Non-invasive diagnostic criteria of hepatocellular carcinoma: Comparison of diagnostic accuracy of updated LI-RADS with clinical practice guidelines of OPTN-UNOS, AASLD, NCCN, EASL-EORTC, and KLSCG-NCC.

PURPOSE: To retrospectively compare the diagnostic performance of different noninvasive diagnostic criteria of HCC including LI-RADS, OPTN-UNOS, AASLD, NCCN, EASL-EORTC, KLCSG-NCC. MATERIALS AND METHODS: We reviewed the medical records of 3,491 pathologically examined liver lesions from January-2011 to January-2015 in our institution. 195 lesions in 133 patients (M:F = 100:33) with chronic hepatitis B/C and/or cirrhosis for any etiology were finally included in our study, with 98 lesions ≥ 2 cm, 72 lesions between 1-2 cm, and 25 lesions < 1 cm. The main comparison was made with the largest nodules of each patient (n = 133). The lesions were retrospectively evaluated for the diagnosis of HCC on DCE-CT or MR using different noninvasive diagnostic criteria including LI-RADS, OPTN-UNOS, AASLD, NCCN, EASL-EORTC, and KLCSG-NCC. With pathological evaluation serving as a gold-standard, sensitivity, specificity, PPV and NPV as well as accuracy of the diagnostic criteria were calculated. RESULTS: There was no statistically significant differences in diagnostic accuracy among noninvasive diagnostic criteria. For 133 lesions of the largest lesion per patient, the overall accuracy was highest with LI-RADS criteria (89.3%) and the overall sensitivity was highest with LI-RADS, AASLD, NCCN criteria (all 89.5%). For 1-2 cm lesions, sensitivity decreased for all criteria in the following order: EASL-EORTC (59.1%), KLCSG-NCC (58.3%), LI-RADS, AASLD, NCCN (all 56.5%), and OPTN-UNOS (22.7%) criteria. OPTN-UNOS had the highest specificity in cirrhotic livers, 91.7%. CONCLUSIONS: The current noninvasive diagnostic criteria of HCC have no statistically significant difference in diagnostic accuracy. Overall, LI-RADS had the highest sensitivity and accuracy among the guidelines. OPTN had the highest specificity for cirrhotic livers.

Characterizing Dehn surgeries on links via trisections.

We summarize and expand known connections between the study of Dehn surgery on links and the study of trisections of closed, smooth 4-manifolds. In particular, we propose a program in which trisections could be used to disprove the generalized property R conjecture, including a process that converts the potential counterexamples of Gompf, Scharlemann, and Thompson into genus four trisections of the standard 4-sphere that are unlikely to be standard. We also give an analog of the Casson-Gordon rectangle condition for trisections that obstructs reducibility of a given trisection.

Bridge trisections of knotted surfaces in 4-manifolds.

We prove that every smoothly embedded surface in a 4-manifold can be isotoped to be in bridge position with respect to a given trisection of the ambient 4-manifold; that is, after isotopy, the surface meets components of the trisection in trivial disks or arcs. Such a decomposition, which we call a generalized bridge trisection, extends the authors' definition of bridge trisections for surfaces in [Formula: see text] Using this construction, we give diagrammatic representations called shadow diagrams for knotted surfaces in 4-manifolds. We also provide a low-complexity classification for these structures and describe several examples, including the important case of complex curves inside [Formula: see text] Using these examples, we prove that there exist exotic 4-manifolds with [Formula: see text]-trisections for certain values of g. We conclude by sketching a conjectural uniqueness result that would provide a complete diagrammatic calculus for studying knotted surfaces through their shadow diagrams.

Multi-institutional survey on imaging practice patterns in pancreatic ductal adenocarcinoma.

