Justin W. Kung

FDG-PET findings in patients with suspected encephalitis.

Purpose: Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) may be used to establish a diagnosis of encephalitis, yet prior descriptions are mainly limited to small case reports. We explore the role of FDG-PET in the diagnostic evaluation of encephalitis. Methods: Brain FDG-PET was acquired in a consecutive case series of 10 cases of suspected encephalitis over a 5-year-period. Cases with positive Lyme serology were excluded. Two expert reviewers graded the FDG-PET studies in blinded fashion with respect to the clinical history. Retrospective review of the clinical history and examination, laboratory findings, electroencephalogram (EEG), and magnetic resonance imaging (MRI) studies was performed. A diagnosis of encephalitis was based on a combination of the clinical and diagnostic examination findings in each case. Results: Encephalitis was diagnosed in 6 of 10 cases. FDG-PET hypermetabolism was demonstrated in 5 cases of encephalitis, most frequently involving the medial temporal lobes. Multifocal hypometabolism was noted in at least 2 regions in all 6 cases of encephalitis, with at least 4 regions of hypometabolism noted in 5 of 6 cases. Nonencephalitis cases revealed hypermetabolism in only 1 of 4 cases, ascribed to status epilepticus. Hypometabolism was evident in all nonencephalitis cases. Conclusion: Encephalitis frequently manifests as FDG-PET hypermetabolism, but focal hypometabolism can also be observed. Seizure activity must be excluded as a possible cause of hypermetabolism in patients suspected of having encephalitis. Because other conditions that can cause hypometabolism may mimic encephalitis clinically, FDG-PET is more likely to serve as an adjunct to lumbar puncture, EEG, and clinical findings rather than a primary diagnostic tool in the management of patients suspected of having encephalitis.

Teaching radiology in the millennial era.

E ven before Cicero’s time, teachers have been widely regarded as invaluable members of society. In medicine, radiologists serve as consummate teachers, playing a crucial role in the education of peers, physiciansin-training, medical students, nurses, and other health care providers. However, few radiologists undergo any formal training in educational theory, methods, or assessment. Despite advances in educational theory related to generational changes in learning, most radiologists still use the traditional lecture format as a means to impart knowledge and casebased conferences to enable learners to apply their knowledge. Few radiologists have taken the time to reflect on their own teaching or to adopt more innovative approaches to teaching that might better meet the needs of their learners. Hence, most radiologists remain teacher-centered rather than learner-centered. As the members of every generation possess unique traits that enable them to acquire and apply knowledge differently, more effective teaching comes from a predominantly learner-centered approach (1). A better understanding of the generational differences between learners and their teachers can only result in more effective teaching (1,2). Many educators have come to recognize specific generational groups who share experiences, values, and identity shaped by world social and cultural events. In the past century, four discrete groups have been described: the silent generation (1928–1945), the baby boomers (1946–1964), generation X (1965–1982), and the millennial generation (1982–2000) (1) (Table 1). An awareness of intergenerational differences in teaching techniques and learning styles can affect teaching effectiveness and learners’ mastery and application of medical information. With the rapid technological advances over the past two decades, millennial learners pose challenges for educators who are not as well versed in technology and do not share the same perspectives with regard to life, the world, and learning needs (1).

Different Effects of Photodynamic Therapy and γ-Irradiation on Vascular Smooth Muscle Cells and Matrix: Implications for Inhibiting Restenosis

