C. C. Kuni

Postoperative diuresis renography and ultrasound in patients undergoing pyeloplasty: Predictors of surgical outcome

The authors reviewed 50 pediatric patients (56 renal units) who underwent pyeloplasty and had serial preoperative and postoperative diuresis renogram and ultrasound studies. Of those patients that clinically improved with surgery, 73% and 91% showed improved renographic patterns in postoperative studies at 3 and 12 months, respectively. Ultrasound demonstrated more gradual improvement in grade and pelvic diameters over longer study intervals. Diuresis renography is an excellent predictor of surgical outcome within 3 months of pyeloplasty and showed change well in advance of that seen on ultrasound. Sonography is better suited to longer term evaluation of grade, pelvic diameter, and renal size.

Role of radiology in medical education: perspective of nonradiologists.

RATIONALE AND OBJECTIVES We asked our nonradiologist colleagues to evaluate and comment on the most desirable format for radiology education. METHODS Questionnaires were distributed to 631 nonradiologist physicians affiliated with the University of Minnesota and representing all medical specialties and academic ranks. Three hundred twenty-seven surveys were returned after one mailing. RESULTS Residency was retrospectively noted to be indispensable for consolidating knowledge of radiology. The overwhelming majority of clinicians in all specialties believed that formal radiologic instruction should be mandatory for medical students (279 of 322; 87%). Film interpretation was believed to be an indispensable part of a medical student radiology rotation (226 of 321; 70%), but many clinicians indicated a need for additional training. A marked disparity in the perceived level of confidence in interpreting radiologic tests during medical school and residency between those who had and those who had not received formal radiologic instruction during medical school was evident. This difference in perceived level of confidence was present even among the most experienced clinicians. CONCLUSIONS Collectively, the nonradiologist clinicians emphasized the need for a mandatory and clinically oriented radiology curriculum during medical school.

Liver transplant rejection and cholestasis : comparison of technetium 99m-diisopropyl iminodiacetic acid hepatobiliary imaging with liver biopsy

To determine whether the scintigraphic evaluation of technetium-99m diisopropyl iminodiacetic acid (DISIDA) uptake and excretion can distinguish among liver transplant patients with biopsy evidence for rejection, cholestasis or neither condition, we reviewed scintigrams and biopsies in 36 patients. There were 76 scintigrams with corresponding biopsies. Uptake and excretion were graded from image data on scales reflecting normal through severely abnormal values. Biopsies were evaluated for findings of cholestasis and rejection. The majority of scintigrams demonstrated normal uptake (60/75, 80%) and delayed excretion (65/76, 85%), which was most marked immediately after transplantation. One-way analysis of variance showed that the mean excretion values significantly differed between patients with normal biopsies and those with cholestasis and/or rejection (P =0.0003). However, mean uptake scores demonstrated no statistically significant difference between these two groups of patients (P =0.1). These findings suggest that 99mTc-DISIDA scintigraphy can differentiate between transplants with and without rejection/cholestasis but not between rejection and cholestasis. If 99mTc-DISIDA excretion is normal, rejection and cholestasis are unlikely.

Resting Tl-201 scintigraphy in the evaluation of coronary artery disease in children with Hurler syndrome.

Severe coronary artery disease may occur early in the course of mucopolysaccharidosis. The authors present radiologic, scintigraphic, and pathologic findings in five patients with Hurler syndrome. Thallium-201 myocardial scintigraphy and selective coronary angiography obtained within 2 days to 6 months were correlated in five patients. Postmortem examination of the coronary arterles was obtained in one patient within hours of angiography. Interobserver agreement on grading of scintigraphic abnormalities was poor. Nonspecific findings on TI-201 studies included septal abnormalities in all five patients. Scintigraphic findings were corroborated by angiography and postmortem results in only 3 of 5 patients. Our findings suggest that resting TI-201 scintigraphy has limited value in the detection of coronary artery disease in patients with Hurler syndrome.

Aerosol scintigraphy in the assessment of therapy for cystic fibrosis.