PURPOSE: To study the practice patterns for performance and interpretation of CT/MRI imaging studies in patients with pancreatic ductal adenocarcinoma (PDAC) at multiple institutions using a survey-based assessment. METHODS: In this study, abdominal radiologists/body imagers on the Society of Abdominal Radiology disease-focused panel for PDAC and from multiple institutions participated in an online survey. The survey was designed to investigate the imaging and reporting practice patterns for PDAC. The survey questionnaire addressed the experience of referring providers, choice of imaging modality for diagnosis and follow-up of PDAC, structured imaging templates utilization for PDAC, and experiences with the use of structured reports. RESULTS: The response rate was 89.6% (43/48), with majority of the respondents working in a teaching hospital or academic research center (95.4%). While 86% of radiologists reported use of structured reporting templates in their practice, only 60.5% used standardized templates specific to PDAC. This lower percentage was despite most of them (77%) being aware of existence of PDAC-specific templates and recognizing their benefits, such as preference by referring providers (83%), improved uniformity (100%), and higher accuracy of reports (76.2%). The common impediments to the use of PDAC-specific templates were interference with efficient workflow (67.5%), lack of interest (52.5%), and complexity of existing templates (47.5%). With regards to imaging practice, 92.7% (n = 40/43) of respondents reported performing dynamic multiphasic pancreatic protocol CT for evaluation of patients with initial suspicion or staging of PDAC. CONCLUSION: Structured reporting templates for PDAC are not universally utilized in subspecialty abdominal/body imaging practices due to concerns of interference with efficient workflow and complexity of templates. Multiphasic pancreatic protocol CT is most frequently performed for evaluation of PDAC.

Staging of pancreatic cancer: resectable, borderline resectable, and unresectable disease.

Pancreatic ductal adenocarcinoma (PDAC) is a relatively common malignancy that carries an overall poor prognosis, with five-year survival below 10%. Despite ongoing research, surgical resection remains the only potentially curative treatment. Therefore, accurate identification of those patients who would benefit from surgical resection is of paramount importance. High-quality imaging and image interpretation is central to this process. Radiology helps in the determination of whether patients are resectable, borderline resectable, or unresectable and guides treatment planning.

Intraperitoneal metastases after transarterial embolization of hepatocellular carcinoma: An observational study.

PURPOSE: Transarterial embolization is frequently used to treat local hepatocellular carcinoma (HCC). While various complications are known to occur following transarterial embolization, only one prior case of peritoneal spread of HCC occurring shortly after transarterial chemoembolization has been reported. We present five cases of peritoneal spread of HCC following transarterial embolization (including bland embolization, conventional transarterial chemoembolization (TACE), and doxorubicin-eluting beads TACE) and identify features common among those cases. METHODS: Search of electronic radiology reports and images identified five patients with imaging before and after treatment of HCC with transarterial embolization and with newly developed peritoneal metastases after treatment. Various patient demographics and tumor characteristics were noted. RESULTS: The mean maximal diameter of the treated HCC tumors was 3.7 cm (range 1.4-11.9 cm). Three of the patients had ascites and treated tumors in the posterior right hepatic lobe, and all patients had subcapsular tumors treated with transarterial embolization before developing peritoneal metastases. The mean time from treatment with transarterial embolization to the development of peritoneal metastases was four months. CONCLUSIONS: Intraperitoneal metastatic disease should be considered a rare but potential complication of transarterial embolization of subcapsular HCC, particularly in patients with ascites and tumors that are in the posterior segments of the right lobe. This potential complication should perhaps be considered when planning transarterial HCC treatment, and radiologists interpreting imaging after transarterial embolization of HCC should assess for peritoneal metastases.

Normal main portal vein diameter measured on CT is larger than the widely referenced upper limit of 13 mm.

OBJECTIVE: We determined mean main portal vein diameter in healthy patients evaluated with CT, compared this value to the "upper limit of normal" reported previously, and evaluated effects of age, sex, height, and BMI on portal vein diameter. MATERIALS AND METHODS: Our cohort of healthy patients underwent abdominal CT as potential renal donors. We excluded patients with evidence of liver or severe cardiac disease. We recorded patients' age, sex, height, weight, and BMI. Patients' main portal vein diameters were measured by fellowship-trained abdominal imagers on non-contrast and post-contrast images in axial and coronal projections at a defined location. A general linear mixed model was used for analysis. RESULTS: 191 patients with 679 main portal vein measurements were included in the analysis. Mean main portal vein diameter was 15.5 ± 1.9 mm; this value was significantly different from the upper limit of normal of 13 mm commonly referenced in the literature (95% CI: 2.22-2.69 mm higher, p < 0.0001). Portal vein diameter does not vary significantly when measured on axial vs. coronal images. On average, post-contrast main portal veins were 0.56 mm larger compared to non-contrast, (95% CI: 0.40-0.71 mm, p < 0.0071). Patient height and BMI are positively correlated with MPV diameter. CONCLUSIONS: Normal mean portal vein diameter measured on CT was significantly larger (mean 15.5 mm) than the accepted upper limit of 13 mm. Contrast-enhanced main portal veins are significantly larger (0.56 mm) than unenhanced. Sex, height, and BMI significantly affect main portal vein diameter.

