Joseph R. Grajo

Online Social Networking for Radiology

Online social networking services have changed the way we interact as a society and offer many opportunities to improve the way we practice radiology and medicine in general. This article begins with an introduction to social networking. Next, the latest advances in online social networking are reviewed, and areas where radiologists and clinicians may benefit from these new tools are discussed. This article concludes with several steps that the interested reader can take to become more involved in online social networking.

Comparison of Sonography and Scintigraphy in the Evaluation of Gallbladder Functional Studies With Cholecystokinin

Objective. Both sonography and scintigraphy have been used to evaluate gallbladder function with the use of sincalide (cholecystokinin [CCK]). However, the reported ejection fractions (EFs) for the two modalities are not the same. The techniques measure slightly different parameters. This study directly compared both techniques performed simultaneously on the same participants. Methods. Twenty healthy volunteers were evaluated with sonography and scintigraphy to estimate the gallbladder EF simultaneously. The gallbladder EF was calculated at 5‐minute intervals for 1 hour. Results. The mean EFs ± SD were 66.3% ± 20% and 49% ± 29% for sonography and scintigraphy, respectively. The mean times to the peak EF were 38 ± 12 and 33 ± 9 minutes for sonography and scintigraphy. An average time of 34 minutes was noted after radiopharmaceutical injection before CCK administration for the scintigraphic studies. The earliest time to the peak EF for sonography was 15 minutes, and the latest time to the peak EF was 60 minutes (mode, 40 minutes); for scintigraphy, the earliest and latest times were 15 and 50 minutes (mode, 30 minutes), respectively. One participant could not be evaluated secondary to nonfilling of the gallbladder on scintigraphy. There was wider variability of the gall‐bladder EF with scintigraphy than sonography. Conclusions. Scintigraphy estimated a lower EF than sonography, had wider EF variability than sonography, and required additional time (>30 minutes more) to complete the study. Scintigraphy could not be performed in 5% of the participants because of nonfilling of the gallbladder. The use of sonography to estimate the gallbladder EF is less time‐consuming and less costly. With these techniques, the range of normal gallbladder EFs should be adjusted for the technique used.

Unusual Ectopic Pregnancies Sonographic Findings and Implications for Management

Ectopic pregnancy is a considerable source of morbidity and mortality for women of childbearing age. Improved detection and increased risk factors have led to a dramatic rise in the incidence of ectopic pregnancy in recent years. Early diagnosis is critical for the health of the patient as well as the success rate of future pregnancies. Besides laparoscopy, sonography is the mainstay for evaluating ectopic pregnancy. It is important to understand the sonographic features of ectopic pregnancies, including unusual cases that occur outside the fallopian tube.

Machine learning for medical ultrasound: status, methods, and future opportunities

Ultrasound (US) imaging is the most commonly performed cross-sectional diagnostic imaging modality in the practice of medicine. It is low-cost, non-ionizing, portable, and capable of real-time image acquisition and display. US is a rapidly evolving technology with significant challenges and opportunities. Challenges include high inter- and intra-operator variability and limited image quality control. Tremendous opportunities have arisen in the last decade as a result of exponential growth in available computational power coupled with progressive miniaturization of US devices. As US devices become smaller, enhanced computational capability can contribute significantly to decreasing variability through advanced image processing. In this paper, we review leading machine learning (ML) approaches and research directions in US, with an emphasis on recent ML advances. We also present our outlook on future opportunities for ML techniques to further improve clinical workflow and US-based disease diagnosis and characterization.

A Fixed Stricture on Routine Cross-sectional Imaging Predicts Disease-Related Complications and Adverse Outcomes in Patients with Crohn's Disease

