Effect of direct neuroradiologist participation in physician marketing on imaging volumes in outpatient radiology.

BACKGROUND AND PURPOSE: Over the past several years, decreased demand for and increased supply of imaging services has increased competition among outpatient imaging centers in the United States. This study hypothesizes that using a radiology sales representative and neuroradiologist as a team in marketing and sales will increase imaging referrals in outpatient imaging. MATERIALS AND METHODS: From January to December 2009, baseline monthly physician referral data of CT and MR scans of 19 referring clinicians (neurologists, neurosurgeons, and anesthesiologists) to an outpatient radiology group were collected. During that time, a nonphysician radiology sales representative visited the referring clinicians' offices every 2 weeks. From January to June 2010, the same radiology sales representative visited the referring clinicians' offices every 2 weeks but was accompanied by a neuroradiologist once a month. From July 2010 to June 2011, the same radiology sales representative visited the referring clinicians' offices twice a month without a neuroradiologist. RESULTS: Cross-sectional imaging referral volumes were approximately 2.5 times greater during the 6-month period using the neuroradiologist for direct physician-to-physician marketing when compared with the volumes achieved with the sales representative alone, and continued neuroradiologist involvement in marketing and sales is required to maintain referral volumes over time. CONCLUSIONS: The impact on imaging referral volumes during the 6-month use of the neuroradiologist for direct physician-to-physician marketing in this study supports the assertion that neuroradiologist visits are an important element in establishing and maintaining a relationship with the referring clinician's office and thereby maximizing imaging referrals.

Fetal urinoma: two new cases and a review of the literature.

OBJECTIVE: To evaluate the functional prognosis of kidneys affected prenatally by urinomas. METHODS: This was a retrospective review of cases of fetal urinoma reported in the literature, as well as two of our own cases. RESULTS: Twenty-three patients with a prenatal diagnosis of urinoma (five bilateral) were included in the analysis. Postnatal ipsilateral renal function was observed in only six of the 28 renal units (i.e. around 20%). CONCLUSIONS: Although the precise causes of urinomas are still unknown, this review shows that in the event of a fetal urinoma, the probability of a non-functional dysplastic ipsilateral kidney lies at around 80%. In-utero puncture only appears to be justified in cases where fluid accumulation has mass effects on adjacent major structures.

Early intertwin differences in myocardial performance during the twin-to-twin transfusion syndrome.

BACKGROUND: In the twin-to-twin transfusion syndrome (TTTS), pressure rather than volume overload is increasingly considered as a key factor in the pathogenesis of the cardiomyopathy of the recipient twin. If this is the case, cardiac dysfunction should be among the first signs observed with TTTS. The objective of this study was to determine whether intertwin differences in myocardial function are modified early in the course of TTTS and whether they can help to differentiate this condition from intrauterine growth restriction (IUGR). METHODS AND RESULTS: Eight variables were analyzed on the first fetal echocardiography on 21 pairs of twins with TTTS and 11 with IUGR. No difference was found between the 2 groups for the cardiothoracic ratio, pulsatility indices in the umbilical and middle cerebral arteries, and peak velocity of the middle cerebral artery. Significant difference was found for ventricular septal thickness, but with no association with the conditions under study. With TTTS, left ventricular shortening fraction was consistently greater in the donor twins, and myocardial performance indices (MPIs) were elevated in the recipient twins. This increase in MPI was caused by a lengthening of the isovolumic periods compared with those of the donor twin: left ventricular and right ventricular isovolumic periods 0.105+/-0.047 and 0.097+/-0.026 seconds, respectively, for the recipient twins versus 0.0561+/-0.46 and 0.065+/-0.03 seconds, respectively, for the donor twins (P<0.001). These changes in the isovolumic periods were mainly due to significant prolongation of isovolumic relaxation times. A change in left ventricular MPI > or =0.09 combined with a change in right ventricular MPI > or =0.05 would identify a TTTS with a sensitivity of 75% and a false-positive rate of 9%. CONCLUSIONS: The observed diastolic function impairment goes along with the pressure-overload pathogenic concept proposed in TTTS. Assessment of intertwin difference in MPI is a valuable tool for early differential diagnosis between TTTS and isolated IUGR.

