Doppler US in patients with crohn disease: vessel density in the diseased bowel reflects disease activity.

PURPOSE: To determine if neovascularization associated with Crohn disease, as detected with Doppler ultrasonography (US), reflects clinical disease activity. MATERIALS AND METHODS: A devised measurement, vessel density, was estimated with color Doppler US. Patients with Crohn disease underwent clinical and laboratory assessment in which the Crohn disease activity index was measured; patients underwent abdominal US the same week. Color Doppler US was performed by using a 7.5-10.0- or 8.0-12.0-MHz transducer, the lowest possible pulse repetition frequency without aliasing, a low wall filter, and high Doppler gain settings. The length and thickness of the affected loops were measured, and the number of color Doppler signals per square centimeter in the bowel loop was counted. Pulsed Doppler US was used to confirm that the signals originated from arteries or veins and not from movement artifacts. RESULTS: Ninety-two patients (aged 7-20 years; mean, 14.85 years; 44 female, 48 male) underwent 119 examinations; 85 were performed in patients with active disease. Affected loops were thicker (10.6 vs 4. 6 mm; P: <.001) and had a higher vessel density with disease (69 of 119 examinations) than during remission (two of 34 examinations; P: <.001). CONCLUSION: Vessel density in affected bowel loops, as estimated with Doppler US, and bowel wall thickness (>5 mm) reflect disease activity in patients with Crohn disease.

Doppler sonography of head and neck masses in children.

This article presents a clinical approach to the investigation of a child with a mass of the head or neck. The anatomy of the head and neck region is reviewed, and the technique of Doppler sonography in children is outlined. The pathology and the sonographic appearance of common head and neck masses specific to children are described.

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.

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.

The kidney in children with tyrosinemia: sonographic, CT and biochemical findings.

BACKGROUND: Tyrosinemia relates to a deficiency of fumarylacetoacetate hydrolase and presents early in life with central nervous system and liver abnormalities. Renal function is often impaired. Little is known about the architecture and function of the kidneys. OBJECTIVE: Imaging changes on US and CT are compared to the function of the kidneys in children with tyrosinemia, and followed after liver transplantation. MATERIALS AND METHODS: Renal sonography, CT and renal function tests in 32 children were reviewed. Renal length, volume, echogenicity and nephrocalcinosis were evaluated. Renal function was assessed by glomerular filtration rate, and the presence of aminoaciduria, acidosis and calciuria. Seventeen children had open renal biopsy during time of liver transplantation. Histology was reviewed. Statistical analyses relating renal structure to function were performed, and repeated after transplantation. RESULTS: The kidneys were enlarged (47 %), hyperechogenic (47 %) and showed nephrocalcinosis (16 %). There was delayed excretion of contrast medium at CT in 64 %. Aminoaciduria was present in 82 % of children, hypercalciuria in 67 %, tubular acidosis in 59 %, and low GFR in 48 %. Delayed excretion of contrast was associated with low GFR (P < 0.05). Renal biopsies showed dilated tubules (81 %), interstitial fibrosis (56 %), glomerulosclerosis (56 %) and tubular atrophy (56 %). During a mean observation period of 3 years following liver transplantation, GFR improved in 50 %, tubular acidosis in 50 % and hypercalciuria in 70 %. No change was noted in renal size or sonographic architecture. CONCLUSION: Renal architecture and function are abnormal in the majority of children with tyrosinemia. Liver transplantation improves renal function in about 50 % of patients, but abnormal renal size and architecture persist.

[Role of transcranial ultrasonography in neuroradiological diagnosis]. / Le rôle de l'écho-Doppler transcrânien en neuroradiologie diagnostique.

Blood flow within the major arteries supplying the brain can be studied with transcranial Doppler sonography, a noninvasive, portable procedure. We describe the technique of examination, as well as indications in children and adults such as the investigation of intracranial stenosis, collateral pathways, vasospasm, cerebral emboli and arteriovenous malformations.

Thickening of the wall of the bile duct due to intramural collaterals in three patients with portal vein thrombosis.

OBJECTIVE: We report three cases of a rare form of cavernoma developed within the wall of the common bile duct. CONCLUSION: To our knowledge, this kind of portal cavernoma has not been described in the literature. Because the cavernoma may be easily confused with other causes of bile duct wall thickening, color Doppler sonography is mandatory for a correct diagnosis.

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.

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.

