Faculty Bibliography

Rapidly enlarging, painful plexiform neurofibromas (PN) in neurofibromatosis type 1 (NF1) patients are at higher risk for harboring a malignant peripheral nerve sheath tumor (MPNST). Fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has been used to support more invasive diagnostic and therapeutic interventions. However, PET/CT imparts an untoward radiation hazard to this population with tumor suppressor gene impairment. The use of FDG PET coupled with magnetic resonance imaging (MRI) rather than CT is a safer alternative but its relative diagnostic sensitivity requires verification. Ten patients (6 females, 4 males, mean age 27 years, range 8-54) with NF1 and progressive PN were accrued from our institutional NF Clinic. Indications for PET scanning included increasing pain and/or progressive disability associated with an enlarging PN on serial MRIs. Following a clinically indicated whole-body FDG PET/CT, a contemporaneous PET/MRI was obtained using residual FDG activity with an average time interval of 3-4 h FDG-avid lesions were assessed for both maximum standardized uptake value (SUVmax) from PET/CT and SUVmax from PET/MR and correlation was made between the two parameters. 26 FDG avid lesions were detected on both PET/CT and PET/MR with an accuracy of 100%. SUVmax values ranged from 1.4-10.8 for PET/CT and from 0.2-5.9 for PET/MRI. SUVmax values from both modalities demonstrated positive correlation (r = 0.45, P < 0.001). PET/MRI radiation dose was significantly lower (53.35% ± 14.37% [P = 0.006]). In conclusion, PET/MRI is a feasible alternative to PET/CT in patients with NF1 when screening for the potential occurrence of MPNST. Reduction in radiation exposure approaches 50% compared to PET/CT.

Interstitial nephritis (IN) is a relatively rare entity in children and adolescents that can be caused by a range of disorders including infection, medications, inflammatory bowel disease, and sarcoid. There is no proven therapy for this condition. We present 2 cases of biopsy-proven interstitial nephritis, of which 1 case was with granulomatous features that presented with unusual sonographic findings of discrete mass lesions in the kidney parenchyma bilaterally. Although a precise cause could not be identified in either case, 1 patient progressed to end-stage kidney disease (ESKD) and the other is in the early stages of treatment. We suggest that recognition of the atypical imaging features of interstitial nephritis may enable early recognition of this condition and avoid confusion with neoplastic or infectious processes.

Purpose: Assess the impact of MR pelvic and lumbosacral neuorgraphy on ultrasound-guided pelvic perineural injections. Materials and Methods: A retrospective review of all ultrasound-guided pelvic perineural injections with prior MR pelvic and/or lumbosacral neurographic imaging over a 5-year period was performed. Demographics, presence of structural pathology on imaging, and immediate and interval pain relief was recorded. Results: 30 total injections were performed among 20 patients accounting for multiple injections in a single visit or multiple visits [mean age at injection: 52.03 (range 23-77), female (n= 24, 80%) male (n=6; 20%)]. In 24 cases a combination of steroid and anesthetic solution was administered. In the remaining 6 cases, only anesthetic solution was administered. Most commonly, injections involved the sciatic nerve (n = 21; 70%). Other injections in our series include pudendal (n=5, 16.7%), genitofemoral (n=2; 6.7%), lateral femoral cutaneous (n=1, 3.3%) and ilioinguinal (n= 1, 3.3%) nerves. Concurrent therapeutic procedures were performed in 10 cases (33%). Pre-procedure MR imaging revealed structural abnormality of the nerve or adjacent soft tissues in 11 of 22 MRIs performed amongst the 20 patients (50%). Pre-procedure ultrasound revealed structural abnormalities associated with the nerve in 9 cases of 19 cases that had complete documentation (47%). Of 26 injections with complete documentation, immediate improvement of symptoms was reported in 22 cases (85%). The remaining 4 cases either began with no pain (n=3), or reported no change in symptoms (n=1). Variable degrees of long-term symptom relief was achieved in 4 injections out of 11 steroid injections for which follow-up was available (37%). Conclusion: Ultrasound-guided perineural injections can be performed for treatment of a variety of pelvic neuropathies. MR imaging prior to sonographic intervention demonstrated an abnormality in nearly half of cases, and is a useful tool to appropriately target perineural injections

Disclosures: All authors have disclosed no financial interests, arrangements or affiliations in the context of this activity. Purpose or Case Report: Current MRI evaluation of appendicitis is limited by duration of examination and patient cooperation. The radially sampled 3D T1 weighted, gradient recalled echo sequence (radial VIBE) is a free-breathing, motion robust sequence that may prove useful in the evaluation of appendicitis in children. The purpose of this investigation is to determine the detection rate of the normal appendix with contrast enhanced (CE) radial VIBE alone compared with CE conventional 3D gradient recalled echo volumetric interpolated breath-hold examination (conventional VIBE) alone and multi-sequence abdominal pelvic MRI including CE radial VIBE. Methods& Materials:We conducted a retrospective, HIPAA compliant and IRB approved study of patients between 7 and 18 years of age who underwent an abdominal and pelvic contrast enhanced MRI between January 1, 2012 and April 1, 2016. Patients with active right lower quadrant inflammation, pelvic masses, or history of appendectomy were excluded. Visualization of the appendix was assessed by two pediatric radiologists with Certificates of Added Qualification by consensus on the following sequences: CE radial VIBE only, CE conventional VIBE only, and multi-sequence MRI which included CE radial VIBE and at least an axial or coronal single shot fast spin echo (SSFSE) or axial T2 weighted spin echo with fat suppression. The detection rates of the appendix for each sequence or combination of sequences were compared with a McNemar test. Results: Ninety-six patients met inclusion criteria. The detection rate of the normal appendix on CE radial VIBE was significantly higher than on CE conventional VIBE (76% vs 57.3%, p=0.003). The detection rate of the normal appendix with multi-sequence MRI was significantly higher than on CE conventional VIBE (81.3% vs 57%, p<0.001). There was no significant difference between the detection rate of the normal appendix on CE radial VIBE and multi-sequence MRI (76% vs 81.3%, p=0.267). When the appendix was not visualized on the CE radial VIBE (n=23) but detected on the multi-sequence MRI (n=9), it was most often visualized on SSFSE (n=8). Conclusions: CE radial VIBE allows superior detection of the normal appendix compared to CE conventional VIBE. The detection rate of the normal appendix on CE radial VIBE alone is nearly as good as when the CE radial VIBE is interpreted with additional sequences