[Ultrasonography of twin pregnancies]. / Echographie des grossesses gémellaires.

Sonographers must be familiar with the diagnostic tools available to them for determining twin pregnancy type. During the first trimester, these tools include the number of chorionic sacs, the number of yolk sacs, and the presence of an inter-twin membrane. During the second trimester, sonographers must look for a difference in sex, the presence of two separate placentas, and a thick vs. thin membrane, or the absence of a membrane. Complications are frequent in twin pregnancies and may be maternal or fetal. Measuring cervical length is the only way for sonographers to predict pre-term labour. A cervical length of< or =2.5 cm before 23 weeks is significant. Some fetal anomalies are more frequent in twin pregnancy than in single pregnancy. The more frequent are: esophageal atresia, omphalocele and cardiac anomalies. Some fetal anomalies are peculiar to twin pregnancy: Siamese twins, digestive atresia, craniofacial deformation and club-foot. A significant growth asymmetry is defined as a CRL of 3 or more millimetres and a difference of 20% in weight. The poly-oligo sequence represents a severe level asymmetry of amniotic fluid in monodiamniotic twins where survival rate without sequelae is 13.6%. The twin-twin transfusion syndrome is an event occurring after the apparition of the poly-oligo sequence, which manifests by discordances in weight and hemodynamic changes leading to myocardial repercussion. Twin embolization syndrome follows the in utero death of a co-twin in a monochorionic twin pregnancy; ischemic events must be monitored in such cases. Cord entanglement is unpredictable and is specific to monochorionic monoamniotic twin pregnancies. Finally, an acardius is a parasitic twin that feeds on its co-twin, resulting in the viable twin's death in 50% of cases.

US of the pediatric female pelvis: a clinical perspective.

When investigating pelvic pathologic conditions in female pediatric patients, one needs to be aware of the developmental changes that take place around puberty. The prepubertal uterus is thin, with a fundus equal in size to the cervix. Owing to the hormonal stimulation of puberty, the uterus enlarges and the fundus becomes prominent. The ovaries are demonstrated with ultrasonography (US) at all ages. Ovarian volume increases after 6 years of age. Microcystic follicles are normally seen throughout childhood. US is the modality of choice for imaging the pediatric female pelvis. The main indications for pelvic US in the pediatric age group are pubertal precocity or pubertal delay, pelvic pain or pelvic masses, and ambiguous genitalia. Vaginal bleeding in the prepubertal child can be due to a vaginal foreign body, vaginal rhabdomyosarcoma, or precocious puberty. Common causes of primary amenorrhea in teenagers include gonadal dysgenesis (Turner syndrome) and müllerian (uterovaginal) anomalies. Pelvic pain or pelvic masses in pediatric patients can be due to ovarian torsion, hemorrhagic ovarian cyst, pelvic inflammatory disease, or ectopic pregnancy.

Reference values for differences between cardio-circulatory variables of normal twin fetuses.

BACKGROUND: No reference values exist concerning the differences between cardio-circulatory variables of normal twin fetuses. The normal data could be useful in the identification of conditions causing opposite hemodynamic effects on each twin. OBJECTIVE: To establish the normal differences among cardio-circulatory parameters of twin fetuses during the second and third trimesters of gestation. MATERIALS AND METHODS: Twenty-seven normal twin pregnancies were used in this longitudinal and prospective study. Doppler-echocardiographic investigations were performed every 2-3 weeks starting at an average of 23.11 +/- 3.13 (mean +/- standard deviation) weeks' gestation. At each visit, the following cardio-circulatory variables were evaluated: the cardio-thoracic ratio, the ventricular wall and septal thicknesses, end-diastolic and systolic diameters, ventricular fractional shortenings, velocity of circumferential fibre shortenings and left and right ventricular outputs. In addition the following measurements were made from Doppler recordings: through both aortic and pulmonary valve the acceleration and ejection times, the peak systolic velocities and the velocity time integrals; and through both mitral and tricuspid valves peak velocities of E and A waves and the E/A ratios. Finally the pulsatility index of the umbilical artery was also evaluated. RESULTS: There was no single variable where the intertwin difference changed with gestational age. No systematic difference between the smaller and larger twin could be demonstrated for any variables except for the cardio-thoracic ratio. CONCLUSION: Reference tables should permit a comparative approach between the two twins in the investigation of life threatening complications such as twin-to-twin transfusion syndrome.