Thyroid Nodule Doubling Time is Not a Reliable Indicator of Benign or Malignant Nature.

Thyroid nodules are often followed up with serial ultrasound imaging. Doubling time is well established in the evaluation of lung nodules. We examined whether benign and malignant thyroid nodules exhibit differences in doubling time.This retrospective, IRB-approved study included patients with nodules aspirated between January and June 2012 (benign), and January 2012 to December 2014 (suspicious or malignant), no interval thyroidectomy, and two ultrasound examinations longer than 180 days apart. Diameters and morphology were assessed by a single observer, demographics recorded, and doubling time calculated. Area under the receiver operating characteristic curve was derived. Society of Radiologists in Ultrasound criteria were used to determine aspiration appropriateness initially and after follow-up.59 patients with 61 nodules were included. Statistically significant between-group differences exist for sex, solidity, echogenicity, and microcalcifications, with no significant differences in doubling time, age, days between studies, vascularity, or mean diameter. Benign nodules' doubling time was 340 to 7134 days (mean, 2196; median, 1593), with 9 nodules that decreased in size. Malignant nodules' doubling time was 451 to 17182 days (mean, 3940; median, 2137), with 7 nodules that decreased in size. Using a threshold of 1100 days, sensitivity and specificity of doubling time to predict malignancy are 19.0% and 86.7%, respectively. Area under the receiver operating characteristic curve is 0.39. Follow-up imaging resulted in 6 additional benign and 0 additional malignant nodules meeting criteria.There is no significant difference in benign or malignant nodules' doubling times, and a decrease in nodule size is nonspecific. These findings challenge the underlying rationale for routine imaging follow-up of thyroid nodules.

Hepatocellular Carcinoma: Review of Epidemiology, Screening, Imaging Diagnosis, Response Assessment, and Treatment.

Hepatocellular carcinoma is a common malignancy for which prevention, screening, diagnosis, treatment, and surveillance demand a multidisciplinary approach. Knowledge of the underlying pathophysiology as well as advances in clinical management should be employed by radiologists to effectively communicate with hepatologists, surgeons, and oncologists. In this review article, we present recent developments in the clinical management of hepatocellular carcinoma.

Attributing awareness to oneself and to others.

This study tested the possible relationship between reported visual awareness ("I see a visual stimulus in front of me") and the social attribution of awareness to someone else ("That person is aware of an object next to him"). Subjects were tested in two steps. First, in an fMRI experiment, subjects were asked to attribute states of awareness to a cartoon face. Activity associated with this task was found bilaterally within the temporoparietal junction (TPJ) among other areas. Second, the TPJ was transiently disrupted using single-pulse transcranial magnetic stimulation (TMS). When the TMS was targeted to the same cortical sites that had become active during the social attribution task, the subjects showed symptoms of visual neglect in that their detection of visual stimuli was significantly affected. In control trials, when TMS was targeted to nearby cortical sites that had not become active during the social attribution task, no significant effect on visual detection was found. These results suggest that there may be at least some partial overlap in brain mechanisms that participate in the social attribution of sensory awareness to other people and in attributing sensory awareness to oneself.

Complex organization of human primary motor cortex: a high-resolution fMRI study.

A traditional view of the human motor cortex is that it contains an overlapping sequence of body part representations from the tongue in a ventral location to the foot in a dorsal location. In this study, high-resolution functional MRI (1.5x1.5x2 mm) was used to examine the somatotopic map in the lateral motor cortex of humans, to determine whether it followed the traditional somatotopic order or whether it contained any violations of that somatotopic order. The arm and hand representation had a complex organization in which the arm was relatively emphasized in two areas: one dorsal and the other ventral to a region that emphasized the fingers. This violation of a traditional somatotopic order suggests that the motor cortex is not merely a map of the body but is topographically shaped by other influences, perhaps including correlations in the use of body parts in the motor repertoire.

Isolation-by-distance and outbreeding depression are sufficient to drive parapatric speciation in the absence of environmental influences.

