William M. Strub

Overnight Preliminary Head CT Interpretations Provided by Residents: Locations of Misidentified Intracranial Hemorrhage

BACKGROUND AND PURPOSE: Our aim was to determine the patterns of error of radiology residents in the detection of intracranial hemorrhage on head CT examinations while on call. Follow-up studies were reviewed to determine if there was any adverse effect on patient outcome as a result of these preliminary interpretations. MATERIALS AND METHODS: Radiology residents prospectively interpreted 22,590 head CT examinations while on call from January 1, 2002, to July 31, 2006. The following morning, the studies were interpreted by staff neuroradiologists, and discrepancies from the preliminary report were documented. Patients’ charts were reviewed for clinical outcomes and any imaging follow-up. RESULTS: There were a total of 1037 discrepancies identified, of which 141 were due to intracranial hemorrhage. The most common types of intracranial hemorrhage that were missed were subdural and subarachnoid hemorrhage occurring in 39% and 33% of the cases, respectively. The most common location for missed subdural hemorrhage was either parafalcine or frontal. The most common location of missed subarachnoid hemorrhage was in the interpeduncular cistern. There was 1 case of nontraumatic subarachnoid hemorrhage that was not described in the preliminary report. Fourteen patients were brought back to the emergency department for short-term follow-up imaging after being discharged. We did not observe any adverse clinical outcomes that resulted from a discrepant reading. CONCLUSION: Discrepancies due to intracranial hemorrhage are usually the result of subdural or subarachnoid hemorrhage. A more complete understanding of the locations of the missed hemorrhage can hopefully help decrease the discrepancy rate to help improve patient care.

Biliary Duct Ablation with N-Butyl Cyanoacrylate

PURPOSE To assess the efficacy of percutaneous insertion of n-butyl cyanoacrylate (NBCA) in the ablation of bile ducts in patients with persistent postsurgical bile leaks in which traditional means of treatment have failed. MATERIALS AND METHODS Ablation of bile ducts with NBCA was performed in six patients (two men and four women). The average length of follow-up was 27 months (range, 13-46 months). Four patients presented after hepatic lobectomy with a persistent bile leak, one patient presented after cholecystectomy with a chronically obstructed bile duct, and one patient presented after cholecystectomy from intraoperative bile duct injury. After access to the biliary system was obtained, a cholangiogram was obtained. After the desired duct was isolated, it was copiously irrigated with saline solution. A glue solution containing NBCA glue, Ethiodol, and tantalum powder was delivered into the duct through a polyethylene catheter that had been irrigated with dextrose solution. RESULTS Four patients had problems arising from isolated segmental ductal systems that had no communication with the normal biliary ductal system and were treated successfully on the first attempt. In two patients, there was communication to the main biliary ductal system and a persistent bile leak occurred that required placement of a coil and a second final gluing procedure. The only complication observed was unintentional spillage of glue into the main biliary system in one patient, which was ultimately clinically insignificant. CONCLUSIONS The use of NBCA glue in obliteration of bile ducts is a safe procedure with excellent results in patients with complications from isolated segmental ducts. Although a repeat procedure may be necessary if the duct communicates with the main biliary tree, the procedure can decrease the morbidity associated with chronic external biliary drainage.

First year radiology residents not taking call: will there be a difference?

Currently, there is a debate in the academic radiology community about whether or not first year residents should take overnight call. The purpose of this study was to track discrepancies on overnight resident preliminary reads on radiographs from the emergency department to see if the experience level of the resident makes a difference. From October 1, 2005 to September 22, 2006, 13,213 radiographs were prospectively interpreted by residents at night at a Level I Trauma Center. Discrepancies were documented after review of the films with the staff radiologist in the morning. The patient’s medical record was then examined to determine if there was any adverse clinical outcome as a result of the reading. Of the 13,184 radiographs interpreted, 120 total discrepancies were identified (overall discrepancy rate 0.9%). First year residents showed a discrepancy rate of 1.59%, higher than other residents, which were ranged from 0.39 to 0.56%. Of the 54 patients with follow-up imaging, the abnormality that was felt to be present by staff persisted on follow-up imaging in 22 cases; however, the abnormality was not present on follow up of the other 32 patients (59.2% of discrepancies with follow-up imaging). Although there is higher rate of discrepancy among reports generated by first year residents, the difference compared to the other levels of experience is small, and its overall significance can be debated. Follow-up imaging often showed that staff interpretations were false positives when there was a discrepancy reported.

Case of Complex Craniofacial Anomalies, Bilateral Nasal Proboscides, Palatal Pituitary, Upper Limbs Reduction, and Amnion Rupture Sequence: Disorganization Phenotype?