Preoperative manual detorsion of the spermatic cord with Doppler ultrasound monitoring in patients with intravaginal acute testicular torsion.

OBJECTIVE: To assess the effectiveness of preoperative manual detorsion in acute testicular torsion. MATERIALS AND METHODS: Between June 1998 and March 1999, seven patients presenting with testicular torsion underwent manual manipulation under US monitoring in order to restore the flow to the testis prior to surgery (orchidopexy). All detorsions were lateral in direction. The success of the manoeuvre was assessed both clinically and sonographically and confirmed at surgery. RESULTS: Six manoeuvres were successful in restoring flow to the testis. The failed attempt in the seventh patient was due to failure to manipulate beyond an initial 1 1/2 rotations (540 degrees). CONCLUSIONS: Preoperative detorsion is the fastest way to relieve testicular ischaemia. However, manual detorsion of the spermatic cord is not a substitute for surgical exploration and bilateral orchidopexy is still necessary.

Prognostic markers in twin pregnancies with an acardiac fetus.

OBJECTIVE: With twin reversed arterial perfusion sequence, the normal cotwin is at risk of heart failure. The purpose of this study was to identify ultrasonographic variables that can help predict prognosis. We hypothesized that variables reflecting the hyperdynamic circulatory condition of the normal fetus and the changes in circulatory impedance in the acardiac mass would correlate with final outcome. METHODS: Ten twin pregnancies with this condition were identified. Follow-up was available for nine. Adverse outcome was defined as death, cardiac failure, or delivery before 30 weeks' gestation for reasons related to the presence of the mass. The following data were collected on the normal fetus: cardiothoracic ratio and left ventricular shortening fraction; and on the mass: maximal length, presence and size of cysts, and presence of a rudimentary heart. The pulsatility index (PI) of the umbilical arteries (UA) of both twins was measured. RESULTS: Four fetuses died, two in utero (22 weeks) and two after cesarean (26 and 31 weeks) for advanced cardiac failure. In the five other cases, the outcome was favorable. The cardiothoracic ratio and presence of cysts or of a rudimentary heart did not correlate with outcome. A PI in the mass' UA significantly lower than that of the normal twin (ratio of 0.71 compared with 1.04 for good outcome, P<.05), an elevated shortening fraction in the second trimester, and a rapid growth rate of the mass were associated with a poor prognosis. CONCLUSION: In pregnancies with twin reversed arterial perfusion sequence, final outcome and treatment decisions can be determined based on hemodynamic criteria.

Soft-tissue venous malformations in pediatric and young adult patients: diagnosis with Doppler US.

PURPOSE: To describe the diagnostic features, appearance, and vascularization pattern of venous malformations (VMs) at Doppler ultrasonography (US). MATERIALS AND METHODS: Between February 1991 and May 1997, 51 soft-tissue VMs were studied with Doppler US in patients between 1 day and 21 years of age (mean age, 9 years). These VMs were located in the maxillofacial region (n = 19), trunk (n = 5), and upper (n = 10) and lower (n = 17) extremities. Twenty-three VMs had venographic confirmation, seven had only histologic confirmation, and 21 had both venographic and histologic confirmation. US was performed with 7.5- or 7-10-MHz linear transducers, a low pulse repetition frequency (mean, 1,680 Hz), and the lowest wall filter (25-50 Hz). RESULTS: At gray-scale US, VMs appeared as hypoechoic, heterogeneous lesions in 82% of cases. All lesions displayed compressibility. In eight lesions (16%), phleboliths were identified, thus confirming the diagnosis of VM. Analysis of vascular flow revealed monophasic, low-velocity flow in 40 VMs (78%), with an average flow velocity of 0.22 kHz. Biphasic flow was noted at the periphery of three lesions, which is indicative of a mixed capillary-venous malformation. The remaining eight lesions did not display any flow. CONCLUSION: In pediatric patients, Doppler US is a noninvasive, easily available, and rapid mode of investigation of vascular lesions and can help confirm the diagnosis of VM when it shows a characteristic flow pattern.

