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Biomedical subjects

H B Patriquin

Publications and source records attributed to H B Patriquin.

At least 19 recordsLinked to original sources
PubMed1999

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.

Amino Acid Metabolism, Inborn Errors↗
PubMed1998

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.

Arteriovenous Malformations↗
PubMed1997

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.

Anastomosis, Surgical↗
PubMed1997

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.

Biliary Tract Diseases↗
PubMed1997

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.

Communicable Diseases↗
PubMed1996

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.

Acute Disease↗
PubMed1994

Accuracy of Doppler sonography in the evaluation of acute conditions of the scrotum in children.

During a 12-month period, 65 boys (newborn to 18 years of age) with acute scrotal pain or swelling underwent Doppler sonography of both testes, followed by scintigraphy (15) and/or surgery (34) and close clinical follow-up for at least 4 months (23). Pulsed Doppler was performed with an ATL UM8 or Quantum II apparatus, using 7.5- or 10-MHz transducers. In 25 patients, color Doppler was also used. The testicular artery was deemed patent if Doppler shifts from branches within the parenchyma could be found. (Doppler signals from scrotal or marginal arteries were considered nondiagnostic). Through surgery, 19 testicular torsions were noted. Seventeen were diagnosed as such with Doppler. Two boys with torsion were deemed normal at the time of both Doppler and scintigraphy evaluation. One boy had a second Doppler examination 13 hours later, which showed no flow. The testicle was necrotic at the time of surgery. The second boy had had 8 hours of symptoms and had a viable testis at the time of surgery. This probably represented intermittent torsion. In six of the 65 cases, no signals could be found on either side, and they were deemed technical failures of the test. Doppler sonography was technically successful in 59 of the 65 patients (91%) and yielded a sensitivity of 89% and specificity of 100%. Comparing the normal and painful side helped to define technical failures. Pulsed Doppler with mechanical sector scanners was more sensitive than color Doppler. Intermittent torsion was missed with both Doppler sonography and scintigraphy. Although ultrasonography cannot replace clinical judgement, it may be very helpful in unclear cases.

Adolescent↗
PubMed1993

Testicular torsion in infants and children: diagnosis with Doppler sonography.

The accuracy of Doppler sonography in the evaluation of testicular torsion was tested in 65 boys (aged 0-18 years) with acute scrotal pain or swelling. All patients underwent pulsed Doppler sonography of both testes, followed by scintigraphy (n = 16) and/or surgery (n = 34) and a close clinical follow-up for 4-8 months (n = 31). Color Doppler sonography was performed in 29 patients. The testicular artery was deemed patent if Doppler shifts from branches within the parenchyma could be found. Surgery revealed 19 cases of testicular torsion, 17 of which were diagnosed with Doppler sonography. There were six technical failures, in which no signals could be found on either side. In four boys, no color signals were obtained in either testis but subsequent examination with a mechanical sector scanner and pulsed Doppler sonography yielded arterial signals. Doppler sonography was successful in 59 of 65 boys (91%) and yielded a sensitivity of 89% and specificity of 100%. Pulsed Doppler sonography with mechanical sector scanners was more sensitive than color Doppler sonography. Intermittent torsion was missed both with Doppler sonography and scintigraphy.

Adolescent↗
PubMed1993

Renal vein thrombosis in children: evidence of early flow recovery with Doppler US.

PURPOSE: To characterize renal arterial and venous Doppler signals in pediatric renal vein thrombosis (RVT) and to study changes in the circulation in the months following the acute event. MATERIALS AND METHODS: Ten patients with proved acute RVT (eight infants and two boys with renal allografts) were studied with serial Doppler ultrasonography (US) of the inferior vena cava and the main renal and intrarenal veins and arteries. RESULTS: The resistance index in the affected vessel was increased by 10% compared with that of the normal side in patients with unilateral RVT. Only the allografts had reversed diastolic flow. Venous flow, which was detected around the thrombus and in intrarenal veins in all native kidneys, was absent during the 1st week in the transplanted kidneys but reappeared thereafter in one. Perirenal collateral vessels were demonstrated with color Doppler US in one baby. Seven of eight native kidneys atrophied, and the allografts failed. CONCLUSION: Classic Doppler signs of RVT--absent venous flow and reversed diastolic arterial flow within the kidney--were present in only the acute phase in transplanted kidneys. These signs are unreliable in RVT of native kidneys.

Child↗
PubMed1992

Infantile hepatic hemangioma: Doppler US.

