Sergio Baldari

Reversible cerebral perfusion alterations in children with transient mutism after posterior fossa surgery

Abstract Mutism is an infrequent and transitory complication observed following posterior fossa surgery. Patients become mute in the immediate postoperative period, with restoration of speech within a few weeks in the absence of additional neurological alterations. The anatomical structures thought to be involved are the connections between the cerebellar dentate nucleus, the ventrolateral nucleus of the contralateral thalamus and the supplementary motor area. In an attempt to understand the pathophysiology of this syndrome, and to depict the perfusion of different brain areas semiquantitatively, in two children who had become mute after posterior fossa surgery we performed a Tc99M-HM-PAO SPECT study during the period of mutism and again when normal speech had returned. In one patient, who had a left cerebellar astrocytoma, the SPECT study showed a marked reduction of cerebral perfusion in the right fronto-parietal region, and in the other, who had a medulloblastoma, a left fronto-temporo-parietal perfusion alteration was observed. When the patients regained normal speech, the follow-up SPECT studies revealed normalization of the cerebral perfusion. This study demonstrates the occurrence of a focal dysfunction of cerebral perfusion in children with cerebellar mutism after posterior fossa surgery. These observations are useful in extending our understanding of the pathophysiology of this postoperative clinical syndrome.

Pediatric bone sarcoma: diagnostic performance of ¹⁸F-FDG PET/CT versus conventional imaging for initial staging and follow-up

OBJECTIVE The purpose of this study was to compare the diagnostic performance of (18)F-FDG PET/CT and conventional imaging for staging and follow-up of pediatric osteosarcoma and skeletal Ewing sarcoma. MATERIALS AND METHODS We calculated sensitivity, specificity, and accuracy of PET/CT and conventional imaging (CT, MRI, bone scanning) for sites of disease and number of lesions. Diagnostic benefit, defined as better characterization of lesions, was evaluated on a per-scan basis, comparing PET/CT and conventional imaging. RESULTS A total of 412 lesions were characterized by imaging in 64 patients (20, osteosarcoma; 44, Ewing sarcoma). For osteosarcoma patients PET/CT was available only at follow-up, where it proved more accurate than conventional imaging for the detection of bone lesions (accuracy, 95% vs 67% for CT and 86% for MRI) and complementary to CT in evaluating lung nodules (sensitivity, 84% vs 94%; specificity, 79% vs 71%) with diagnostic benefit in 18% of examinations. In patients with Ewing sarcoma, PET/CT tended to perform better during follow-up than at initial staging (accuracy, 85% vs 69%). For lung findings, PET/CT was more specific than CT but was less sensitive. The diagnostic benefit of PET/CT was greater at staging (28%) than during followup (9%). On a per-patient basis, PET/CT provided diagnostic benefit in 21 of 44 patients with Ewing sarcoma and nine of 20 patients with osteosarcoma at least once during clinical management. CONCLUSION FDG PET/CT provides diagnostic benefit in Ewing sarcoma and osteosarcoma, with the exception of small lung nodules. Prospective studies are needed to define the best imaging algorithm and combination of tests in the staging and follow-up of patients with pediatric bone sarcoma.

Comparison Between 99mTc-Diphosphonate Imaging and MRI With Late Gadolinium Enhancement in Evaluating Cardiac Involvement in Patients With Transthyretin Familial Amyloid Polyneuropathy

OBJECTIVE Cardiac involvement is not rare in systemic amyloidosis and is associated with poor prognosis. Both (99m)Tc-diphosphonate imaging and cardiac MRI with late gadolinium enhancement are considered valuable tools in revealing amyloid deposition in the myocardium; however, to our knowledge, no comparative study between the two techniques exists. We compared findings of these two techniques in patients with transthyretin-familial amyloid polyneuropathy (FAP). SUBJECTS AND METHODS Eighteen patients with transthyretin-FAP underwent (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement. Images were visually evaluated by independent readers to determine the presence of radiotracer accumulation or late gadolinium enhancement-positive areas at the level of cardiac chambers. RESULTS Interobserver agreement ranged from moderate to very good for (99m)Tc-diphosphonate imaging findings and was very good for findings of MRI with late gadolinium enhancement. Left ventricle (LV) radiotracer uptake was found in 10 of 18 patients, whereas LV late gadolinium enhancement-positive areas were found in eight of 18 patients (χ(2) = 0.9; p = 0.343). One hundred fifty-nine LV segments showed (99m)Tc-diphosphonate accumulation, and 57 LV segments were late gadolinium enhancement positive (p < 0.0001). Radiotracer uptake was found in the right ventricle (RV) in eight patients and in both atria in five patients, whereas MRI showed that RV was involved in three patients and both atria in six patients; the differences were not statistically significant (RV, p = 0.07; atria, p = 1). Intermodality agreement between (99m)Tc-diphosphonate imaging and MRI ranged from fair to good. CONCLUSION Our study shows that, although (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement have similar capabilities to identify patients with myocardial amyloid deposition, cardiac amyloid infiltration burden can be significantly underestimated by visual analysis of MRI with late gadolinium enhancement compared with (99m)Tc-diphosphonate imaging.