Pyruvate carboxylase deficiency: prenatal onset of ischemia-like brain lesions in two sibs with the acute neonatal form.

Pyruvate carboxylase (PC) is a key enzyme in the gluconeogenesis and anaplerotic metabolic pathways. PC deficiency is a rare autosomal recessive disorder with three clinical presentations: an infantile form, a severe neonatal form, and a benign form. We report brother and sister sibs with the severe form of PC deficiency. Both had macrocephaly and severe ischemia-like brain lesions at birth and died in the first week of life with intractable lactic acidemia. In the girl, increased head circumference and periventricular leukomalacia (PVL) were detected on fetal ultrasonography at 29.4 weeks of gestation. PC activity in cultured skin fibroblasts was <2% of control. This is the first reported case of ischemia-like brain lesions documented prenatally in PC deficiency. The lesions were detected at a time of maximal periventricular metabolic demand. We postulate that energy deprivation induced by PC deficiency impairs astrocytic buffering capacity against excitotoxic insult and compromises normal microvascular morphogenesis and autoregulation, both mechanisms leading to cystic degeneration of the periventricular white matter. Discovery of cystic PVL on cerebral ultrasound at birth in a newborn infant presenting with primary lactic acidemia is highly suggestive of PC deficiency. Moreover, PC deficiency should also be considered when ischemia-like brain lesions are documented by fetal ultrasonography.

Liver disease in children with cystic fibrosis: US-biochemical comparison in 195 patients.

PURPOSE: To determine if abnormal liver architecture at ultrasonography (US) is related to abnormal function in children with cystic fibrosis (CF). MATERIALS AND METHODS: For 1 year, all 195 children (112 boys, 83 girls; mean age, 8.5 years) attending a CF clinic underwent abdominal US and a standard set of liver function tests. Aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyltransferase levels were analyzed. US signs were interpreted as follows: hypoechogenicity with prominent portal tracks as edema, hyperechogenicity as steatosis, and increased attenuation and nodules within or at the edge of the liver as cirrhosis. Signs of portal hypertension also were sought. US signs were compared with liver function test results. RESULTS: Liver sonograms were abnormal in 38 children (19%); of these, 24 (63%) had abnormal test results. The 157 children with normal liver architecture had a much lower prevalence of biochemical abnormality (33 patients [21%]; P < or = .001). All eight children with signs of portal hypertension had abnormal test results. Fourteen (82%) of 17 children with signs of cirrhosis had abnormal liver function. Eight (57%) of 14 patients with signs of steatosis had abnormal function. Diffuse hypoechogenicity of the liver with prominent portal tracks in 16 patients was associated with abnormal function in only five patients. CONCLUSION: The relation between abnormal liver architecture at US and results of three liver function tests in children with CF was significant. The most specific US abnormalities related to abnormal function are signs suggestive of portal hypertension and cirrhosis.

Incidence and risk factors of catheter-related deep vein thrombosis in a pediatric intensive care unit: a prospective study.

OBJECTIVE: To estimate the incidence and to characterize risk factors for central venous catheter (CVC)-related deep vein thrombosis (DVT) in a pediatric intensive care unit. STUDY DESIGN: Consecutive children admitted to a pediatric intensive care unit who required a CVC for more than 48 hours were examined by Doppler ultrasonography of the catheterized vein at days 2, 4, 6, or 7 after insertion and weekly thereafter until CVC removal. RESULTS: The incidence of CVC-related DVT was 18.3% (17 of 93) (95% confidence interval = 10.2% to 25.8%). Thromboses were diagnosed within the first 4 days of catheter placement for 15 of 17 CVC-related thromboses. Multivariate analysis showed that risk factors most predictive of CVC-related DVT were presence of a cancer (odds ratio = 17.23, 95% confidence interval = 1.5 to 194) and young age (odds ratio for age = 0.72, 95% confidence interval = 0.54 to 0.96). CONCLUSION: The frequency of CVC-related DVT is substantial in pediatric intensive care units. Risk is highest during the 4 days after insertion and decreases thereafter. The clinical impact, optimal prevention, and therapy of these thromboses remain to be determined.

