Potential benefits of photon counting detector computed tomography in pediatric imaging.

Photon counting detector (PCD) CT represents the newest advance in CT technology, with improved radiation dose efficiency, increased spatial resolution, inherent spectral imaging capabilities, and the ability to eliminate electronic noise. Its design fundamentally differs from conventional energy integrating detector CT because photons are directly converted to electrical signal in a single step. Rather than converting X-rays to visible light and having an output signal that is a summation of energies, PCD directly counts each photon and records its individual energy information. The current commercially available PCD-CT utilizes a dual-source CT geometry, which allows 66 ms cardiac temporal resolution and high-pitch (up to 3.2) scanning. This can greatly benefit pediatric patients by facilitating high quality fast scanning to allow sedation-free imaging. The energy-resolving nature of the utilized PCDs allows "always-on" dual-energy imaging capabilities, such as the creation of virtual monoenergetic, virtual non-contrast, virtual non-calcium, and other material-specific images. These features may be combined with high-resolution imaging, made possible by the decreased size of individual detector elements and the absence of interelement septa. This work reviews the foundational concepts associated with PCD-CT and presents examples to highlight the benefits of PCD-CT in the pediatric population.

Meckel diverticulum in the pediatric population: Patient presentation and performance of imaging in prospective diagnosis.

PURPOSE: To determine the most common presentations of Meckel diverticulum (MD) in children and the performance of imaging modalities in prospective diagnosis. MATERIALS AND METHODS: A 28-year retrospective review was performed of children under 18 years of age with MD listed as a diagnosis on pathology and/or surgical reports. The medical record was reviewed to determine presenting clinical scenarios. All imaging performed for each case was reviewed. RESULTS: Seventy-six patients met inclusion criteria. Of the surgically removed MD, most presented with abdominal symptoms (n = 31, 41%); gastrointestinal (GI) bleeding (n = 15, 20%), or both abdominal symptoms and GI bleeding (n = 7, 9%). Twenty-nine percent of MD were discovered incidentally at surgery performed for other reasons. Of the symptomatic MD, only 31% were prospectively diagnosed. For patients with abdominal symptoms, CT had a sensitivity of 13% (3/24) while nuclear medicine (NM) scan had a sensitivity of 0% (0/2). For patients with GI bleed, CT had a sensitivity of 29% (2/7) and NM scan had a sensitivity of 71% (10/14). For patients with both abdominal symptoms and GI bleed, CT was 0% (0/2) and NM scan 75% (3/4) sensitive. CONCLUSION: MD as a cause of abdominal symptoms and gastrointestinal bleeding may be difficult to diagnose due to nonspecific presentations and nonspecific findings. Most prospectively diagnosed MD are on NM scan in patients with GI bleed with abdominal pain (sensitivity of >70%). CT is relatively insensitive for MD in all symptomatology groups (0 to 29%).

Reproducibility of Lung and Liver Volume Measurements on Fetal Magnetic Resonance Imaging in Left-Sided Congenital Diaphragmatic Hernia.

INTRODUCTION: Congenital diaphragmatic hernia (CDH) affects 1 in 3,000 live births and is associated with significant morbidity and mortality. METHODS: A review of fetal magnetic resonance imaging (MRI) examinations was performed for fetuses with left CDH and normal lung controls. Image review and manual tracings were performed by 4 pediatric radiologists; right and left lung volumes in the coronal and axial planes as well as liver volume above and below the diaphragm in the coronal plane were measured. Intra- and interreviewer reproducibility was assessed using intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS: Excellent intra- and interreviewer reproducibility of the right and left lung volume measurements was observed in both axial planes (interreviewer ICC: right lung: 0.97, 95% CI: 0.95-0.99; left lung: 0.97, 95% CI: 0.95-0.98) and coronal planes (interreviewer ICC: right lung: 0.97, 95% CI: 0.95-0.98; left lung: 0.96, 95% CI: 0.93-0.98). Moderate-to-good interreviewer reproducibility was observed for liver volume above the diaphragm (ICC 0.7, 95% CI: 0.59-0.81). Liver volume below the diaphragm had a good-to-excellent interreviewer reproducibility (ICC 0.88, 95% CI: 9.82-0.93). CONCLUSIONS: The present study demonstrated an excellent intra- and interreviewer reproducibility of MRI lung volume measurements and good-to-moderate inter- and intrareviewer reproducibility of liver volume measurements after standardization of the methods at our fetal center.