Gastrointestinal sequelae in survivors of congenital diaphragmatic hernia

Background: Gastrointestinal sequelae have been sporadically reported in survivors of congenital diaphragmatic hernia (CDH). The aim of the present paper was to evaluate the gastrointestinal morbidity in infant, adolescent and adult patients who had undergone repair of CDH.

Vesicoureteral reflux: comparison between urosonography and radionuclide cystography

Our aim was to compare contrast-enhanced color Doppler voiding urosonography (VUS) and direct radionuclide voiding cystography (DRVC) to determine the usefulness of ultrasonography (US) in the detection and grading of vesicoureteral reflux (VUR). In this study, the two techniques were performed simultaneously on a group of 64 children referred for the evaluation of VUR. DRVC detected VUR in 54/128 ureterorenal units, and VUS confirmed reflux in 44 (81%). Only in two cases was the reflux not confirmed by DRVC (97% specificity). Ten units with minimal grade I VUR detected by DRVC were not identified by VUS. For identification of grade II and III reflux, sensitivity of VUS reached 100%. Ten units with grade I VUR at DRVC presented grade II at VUS. Eleven units with grade II VUR at DRVC presented grade III at VUS. In conclusion, contrast-enhanced VUS is a useful diagnostic tool for the detection of VUR in children. Our data suggest a higher diagnostic accuracy of urosonography compared to radionuclide cystography in the determination of the grade of VUR; this may have significant consequences on the management of young patients affected by VUR.

What is New on Thyroid Cancer Biomarkers

Thyroid cancer harbours in about 5% of thyroid nodules. The majority of them are well-differentiated cancers originating from the follicular epithelium, and are subdivided into papillary and follicular carcinomas. Undifferentiated carcinomas and medullary thyroid carcinomas arising from C cells are less common. Although most thyroid nodules are benign, distinguishing thyroid cancer from benign lesions is crucial for an appropriate treatment and follow-up. The fine needle aspiration cytology (FNAC) allows the diagnosis of nature of thyroid nodules in the majority of cases. However, FNAC has some limitations, particularly in the presence of follicular lesions which can appear dubious in rare instances even at histology. In an effort to improve diagnostic accuracy and offer new prognostic criteria, several immunohistochemical and molecular markers have been proposed. However, most of them have to be validated on large series before being used in routine practice.

Can Neutrophil Gelatinase–associated Lipocalin Help Depict Early Contrast Material–induced Nephropathy?

PURPOSE To evaluate the utility of serum and urinary neutrophil gelatinase-associated lipocalin (NGAL) in depicting an event of contrast material-induced nephropathy (CIN) in patients who received iodinated contrast media, gadoterate meglumine, or radiopharmaceutical technetium-99m ((99m)Tc) and to evaluate the protective effect exerted by isotonic saline infusion, sodium bicarbonate administration, or N-acetylcysteine administration. MATERIALS AND METHODS Institutional ethics committee approval was given, and informed consent was obtained. One hundred twenty patients were enrolled in a prospective study and divided into three groups: iomeprol group, magnetic resonance (MR) imaging group (gadoterate meglumine), and renal scintigraphy group ((99m)Tc). They randomly received N-acetylcysteine, physiologic saline, or sodium bicarbonate. Receiver operating characteristic (ROC) analysis, Kaplan-Meier curves, and Cox proportional hazard regression analysis were used. RESULTS In the MR imaging and renal scintigraphy groups, there were significant changes in serum creatinine and NGAL levels, and there were no cases of CIN. In the iomeprol group, an early rise in NGAL was found, while serum creatinine level changes occurred 24 hours after contrast material administration. At ROC analysis, NGAL showed high sensitivity and specificity (serum NGAL: area under the curve, 0.995; 95% confidence interval [CI]: 0.868, 0.992; urinary NGAL: area under the curve, 0.992; 95% CI: 0.925, 1.000) in identifying CIN 8 hours after iomeprol administration. Regression analysis showed that NGAL independently predicted CIN. Administration of N-acetylcysteine, sodium bicarbonate, or physiologic saline did not influence NGAL level. CONCLUSION NGAL depicted CIN in patients who received iodinated contrast material within 8 hours of contrast material administration. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120578/-/DC1.