Soft-tissue hemangiomas in infants and children: diagnosis using Doppler sonography.

OBJECTIVE: We describe the sonographic appearance and vascularization of hemangiomas and determine if vessel density and peak systolic Doppler shifts distinguish hemangiomas from other superficial soft-tissue masses. SUBJECTS AND METHODS: Our pilot study included 20 infants and children with hemangiomas who were to undergo biopsy before treatment with interferon alpha-2b. We used Doppler sonography to determine the number of vessels per square centimeter, peak arterial Doppler shift, resistive index, and signs of arteriovenous shunting. All hemangiomas showed high vessel density (more than five per square centimeter) and high Doppler shifts (more than 2 kHz), and these two factors became our diagnostic criteria. A prospective study of 116 patients was then carried out. One hundred sixteen consecutive pediatric patients with superficial soft-tissue masses were examined using Doppler sonography; sonographic findings were compared with the final diagnoses that were established by biopsy, CT, or clinical follow-up. RESULTS: The final diagnoses included 70 hemangiomas, 20 venous malformations, three arteriovenous malformations, three arteriolocapillary malformations, and 20 other masses. Fifty-nine lesions showing high vessel density (more than five per square centimeter) and a peak arterial Doppler shift exceeding 2 kHz were correctly diagnosed as hemangiomas (sensitivity, 84%; specificity, 98%). One arteriovenous malformation showed high vessel density and high Doppler shifts, but none of the other masses that were not hemangiomas did. Eleven patients with hemangiomas who were being treated with interferon at the time of the study fulfilled only one of the two diagnostic criteria. CONCLUSION: High vessel density and high peak arterial Doppler shift can be used to distinguish hemangiomas from other soft-tissue masses.

[Diagnostic prenatal ultrasonography of malformations of the fetal anterior abdominal wall]. / Diagnostic échographique anténatal des malformations de la paroi anterieure du foetus.

Abdominal wall defects include a broad spectrum of structural malformations with variable severity and prognosis. The purpose of prenatal ultrasound examination is to correctly diagnose and classify these malformations according to their localization (particularly their relation to the umbilical cord insertion), their contents, their size and associated malformations or karyotypic abnormalities. Based on this examination, two groups can be distinguished: gastroschisis or omphalocele (when the latter is isolated, in particular without karyotypic abnormalities) which can be surgically corrected at birth, and for which predictive criteria of outcome must be evaluated (vitality of herniated bowel, size and contents of omphalocele); severe malformations (ectopia cordis, cloacal exstrophy, Beckwith-Wiedemann syndrome, short umbilical cord, amniotic band syndrome) for which pregnancy termination could be proposed.

Pancreatic injury in the hemolytic-uremic syndrome.

In a retrospective review of 241 cases with hemolytic-uremic syndrome, there was evidence of pancreatic involvement in 2 patients, abnormal ultrasounds in 4 patients, and pancreatic injury in 3 of 8 patients undergoing autopsy. Pancreas ultrasound examination, available in 134 cases, was very valuable in identifying those with pancreatic injury.

Potential value of fetal echocardiography in the differential diagnosis of twin pregnancy with presence of polyhydramnios-oligohydramnios syndrome.

OBJECTIVE: Our purpose was to establish whether index values of cardiac performance could discriminate between the twin-twin transfusion syndrome and placental insufficiency as the etiology of the polyhydramnios-oligohydramnios sequence in monochorionic diamniotic twins. STUDY DESIGN: Thirteen monochorionic diamniotic twin pregnancies with ultrasonographic evidence of polyhydramnios-oligohydramnios sequence had a complete echocardiography. The etiology was confirmed postnatally: placental insufficiency in eight pairs and the twin-twin transfusion syndrome in five. Intertwin comparisons were made for the following cardiac parameters: cardiothoracic index, end-diastolic thickness of the ventricular walls and septum, aortic and pulmonary artery Doppler peak velocities, ejection and acceleration times, left ventricular shortening fraction, and combined cardiac output and output indexed to fetal weight. RESULTS: All five recipient twins had thickened ventricular walls. The left ventricular shortening fractions and outputs were significantly increased in the donor twin with twin-twin transfusion syndrome and normal in placental insufficiency. CONCLUSION: In twin-twin transfusion syndrome the donor twin shows evidence of a hyperdynamic cardiac state. Intertwin comparison of cardiac parameters, especially the left ventricular shortening fraction, can be considered a useful tool in diagnosing the different etiologies of the polyhydramnios-oligohydraminos sequence.