Asymptomatic macrocephaly: to scan or not to scan.

BACKGROUND: Macrocephaly is a common finding in infants and is often idiopathic or familial. In the absence of clinical signs and symptoms, it can be difficult to determine when concern for underlying pathology is justified. OBJECTIVES: The objectives of this study were to determine the utility of screening head ultrasound (US) in asymptomatic infants with macrocephaly and to identify clinical factors associated with significant US findings. MATERIALS AND METHODS: A 20-year retrospective review was performed of infants undergoing head US for macrocephaly or rapidly increasing head circumference. Data collected included age, gender, head circumference at birth and at the time of US, specialty of the ordering physician, US findings, computed tomography (CT) or magnetic resonance imaging (MRI) findings, and clinical course including interventions. RESULTS: Four hundred and forty infants met inclusion criteria. Two hundred and eighty studies (64%) were found to be normal, 137 (31%) had incidental findings, 17 (3.8%) had indeterminate but potentially significant findings, and 6 (1.4%) had significant findings. Twenty of the 23 infants with indeterminate or significant findings had subsequent CT or MRI. This confirmed significant findings in eight infants (1.8%): three subdural hematomas, two intracranial tumors, two aqueductal stenoses, and one middle fossa cyst. Five of the eight infants required surgical procedures. The only statistically significant association found with having a significant finding on head US was head circumference at birth. CONCLUSION: Ultrasound is a useful initial study to evaluate infantile macrocephaly, identifying several treatable causes in our study and, when negative, effectively excluding significant pathology.

Procedure for optimal implementation of automatic tube potential selection in pediatric CT to reduce radiation dose and improve workflow.

It is important to employ radiation dose reduction techniques in pediatric computed tomography (CT) to reduce potential risks of radiation-induced malignancy. Automatic tube potential (kV) selection tools have been developed and become available on many CT scanners, which select the optimum kV based on the patient size and clinical task to improve the radiation dose efficiency. However, its use in pediatric CT has been mostly empirical, following manufacturer's default recommendation without solid demonstration for quality improvement. This study aimed to implement an automatic tube potential tool (CAREkV, Siemens Healthcare) into routine pediatric CT practice, using the "Plan-Do-Study-Act" quality improvement process, in place of an existing kV/mAs technique chart. The design of this quality improvement project involved Plan-Do-Study-Act stages. Plan and Do stages identified the criteria for optimal automatic kV selection; a range of phantoms representing typical pediatric groups were scanned on a dual-source 128-slice scanner using a fast-pitch scanning mode. The identified CAREkV settings were implemented into the CT protocol and evaluated after a 6-month period. In the Study stage, an objective evaluation of the image metrics and radiation dose for two similar patient cohorts using CAREkV and the technique-chart, respectively, were compared. The kV selected, image quality and radiation dose determined by CAREkV were comparable to those obtained while using the technique-chart. The CAREkV was successfully implemented into our pediatric abdominopelvic CT practice. By utilizing the "PDSA" process optimal image quality and radiation dose reduction were achieved with an automatic kV selection tool to improve CT workflow.

Multifocal subacute osteomyelitis in adjacent bones in the ankle without septic joint.

Osteomyelitis is an inflammation involving bone and/or bone marrow most often the result of bacterial infection of the bone. In children, osteomyelitis most often has an acute presentation and is caused by hematogenous spread. When osteomyelitis is seen in the extremities, conventional radiography is the first-line imaging modality preformed for diagnosis with magnetic resonance imaging employed for further delineation or as a problem-solving tool. A healthy 6-year-old female presented with a history of nonspecific left leg pain for 3-5 weeks which gradually progressed to focal left ankle pain and swelling. Further workup revealed multifocal subacute osteomyelitis with Brodie's abscesses seen on imaging in the absence of a septic joint. This was an uncommon presentation for the following reasons: Patients with multifocal osteomyelitis usually present in the acute setting, as opposed to the subacute setting. When osteomyelitis is multifocal or Brodie's abscesses are present adjacent to the joint capsule, concomitant septic joint is commonly seen.

The Reemergence of Ketamine for Treatment in Critically Ill Adults.