gamma-Irradiation (gamma-RT) and photodynamic therapy (PDT) are known to inhibit intimal hyperplasia. The common mechanism is that both modalities produce free radicals, but unlike gamma-RT, PDT generates them through the absorption of light by photosensitizers. The purpose of this in vitro study was to assess the differences that PDT and gamma-RT have on the fibroproliferative response after vascular injury by comparing their effects on vascular smooth muscle cells (SMCs) and on the extracellular matrix (ECM). Mitochondrial activity (tetrazolium salt), proliferation ([(3)H]thymidine incorporation), and the mechanisms of cell death (terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling [TUNEL] staining) were used to assess differences between PDT (100 J/cm(2)) and gamma-RT (10 or 20 Gy) on SMC injury. The different effects on bioregulatory molecules were investigated by quantitating the proliferation of SMCs cultured with conditioned medium and on treated ECM. PDT of SMCs reduced proliferation and mitochondrial activity (0.5+/-0.75% and 1.7+/-4.25%, respectively, P<0.0001), whereas gamma-RT of SMCs decreased cell proliferation but did not affect metabolic activity. Stimulation with calf serum of gamma-RT-treated SMCs did not affect proliferation but increased mitochondrial enzyme activity (160+/-11%, P<0.0005). The conditioned medium, derived from PDT- but not gamma-RT-treated SMCs, did not stimulate effector SMC proliferation compared with gamma-RT-treated SMCs (16+/-4.1% versus 80+/-16.8%, P<0.0001). Apoptosis was the principle cytotoxic mechanism after PDT, whereas gamma-RT cells were growth arrested but viable. PDT of the ECM reduced effector SMC proliferation compared with controls and gamma-RT cells (18+/-6.5% versus 100+/-17.7% and 84+/-8.9%, respectively, P<0.0001). These data suggest that gamma-RT and PDT may inhibit restenosis but by different mechanisms. The effects of PDT are more diverse and may result in improved outcome while avoiding the teratogenic exposure due to ionizing irradiation.

Resident and Attending Physician Attitudes Regarding an Audience Response System

PURPOSE Audience response system (ARS) technology is increasingly being incorporated into radiology education. The aim of this study was to gauge resident and attending physician attitudes regarding the use of an ARS in resident conferences. METHODS An anonymous survey was sent to 38 residents and 57 attending physicians to gauge their attitudes regarding the use of an ARS in resident lectures using a 5-point, Likert-type scale (1 = strongly disagree, 2 = disagree, 3 = neither agree nor disagree, 4 = agree, and 5 = strongly agree). RESULTS A total of 30 of 38 residents (78.9%) and 26 of 57 attending radiologists (45.6%) responded. Residents viewed the incorporation of an ARS into lectures positively, replying that they learned better from lectures incorporating an ARS (mean, 4.03; 95% confidence interval [CI], 3.74-4.32), felt more comfortable answering questions using it (mean, 4.53; 95% CI, 4.25-4.81), and were more likely to attend a lecture that incorporated its use (mean, 3.70; 95% CI, 3.37-4.03). The use of an ARS by attending physicians was limited (9 of 26 [34.6%]), with respondents citing a lack of adequate training. Those attending physicians who used it viewed the system positively, stating that residents were more engaged when they used an ARS (mean, 4.33; 95% CI, 3.87-4.79). An ARS somewhat helped the faculty members gauge resident understanding of the lecture material (mean, 3.67; 95% CI, 2.95-4.40) and prepare future lectures (mean, 3.33; 95% CI 2.68-3.98). CONCLUSIONS Both residents and attending physicians favorably view audience response technology as a means to enhance education in didactic and case-based settings. Increased training on how to incorporate its use into teaching may drive additional utilization.