Liver transplantation: review of the literature. Part 2: Vascular and biliary complications.

The first attempted human orthotopic liver transplantation, in 1963, involved a child with biliary atresia, who died on the operating table as a result of uncontrollable coagulopathy. Improvements in immunosuppression, surgical technique, medical imaging and postoperative care, as well as more stringent patient selection, have allowed the development of liver transplantation and its universal acceptance as the treatment for a variety of liver diseases. The radiologist plays a major role in the multidisciplinary transplantation team and must be familiar with each stage of orthotopic liver transplantation and its associated complications. In the first article of this series (Can Assoc Radiol J 1997;48[3]:171-178), the authors reviewed the anatomic features and current concepts relevant to orthotopic topic liver transplantation. In this, the second article, they discuss the vascular and biliary complications of the operation, and the third article will cover the medical complications.

Liver transplantation: review of the literature. Part 1: Anatomic features and current concepts.

The first attempted human orthotopic liver transplantation, in 1963, involved a child with biliary atresia, who died on the operating table as a result of uncontrollable coagulopathy. Improvements in immunosuppression, surgical technique, medical imaging and postoperative care, as well as more stringent patient selection, have allowed the development of liver transplantation and its universal acceptance as the treatment for a variety of liver diseases. The radiologist plays a major role in the multidisciplinary transplantation team and must be familiar with each stage of orthotopic liver transplantation and its associated complications. In the first article of this series, the author reviews the anatomic features and current concepts relevant to orthotopic liver transplantation. Future articles will discuss the vascular, biliary and medical complications of the operation.

Echogenic dilated bowel loops before 21 weeks' gestation: a new entity.

OBJECTIVE: The purpose of this study was to determine the outcome at birth for fetuses in which echogenic dilated bowel loops (EDBL) are detected before 21 weeks of gestation. MATERIALS AND METHODS: A retrospective study was undertaken of 45 patients with EDBL. Sonographic criteria included dilated bowel with an echogenic wall. EDBL was divided into two categories: the isolated and the complex (associated with other abnormalities). When the EDBL affected only one quadrant of the fetal abdomen, it was referred to as the local form, and when it was observed in more than one quadrant, it was termed the diffuse form. RESULTS: Intestinal dilatation of 2-8 mm was revealed on sonography in 21 fetuses with the isolated form of EDBL. Follow-up sonography showed resolution of EDBL in 20 cases. The outcome at birth was normal in 19 (90%) cases. The 20th fetus was born with jejunal atresia, and the remaining fetus died after cordocentesis. Twenty-four fetuses with the complex form of EDBL also had intestinal dilatation of 2-8 mm shown on sonography. Nine (38%) of these fetuses were born alive: six had gastroschisis; two had meconium peritonitis; and one had vertebral defects, imperforate anus, tracheoesophageal fistula, and radial and renal dysplasia (VATER). In these cases, resolution of EDBL was noticed at sonographic follow-up. Fourteen (58%) of the 24 fetuses were aborted. The remaining fetus died after amniocentesis. The incidence of normalcy is comparable in both local and diffuse dilatation. Amniocentesis was performed in 15 cases. Disaccharidase activity was measured in 13 patients. Low disaccharidase activity was detected in 10 (77%) of 13 cases. We saw cystic fibrosis in none of the 45 fetuses. Infection was detected before and at birth in five (11%) cases. CONCLUSION: EDBL is a new entity that is most likely related to temporary obstruction. A fetus with the isolated form has a good prognosis, whereas a fetus with the complex form has an outcome directly related to the severity of associated abnormalities.