OBJECTIVES: To assess the evidence and discuss the risks and clinical relevance of ketamine for the treatment of various disease states impacting the adult critically ill population. DATA SOURCES: A literature review was performed using PubMed evaluating primary literature published until August 2018. STUDY SELECTION: Case reports, observational studies (cohort, case-control), and randomized controlled trials involving patients 18 years and older in a nonperioperative setting using either IV or intramuscular ketamine were included for analysis. Uses of ketamine discussed focused on critically ill patients in the ICU and emergency department settings. DATA EXTRACTION: Included studies were evaluated for dosing, outcomes, and adverse effects of ketamine. For each study, the design, population, intervention, investigated outcomes, and results were assessed. DATA SYNTHESIS: The evidence was organized according to use of ketamine, which included pain, sedation, status asthmaticus, alcohol withdrawal syndrome, status epilepticus, and acute behavioral psychologic disturbances. Evaluation of the evidence was based on the included primary literature along with any related guideline recommendations. CONCLUSIONS: Ketamine has suggested potential benefit in several disease states impacting critically ill patients including pain, alcohol withdrawal syndrome, status epilepticus, and acute agitation. Further supporting evidence is needed to validate its use in the setting of critical illness.

Changes in factors influencing fellowship choices among radiology residents from 2008 to 2018 and methods that may increase interest in the pediatric radiology subspecialty.

BACKGROUND: Fewer residents are choosing a career in pediatric radiology, which is contributing to an ongoing shortage of pediatric radiologists. OBJECTIVE: To identify potential causes of reduced interest in pediatric radiology as a career given a projected worsening of a nationwide shortage of pediatric radiologists. MATERIALS AND METHODS: An online questionnaire using previously published questions was approved and distributed by the Program Directors in Diagnostic Radiology to diagnostic radiology residents on behalf of the Society for Pediatric Radiology (SPR). Descriptive statistics including means with standard error and independent t-tests were used to compare mean scores between survey years. RESULTS: Nearly all of the 353 respondents (90.9%) planned on pursuing a fellowship. The majority (57.7%) identified their fellowship subspecialty before the 3rd year of residency with only 5.7% selecting pediatric radiology. Overall, 18.2% of survey respondents favored academic practice compared to 40% in the pediatric radiology subgroup. Fellowship choices were most strongly based on area of strong personal interest, marketability and area of strong personal knowledge, while the pediatric radiology subgroup emphasized area of strong personal interest, increased interaction with other physicians and enjoyable residency rotations. The pediatric radiology subgroup believed their impact on patient care was more significant than other subspecialties. Pediatric radiology job opportunities were thought to be more limited, geographically confining, and to have lower salaries than other subspecialties. More flexible job opportunities and higher demand were identified as factors needing to change before a resident would consider a pediatric radiology career. CONCLUSION: The influence on fellowship selection is multifactorial. By emphasizing the favorable job market and marketability of pediatric radiology in all practice types/geographic locations, correcting perceived salary gaps and stressing the impact on patient care as early as medical school, the number of residents choosing a career in pediatric radiology may grow.

Comparison of two small bowel distending agents for enterography in pediatric small bowel imaging.

OBJECTIVE: To evaluate the ability of pediatric patients with known or suspected inflammatory bowel disease to ingest a new oral distending agent at CT or MR enterography (CTE/MRE), and to determine the impact on small bowel (SB) distension and diagnostic confidence. MATERIALS AND METHODS: The study design is that of retrospective review of pediatric patients who underwent CTE or MRE from January 2014 to June 2016. Patients ingested low-concentration barium suspension or flavored beverage containing sorbitol and mannitol. The need for nasogastric tube (NGT) administration, amount ingested, emesis, distal extent of contrast, SB distension, terminal ileum (TI) transverse dimension, and diagnostic confidence in TI disease were assessed. Three radiologists each blindly reviewed a subset of the studies. RESULTS: Of the total 591 scans in 504 patients, 316 scans used low-concentration barium suspension and 275 scans flavored beverage. Nearly all consumed the entire amount (97% vs. 96%). Low-concentration barium suspension exams required NGT more often (7% [23/316] vs. 1% [3/275]; p < 0.0003), and tended to have more emesis (3% [9/316] vs. 1% [3/275]; p = 0.13). Diagnostic confidence score was nearly identical (p = 0.94). Qualitative and quantitative analyses showed no difference in SB distension, except for distension of mid-ileum (flavored beverage > low-concentration barium suspension; p = 0.02). Flavored beverage exams demonstrated a slight increase in distal extent of luminal distension (p = 0.02). CONCLUSIONS: A new flavored beverage distends small bowel as well as low-concentration barium suspension, with decreased requirement for NGT insertion and improved distal extent of luminal distension, and without any decrease in diagnostic confidence in the presence or the absence of TI disease.