A commonly held view in evolutionary biology is that speciation (the emergence of genetically distinct and reproductively incompatible subpopulations) is driven by external environmental constraints, such as localized barriers to dispersal or habitat-based variation in selection pressures. We have developed a spatially explicit model of a biological population to study the emergence of spatial and temporal patterns of genetic diversity in the absence of predetermined subpopulation boundaries. We propose a 2-D cellular automata model showing that an initially homogeneous population might spontaneously subdivide into reproductively incompatible species through sheer isolation-by-distance when the viability of offspring decreases as the genomes of parental gametes become increasingly different. This simple implementation of the Dobzhansky-Muller model provides the basis for assessing the process and completion of speciation, which is deemed to occur when there is complete postzygotic isolation between two subpopulations. The model shows an inherent tendency toward spatial self-organization, as has been the case with other spatially explicit models of evolution. A well-mixed version of the model exhibits a relatively stable and unimodal distribution of genetic differences as has been shown with previous models. A much more interesting pattern of temporal waves, however, emerges when the dispersal of individuals is limited to short distances. Each wave represents a subset of comparisons between members of emergent subpopulations diverging from one another, and a subset of these divergences proceeds to the point of speciation. The long-term persistence of diverging subpopulations is the essence of speciation in biological populations, so the rhythmic diversity waves that we have observed suggest an inherent disposition for a population experiencing isolation-by-distance to generate new species.

Over-pointing technique: an approach to past-pointing arthroscopic knots on alternating suture posts without alternating the knot pusher.

As arthroscopic reconstructive surgery evolves, new techniques that improve operative efficiency while maintaining proven technical principles will enhance a surgeon's skill repertoire. A secure arthroscopic knot requires placing a series of reversed half-hitches on alternating posts and has traditionally involved alternating the knot-passing device between suture limbs to "past-point" each half-hitch, ensuring overall knot security. To increase the speed of knot-tying, a technical variation of keeping the knot pusher on the same suture limb throughout the knot-tying process, while still alternating posts, can be used. This technique involves alternately "pushing" and "pulling" sequential half-hitches into place. It is important to note that although conventional past-pointing is performed when "pulling" a half-hitch, it cannot be performed when purely "pushing" a half-hitch. In this article we describe a novel technique of "over-pointing" to be performed when pushing half-hitches into place. This is meant to be a complement to past-pointing by use of the knot pusher to advance the half-hitch and tighten the knot by over-riding the knot, effectively providing the equivalent of past-pointing by "pulling" the knot tight. In this way, a knot can be constructed without removing the device from the initial post strand of suture, saving time while maintaining the principles of secure knot-tying.

Assessment of age-related changes in abdominal organ structure and function with computed tomography and positron emission tomography.

With the size of the aged population in the United States expected to grow considerably during the next several decades, the number of imaging studies performed on such aged individuals will similarly increase. Thus, it is important to understand normal age-related changes in the structural and functional imaging appearance of the abdominal organs. We therefore present preliminary data and a review of the literature relevant to structural and functional changes in the abdominal organs of children and older adults. In a retrospective study of both adult and pediatric populations, we used computed tomography (CT), positron emission tomography (PET), and PET/CT imaging to investigate age-associated changes in size, attenuation, and metabolic function of the abdominal organs. Organs of interest include the liver, spleen, pancreas, kidneys, adrenal glands, stomach, small bowel, colon, and rectum. Although volumes of adult liver, spleen, pancreas, and kidneys do not change significantly with age, adult left and right adrenal gland volumes do significantly increase with age (r = 0.2823, P = 0.0334, and r = 0.3676, P = 0.0049, respectively). Also, the attenuation of adult liver (r = -0.2122, P = 0.0412), spleen (r = -0.4508, P < 0.0001), pancreas (r = -0.5124, P = 0.0007), and left and right adrenal gland (r = -0.5835, P < 0.0001 and r = -0.6135, P < 0.0001, respectively) decrease significantly with increasing age. Every organ studied in the pediatric population demonstrates a positive association between organ volume and age. Significant age-related changes in organ function are noted in the adult liver and small bowel, with the liver demonstrating a positive association between metabolic activity and age (r = 0.4434, P = 0.0029) and the small bowel showing an inverse association between mean small bowel standardize uptake value and age (r = -0.2435, P = 0.0174). Also, the maximum overall small bowel and colon metabolic activity in children increases with age (r = 0.6478, P = 0.0008). None of the other organs studied (ie, spleen, pancreas, adrenal glands, stomach, colon, rectum) demonstrate significant changes in metabolism with advancing age. The metabolic volumetric product (calculated as the product of organ volume and mean organ SUV) of the liver and spleen does not change significantly with age. In conclusion, various abdominal organs demonstrate differential changes in volume, attenuation, and/or metabolism with increasing age in pediatric and adult populations.

