993 and 1998 were reviewed. Traumatic (group I, n=20, average age 34.2 years, range 15-49 years) and non-traumatic tears (group II, n=26, average age 54.1 years, range 50-68 years) formed the two study groups. Mean follow-up lasted 47.1 months (range 13-105 months) in group I and 41.4 months (range 11-94 months) in group II. Assessment included postoperative shoulder function with Constant and Murley's score and visual analogue scale (VAS). RESULTS: Significantly ( p=0.0019) better results were observed in group I with an average of 94.1 points for Constant's score, compared with 75.3 points in group II. Postoperative shoulder function was not affected regarding full-thickness or partial tears ( p=0.239) in group I. VAS revealed an excellent or good result in all patients of group I ( n=20) and 50% of group II ( n=13/26). Quantitative comparison of postoperative ROM demonstrated significantly better results in forward flexion ( p=0.013), abduction ( p=0.0019) and external rotation ( p=0.0042) for group I. The remaining postoperative external rotation deficit for group II with a loss of 31% compared with group I (38.9 degrees vs 56.6 degrees ) was statistically and clinically relevant. CONCLUSION: The results demonstrate that surgical reconstruction of traumatic and non-traumatic rotator cuff tears is a successful procedure. Comparison of both groups revealed significantly better postoperative results in the younger, traumatic collective.