Long-term follow up of neonatally diagnosed primary megaureter: rate and predictors of spontaneous resolution

Abstract Objective. Primary megaureter (PM) represents 6–10% of all antenatal displaced urinary malformations. Spontaneous resolution of PM is a well-known event. This long-term follow-up study evaluated the incidence and rate of resolution of PM. Some predictive factors were revised, based on morphological classification and scintigraphic pattern. Material and methods. Sixty neonates with PM were followed. The diagnosis was confirmed by ultrasound examination and 99mTc-DTPA diuretic renal scan. All the observed patients underwent antibiotic prophylaxis. All conservatively treated children were followed from 6 months to 15 years. Follow-up consisted of monthly urine cultures, renal ultrasound and DTPA diuretic renography. Hydroureteronephrosis was considered to have resolved when a retrovesical cross-sectional diameter of ureter less than 6 mm was found. Results. In total, 72 PM were identified in this series. At the end of the follow-up period, 38 PM (52.8%) had resolved, in 18 PM (25%) ureteral dilatation persisted and 16 PM (22.2%) required a surgical procedure. The median age at resolution was significantly affected by presenting hydronephrosis grade and cross-sectional diameter at diagnosis, but not by gender. The 99mTc-DTPA renogram results showed no functional impairment in resolved and persisting cases, even after long-term observation. Conclusions. The data show that 22% of neonatal PM require surgical treatment. Poor drainage on 99mTc-DTPA scan, grade IV–V hydronephrosis and ureteric diameter more than 15.0 mm were statistically significant and independent predictive factors for surgery. The time to spontaneous resolution in neonatally diagnosed PM may exceed 3.6 years, after which recovery is rare.

Transcranial Doppler Ultrasonography in the Assessment of Cerebral Circulation Arrest: Improving Sensitivity by Trancervical and Transorbital Carotid Insonation and Serial Examinations

IntroductionTranscranial Doppler (TCD) can detect the cerebral circulation arrest (CCA) in brain death. TCD is highly specific, but less sensitive because of false-negatives accounting for up to 10%. The aim of the study was to explore the diagnostic accuracy of TCD and to determine whether it can be augmented by strategies such as the insonation of the extracranial internal carotid artery (ICA) and sequential examinations.MethodsData of 184 patients, who met clinical criteria of brain death, observed from 1998 through 2006, were retrospectively reviewed. The study of cerebral arteries was performed through the transtemporal approach, suboccipital insonation of the vertebro-basilar system, transorbital insonation of the ICA and ophthalmic artery, and transcervical insonation of the extracranial ICA. Repeated exams were performed in cases of persistent diastolic flow.ResultsThe specificity of the testing was 100%, no false-positive cases were recorded. The sensitivity of conventional TCD examination was 82.1%. The insonation of the extracranial ICA increased sensitivity to 88% allowing the detection of CCA in those patients lacking temporal windows; serial examinations further increased sensitivity to 95.6%.ConclusionsThe addition of insonation of the cervical ICA and of the siphon increased sensitivity of TCD. Nevertheless, a CCA flow patterns may appear later on those segments. Serial examinations, may be needed in those cases.

Transthyretin‐related familial amyloidotic polyneuropathy: description of a cohort of patients with Leu64 mutation and late onset

Transthyretin‐related familial amyloidotic polyneuropathy (TTR‐FAP) usually presents itself as a progressive sensorimotor polyneuropathy with severe autonomic dysfunction and cardiomyopathy. Eighteen patients carrying the Leu64 mutation underwent a series of regular follow‐ups, including: neurological examination, electroneurography, electromyography, electrocardiography and echocardiography, blood analysis, a questionnaire on autonomic symptoms, cardiovascular autonomic tests and a 99mTc‐DPD examination study. A late onset of a slowly progressive disease which reached its terminal stage after about 10  years was observed. The onset was mainly a length‐dependent sensory neuropathy, although a focal onset with carpal tunnel syndrome was detected in three patients. At the onset of the disease, autonomic dysfunction was present in a small number of patients, but, within a few years, this had manifested in all members of the sample group. The only extra‐neurological manifestations were cardiac related. It is reasonable to consider Southern Italy as an endemic focus of TTR‐FAP. An underestimation of disease prevalence could be caused by a late onset of FAP, which can manifest in patients up to their late 70s. Follow‐up of asymptomatic individuals may permit the early detection of symptoms and signs, allowing a detailed record of the natural history of the disease from the beginning and facilitating prompt treatment.