Fluoroscopy: An essential diagnostic modality in the age of high-resolution cross-sectional imaging

The importance of fluoroscopy as an imaging modality has been minimized relative to other cross-sectional modalities, including high-resolution computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound. Fluoroscopy examinations have decreased in clinical practice due to reduced appreciation of its usefulness, insufficient training of residents, fewer staff with adequate expertise, and poor reimbursements relative to other modalities. We revisit and build upon the prior literature and history of this decreased utilization. We then seek to prove continued value, through categorized examples and within multiple subspecialties, wherein fluoroscopy plays an integral part toward clinical diagnoses as well as optimizing patient outcomes. This is particularly true for motility and esophageal disorders, where structure and function with real-time evaluation is essential.  We additionally show several post-operative cases where the synergy of fluoroscopy with CT and endoscopy is apparent.  The fluoroscopic radiologist also has the unique ability to vary patient positioning, as opposed to traditional CT or MRI, where orthogonal views are employed without positional or temporal changes. We turn attention to the modern era, with synergistic and novel cases demonstrating that fluoroscopy remains instrumental toward achieving a diagnosis alongside other modalities. Our cases stress the need to maintain expertise in fluoroscopy skill, and underline its continued importance in residency training programs.  We conclude that fluoroscopy is a relatively inexpensive modality that is often under-appreciated in diagnostic radiology. We suggest that competency in fluoroscopy is crucial for future generations of radiologists to both work with their peers, as well as to aid clinicians in the optimal treatment of patients.     

The role of the sagittal view of the ductal arch in identification of fetuses with conotruncal anomalies using 4-dimensional ultrasonography.

OBJECTIVE: Conotruncal anomalies represent one fifth of all congenital heart defects (CHDs) detected in the fetus. However, the spatial relationship of the great vessels is incorrectly defined in about 20% of these cases. The sagittal view of the ductal arch is considered a standard ultrasonographic view in fetal echocardiography and can be easily visualized using 4-dimensional (4D) ultrasonography. This study was designed to determine the role of this ultrasonographic plane for the prenatal diagnosis of conotruncal anomalies. METHODS: We reviewed 4D volume data sets, acquired with the spatiotemporal image correlation technique, from fetuses with and without confirmed conotruncal anomalies. The visualization rate of the sagittal view of the ductal arch was compared among groups using standardized multiplanar views. RESULTS: This study included 183 volume data sets from fetuses in the following groups: (1) normal echocardiographic findings (n = 130); (2) conotruncal anomalies (n = 18); and (3) other CHDs (n = 35). Volumes of poor image quality were excluded from analysis (8.2% [15/183]). The visualization rate of the sagittal view of the ductal arch was significantly lower in fetuses with conotruncal anomalies (5.6% [1/18]) than that in fetuses without abnormalities (93.1% [108/116]) and that in fetuses with other CHDs (79.4% [27/34]; P < .01). Absence of visualization of the sagittal view of the ductal arch was associated with a likelihood ratio of 9.44 (95% confidence interval, 5.8-15.5) to have conotruncal anomalies. CONCLUSIONS: The sagittal view of the ductal arch may play an important role in the screening and prenatal diagnosis of conotruncal anomalies in 4D ultrasonography.     

Exposure to music and noise-induced hearing loss (NIHL) among professional pop/rock/jazz musicians

Noise-induced hearing loss (NIHL) has been extensively studied in industrial work environments. With the advent of new technologies, loud music has been increasingly affecting listeners outside of the industrial setting. Most research on the effects of music and hearing loss has focused on classical musicians. The purpose of the current study was to examine the relationship between the amount of experience a professional pop/rock/jazz musician has and objective and subjective variables of the musician''s hearing loss. This study also examined professional pop/rock/jazz musicians’ use of hearing protection devices in relation to the extent of their exposure to amplified music. Forty-four pop/rock/jazz musicians were interviewed using the Pop/Rock/Jazz Musician''s Questionnaire (PRJMQ) in order to obtain self-reported symptoms of tinnitus and hyperacusis. Forty-two of the subjects were also tested for air-conduction hearing thresholds in the frequency range of 1-8 kHz. Results show that the extent of professional pop/rock/jazz musicians’ exposure to amplified music was related to both objective and subjective variables of hearing loss: Greater musical experience was positively linked to higher hearing thresholds in the frequency range of 3-6 kHz and to the subjective symptom of tinnitus. Weekly hours playing were found to have a greater effect on hearing loss in comparison to years playing. Use of hearing protection was not linked to the extent of exposure to amplified music. It is recommended that further research be conducted with a larger sample, in order to gain a greater understanding of the detrimental effects of hours playing versus years playing.     