Radiation Dose Reduction in Pediatric Body CT Using Iterative Reconstruction and a Novel Image-Based Denoising Method.

OBJECTIVE: The objective of this study was to evaluate the radiation dose reduction potential of a novel image-based denoising technique in pediatric abdominopelvic and chest CT examinations and compare it with a commercial iterative reconstruction method. MATERIALS AND METHODS: Data were retrospectively collected from 50 (25 abdominopelvic and 25 chest) clinically indicated pediatric CT examinations. For each examination, a validated noise-insertion tool was used to simulate half-dose data, which were reconstructed using filtered back-projection (FBP) and sinogram-affirmed iterative reconstruction (SAFIRE) methods. A newly developed denoising technique, adaptive nonlocal means (aNLM), was also applied. For each of the 50 patients, three pediatric radiologists evaluated four datasets: full dose plus FBP, half dose plus FBP, half dose plus SAFIRE, and half dose plus aNLM. For each examination, the order of preference for the four datasets was ranked. The organ-specific diagnosis and diagnostic confidence for five primary organs were recorded. RESULTS: The mean (± SD) volume CT dose index for the full-dose scan was 5.3 ± 2.1 mGy for abdominopelvic examinations and 2.4 ± 1.1 mGy for chest examinations. For abdominopelvic examinations, there was no statistically significant difference between the half dose plus aNLM dataset and the full dose plus FBP dataset (3.6 ± 1.0 vs 3.6 ± 0.9, respectively; p = 0.52), and aNLM performed better than SAFIRE. For chest examinations, there was no statistically significant difference between the half dose plus SAFIRE and the full dose plus FBP (4.1 ± 0.6 vs 4.2 ± 0.6, respectively; p = 0.67), and SAFIRE performed better than aNLM. For all organs, there was more than 85% agreement in organ-specific diagnosis among the three half-dose configurations and the full dose plus FBP configuration. CONCLUSION: Although a novel image-based denoising technique performed better than a commercial iterative reconstruction method in pediatric abdominopelvic CT examinations, it performed worse in pediatric chest CT examinations. A 50% dose reduction can be achieved while maintaining diagnostic quality.

Pediatric appendiceal ultrasound: accuracy, determinacy and clinical outcomes.

BACKGROUND: Ultrasonography is considered the most appropriate initial imaging study in the evaluation of acute appendicitis in children but has recently come under criticism with reports of low specificity and high indeterminate study rates, particularly when used in obese patients and patients early in the course of their disease, or when performed by sonographers with limited experience. OBJECTIVE: To (1) assess the impact of patient factors (gender, age, body mass index, and symptom duration) and system factors (call status or year of exam) on pediatric appendiceal US accuracy and indeterminate study rate, (2) assess the impact of indeterminate study results on follow-up CT and negative laparotomy rates and (3) present strategies to reduce the rate of indeterminate US studies and improve accuracy. MATERIALS AND METHODS: We retrospectively reviewed all US reports performed for the assessment of acute appendicitis in children <18 years old at Mayo Clinic Rochester from January 2010 to June 2014. RESULTS: A total of 790 US examinations were performed in 452 girls (57%) and 338 boys (43%). The prevalence of appendicitis was 18.5% (146/790). There were 109 true-positive, 440 true-negative, 17 false-positive, 6 false-negative, 218 equivocal and 41 technically inadequate US studies. A definitive interpretation was made in 72% of the studies, with an accuracy, sensitivity and specificity of 0.960, 0.948 and 0.963, respectively. No patient or system factors significantly affected US accuracy. Indeterminate studies (28%) had significantly higher CT utilization (46% vs. 11%) and normal appendectomy rates (6.9% vs. 3.5%). CONCLUSION: US should be the initial imaging study of choice for pediatric appendicitis. When a definitive interpretation was given, the accuracy was 96%, was independent of patient and system factors and resulted in reduced follow-up CTs and negative laparotomies. Accuracy can be increased by requiring the presence of periappendiceal inflammatory changes prior to interpreting a mildly distended appendix as positive for acute appendicitis. The indeterminate study rate can be reduced by not requiring visualization of the normal appendix for the exclusion of acute appendicitis.