Liver transplantation: review of the literature. Part 3: Medical 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 liver transplantation. In the second article (Can Assoc Radiol J 1997;48[4]: 231-242), they discussed the vascular and biliary complications of the operation. This, the third and final article in the series, covers the medical complications.

Imaging features of type 1 hereditary tyrosinemia: a review of 30 patients.

Hereditary tyrosinemia type 1, a common genetic disorder in the province of Quebec, is characterized by a deficiency of fumarylacetoacetate hydrolase. In this autosomal recessive disorder of tyrosine metabolism, the accumulation of succinylacetone leads to neurologic crises, acute and chronic liver failure, complex renal tubulopathy, rickets and a hemorrhagic syndrome. Liver trans- plantation has dramatically modified the spontaneous course of this lethal disease. The present paper describes the imaging features of tyrosinemia in 30 patients followed from 1980 to 1995 at Hôpital Sainte-Justine, Montreal, Canada.

Appendicitis in children and young adults: Doppler sonographic-pathologic correlation.

OBJECTIVE: The purpose of this study was to determine the following: whether the arterial supply of a normal appendix is visible with Doppler sonography; whether the physiologic vasodilatation that accompanies childhood appendicitis is visible; what Doppler patterns appear once necrosis of the appendix has occurred; what Doppler shifts are visible with chronic, recurrent appendicitis; and whether other conditions in the right lower quadrant can mimic the Doppler sonographic patterns of appendicitis. MATERIALS AND METHODS: Twenty-five fasting patients without abdominal pain or intestinal disease and 45 patients (1-25 years old; mean, 8 years old) with right lower quadrant pain and suspected appendicitis were examined sonographically, using 5- and 7-MHz linear, color, and pulsed Doppler transducers. Arterial signals were sought within the appendix and neighboring tissues, counted, and classified as sparse (1-2), moderate (3-4), or abundant (>4). The resistive index (RI) was measured. Thirty patients who underwent surgery were retained for surgical and pathologic correlation, and only they formed the appendicitis study. RESULTS: A normal appendix was found in 10 patients. Doppler shifts were sparse, and diastolic flow was low or absent (RI, 0.85-1). Acute uncomplicated appendicitis was found in 13 patients, who had abundant color Doppler signals throughout most of the appendix, with high diastolic flow (RI, 0.40-0.77; mean, 0.54). Acute necrotic appendicitis with perforation was found in 11 children, eight of whom showed no signals in the necrotic area at the tip. Few or no signals were seen in the remainder of the appendix (RI, 0.33-0.90; mean, 0.54). In two patients, signals were abundant in the tissues surrounding the appendix. Recurrent or chronic appendicitis was found in three patients, previously diagnosed as having Crohn's disease, psychosomatic illness, or nonspecific abdominal pain. The appendix had Doppler signals confined to the tip (RI, 0.63-0.83; mean, 0.75). Other diagnoses were found in three patients, in whom the appendix was not seen. There were abundant color signals in the intestinal wall and adjacent tissues in the right lower quadrant. Two patients had Crohn's disease, and the third had an unsuspected early pregnancy. The appendix was normal in all. CONCLUSION: Acute appendicitis is accompanied by inflammatory hypervascularity reflected as an increased number of color signals and higher diastolic Doppler shifts as compared with those found in normal persons. No Doppler shifts are identified in areas of appendiceal ischemia. Other acute inflammation in the right lower quadrant also produces numerous Doppler shifts with high diastolic flow, as does ovulation. Care must be taken to identify the source of these Doppler signals. The changing vascularity of healing, recurrent, and chronic appendicitis promises to further our understanding of the pathogenesis and evolution of this disease.

Power doppler sonography: basic principles and clinical applications in children.

Power Doppler sonography is a new technique that displays the strength of the Doppler signal in color, rather than the speed and direction information. It has three times the sensitivity of conventional color Doppler for detection of flow and is particularly useful for small vessels and those with low-velocity flow. Power Doppler sonography shows potential for detecting areas of ischemia in the kidney, brain, and prepubertal testis and for demonstrating hyperemia in areas of inflammation. Its increased sensitivity to motion and flash artifact, however, limits its application in children. Power Doppler is useful as an adjunct to conventional color and pulsed Doppler sonography.

Cavernous transformation of the portal vein: patterns of intrahepatic and splanchnic collateral circulation detected with Doppler sonography.

