Effect of vertebral compression fractures on aortic neck angulation after endovascular aneurysm repair.

OBJECTIVE: Aortic neck angulation (ANA) prior to endovascular aneurysm repair (EVAR) and its changes after EVAR are considered important predictors of postoperative complications. We sought to assess the effects of vertebral body height loss on ANA in patients post-EVAR. METHODS: All patients who had undergone EVAR for infrarenal aortic aneurysms in our institution between August 2010 and December 2018 were assessed. Anterior and posterior vertebral body heights were measured in all patients on preoperative, early postoperative, and follow-up computed tomography scans (T12-L5 vertebral bodies). Patients who had significant height loss in their follow-up period were designated as the Study group. These were matched to a Control group of the same size using propensity-score matching based on age, gender, and duration between follow-up scans. Aortic neck morphology indices including ANA and its changes were measured, and information related to postoperative endoleaks and aneurysm sac size were extracted in the Study and Control groups. RESULTS: During the follow-up period, 10 of 185 patients had a radiologically significant vertebral body compression fracture. There was no significant difference between the Study (n = 10) and Control groups in age (77.6 ± 6.9 vs 77.2 ± 7.5 years; P = .64), gender (seven males and three females in each group; P = 1.0), duration between postoperative scans (1830 ± 665 vs 1800 ± 670 days; P = .25), preoperative ANA (36.0° ± 15.6° vs 42.4° ± 18.6°; P = .41), and early postoperative ANA (21.9° ± 11.7° vs 20.9° ± 16.3°; P = .72). Changes in ANA in the postoperative period (7.2° ± 11.1° vs -4.7° ± 6.7°; P = .009; power = .838) were significantly higher in the Study group. CONCLUSIONS: Post-EVAR vertebral body compression fractures exacerbate ANA. Awareness of this can guide both preoperative assessment and postoperative management and follow-up.

Arrhythmias in Children with Peripherally Inserted Central Catheters (PICCs).

To analyze the prevalence, types, and risk factors for cardiac arrhythmias associated with peripherally inserted central catheters (PICCs) in children. This is a case-control single center retrospective study. From 3180 PICCs inserted in children (< 18 years old) between 2009 and 2013, cases with new onset arrhythmias were identified. Demographics, type and timing of arrhythmias, and possible risk factors were analyzed. ECGs, rhythm strips, physicians' records, and anti-arrhythmic management were confirmatory. The level of the PICC's tip in the superior vena cava (SVC) or right atrium (RA) was ascertained from chest X-rays and counted in rib units (RU) and vertebra units (VU). Cases were matched (1:1 ratio) to controls by weight and date of insertion. Descriptive statistics were performed. A two-sided p value < 0.05 was considered significant. Thirty-one children (1%) developed arrhythmias, 16/31 (56%) were males, and 24/31 (77%) were < 1-year age. Arrhythmias were atrial 22 (71%), ventricular 4 (13%), and undetermined 5 (16%). Median PICC dwell time was 16 days. 14/31 (45%) cases and 9/31 (29%) controls had underlying structural heart disease. PICCs central tip position was lower among cases than controls (RU 6 vs 5). Odds Ratio for developing arrhythmia was 4.5 (95% CI 0.98-20.83) if the tip lays below 6.25RU. Arrhythmias were resolved with anti-arrhythmic agents in 52% (16/31) and with PICC exchange/manipulation in 32% (10/31) cases. Two children died unrelated to arrhythmia. Prevalence of arrhythmias associated with PICCs in children is low (1%). Arrhythmias are 4.5 times more likely when PICC's central tip position is deeper than 6.25RU.

Hypoxia Detection in Infiltrative Astrocytoma: Ferumoxytol-based Quantitative BOLD MRI with Intraoperative and Histologic Validation.