Trends in CT Utilization for Pediatric Fall Patients in US Emergency Departments.

RATIONALE AND OBJECTIVES: Falls are a common cause of emergency department (ED) visits in the United States. We evaluated trends in computed tomography (CT) utilization for pediatric fall victims in the United States from 2001 to 2010. MATERIALS AND METHODS: Using the National Hospital Ambulatory Medical Care Survey from 2001 to 2010, we identified all visits of pediatric (aged <18 years) patients presenting to EDs after falls. This database surveys approximately 500 EDs per year for 4 weeks providing national estimates on ED resource utilization and outcomes. We studied trends in CT utilization and proportion of visits with life-threatening conditions after falls. We also studied the association between CT utilization rates and demographic characteristics and admission status. RESULTS: A total of 9763 unweighted observations for a total of 32,432,686 pediatric fall patients were seen in US EDs from 2001 to 2010. The proportion of pediatric fall patients receiving CT increased from 5.3% in 2001 to a peak of 16.6% in 2009 and decreased to 11.3% in 2010, whereas the proportion of pediatric fall patients with life-threatening conditions fluctuated between 1.2% and 3.3% during this period. In multivariate logistic regression analysis, each increasing year was independently associated with CT utilization (odds ratio [OR], 1.15; 95% confidence interval [CI], 1.14-1.16). Patients aged 0-1 years had higher odds of CT utilization than patients aged 13-17 years (OR, 2.27; 95% CI, 2.26-2.27). CONCLUSIONS: There was a twofold increase in CT utilization among pediatric fall visits from 2001 to 2010. When controlling for demographic and clinical variables, increasing year was independently associated with CT utilization. These findings suggest that CT may be overutilized among pediatric fall patients.

Pick up a book or "google it?" a survey of radiologist and trainee-preferred references and resources.

The purpose of this study was to investigate radiologist and trainee-preferred sources for solving imaging questions. The institutional review board determined this study to be exempt from informed consent requirements. Web-based surveys were distributed to radiology staff and trainees at 16 academic institutions. Surveys queried ownership and use of tablet computers and habits of utilization of various electronic and hardcopy resources for general reference. For investigating specific cases, respondents identified a single primary resource. Comparisons were performed using Fisher's exact test. For staff, use of Google and online journals was nearly universal for general imaging questions (93 [103/111] and 94 % [104/111], respectively). For trainees, Google and resident-generated study materials were commonly utilized for such questions (82 [111/135] and 74 % [100/135], respectively). For specific imaging questions, online journals and PubMed were rarely chosen as a primary resource; the most common primary resources were STATdx for trainees and Google for staff (44 [55/126] and 52 % [51/99], respectively). Use of hard copy journals was nearly absent among trainees. Sixty percent of trainees (78/130) own a tablet computer versus 41 % of staff (46/111; p = 0.005), and 71 % (55/78) of those trainees reported at least weekly use of radiology-specific tablet applications, compared to 48 % (22/46) of staff (p < 0.001). Staff radiologists rely heavily on Google for both general and specific imaging queries, while residents utilize customized, radiology-focused products and apps. Interestingly, residents note continued use of hard copy books but have replaced hard copy journals with online resources.

A novel sclerosing skeletal dysplasia with mixed sclerosing bone dysplasia, characteristic syndromic features, and clinical and radiographic evidence of male-male transmission.

We report on a father and his 4-year-old son sharing a characteristic dysmorphic facial phenotype (including hyperteleroism, prominent forehead, and wide nasal bridge), macrocephaly, hearing loss, palatal clefting, developmental delay, hypotonia and bony abnormalities including marked cranial sclerosis and sclerosis of the ribs and long bones, which evolved in severity in the son between the ages of 2 and 4 years. The father's radiographs also showed prominent coarse striations, patchy metaphyseal sclerotic plaques, markedly increased bone density and cortical thickening of long bones, and significant degenerative changes in the thoracic spine. The son has an additional history of sleep apnea resulting from multi-level airway obstruction that includes adenoid hypertrophy, lingual tonsil hypertrophy, subglottic stenosis, and supra-arytenoid tissue consistent with laryngomalacia and tracheomalacia. The clinical, radiographic, and genetic findings in father and son are consistent with a sclerosing skeletal dysplasia syndrome with similarities to mixed sclerosing bone dysplasia (MSBD) including metaphyseal plaques, osteopathia striata, and cranial sclerosis (OS-CS). This family may represent one of the first descriptions of familial inheritance and evolving phenotype in MSBD. The evidence for male-male transmission would support the existence of an autosomal mechanism of inheritance for a novel form of MSBD with characteristic syndromic features.