OBJECTIVE: Cavernous transformation of the portal vein is defined as the formation of venous channels within or around a previously thrombosed portal vein. The purpose of this work was to study the hemodynamic consequences of cavernous transformation of the portal vein in a group of afflicted patients by use of Doppler sonography. We wished to study the evolution from portal vein thrombosis to the formation of cavernous transformation, the extent of resulting extrahepatic collateral channels, and the patterns of splanchnic collateral circulation. MATERIALS AND METHODS: Seventy-five patients (48 adults and 27 children) with cavernous transformation of the portal vein were studied with color and/or pulsed Doppler sonography. Blood flow in the extrahepatic portal vein, in its segmental branches, in the hepatic veins and artery, and in the splanchnic veins was examined. Collateral pathways were sought. For nine patients with acute thrombosis of the portal vein, serial examinations were performed during the formation of cavernous transformation. RESULTS: In nine patients, a fresh thrombus filled and distended the portal vein and became recanalized within a few days. Tortuous vessels appeared at the porta hepatis. These were characterized as veins or arteries with Doppler sonography. Soon the portal vein could no longer be identified within the mass of tortuous vessels. The cavernous transformation developed within 6-20 days of the acute thrombosis. A spongelike mass of collateral vessels around the main portal vein was seen in all but two patients. Intrahepatic extension of the cavernous transformation was seen in 57 patients (76%) and involved one or more intrahepatic portal veins. Two types of collateral circulation were observed: portosystemic, mainly through the left gastric and the perisplenic veins (the caput medusae, i.e., the paraumbilical-to-abdominal venous route, was never seen); and portoportal, from the periportal or pericholecystic venous channels to the intrahepatic portal veins. In nine patients, flow within unaffected intrahepatic branches of the portal vein was reversed as directed toward the cavernous transformation surrounding other, thrombosed intrahepatic segments of the portal vein. CONCLUSION: After thrombosis of the portal vein, portoportal venous channels may form not only at the porta hepatis but also within the liver. Intrahepatic blood may be shunted from one segmental portal vein to another. In addition, portosystemic collateral channels are formed, suggesting that, despite extensive hemodynamic adaptations, portal hypertension ensues.

Short- and long-term hemodynamic effects of transjugular intrahepatic portosystemic shunts: a Doppler/manometric correlative study.

OBJECTIVE: The purposes of this study were to evaluate the effect of a well-functioning transjugular intrahepatic portosystemic shunt (TIPS) on the splanchnic and intrahepatic circulation, to determine if sonographic measurements can predict shunt dysfunction before clinical manifestations of portal hypertension occur, and to compare Doppler sonographic findings with portocaval gradient measurements before and after shunt revision. SUBJECTS AND METHODS: Forty-four patients with cirrhosis (n = 43) and myelofibrosis (n = 1) who underwent successful TIPS insertion were included in this prospective study. Indications for TIPS placement were: refractory ascites (24 patients), bleeding esophageal varices (17 patients), portal hypertensive gastropathy (two patients), and bleeding colonic varices (one patient). The portal vein and the inferior vena cava were catheterized; and the portocaval gradient was recorded before TIPS placement, at 2 and 12 months after TIPS placement, and when clinical or Doppler findings suggested shunt dysfunction. Doppler studies were done within 1 week before TIPS placement, within 2 days after TIPS placement, every 2-3 months thereafter, and before and after a TIPS revision. The Doppler studies included flow volume measurements in the portal vein and in the stent, as well as determination of the direction of flow in the segmental branches of the portal vein, in the splanchnic veins, and in portosystemic collaterals. Changes in Doppler findings and in catheter pressure measurements were compared using Spearman's rank correlation test. Significance was set at the .05 level. RESULTS: A marked decrease (-51%) in portocaval gradient was observed after TIPS placement. At Doppler sonography, portal vein velocity and diameter were both higher after TIPS placement, resulting in a marked increase in portal venous flow (170%). Mean flow velocity in the shunt was 55.8 +/- 3.6 cm/sec, and flow volumes in the shunt and in the main portal vein were 1596 ml/min and 1731 ml/min, respectively (p = nonsignificant). Dysfunction of the stent occurred in 27% of the patients. Changes in stent blood flow volume were closely related to changes in the portocaval gradient (r = -0.67, p < .001). Reduction of blood flow volume in the stent or change of direction of flow in intrahepatic portal veins or in collateral veins signaled shunt dysfunction (84% sensitivity, 89% specificity). CONCLUSION: Marked hemodynamic changes in the portal venous system occur soon after a TIPS procedure. Monitoring of shunt function with periodic Doppler sonography, including calculation of shunt blood flow, is useful in detecting shunt dysfunction before clinical signs occur.