We report a case of a dizygotic twin with complex abnormalities of head, body, and limbs. The anomalies include the following: lateral and midline cleft upper lip, ectopic palatal pituitary, natal teeth, bilateral nasal proboscides with an absent nose, left microphthalmia with conjunctival-lined cyst, right ocular dysgenesis, bilateral retinal dysplasia, platybasia with skull asymmetry, hydrocephalus secondary to aqueductal atresia, brain hemispheric asymmetry with a parietal–occipital cortical flap, agenesis of posterior corpus callosum, absence of the olfactory nerves and left anterior cerebral artery, leptomeningeal and intraventricular heterotopias, right radial longitudinal terminal meromelia with constriction rings of fingers, partial syndactyly of the third and fourth left fingers, dorsiflexed great toes and pes equinovarus bilaterally, and multiple skin tags with a sacral appendage. Additionally, this twins placental disc and extraplacental membranes were devoid of amnion. We regard these anomalies as a possible expression of the human homologue of the disorganization phenotype or another gene mutation. Nevertheless, an abnormality of blastogenesis with early damage to organizing tissues of the frontonasal region and limbs, or a vascular disruption, cannot be excluded. Early amnion rupture sequence (possible extraamniotic pregnancy with amniotic bands, limb reduction defects with Streeter bands, and multiple skin tags tapering into amniotic bands) was also present in this case, and may have acted as a contributing factor.

Self-inflicted transorbital and intracranial injury from eyeglasses

Orbital injuries are commonly seen in the emergency department, and if they are high-energy they can lead to concomitant intracranial injuries. Plain films, CT, MRI, and ultrasound are used in various combinations to evaluate the extent of these injuries. We describe a unique case of self-inflicted transorbital penetrating intracranial injury from the temporal wire rim of a pair of eyeglasses. Imaging well demonstrates the full course of the wire rim in situ, and pathoanatomic correlates are highlighted.

Reducing the gray zone: imaging spectrum of hypoperfusion and hypoxic brain injury in adults

The purpose of this pictorial essay is to illustrate the computed tomography and magnetic resonance imaging manifestations of hypoperfusion and hypoxic brain injury in adults, a clinical scenario not uncommon in the emergency room setting. The imaging findings can be subtle or marked depending on the type of injury and the time elapsed from injury to imaging. Accurate recognition of the imaging findings in hypoperfusion and hypoxic injury in adults is important for accurate therapy and family-patient counseling.

First-year radiology residents not taking call:what is your position?

Dear Editor: We appreciate Dr. Baker’s interest in our article. Our intention was to present data and spur discussion on an important topic, which it obviously has. We felt that the proposed changes would be “dramatic” for many programs, as many currently have first-year residents taking call “independently.” Some academic departments have scarce resources, and may need to alter their current, and often overworked, staff coverage. It will be “dramatic” as it will change the way programs currently cover after-hours care. It would seem that if proponents of the change want a more experienced resident taking call, due to a lower discrepancy rate, then one should always want the most experienced staff radiologist interpreting the study for the same reasons. In our mind, the most experienced radiologist, in addition to having the ability to manage and lead, is also the chairman of the department or at least a division head. We agree that patient care is of the utmost importance, so should it then not follow that the most experienced radiologist reads every study? Or for that matter, should all studies be double-read or only be read by fellowship trained radiologists? One only needs to examine the work of Erly et al. [1], where head CT scans interpreted by community radiologist were compared to the readings of neuoradiologists. The authors found a 2% rate of significant disagreement, which included overlooked subdural hematomas, contusions, and subarachnoid hemorrhage by the community radiologists. Having the most experienced physician involved in patient care, regardless of the specialty, is ideal but not always possible. What is often lost in the discussion is the percent of true abnormalities, which is shown in Table 2. We found that the frequency for correct abnormalities identified by staff with >15 years experience is significantly higher than that of other staff at p<0.05. However, we observed that identifying a true abnormality was not associated with the level of resident training, although our numbers are small. Furthermore, what is often lost in the discussion is how staff radiologists performed on follow-up, further supporting the work of Rhea et al. [2] that residents are being judged against an imperfect clinical standard. Attendings also make mistakes, although we are aware that they must serve as the gold standard by which residents are judged. In the end, the interpretation of the significance of all of the data as a whole is left to the reader. In summary, the balance of clinical training, graded clinical responsibility, and providing the highest levels of patient care is the challenge of academic radiology. The quality assurance data available in many radiology departments should be commended, as they likely exceed those of other specialties. We are currently focusing on identifying the most common areas of resident misinterpretation [3] and using the results to improve resident education at all levels. We look forward to future studies in this realm after the residency review committee change is implemented to determine its full impact. Emerg Radiol (2008) 15:81–82 DOI 10.1007/s10140-007-0653-6