Tuberous sclerosis (TS) is an autosomal dominant condition associated with mutations in the TSC1 and/or TSC2 genes. Clinical manifestations are multisystemic, and they often include lesions in the brain, skin, heart, kidneys, and bones. TSC2 gene mutations can be seen concomitantly with autosomal dominant polycystic kidney disease gene mutations. We present a case of a fetus with prenatal diagnosis of TS that had unique asymmetrical distribution of renal cystic disease. We describe the extensive work up with both fetal and neonatal magnetic resonance imaging with correlating images of the unilateral polycystic renal disease in addition to typical TS brain findings.

Purpose or Case Report: To evaluate the reliability of the UTD classification system Table A. Cross-tabulation of results summarizing inter-reader agreement. There are three distinct reader pairs: score 1 is the score from the arbitrarily designated first reader in each pair and score 2 is from the remaining reader in each pair. Numbers in red denote instances of disagreement. Methods &Materials: This IRB approved, retrospective study included 129 renal ultrasound examinations performed from May 2010 - May 2015 in patients less than 6 months of age for the clinical indication of prenatal hydronephrosis identified by key word search in PACS. Three pediatric radiologists independently reviewed each study for the following: anterior posterior renal pelvic diameter (APRPD), central calyceal dilation (CCD), peripheral calyceal dilation (PPD), renal parenchymal appearance (PA), renal parenchymal thickness (PT), ureteral abnormality, and bladder abnormality. Readers assigned each study a UTD category (normal, UTD P1, UTD P2, UTD P3). Inter-rater percent agreement for individual criteria and overall UTD categorization was assessed. Results: There was overall good inter-reader agreement in assessment of individual criteria (APRPKD, PA, PT, ureter, and bladder) ranging from 85.3 to 96.1% for 3 reader pairs. Inter-reader agreement for CCD and PCD was slightly lower, ranging from 69.0 to 97.7%. Inter-reader agreement for overall risk assesment ranged from 50.4 to 67.4%. Agreement across 3 readers was 48.8% for CCD, 64.3% for PCD, and 37.2% for overall risk stratification. Conclusions: The new UTD classification system is intended to guide clinical management of postnatal urinary tract dilation. For it to be widely accepted and useful, users need to apply it with precision and accuracy. Poor agreement for categorization of risk assessment among our experienced readers suggests that further clarification of the system or training for users is necessary for its optimal use in clinical practice. (Table presented)

BACKGROUND: The effect of perforated appendicitis on the adnexa is an issue of concern and controversy. Long-term fertility studies have been conflicting. CASE: We present the case of a patient with chronic pelvic infections, salpingitis, and hydrosalpinx after perforated appendicitis. SUMMARY AND CONCLUSION: Magnetic resonance imaging was helpful in diagnosing a chronically obstructed fallopian tube, likely secondary to the dense adhesions from her previously treated perforated appendicitis. Salpingectomy relieved her symptoms of chronic pain and recurrent infections.

OBJECTIVE: The purpose of this article was to assess the feasibility of golden-angle radial acquisition with compress sensing reconstruction (Golden-angle RAdial Sparse Parallel [GRASP]) for acquiring high temporal resolution data for pharmacokinetic modeling while maintaining high image quality in patients with Crohn disease terminal ileitis. MATERIALS AND METHODS: Fourteen patients with biopsy-proven Crohn terminal ileitis were scanned using both contrast-enhanced GRASP and Cartesian breath-hold (volume-interpolated breath-hold examination [VIBE]) acquisitions. GRASP data were reconstructed with 2.4-second temporal resolution and fitted to the generalized kinetic model using an individualized arterial input function to derive the volume transfer coefficient (K(trans)) and interstitial volume (ve). Reconstructions, including data from the entire GRASP acquisition and Cartesian VIBE acquisitions, were rated for image quality, artifact, and detection of typical Crohn ileitis features. RESULTS: Inflamed loops of ileum had significantly higher K(trans) (3.36 +/- 2.49 vs 0.86 +/- 0.49 min(-1), p < 0.005) and ve (0.53 +/- 0.15 vs 0.20 +/- 0.11, p < 0.005) compared with normal bowel loops. There were no significant differences between GRASP and Cartesian VIBE for overall image quality (p = 0.180) or detection of Crohn ileitis features, although streak artifact was worse with the GRASP acquisition (p = 0.001). CONCLUSION: High temporal resolution data for pharmacokinetic modeling and high spatial resolution data for morphologic image analysis can be achieved in the same acquisition using GRASP.