Purpose To validate ferumoxytol-based quantitative blood oxygenation level-dependent (BOLD) MRI for mapping oxygenation of human infiltrative astrocytomas by using intraoperative measurement of tissue oxygen tension and histologic staining. Materials and Methods Fifteen patients with infiltrative astrocytomas were recruited into this prospective multicenter study between July 2014 and December 2016. Prior to treatment, participants underwent preoperative quantitative BOLD MRI with ferumoxytol to generate tissue oxygen saturation (StO2) maps. Two intratumoral sites were identified, one with low StO2 and one with high StO2. Neuronavigation was used to locate sites intraoperatively for insertion of oxygen-sensing probes to measure local tissue oxygen tension (PtO2). Biopsies from both sites were taken and stained for markers of hypoxia (hypoxia-inducible factor 1α, carbonic anhydrase IX) and neoangiogenesis (vascular endothelial growth factor, endoglin [CD105]). Spearman correlation and nonparametric sign-rank tests were used to analyze data. Results Ten patients with median age of 58.5 years (interquartile range, 25 years; four men and six women) completed the study. Because there is no linear relationship between StO2 and PtO2, the ratios of low to high StO2 versus low to high PtO2 in each patient were compared and a significant correlation was found (r = 0.73; P = .01). Pathologic analyses revealed differences between carbonic anhydrase IX (P = .03) for sites of low StO2 versus high StO2. CD105 displayed a similar trend but was not significant (P = .09). Conclusion Ferumoxytol-based quantitative blood oxygenation level-dependent MRI can potentially be used as a noninvasive surrogate for oxygenation mapping in infiltrative astrocytomas. This technique can potentially be integrated in treatment planning for aggressive targeting of hypoxic areas in tumors.

Incidental splenic nodules found on MR imaging done for assessment of iron overload in children.

BACKGROUND: MR imaging is used to assess iron overload in patients with hemoglobinopathies and in those who have undergone multiple blood transfusions. Sometimes splenic nodules are found incidentally on these examinations and this may cause diagnostic uncertainty. OBJECTIVE: To determine the prevalence, imaging characteristics and evolution of splenic nodules found on MR imaging for iron overload evaluation. MATERIALS AND METHODS: Retrospective review of all MR imaging examinations performed for iron overload assessment from 2005 to 2015 in a tertiary pediatric hospital. The presence of focal splenic nodules including number, size, signal characteristics and changes on follow-up MR imaging were recorded. Relevant patient clinical information including underlying hematological disease was also documented. RESULTS: A total of 318 patients had MR imaging for iron overload assessment. Of these, 25 (8%) had at least one incidental splenic nodule. Sickle cell disease was present in 22 patients (88%) and thalassemia in 3 (12%). On intermediate-weighted spin-echo images, the nodules had high signal intensity compared to the remainder of the spleen in 23 patients (92%) and low signal intensity in the remaining 2 (8%). In all patients (100%) the nodules showed progressive loss of signal intensity with increasing echo time values. Follow-up MR imaging was performed in 20 (80%) patients, which showed an increase in the size of the splenic nodules in 7 patients (35%) stability in 11 (55%) and a decrease in size in 2 (10%). CONCLUSION: It is not uncommon to find splenic nodules during MR evaluation of iron overload. In patients with sickle cell disease, most of these nodules are thought to represent preserved splenic tissue and appear hyperintense compared to the remainder of the spleen. They frequently remain stable on follow-up imaging, although about a third of them may show growth. Awareness of these nodules is important to avoid concern for potential malignancy and unnecessary investigations.

Radiologic Differences between Human Papillomavirus-Related and Human Papillomavirus-Unrelated Oropharyngeal Carcinoma on Diffusion-Weighted Imaging.

