90Y Resin Microspheres Radioembolization for Colon Cancer Liver Metastases Using Full-Strength Contrast Material.

OBJECTIVES: To assess safety and efficacy of 90Y resin microspheres administration using undiluted non-ionic contrast material (UDCM) {100% Omnipaque-300 (Iohexol)} in both the "B" and "D" lines. MATERIALS AND METHODS: We reviewed all colorectal cancer liver metastases patients treated with 90Y resin microspheres radioembolization (RAE) from 2009 to 2017. As of April 2013, two experienced operators started using UDCM (study group) instead of standard sandwich infusion (control group). Occurrence of myelosuppression (leukopenia, neutropenia, erythrocytopenia or/and thrombocytopenia), stasis, nontarget delivery (NTD), median fluoroscopy radiation dose (FRD), median infusion time (IT), liver progression-free (LPFS) and overall survivals (OS) was evaluated. Complications within 6 months post-RAE were reported according to CTCAE v3.0 criteria. RESULTS: Study and control groups comprised 23(28%) and 58(72%) patients, respectively. Median follow-up was 9.1 months. There was no statistically significant difference in myelosuppression incidence within 6 months post-RAE between groups. Median FRD and IT for study and control groups were 44.6 vs. 97.35 Gy/cm2 (p = 0.048) and 31 vs. 39 min (p = 0.006), respectively. A 38% lower stasis incidence in study group was not significant (p = 0.34). NTD occurred in 1/27(4%) study vs. 5/73(7%) control group procedures (p = 1). Grade 1-2 and grade 3-4 toxicities between study and control group patients were 36%(8/22) vs. 45%(26/58), p = 0.61 and 9%(2/22) vs. 16%(9/58), p = 0.72, respectively. There was no difference in LPFS and OS between groups. CONCLUSION: Administration of 90Y resin microspheres using UDCM in both lines is safe and effective, resulting in lower fluoroscopy radiation dose and shorter infusion time, without evidence of myelosuppression or increased stasis incidence.

Obesity conveys poor outcome in patients with hepatocellular carcinoma treated by transarterial chemoembolization.

PURPOSE: The purpose of this retrospective study was to evaluate the impact of obesity on radiologic outcomes in patients with hepatocellular carcinoma (HCC) treated by transarterial chemoembolization (TACE). MATERIALS AND METHODS: A total of 100 TACE procedures performed in 57 patients (42 men, 15 women) with a mean age of 62 years±8.4 (SD) (range: 39-83 years) were retrospectively reviewed. The 1-2-month follow-up computed tomography or magnetic resonance imaging examinations was assessed for new or residual disease and radiologic response using mRECIST criteria. Patients were categorized into two groups according to body mass index (BMI). Patients with BMI<25kg/m2 were further referred as to low BMI patients and those with BMI≥25kg/m2 as high BMI patients. Outcomes were compared between the two groups. RESULTS: Low and high BMI patients were similar in regard to age, gender, HCC etiology and stage, and pre-procedure disease burden. TACE for high BMI, compared to low BMI, patients resulted in lower complete response (39% vs. 66%) and higher progressive disease (21% vs. 5%) rates (P=0.04), and higher rates of residual disease (63% vs. 39%, P=0.02) and new lesions in untreated liver (39% vs. 18%, P=0.04) on 1-2-month follow-up imaging. CONCLUSIONS: High BMI is associated with significantly more residual disease, new lesions, and progressive disease in patients with HCC treated by TACE.

Diagnostic yield of emergency department arch-to-vertex CT angiography in patients with suspected acute stroke.

BACKGROUND AND PURPOSE: Our aim was to investigate how often relevant diagnostic findings in an arch-to-vertex CTA scan, obtained specifically as part of the acute stroke CT protocol, are located in the head, neck, and upper chest regions. MATERIALS AND METHODS: Radiology reports were reviewed in 302 consecutive patients (170 men, 132 women; median ages, 66 and 73 years, respectively) who underwent emergency department investigation of suspected acute stroke between January and July 2010. Diagnostic CTA findings relevant to patient management were recorded for the head, neck, and chest regions individually. Additionally, the contributions to the total CTA scan effective dose were estimated from each of the 3 anatomic regions by using the ImPACT CT Dose Calculator. RESULTS: Of the 302 patients, 161 (54%) had relevant diagnostic findings in the head; 94 (31%), in the neck; and 4 (1%), in the chest. The estimated contributions to the total CTA scan dose from each body region, head, neck, and upper chest, were 14 ± 2%, 33 ± 5%, and 53 ± 6%, respectively. CONCLUSIONS: Most clinically relevant findings are in the head and neck, supporting inclusion of these regions in arch-to-vertex CTA performed specifically in patients with acute stroke in the emergency department. Further studies are required to investigate extending the scan to the upper chest because only 1% of patients in our study had clinically relevant findings in the mediastinum, yet half the CTA effective dose was due to scanning in this region.