Clinical and Radiologic Predictive Factors of Septic Hip Arthritis

OBJECTIVE The purpose of our study was to identify the clinical and radiologic factors associated with a positive culture during image-guided hip joint aspiration. MATERIALS AND METHODS We performed a retrospective analysis of 167 consecutive hip aspirations for septic arthritis at a large tertiary medical center. Chart review was performed on the following clinical factors: serum WBC count≥11×10(3)/μL, serum erythrocyte sedimentation rate (ESR)≥20 mm/h, C-reactive protein (CRP)≥100 mg/L, synovial fluid WBC count, synovial fluid polymorphonuclear (PMN) leukocytes≥90%, fever, immunosuppression, antibiotic use, diabetes, presence of a prosthesis, and IV drug use (IVDU). Radiologic studies were reviewed for the following imaging and technical factors: presence of a sinus tract, fluid turbidity, volume of fluid (mL) aspirated, and whether the fluid analyzed was primarily aspirated or reaspirated after lavage. Logistic regression was used to calculate odds ratio (OR) and 95% CI. RESULTS Of the 167 aspirations, 29 (17.4%) had positive cultures; 6 of 29 (20.7%) positive cultures occurred in reaspirated lavage fluid. On multivariate analysis using logistic regression with stepwise backward elimination, the significant clinical and radiologic predictors were elevated WBC (OR, 4.4; 95% CI, 1.1-17.3), high percentage of synovial fluid PMN leukocytes (OR, 10.6; 95% CI, 2.9-39.8), IVDU (OR, 9.0; 95% CI, 1.3-64.7), and fluid turbidity (OR, 20.5; 95% CI, 6.9-61.4). CONCLUSION Positive hip cultures are associated with elevated serum WBC, IVDU, high percentage of synovial fluid PMN leukocytes, and fluid aspirate turbidity. Reaspiration of lavage fluid with either nonbacteriostatic saline or contrast material can yield positive cultures.

Imaging of Adult Flatfoot: Correlation of Radiographic Measurements With MRI

OBJECTIVE. The purpose of this study is to determine whether radiographic foot measurements can predict injury of the posterior tibial tendon (PTT) and the supporting structures of the medial longitudinal arch as diagnosed on MRI. MATERIALS AND METHODS. After institutional review board approval, 100 consecutive patients with radiographic and MRI examinations performed within a 2-month period were enrolled. Thirty-one patients had PTT dysfunction clinically, and 69 patients had other causes of ankle pain. Talonavicular uncoverage angle, incongruency angle, calcaneal pitch angle, Meary angle, cuneiform-to-fifth metatarsal height, and talar tilt were calculated on standing foot or ankle radiographs. MRI was used to assess for abnormalities of the PTT (tenosynovitis, tendinosis, and tear) and supporting structures of the medial longitudinal arch (spring ligament, deltoid ligament, and sinus tarsi). Statistical analysis was performed using the chi-square and Fisher exact tests for categoric variables; the Student t test was used for continuous variables. RESULTS. There was a statistically significant association of PTT tear with abnormal talonavicular uncoverage angle, calcaneal pitch angle, Meary angle, and cuneiform-to-fifth metatarsal height. PTT tendinosis and isolated tenosynovitis had a poor association with most radiologic measurements. If both calcaneal pitch and Meary angles were normal, no PTT tear was present. An abnormal calcaneal pitch angle had the best association with injury to the supporting medial longitudinal arch structures. CONCLUSION. Radiographic measurements, especially calcaneal pitch and Meary angles, can be useful in detecting PTT tears. Calcaneal pitch angle provides the best assessment of injury to the supporting structures of the medial longitudinal arch.

Comparison of Battery-Powered and Manual Bone Biopsy Systems for Core Needle Biopsy of Sclerotic Bone Lesions.

OBJECTIVE The purpose of this study was to compare manual and battery-powered bone biopsy systems for diagnostic yield and procedural factors during core needle biopsy of sclerotic bone lesions. MATERIALS AND METHODS A total of 155 consecutive CT-guided core needle biopsies of sclerotic bone lesions were performed at one institution from January 2006 to November 2014. Before March 2012, lesions were biopsied with manual bone drill systems. After March 2012, most biopsies were performed with a battery-powered system and either noncoaxial or coaxial biopsy needles. Diagnostic yield, crush artifact, CT procedure time, procedure radiation dose, conscious sedation dose, and complications were compared between the manual and battery-powered core needle biopsy systems by Fisher exact test and t test. One-way ANOVA was used for subgroup analysis of the two battery-powered systems for procedure time and radiation dose. RESULTS The diagnostic yield for all sclerotic lesions was 60.0% (93/155) and was significantly higher with the battery-powered system (73.0% [27/37]) than with the manual systems (55.9% [66/118]) (p = 0.047). There was no significant difference between the two systems in terms of crush artifact, procedure time, radiation dose, conscious sedation administered, or complications. In subgroup analysis, the coaxial battery-powered biopsies had shorter procedure times (p = 0.01) and lower radiation doses (p = 0.002) than the coaxial manual systems, but the noncoaxial battery-powered biopsies had longer average procedure times and higher radiation doses than the coaxial manual systems. CONCLUSION In biopsy of sclerotic bone lesions, use of a battery-powered bone drill system improves diagnostic yield over use of a manual system.