BACKGROUND AND PURPOSE: Human papilloma virus-related oropharyngeal carcinoma (HPV+ OPC) is a unique entity compared to HPV-unrelated (HPV-) OPC. Previous studies were inconclusive regarding the differences between HPV+ and HPV- OPCs on diffusion-weighted imaging (DWI). This study sought to determine if there is an association between HPV status and apparent diffusion coefficient (ADC) values as an imaging biomarker in OPCs. MATERIALS AND METHODS: OPC patients with pretreatment MRI including DWI were retrospectively reviewed and analyzed as a blinded, controlled cohort. HPV status was biopsy-ascertained with p16 staining. ADC values were determined by placing the largest possible circular region of interest in solid portions of primary tumors and/or metastatic lymph nodes. Necrotic and cystic portions were excluded. RESULTS: Twenty-eight HPV+ and 12 HPV- patients were included. Adjusted for age and sex, ADC values were significantly lower in HPV+ OPC primary tumors (p = 0.013) and lymph node metastases (p = 0.013). The area under the curve (AUC) was 0.85 and 0.90, respectively. A model with a linear combination of the 2 variables yielded an AUC of 0.92. CONCLUSION: ADC values were significantly lower in both the primary tumors and lymph node metastases in HPV+ OPCs compared to HPV- OPCs. These results confirm the results of prior studies.

Coupling of prefrontal gamma amplitude and theta phase is strengthened in trace eyeblink conditioning.

Trace eyeblink conditioning requires animals to associate a neutral stimulus (CS) and an aversive periorbital shock (US) that occurred moment later. Acquisition in this conditioning depends on several forebrain regions including the hippocampus, medial prefrontal, and entorhinal cortices in addition to the cerebellum. Activities of single and population neurons in these regions show several patterns of change with the conditioning. For example, the power and synchronization of theta oscillations are correlated with the rate of acquisition. Yet, little is known about how neuronal oscillations at other frequency bands change with the conditioning. The present study examined changes in gamma oscillations, which are typically associated with spiking activity of individual cells. We found that after CS offset the power of gamma oscillations at 35-45 Hz fluctuated at about 7 Hz. This rhythmic fluctuation of gamma power was observed in all three regions and locked to local theta oscillations at 4-8 Hz. Furthermore, over the course of 10 days of acquisition sessions, the coupling of gamma power and theta phase became stronger in the medial prefrontal cortex while it did not change in the hippocampus or lateral entorhinal cortex. Neither theta nor gamma power in any of the regions significantly changed across sessions, rejecting a possibility that the observed increase in prefrontal theta-gamma coupling was secondary to an increase in theta or gamma power. The theta-gamma coupling between different regions did not significantly change across sessions. These results suggest that prefrontal gamma oscillations become more effectively coordinated with concurrent theta oscillations in trace eyeblink conditioning. This may result in a stronger impact of prefrontal neuronal firing responses to the CS on the processing in down-stream regions, such as the lateral entorhinal cortex and/or pontine nuclei.

Incidentally found hyperreactio luteinalis in pregnancy.

Hyperreactio luteinalis (HL) is a rare pregnancy-related condition in which the ovaries become massively enlarged bilaterally, occupied by multiple benign theca lutein cysts, secondary to increased ovarian stimulation by beta-human chorionic gonadotropin (B-hCG). HL should resolve spontaneously postpartum, however, their occurrence has led some physicians unfamiliar with the natural history of the condition to perform unnecessary ovarian cystectomies or oophorectomies. A healthy 32-year-old woman was incidentally found to have new onset multicystic ovaries on ultrasound at 31 + 3 weeks gestational age, which continued to enlarge, with a maximum volume of ∼448.0 cm3 and ∼323.5 cm3 in right and left ovaries, respectively. She also developed signs and symptoms of hyperandrogenism, and later abdominal pain which ultimately expedited delivery. This paper demonstrates that familiarity with HL as a clinical entity, its typical presentation and natural history, and targeting conservative management is paramount in minimizing iatrogenic harm by obstetricians given the increased use of ultrasound in pregnancy. Patients presenting after the first trimester with bilateral multicystic ovaries with a "spoke wheel" appearance on ultrasound, hyperandrogenism, abnormally elevated B-hCG, or symptoms consistent with elevated B-hCG should prompt a possible diagnosis.