Heidi Patriquin

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.

Investigation of childhood blunt abdominal trauma: a practical approach using ultrasound as the initial diagnostic modality

During a 5.5-year retrospective study (1979–84) 170 children with blunt abdominal trauma were investigated with intravenous urography (IVU), ultrasound (US) and scintigraphy. For the investigation of the last 71 children (after 1982) a 4th generation CT scanner was available in the same department. The results of radiologic investigations were compared with clinical outcome in 157 and results at laparotomy in 13 children. During the study period, real time US became the first line screening tool, and was combined with IVU in suspected renal trauma. In spite of permanent accessibility of CT since November 1982, the latter was used only in complex diagnostic problems or in children with multiple injuries (8% of the series). There were no deaths resulting from abdominal trauma. During the study, the incidence of splenectomy and exploratory laparotomy decreased, and no diagnostic peritoneal lavage were performed after 1980.

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.

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.

Antenatal diagnosis of ovarian cysts: natural history and therapeutic implications

A retrospective study from 1980 to 1990 shows 29 ovarian cysts in 27 patients diagnosed by prenatal ultrasound performed between 28 and 38 weeks of gestation. Ten patients underwent surgery, 17 patients were observed with serial ultrasound. Delayed good quality sonograms after spontaneous resolution of the cyst in a selected group of 7 patients showed restoration of a normal ovarian anatomy. The size of the cyst and/or its sonographic characteristics are the 2 main factors for deciding a conservative or a surgical management.

The bobble-head doll syndrome. A curable entity.

Abstract A curious and characteristic anteroposterior bobbing or nodding of the head in a 6-year-old boy led to detailed neuroradiological examination which disclosed a large arachnoid cyst in the third ventricle. Removal of the cyst resulted in disappearance of the movement. Associated mild lower limb weakness and ataxia also improved.

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 succinyiacetone leads to neurologic crises, acute and chronic liver failure, complex renal tubulopathy, rickets and a hemorrhagic syndrome. Liver transplantation 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.

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.

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.

Fetal lobation. An anatomo-ultrasonographic correlation.

Remnants of the fusion of fetal renunculi have been mistaken for renal scars or tumors. We compared anatomic cuts of 24 cadaveric kidneys with fetal lobation (ages ranged from 16 weeks gestation to 49 years) to identical ultrasonographic sections performed in a water bath and to sonograms of healthy persons of similar ages as the cadavers. Fetal lobation was characterized as follows: there were fine, linear demarcations indenting the renal surface, separating normal lobes, consisting of a central pyramid and surrounding cortex. Separate renunculi seen in early fetal life progressively fuse throughout gestation, leaving interlobar grooves. During the third trimester, the renal surface becomes smoother and the interlobar grooves become invisible. One prominent indentation of the renal surface, the interrenuncular junction, incorporates perirenal fat and invaginates the anterior surface of the upper third of the kidney to the hilum and is the most easily visible remnant of fetal lobation. The sharply defined linear remnants of interlobar grooves should not be mistaken for scars, which are wider, less well defined and always associated with loss of renal cortex.