Exposing hidden truncation-related errors in acute stroke perfusion imaging.

BACKGROUND AND PURPOSE: The durations of acute ischemic stroke patients' CT or MR perfusion scans may be too short to fully sample the passage of the injected contrast agent through the brain. We tested the potential magnitude of hidden errors related to the truncation of data by short perfusion scans. MATERIALS AND METHODS: Fifty-seven patients with acute ischemic stroke underwent perfusion MR imaging within 12 hours of symptom onset, using a relatively long scan duration (110 seconds). Shorter scan durations (39.5-108.5 seconds) were simulated by progressively deleting the last-acquired images. CBV, CBF, MTT, and time to response function maximum (Tmax) were measured within DWI-identified acute infarcts, with commonly used postprocessing algorithms. All measurements except Tmax were normalized by dividing by the contralateral hemisphere values. The effects of the scan duration on these hemodynamic measurements and on the volumes of lesions with Tmax of >6 seconds were tested using regression. RESULTS: Decreasing scan duration from 110 seconds to 40 seconds falsely reduced perfusion estimates by 47.6%-64.2% of normal for CBV, 1.96%-4.10% for CBF, 133%-205% for MTT, and 6.2-8.0 seconds for Tmax, depending on the postprocessing method. This truncation falsely reduced estimated Tmax lesion volume by 71.5 or 93.8 mL, depending on the deconvolution method. "Lesion reversal" (ie, change from above-normal to apparently normal, or from >6 seconds to ≤6 seconds for the time to response function maximum) with increasing truncation occurred in 37%-46% of lesions for CBV, 2%-4% for CBF, 28%-54% for MTT, and 42%-44% for Tmax, depending on the postprocessing method. CONCLUSIONS: Hidden truncation-related errors in perfusion images may be large enough to alter patient management or affect outcomes of clinical trials.

Spatial cognition and the human navigation network in AD and MCI.

BACKGROUND: The mechanisms underlying navigation impairments in Alzheimer disease (AD) are unknown. We characterized navigation in AD and mild cognitive impairment (MCI) to test the hypothesis that navigation disability reflects selective impairments in spatial cognition and relates to atrophy of specific brain regions. METHODS: We compared 13 mild AD and 21 MCI patients with 24 controls on a route-learning task that engaged various spatial processes. Using structural MRI and optimized voxel-based morphometry, we also investigated the neural correlates of spatial abilities in a subset of subjects (10 AD, 12 MCI, 21 controls). RESULTS: AD and MCI patients recognized landmarks as effectively as controls, but could not find their locations on maps or recall the order in which they were encountered. Half of AD and one-quarter of MCI patients got lost on the route, compared with less than 10% of controls. Regardless of diagnosis, patients who got lost had lower right posterior hippocampal and parietal volumes than patients and controls who did not get lost. The ability to identify locations on a map correlated with right posterior hippocampal and parietal volumes, whereas order memory scores correlated with bilateral inferior frontal volumes. CONCLUSIONS: The navigation disability in Alzheimer disease and mild cognitive impairment (MCI) involves a selective impairment of spatial cognition and is associated with atrophy of the right-lateralized navigation network. Extensive spatial impairments in MCI suggest that navigation tests may provide early markers of cognitive and neural damage.

Perinatal anoxia degrades auditory system function in rats.

Little is known about the neural bases of the reduced auditory and cortical processing speeds that have been recorded in language-impaired, autistic, schizophrenic, and other disabled human populations. Although there is strong evidence for genetic contributions to etiologies, epigenetic factors such as perinatal anoxia (PA) have been argued to be contributors, or causal, in a significant proportion of cases. In this article, we explored the consequences of PA on this elementary aspect of auditory behavior and on auditory system function in rats that were briefly perinatally anoxic. PA rats had increased acoustic thresholds and reduced processing efficiencies recorded in an auditory behavioral task. These rats had modestly increased interpeak intervals in their auditory brainstem responses, and substantially longer latencies in poststimulus time histogram responses recorded in the primary auditory cortex. The latter were associated with degraded primary auditory cortex receptive fields and a disrupted tonotopy. These processing deficits are consistent with the parallel behavioral and physiological deficits recorded in children and adults with a history of language-learning impairment and autism.