The duplex Doppler ultrasound (US) characteristics of 13 infantile hepatic hemangiomas were reviewed to assess the utility of these characteristics in diagnosis and follow-up. Clinical correlation was available for all children, with a histologic diagnosis established in three. A variety of tumoral flow patterns were demonstrated, including arterial and venous signals with high-frequency shifts, arteries with little systolic-diastolic flow variation, and low-frequency arterial and venous signals. Follow-up studies in 12 infants documented slower flow within the tumors; one child underwent immediate surgery without follow-up examination. The Doppler US characteristics of infantile liver hemangiomas are variable and overlap with those described in the literature for malignant tumors. Doppler US is most useful in follow-up by allowing monitoring of changes in flow within tumors after therapeutic embolization or conservative management.

Blood Flow Velocity↗
PubMed1992

Stenosis of the renal artery: assessment of slowed systole in the downstream circulation with Doppler sonography.

Slowing and dampening of systole in the arterial network distal to stenosis is a well-known Doppler sign of severe arterial stenosis. To determine whether this sign is present in boys and girls with such stenosis, intrarenal Doppler curves (acceleration index [AI] and resistive index [RI]) were compared with findings on renal arteriograms in 20 boys and girls; the AI was also measured in 10 boys and girls without renal disease. Statistical analysis of AI and RI measurements was performed. Eleven of 32 renal arteries were normal. The normal AI was 4.0-7.0; in arteries with greater than 75% stenosis, the AI was 0.7-1.7. In five arteries studied after angioplasty, the AI had changed from 0.7-1.5 to 4.0-5.6 at the first posttreatment examination (performed 28 hours to 1 week after angioplasty), and it remained normal during the 3-year follow-up period. In kidneys with stenotic arteries, the RIs were lower (0.43-0.54) than in healthy subjects (0.56-0.63). Regression and correlation coefficients of AI and RI measurements were statistically significant, and discrimination between normal arteries and those with greater than 75% stenosis was excellent.

Child↗
PubMed1991

Doppler sonography in renal diseases.

Using Doppler sonography, the circulation of the kidney can now be studied in the living person in various physiologic or pathologic situations. Our understanding of renal hemodynamics, gleaned from experimental animal models as well as human studies, is being enhanced by Doppler examination and the clinical uses are expanding. Some early concepts, sometimes hastily postulated, are being questioned. The highlights of ongoing debates and the results of animal studies that further our understanding of Doppler examinations in patients are the subject of this review.

Doppler Effect↗
PubMed1990

Normal portal venous diameter in children.

A study was conducted on 156 children, in whom the portal veins were measured using standard real time ultrasonography. Knowledge of the normal dimension may be important in patients with liver disease.

Adolescent↗
PubMed1989

Hemolytic-uremic syndrome: intrarenal arterial Doppler patterns as a useful guide to therapy.

Seventeen children with acute renal failure due to the hemolytic-uremic syndrome were examined with duplex Doppler ultrasound. Serial measurements of intrarenal arterial pulsatility were obtained by means of the Pourcelot index. These were compared with daily urine volume, both during the phase of renal failure (during which most of the children were undergoing peritoneal dialysis) and during recovery of renal function. During oliguria or anuria there was either no intrarenal arterial flow (ie, absent Doppler shifts), or absent, reversed, or markedly reduced diastolic flow. Within 24-48 hours after diastolic Doppler shifts returned to normal, diuresis occurred. The Doppler examination enabled prediction of recovery and allowed dialysis treatment to be abbreviated or, in some cases, canceled.

Acute Kidney Injury↗
PubMed1985

Medullary sponge kidney in childhood.

Medullary sponge kidney is reported in six children aged 2-18 years. One child was asymptomatic; the others had hematuria or a urine-concentrating defect. Renal function and size were otherwise normal, as was liver function. The diagnosis was made at excretory urography according to criteria established in adults. Sonography revealed hyperechogenic pyramids, at first at the periphery, later generalized. Computed tomography proved this to be calcium. Medullary sponge kidney is rare but exists in children. Sonography is very sensitive to the pyramidal nephrocalcinosis that complicates this disease and explains the frequent presenting symptom of hematuria in these children.

Adolescent↗
PubMed1984

Late sequelae of juvenile rheumatoid arthritis of the hip: a follow-up study into adulthood.

A 4-13 year follow up study of 29 patients with juvenile rheumatoid arthritis into adulthood revealed several structural deformities of the hips: coxa magna, short femoral neck, subluxations associated with large cyst-like erosions of femur and acetabulum near the ligamentum teres and a flattened, wide femoral head (without steroid treatment). The deformities evoke the possibility of ischemia of the femoral head in the presence of active, compressive synovial proliferation during the growth period in a joint with largely intra-articular nutrient vessels.

Adolescent↗