Detection of age-related changes in thoracic structure and function by computed tomography, magnetic resonance imaging, and positron emission tomography.

It is useful to understand the normal changes in structure and function in the thorax that occur with age. Thus, we present the following quantitative preliminary data obtained from retrospective quantitative analysis of computed tomography (CT) and positron emission tomography (PET) examinations in subjects 0 to 90 years of age: Mean lung standard uptake values were found to significantly increase with increasing age and with increasing body mass index (BMI). Mean lung attenuation was seen to statistically significantly decrease with increasing age in subjects who had a CT scan, had a nonsignificant tendency to decrease with increasing age in subjects with a PET/CT scan, had a nonsignificant tendency to increase with increasing BMI, and was seen to significantly increase with increasing mean lung standard uptake values. Mean lung volumes were not noted to significantly change with increasing age in adult subjects whether or not they were normalized to the craniocaudal thoracic lengths, although mean lung volumes significantly increased with increasing age in pediatric subjects. Mean lung volumes had a nonsignificant tendency to decrease with increasing BMI, although normalized mean lung volumes significantly decreased with increasing BMI. Lung metabolic volumetric products were not noted to significantly change with increasing BMI or with increasing age. In this work, we also review the literature regarding normal structural and functional changes in the thorax with age.

The effect of double-row fixation on initial repair strength in rotator cuff repair: a biomechanical study.

PURPOSE: The purpose of this study was to compare the initial mechanical strength of 3 rotator cuff repair techniques. METHODS: A total of 30 fresh-frozen cadaveric shoulders were prepared, and full-thickness supraspinatus tears were created. Specimens were randomized and placed into 3 groups: (1) transosseous suture technique (group I: TOS, n = 10, 6F/4M), (2) single-row suture anchor fixation (group II: SRSA, n = 10, 6F/4M), and (3) double-row suture anchor fixation (group III: DRSA, n = 10, 6F/4M). Each specimen underwent cyclic load testing from 5 N to 180 N at a rate of 33 mm/sec. The test was stopped when complete failure (repair site gap of 10 mm) or a total of 5,000 cycles was attained. RESULTS: Group I (TOS) failed at an average of 75.3 +/- 22.49 cycles, and group II (SRSA) at an average of 798.3 +/- 73.28 cycles; group III (DRSA) had no failures because all samples were stopped when 5,000 cycles had been completed. Fixation strength of the DRSA technique proved to be significantly greater than that of SRSA (P < .001), and both suture anchor groups were significantly stronger than the TOS group (P < .001). CONCLUSIONS: Suture anchor repairs were significantly stronger than transosseous repairs. Furthermore, double-row suture anchor fixation was significantly stronger than was single-row repair. Therefore, double-row fixation may be superior to other techniques in that it provides a substantially stronger repair that could lead to improved biologic healing. CLINICAL RELEVANCE: A high incidence of incomplete healing occurs in rotator cuff repair. Use of double-row fixation may help the clinician to address some deficiencies in current methods by increasing the strength of the repair, potentially leading to improved healing rates.

Rotator cuff repair: the effect of double-row fixation on three-dimensional repair site.

There is a high rate of recurrent and residual tears after rotator cuff repair surgery. Recent cadaveric studies have provided surgeons with new knowledge about the anatomy of the supraspinatus tendon insertion. Traditional repair techniques fail to reproduce the area of the supraspinatus insertion, or footprint, on the greater tuberosity anatomically. Double-row suture anchor (DRSA) fixation is a new technique that has been developed to restore the supraspinatus footprint better. In this study, 3-dimensional mapping was used to determine the area of the footprint recreated with 3 different repair methods: a transosseous simple suture technique, fixation with a single row of suture anchors, and DRSA fixation. The DRSA fixation technique consistently reproduced 100% of the original supraspinatus footprint, whereas the single-row suture anchor fixation and transosseous simple suture techniques reproduced only 46% and 71% of the insertion site, respectively. Therefore, the footprint area of the DRSA fixation technique was significantly larger (P < .05) than that of the other 2 techniques. Furthermore, double-row fixation may provide a tendon-bone interface better suited for biologic healing and restoring normal anatomy.