Background: Patients with Crohns disease (CD) typically undergo multiple cross-sectional imaging exams including computed tomography and magnetic resonance enterography during the course of their disease. The aim was to identify imaging findings that predict future disease-related poor outcomes. Methods: This was a retrospective, case control study at a single tertiary center. Cases were CD patients diagnosed with complications (bowel obstruction, perforation, internal fistula, or abscess); controls were CD patients without complications. Two radiologists blinded to clinical outcomes, independently scored cross-sectional imaging examinations obtained before the complication. Results: One hundred eight patients (67 F; 41 M) with CD (51 cases; 57 controls) were included. For the cases, 21 had internal fistulae, 15 had bowel obstructions, 13 had abdominal abscesses, and 2 developed bowel perforations. Patients with complications were more likely to have a fixed small bowel stricture on cross-sectional imaging (P = 0.01). A patient with a stricture and upstream dilatation was 3.4 times more likely to develop a complication in the next 2 years. When present in the setting of hypervascularity and/or evidence of active inflammation, the risk increased further to 15-fold. Cases were more likely to be active smokers (29% versus 12%, P = 0.033). Cases had more evidence of inflammation based on higher Harvey Bradshaw Index values and inflammatory biomarkers and lower hemoglobin values. Conclusions: Information from radiologic studies, especially the presence of fixed strictures, can predict future CD complications. These findings, along with smoking and ongoing inflammation, should alert the clinician to the possibility of future complications.

Multiple Endocrine Neoplasia Syndromes: A Comprehensive Imaging Review.

MEN1, MEN2, and MEN4 comprise a series of familial disorders involving the simultaneous occurrence of tumors in more than one endocrine organ, collectively known as multiple endocrine neoplasia. Patients with this family of disorders develop tumors of the parathyroid gland, pancreas, pituitary gland, adrenal gland, and thyroid gland, along with miscellaneous neuroendocrine tumors of the respiratory and gastrointestinal tracts. Although some patients undergo early prophylactic surgical management, particularly in the setting of familial medullary thyroid carcinoma, many develop tumors later in life. These tumors are often discovered at imaging for screening purposes. Recognition of the imaging features of the known tumors is important for appropriate patient management.

Surgery for Obesity and Related Diseases: II. Experimental Validation of Longitudinal Speed of Sound Estimates in the Diagnosis of Hepatic Steatosis

This study validates a non-invasive, quantitative technique to diagnose steatosis within tissue. The proposed method is based on two fundamental concepts: (i) the speed of sound in a fatty liver is lower than that in a healthy liver and (ii) the quality of an ultrasound image is maximized when the beamformers speed of sound matches the speed in the medium under examination. The method uses image brightness and sharpness as quantitative image-quality metrics to predict the true sound speed and capture the effects of fat infiltration, while accounting for the transmission through subcutaneous fat. Ex vivo testing on sheep liver, mouse livers and tissue-mimicking phantoms indicated the techniques ability to predict the true speed of sound with errors less than 0.5% and to quantify the inverse correlation between fat content and speed of sound.

Surgery for Obesity and Related Diseases: I. A Novel Approach to the Quantification of the Longitudinal Speed of Sound and Its Potential for Tissue Characterization

Described here is a method to determine the longitudinal speed of sound in speckle-dominated ultrasound images. The method is based on the concept that the quality of an ultrasound image is maximized when the beamformers speed of sound matches the speed in the medium. The method captures the quality of the ultrasound image using two quantitative image-quality metrics: image brightness and sharpness around the intended focal zone. The proposed method requires no calibration, is computationally efficient and is deployable on commercial ultrasound systems without hardware or software modifications. Ex vivo testing on tissue-mimicking phantoms indicates the methods accuracy in predicting the true speed of sound to within 1% of ground truth values.

Diagnostic Performance of Shear Wave Elastography in Patients With Autoimmune Liver Disease: Shear Wave Elastography in Autoimmune Liver Disease

To assess performance of shear wave elastography for evaluation of fibrosis and the histologic stage in patients with autoimmune liver disease (ALD) and to validate previously established advanced fibrosis cutoff values in this cohort.

Principles of ultrasound elastography

Tissue stiffness has long been known to be a biomarker of tissue pathology. Ultrasound elastography measures tissue mechanical properties by monitoring the response of tissue to acoustic energy. Different elastographic techniques have been applied to many different tissues and diseases. Depending on the pathology, patient-based factors, and ultrasound operator-based factors, these techniques vary in accuracy and reliability. In this review, we discuss the physical principles of ultrasound elastography, discuss differences between different ultrasound elastographic techniques, and review the advantages and disadvantages of these techniques in clinical practice.