Quantitation of basal dyssynchrony and acute resynchronization from left or biventricular pacing by novel echo-contrast variability imaging

OBJECTIVES: This study sought to test a novel echocardiographic method based on contrast variability imaging (CVI), to quantify cardiac dyssynchrony and magnitude of resynchronization achieved by left ventricular (LV) and biventricular (BiV) pacing therapy. BACKGROUND: Left ventricular or BiV pacing is a promising new therapy for patients with heart failure and intraventricular conduction delay. However, precise quantitation of the extent of resynchronization achieved remains scant. METHODS: Ten patients treated with BiV or LV pacing therapy were studied. Echo-contrast was infused slowly, and gated images were acquired before and during contrast appearance. The temporally normalized variance derived from 30 to 50 sequential beats was determined at each pixel to yield the CVI image-displaying improved wall delineation. Systolic regional fractional area of radial sectors was calculated with active and temporarily suspended (AAI) pacing. All analyses were performed blinded to both patient and treatment. RESULTS: Pacing increased septal inward motion from -20.4 +/- 9.6% to -30.5 +/- 14.0%, whereas lateral wall motion occurred earlier with no net magnitude change. Both spatial and temporal dyssynchrony in the LV declined nearly 40% with LV or BiV pacing (p < or = 0.001), and this correlated with increasing ejection fraction (31% to 39%; p < 0.02; p < 0.004 for correlation with dyssynchrony). CONCLUSIONS: The new imaging and regional dyssynchrony analysis methods provide quantitative assessment of resynchronization analogous to that previously obtained only by tagged magnetic resonance imaging. This could provide a useful noninvasive method for both identifying candidates and following long-term therapy.     

Astrocytes facilitate melanoma brain metastasis via secretion of IL‐23

Melanoma is the leading cause of skin cancer mortality. The major cause of melanoma mortality is metastasis to distant organs, frequently to the brain. The microenvironment plays a critical role in tumourigenesis and metastasis. In order to treat or prevent metastasis, the interactions of disseminated tumour cells with the microenvironment at the metastatic organ have to be elucidated. However, the role of brain stromal cells in facilitating metastatic growth is poorly understood. Astrocytes are glial cells that function in repair and scarring of the brain following injury, in part via mediating neuroinflammation, but the role of astrocytes in melanoma brain metastasis is largely unresolved. Here we show that astrocytes can be reprogrammed by human brain‐metastasizing melanoma cells to express pro‐inflammatory factors, including the cytokine IL‐23, which was highly expressed by metastases‐associated astrocytes in vivo. Moreover, we show that the interactions between astrocytes and melanoma cells are reciprocal: paracrine signalling from astrocytes up‐regulates the secretion of the matrix metalloproteinase MMP2 and enhances the invasiveness of brain‐metastasizing melanoma cells. IL‐23 was sufficient to increase melanoma cell invasion, and neutralizing antibodies to IL‐23 could block this enhanced migration, implying a functional role for astrocyte‐derived IL‐23 in facilitating the progression of melanoma brain metastasis. Knocking down the expression of MMP2 in melanoma cells resulted in inhibition of IL‐23‐induced invasiveness. Thus, our study demonstrates that bidirectional signalling between melanoma cells and astrocytes results in the formation of a pro‐inflammatory milieu in the brain, and in functional enhancement of the metastatic potential of disseminated melanoma cells. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Beat-to-beat QT interval variability associated with acute myocardial ischemia.

Beat-to-beat QT interval variability (QTV) quantifies lability in ventricular repolarization. We hypothesized that myocardial ischemia destabilizes ventricular repolarization and increases QTV. We analyzed 2-hour 2-lead digitized electrocardiogram records of 68 patients in the European ST-T Database. All patients had ischemic episodes during the 2-hour record, annotated by the developers of the database. We determined the normalized QTV (QTVnorm), QT variability index (QTVI), and normalized heart rate variability (HRVnorm) for each 5-minute epoch by automated analysis. QTVnorm was greater during ischemic episodes than during nonischemic episodes (1.41 +/- 0.77 vs. 0.88 +/- 0.23, P <.0001). There was no significant difference in HRVnorm between ischemic and nonischemic episodes (1.22 +/- 0.63 vs. 0.94 +/- 0.18, not significant). The QTVI was higher during ischemic episodes than during nonischemic episodes (0.14 +/- 0.31 vs. -0.051 +/- 0.12, P <.0001). Acute ischemia is associated with labile ventricular repolarization, which manifests as enhanced beat-to-beat QT interval variability. The association between ischemic repolarization liability and arrhythmic risk deserves further study.