Robert A. Kaufman

Blunt hepatic injury and elevated hepatic enzymes: A clinical correlation in children*

During a recent prospective nonrandomized comparison of noninvasive imaging techniques in 100 children with suspected major blunt abdominal injury, an interesting subset of patients was defined. Of 95 hemodynamically stable patients, 44 were found to have immediate elevation of hepatic enzymes (SGOT, SGPT greater than 30 IU). Nineteen of these children (43%) were subsequently shown to have significant liver injuries. No child with a liver injury had normal enzymes on admission. The level of enzyme elevation (SGOT chi 890 +/- 142 IU, SGPT chi 536 +/- 105 IU) in those with liver injuries is significantly greater than those without injury (SGOT chi 273 +/- 44 IU, SGPT chi 115 +/- 19 IU) (P less than or equal to 0.0001 SGOT. P less than or equal to 0.0001 SGPT). Our study has allowed definition of a group of children who are at significant risk for liver injury based on immediately available serum determinations of GOT and GPT. We have begun to use this information in our institution to select children for further noninvasive imaging. We recommend that these studies be obtained emergently in all children with suspected upper abdominal trauma.

Cholangitis Associated With Cryptococcus neoformans

A 15-yr-old girl presented with complaints of right upper quadrant pain and jaundice. Elevation of serum alkaline phosphatase, signs of protal hypertension, and computed tomographic scan findings suggested a diagnosis of primary sclerosing cholangitis. However, cultures of the bile and of the common bile duct specimen obtained during a surgical procedure grew Cryptococcus neoformans. Treatment with amphotericin B was begun. An episode of upper gastrointestinal bleeding, however, led to the hepatorenal syndrome, and the patient died before antifungal therapy was completed. At autopsy, active sclerosing cholangitis associated with cryptococci involved the common bile duct. We suggest that opportunistic infection of the biliary tree should be considered in pediatric patients with presumed primary sclerosing cholangitis.

Preoperative diagnosis of splenic cysts in children by gray scale ultrasonography.

Ultrasonography is a useful noninvasive modality for the diagnosis of splenic cysts in children. Characteristic features plus the typical clinical and radiographic presentation should obviate the need for further more invasive and costly techniques which add little to diagnostic accuracy. Additional advantages offered by ultrasound a minimal patient discomfort, no ionizing radiation, and immediate reassurance to parents that the mass is a cyst. We report two cases of epidermoid splenic cysts preoperatively diagnosed by ultrasonography. The typical sonographic characteristics are presented and the sonographic differential diagnosis is discussed.

How to Appropriately Calculate Effective Dose for CT Using Either Size-Specific Dose Estimates or Dose-Length Product

OBJECTIVE The purpose of this study is to show how to calculate effective dose in CT using size-specific dose estimates and to correct the current method using dose-length product (DLP). MATERIALS AND METHODS Data were analyzed from 352 chest and 241 abdominopelvic CT images. Size-specific dose estimate was used as a surrogate for organ dose in the chest and abdominopelvic regions. Organ doses were averaged by patient weight-based populations and were used to calculate effective dose by the International Commission on Radiological Protection (ICRP) report 103 method using tissue-weighting factors (EICRP). In addition, effective dose was calculated using population-averaged CT examination DLP for the chest and abdominopelvic region using published k-coefficients (EDLP = k × DLP). RESULTS EDLP differed from EICRP by an average of 21% (1.4 vs 1.1) in the chest and 42% (2.4 vs 3.4) in the abdominopelvic region. The differences occurred because the published kcoefficients did not account for pitch factor other than unity, were derived using a 32-cm diameter CT dose index (CTDI) phantom for CT examinations of the pediatric body, and used ICRP 60 tissue-weighting factors. Once it was corrected for pitch factor, the appropriate size of CTDI phantom, and ICRP 103 tissue-weighting factors, EDLP improved in agreement with EICRP to better than 7% (1.4 vs 1.3) and 4% (2.4 vs 2.5) for chest and abdominopelvic regions, respectively. CONCLUSION Current use of DLP to calculate effective dose was shown to be deficient because of the outdated means by which the k-coefficients were derived. This study shows a means to calculate EICRP using patient size-specific dose estimate and how to appropriately correct EDLP.

Liver-spleen computed tomography a method tailored for infants and children

Abstract A detailed approach to liver-spleen computed tomography in the pediatric patient is presented, including sections on indications, patient preparation, sedation, technique of scanning, radiation dosimetry, and potential pitfalls encountered in scanning. The advantages of dynamic scanning with table incrementation are stressed.

A Comprehensive Risk Assessment Method for Pediatric Patients Undergoing Research Examinations Using Ionizing Radiation: How We Answered the Institutional Review Board.

OBJECTIVE The objectives of this study are to establish a comprehensive method for radiation dose estimates for the most common imaging examinations performed for research, for internal use of institutional review board (IRB) and radiation safety committees; to provide investigators with relative examination doses so that they may better assess the potential radiation effects and risks for research subjects; and to provide simplified language that investigators can use in consent documents. MATERIALS AND METHODS Nineteen common radiation-based examinations used in clinical research at our institution were identified. For each modality (CT, digital radiography, dual-energy x-ray absorptiometry, PET/CT, and nuclear medicine), a comprehensive patient-specific dosimetry method was established. Effective dose was calculated according to average population calculated doses for the following age groups: 0-1, 2-8, 9-13, 14-15, and older than 15 years. RESULTS Estimated effective dose values were tabulated and posted on our institutional IRB intranet site for use by IRB and radiation safety committee members and institutional investigators. Relative examination dose levels were compared for all ages and for all examinations. A three-tiered approach to establish consent language for radiation exposure was established for research subjects receiving an effective dose less than 3 mSv, a dose between 3 and 50 mSv, and a dose greater than 50 mSv. CONCLUSION The method to estimate effective dose was tabulated for 19 of the most common ionizing radiation examinations at our institute. These results will act as a resource to help investigators better understand the implications of radiation exposure in research and can assist investigators in protocol development and correct categorization of radiation exposure risk.