Abhay Srinivasan

Angioplasty for Renal Artery Stenosis in Pediatric Patients: An 11-year Retrospective Experience

PURPOSE Studies of long-term percutaneous transluminal angioplasty (PTA) results have been less extensive in children than in adults. The authors sought to evaluate the outcomes of PTA for pediatric renovascular hypertension. MATERIALS AND METHODS The authors retrospectively evaluated 19 hypertensive children (ages 2-18 years) who underwent renal PTA from 1997-2009. Angiograms were reviewed in consensus to characterize lesions. This information was correlated with data from chart review to determine clinical outcomes. RESULTS Seven patients had neurofibromatosis type 1 (NF1), and 12 had fibromuscular dysplasia (FMD); one was lost to follow-up. Technical success was achieved in 29 of 32 lesions (91%). Cure of hypertension was achieved in seven of 18 patients (39%) and improvement in three (17%). There was a failed hypertension response in eight (44%): two with refractory stenosis, four with recurrent stenosis, and two with no response despite technical success. PTA was repeated in five children, all with failed response. Cure or improvement was seen in five of seven patients with NF1 and five of 11 with FMD. Most (nine of ten) patients with cure/improvement had single lesions or discrete lesions ≤ 10 mm. Residual stenosis < 10% was associated with cure/improvement (P = .0395). Three of five with bilateral and two of two with intraparenchymal disease demonstrated failure. The percentage of initial stenosis and presence of ostial lesions, aneurysms, or collaterals were not predictive of clinical response to PTA (P > .05). Cutting balloons were used after failure to efface with conventional balloons in seven patients and was successful in five of seven. CONCLUSIONS Despite a high rate of technical success, PTA provided a clinical benefit in a smaller majority of children. This study characterizes the utility of pediatric renal angioplasty and suggests criteria that may be prognostic of patient response.

Neonatal scrotal abscess: a differential diagnostic challenge for the acute scrotum

One week after a Ladd procedure, a 21-day-old infant was noted to have an enlarging and tender left hemiscrotum (Fig. 1), with fever and elevated white blood cell count. Sonography (Fig. 2) demonstrated a heterogeneously echogenic and avascular mass occupying the hemiscrotum, with wall thickening (double-headed arrow) showing hyperemia (arrow). A normal testis was not seen, and the processus vaginalis was not patent. The spermatic cord was not twisted. The right testis was normal (arrowhead). Emergency exploration revealed a large amount of purulent material under pressure, which was drained. The testis was adherent to the scrotal wall and was viable, and the spermatic cord had no twist. Cultures demonstrated Bacteroides fragilis. Scrotal abscess is rare in the pediatric population. In most of the reported cases [1, 2], patients had recently undergone laparotomy or laparoscopy. The differential diagnosis includes missed torsion, testicular rupture from trauma, and neoplasm. In institutions where surgical

Percutaneous Treatment of Lymphatic Malformations

Lymphatic malformations are slow-flow vascular anomalies composed of dilated lymphatic channels and cysts of varying sizes. Percutaneous treatments, particularly sclerotherapy, play an important role in the treatment of these lesions, often obviating the need for surgical intervention. Owing to the complex nature of these lesions, a multidisciplinary approach should be used to guide diagnosis and management. This submission focuses on the workup and treatment of pediatric lymphatic malformations at our institution, with a focus on sclerotherapy. Therapeutic outcomes and the management of postprocedural complications are also discussed.

CT diagnosis of appendicitis in children: comparison of orthogonal planes and assessment of contrast opacification of the appendix.

Objective The aim of this study was to determine which plane is best for identification of the appendix and to assess if opacification of the appendix impacts visualization. Methods Retrospective review of 218 computed tomography examinations performed for suspected appendicitis was conducted by 2 pediatric radiologists evaluating conspicuity of the appendix depending on orthogonal plane and enteric contrast. Results Of the 180 cases in which the appendix was visualized, 154 were performed with multiplanar reformations. The best plane for identification of the appendix was coronal in 96, axial in 41, and sagittal in 17. Of the 218 computed tomography examinations, 169 had enteric contrast. The appendix was identified in 180 cases and completely opacified in 62, partially opacified in 26, without opacification in 59, and air filled in 33. Of the 38 cases in which the appendix was not identified, 29 had enteric contrast administration. In 131 of the 218 cases, the appendix was normal, and 58% demonstrated partial or complete opacification of the appendix. In 35 of the 218 cases, appendicitis was found, and there was predominantly no opacification or at most partial opacification of the appendix. Conclusions The coronal plane is best to identify the appendix. No enteric contrast is required to visualize appendicitis.

Prospective evaluation of MR overlay on real-time fluoroscopy for percutaneous extremity biopsies of bone lesions visible on MRI but not on CT in children in the interventional radiology suite

Magnetic resonance imaging (MRI) often provides better visualization of bone marrow abnormalities than computed tomography (CT) or fluoroscopy, but bone biopsies are usually performed using conventional CT or, more recently, C-arm CT guidance. Biopsies of bone lesions solely visible on MRI are often challenging to localize and require the operator to review the MRI on a separate console to correlate with MRI anatomical landmarks during the biopsy. The MR overlay technique facilitates such biopsies in the angiographic suite by allowing the pre-procedural 3-D MRI to be overlaid on intraprocedural 2-D fluoroscopy. This study describes our initial experience with the MR overlay technique in the angiography suite during pediatric percutaneous extremity bone biopsies of lesions visible on MRI but not on CT or fluoroscopy and demonstrates its utility in relevant clinical cases.

The rare solid fetal lung lesion with T2-hypointense components: prenatal imaging findings with postnatal pathological correlation

BackgroundAt fetal MR, congenital lung lesions are usually T2 hyperintense with respect to normal lung parenchyma. Some lesions, however, demonstrate unusual patterns of T2 hypointensity, sometimes in a rosette-like pattern. These lesions usually present a diagnostic conundrum.ObjectiveTo evaluate the imaging findings and pathological characterization of fetal solid lung lesions with elements showing T2-hypointense signal with respect to lung.Materials and methodsThis is a retrospective study of lung lesions with elements showing T2 hypointensity treated prenatally and postnatally at our center and with available pathological evaluation. Prenatal imaging evaluation included US and MR; postnatal evaluation consisted of pathological examination of the lesion. We also performed prenatal and postnatal chart review.ResultsSix cases met study criteria. Areas of decreased echogenicity/T2-hypointense signal were more conspicuous at MR than US. At pathology, these areas correlated with immature parenchymal development and increased mesenchymal tissue. Five of these lesions were congenital pulmonary airway malformations (CPAM); one was a congenital peribronchial myofibroblastic tumor (CPMT). The lesions did not significantly change in size after steroid administration. They were all large in volume and were associated with increased amniotic fluid. All cases of CPAM underwent premature delivery (one of them weeks after fetal surgical resection of the lesion for worsening hydrops); the fetus with CPMT was delivered at term. The neonate with CPMT succumbed shortly after birth secondary to lung hypoplasia; the remaining five neonates survived.ConclusionThe differential diagnoses of prenatal lung lesions that contain unusual T2-hypointense elements include CPAM and CPMT. The T2-hypointense areas appear to correlate with increasing degree of immaturity at histology. None of the lesions significantly changed in size after prenatal administration of steroids. All cases with CPAM lesions did well despite persistent polyhydramnios and premature birth. The single case of CPMT, however, resulted in neonatal demise shortly after birth secondary to pulmonary hypoplasia. It is important that fetal radiologists, obstetricians and fetal surgeons alike are aware of these lesions so that appropriate diagnosing and parental counseling can be reached.