Thirteen patients with cystic fibrosis (aged 11 to 32 years) who were hospitalized for exacerbation and who had sputum cultures positive for Pseudomonas organisms were treated initially for 4 days with bronchodilators and physiotherapy followed by the addition of antibiotic (14 days, n = 8) or placebo (14 days, n = 4; 7 days, n = 1). Tc-99m DTPA aerosol scintigraphy was performed on the day before bronchodilators and physiotherapy, on the day before antibiotic or placebo, and on the day after completion of antibiotic or placebo therapy. Scintigrams were evaluated for change in the number of nonventilated segments and change in the number of bronchial deposits of aerosol. Sixty-nine percent of patients showed improvement after bronchodilators and physiotherapy alone. Sixty-two percent showed further improvement after antibiotic or placebo was added; this improvement was independent of whether antibiotic or placebo was administered (P > 0.1). These aerosol scintigraphy results failed to demonstrate that the effectiveness of bronchodilators and physiotherapy is enhanced by antibiotics in the treatment of cystic fibrosis exacerbations.

Reverse mismatch between perfusion and aerosol ventilation in transplanted lungs

Thirty ventilation-perfusion pulmonary scintigraphic studies were performed in 13 patients who had undergone unilateral lung transplantation. Ventilation–perfusion mismatch (ventilation better than perfusion) was judged absent, mild, moderate, or severe in the transplanted and native lungs. Ventilation-perfusion mismatch was significantly worse in the transplanted lungs (p<.0001). Findings of lung biopsies and chest roentgenograms failed to correlate with the severity of ventilation-perfusion mismatch. Hypoxic pulmonary vasoconstriction appears to be significantly impaired in most unilateral lung transplants; the mechanism for this impairment is unclear.

A comparison of single blood sample and multiple blood sample methods to measure GFR in a pediatric population

Several single-sample, Cr-51 EDTA based methods of estimating glomerular filtration rate in children have been proposed. The authors retrospectively reviewed our experience in 467 pediatric patients using Tc-99m DTPA and 4 ultrafiltered serum samples drawn 2-4 hours postinjection. The authors used the 2-hour specimens for the single-sample method. Regression analysis of the 2 techniques revealed significant scatter. Mathematically, it was shown that the error of the singlesample method was minimized when the clearance t½ equalled the sampling time x 0.693. This model predicted a 300% error when the t½ was varied to its observed extremes. The observed error of the single-sample method fit this theoretical prediction very well. Analysis of a two-sample method versus the four-sample method showed no improvement in results. In a subset of 18 unfiltered plasma samples, the glomerular filtration rate was falsely low in 12 patients. The authors conclude that multiple blood samples and serum ultrafiltration are required to accurately measure glomerular filtration rate when using Tc-99m DTPA.

Comparison of Tc-99m DTPA aerosol ventilation studies with pulmonary function testing in cystic fibrosis

In 43 patients with cystic fibrosis, the results of 122 Tc-99m DTPA aerosol ventilation (DAV) studies were compared with pulmonary function tests (PFTs) that were performed within 24 hours of the DAV studies. The DAV studies were evaluated blindly for (A) number of pulmonary segments showing little or no ventilation, (B) number of foci of bronchial deposition of aerosol, and (C) subjective overall improvement, lack of change, or worsening from the previous study. (A) and (B) correlated significantly with all PFTs (ps < .001, rs = -.51 to -.73). Changes in (A) and (B) also correlated with changes in PFTs (ps ≤ .001, rs = -.37 to -.58). The three populations in (C) were significantly different from each other with respect to changes in all PFTs (p ≤ .002). Intervals between studies showing subjective improvement, no change, and worsening averaged 60, 133, and 306 days, respectively. These results suggest that DAV is an indicator of both regional and global pulmonary function and may be useful in evaluating patients with cystic fibrosis.

The lymphoscintigraphic evaluation of patients with Klippel-Trenaunay syndrome.

Lymphoscintigraphy performed with Tc-99m-labelled antimony sulfur colloid is useful in the selection of patients for vascular microsurgery. Klippel-Trenaunay syndrome is characterized by multiple hemangiomata, limb hypertrophy, and vascular and lymphatic abnormalities. Lymphoscintigraphy findings in this syndrome are demonstrated

Scrotal urinoma as a complication of renal transplantation

Scrotal swelling and tenderness in the posttransplant period may be secondary to urine extravasation. Contrast cystography and ultrasound examination are often suboptimal means of diagnosis of scrotal urinoma. Scintigraphy is the method of choice for detection of this unusual complication of renal transplantation