Chronic tibial nonunion in a Rothmund-Thomson syndrome patient.

Rothmund-Thomson syndrome (RTS) is an autosomal recessive disorder caused by biallelic mutations in RECQL4, a helicase involved with chromosomal instability and DNA repair. Patients typically present with a poikilodermatous facial rash, photosensitivity, congenital bony abnormalities, short stature, and have a predilection for osteosarcoma and cutaneous malignancies. We present a 34-year-old male RTS patient, previously diagnosed with osteosarcoma of the right forearm which was successfully treated with resection and chemotherapy, who has had multiple tibial fractures and has suffered from chronic nonunion of the proximal tibias bilaterally for greater than 9 years. The patient subsequently developed generalized lower extremity osteopenia with normal calcium homeostasis and calcitriol levels. As the RTS population continues to reach greater ages we must be mindful of other health concerns that may develop. Bone health is one considerable concern with a large portion of patients having congenital bony abnormalities and many receiving chemotherapy for osteosarcoma. We conclude that screening for bone health and supplementation with calcium and vitamin D may be warranted in RTS patients with a history of fractures and osteosarcoma treatment.

Deficiency of interleukin-1-receptor antagonist syndrome: a rare auto-inflammatory condition that mimics multiple classic radiographic findings.

Deficiency of interleukin-1-receptor antagonist (DIRA) syndrome is a newly identified inflammatory disease of the skeleton and appendicular soft tissues presenting in early infancy that has yet to be reported in the radiology literature. The radiological manifestations of DIRA syndrome include multifocal osteitis of the ribs and long bones, heterotopic ossification and periarticular soft-tissue swelling. Thus, the pediatric radiologist should be made aware of this novel disease because its radiographic findings can mimic multiple other disease entities. With knowledge of the unique clinical presentation of DIRA syndrome and its multiple radiographic manifestations, the pediatric radiologist may be the first to suggest the correct diagnosis.

Optimal tube potential for radiation dose reduction in pediatric CT: principles, clinical implementations, and pitfalls.

In addition to existing strategies for reducing radiation dose in computed tomographic (CT) examinations, such as the use of automatic exposure control, use of the optimal tube potential also may help improve image quality or reduce radiation dose in pediatric CT examinations. The main benefit of the use of a lower tube potential is that it provides improved contrast enhancement, a characteristic that may compensate for the increase in noise that often occurs at lower tube potentials and that may allow radiation dose to be substantially reduced. However, selecting an appropriate tube potential and determining how much to reduce radiation dose depend on the patient's size and the diagnostic task being performed. The power limits of the CT scanner and the desired scanning speed also must be considered. The use of a lower tube potential and the amount by which to reduce radiation dose must be carefully evaluated for each type of examination to achieve an optimal tradeoff between contrast, noise, artifacts, and scanning speed.

The "good" dean's letter.

PURPOSE: To determine whether a correlation exists between the term "good" on the summative, comparative assessment of a student's Medical Student Performance Evaluation (MSPE) and his or her actual performance in medical school. METHOD: The authors reviewed the MSPEs submitted to three residency programs to determine the presence of the term "good" in either the summary paragraph or the appendices. Next, they noted, for institutions using "good," the percentile rankings of those students who received "good" as a descriptor. To examine the consistency among institutions regarding the percentile ranking denoted by "good," they dichotomized the data into students below and above the bottom 25th percentile. They analyzed the data using a nonparametric test because of their nonnormal distribution. RESULTS: The authors collected MSPEs from 122 of the 125 Liaison Committee on Medical Education-accredited medical schools that were graduating students in 2008. Of these 122 institutions, 34 (28%) used the term "good." All 34 institutions used the term to characterize students in the bottom 50% of the graduating class. The authors found a significant difference in the percentile ranking of students described as "good" between institutions using it to describe the bottom 25% and institutions using the term to describe those in the 25th to 50th percentiles (median ranking of 12.5% versus 30%, P < .0001). CONCLUSIONS: Overall, the term "good" in the MSPE describes students in the bottom 50% of the class; therefore, the term "good," as used to describe performance in medical school, consistently indicates below-average performance.