Lipomatosis of the sciatic nerve secondary to compression by a desmoid tumor

Lipomatosis of nerve is a rare benign tumor-like process characterized by infiltration of the epineurium by adipose and fibrous tissue leading to nerve enlargement. We describe a case of lipomatosis of the sciatic nerve compressed by an adjacent desmoid tumor. This case supports the hypothesis that lipomatosis of nerve may form as a result of irritation or compression by adjacent structures.

On-Call Musculoskeletal Radiographs: Discrepancy Rates Between Radiology Residents and Musculoskeletal Radiologists

OBJECTIVE The purpose of this study was to determine the rate of discrepancy between radiology residents and attending musculoskeletal radiologists in interpretation of on-call musculoskeletal radiographs. MATERIALS AND METHODS We performed a retrospective review of 2219 consecutive musculoskeletal radiology reports on patients who visited the emergency department between January 2009 and December 2010. The images were initially interpreted overnight by on-call residents (postgraduate years 3-5), and a final interpretation was rendered the next morning by a musculoskeletal radiologist. The reports were evaluated for major discrepancies, such as missed fractures, osteomyelitis, foreign bodies, tumors, and acute arthritic conditions, which were defined as cases in which a change in clinical management was needed and required notification of the emergency care provider. RESULTS The overall discrepancy rate was 1.8% (40/2219). Fractures accounted for 62.5% (25/40) of missed findings. Fractures involving the upper extremity, particularly the hand and wrist (2.2% [9/405]), were the most frequently missed. Radial fractures accounted for 50% (7/14) of the missed upper extremity fractures. Foreign bodies (10% [4/40]) and tumorlike lesions (7.5% [3/40]) accounted for the next most common misses. Finally, independent resident readings in the on-call setting had little adverse effect on patient care. CONCLUSION In the on-call setting, the low discrepancy rate between interpretations of musculoskeletal radiographs by residents and by musculoskeletal attending radiologists is comparable to that reported for other body parts and modalities. Residents should be aware of the relatively high rate of missed pathologic findings in the upper extremity, especially the radius.

Teaching Principles of Patient-Centered Care During Radiology Residency.

RATIONALE AND OBJECTIVES Patient-centered healthcare delivery has become increasingly established as a cornerstone of quality medical care, but teaching these principles in a radiology residency setting is often difficult and ineffective in a traditional lecture format. We developed a novel educational session in which actual patient letters about a healthcare provider are used to facilitate a case-based discussion of key principles of patient-centered care. MATERIALS AND METHODS A novel patient letter-facilitated, case-based session was conducted at two different university-based teaching institutions. Prior to the educational session, patient letters introducing the principles of patient-centered care were distributed to residents for review. During the session, radiology-specific cases were discussed in the context of the principles introduced by the letters. A post-session survey was administered to evaluate the efficacy and usefulness of the session. RESULTS Forty-six of the 61 session attendees (75%) completed the post session survey. Most respondents (93%) preferred this case-based, interactive session to a typical didactic session. A majority of the residents indicated that both the patient letters (64%) and radiology specific cases (73%) helped them think differently about how they interact with patients. They indicated that the session enhanced their understanding of professionalism (3.7 out of 5.0 [95% CI 3.4-4.0]) and increased their motivation to become more patient-centered (3.0 out of 4.0 [95% CI 2.8-3.3]). CONCLUSIONS Our findings suggest that patient letter-facilitated, case-based sessions may influence resident attitudes regarding the principles of patient-centered care and may help to increase resident motivation to become more patient-centered in their own practice.