Evaluation of a novel optical smartphone blood pressure application: a method comparison study against invasive arterial blood pressure monitoring in intensive care unit patients

Background

Arterial hypertension is a worldwide public health problem. While it is currently diagnosed and monitored non-invasively using the oscillometric method, having the ability to measure blood pressure (BP) using a smartphone application could provide more widespread access to hypertension screening and monitoring. In this observational study in intensive care unit patients, we compared blood pressure values obtained using a new optical smartphone application (OptiBP™; test method) with arterial BP values obtained using a radial artery catheter (reference method) in order to help validate the technology.

Methods

We simultaneously measured three BP values every hour for five consecutive hours on two consecutive days using both the smartphone and arterial methods. Bland–Altman and error grid analyses were used for agreement analysis between both approaches. The performance of the smartphone application was investigated using the Association for the Advancement of Medical Instrumentation (AAMI) and the International Organization for Standardization (ISO) definitions, which require the bias ± SD between two technologies to be below 5 ± 8 mmHg.

Results

Among the 30 recruited patients, 22 patients had adequate OptiBP™ values and were thus analyzed. In the other 8 patients, no BP could be measured due to inadequate signals. The Bland–Altman analysis revealed a mean of the differences ± SD between both methods of 0.9 ± 7 mmHg for mean arterial pressure (MAP), 0.2 ± 14 mmHg for systolic arterial pressure (SAP), and 1.1 ± 6 mmHg for diastolic arterial pressure (DAP). Error grid analysis demonstrated that the proportions of measurement pairs in risk zones A to E were 88.8% (no risk), 10% (low risk), 1% (moderate risk), 0% (significant risk), and 0% (dangerous risk) for MAP and 88.4%, 8.6%, 3%, 0%, 0%, respectively, for SAP.

Conclusions

This method comparison study revealed good agreement between BP values obtained using the OptiBP™ and those done invasively. The OptiBP™ fulfills the AAMI/ISO universal standards for MAP and DAP (but not SAP). Error grid showed that the most measurements (≥ 97%) were in risk zones A and B.

Trial registration

ClinicalTrials.gov registration: NCT04728477

Significant blunt bowel and mesenteric injury - Comparison of two CT scoring systems in a trauma registry cohort

PURPOSE

This study evaluated and compared two imaging-based scoring systems for the detection of significant blunt bowel and mesenteric injury (sBBMI) by emergency computed tomography (CT).

METHODS AND MATERIALS

We included all consecutive adult polytrauma patients admitted to our emergency department following a road traffic accident from January 2008 to June 2015, provided that intravenously contrast-enhanced whole-body CT examination was performed immediately after hospital admission. Two radiologists, blinded to patients' outcome, reviewed the CT examinations for distinctive direct intestinal or mesenteric vascular injury and indirect signs of abdominal injury. These findings were correlated with the patients' surgical or interventional radiology findings, autopsy, or clinical follow-up (>24 h). Two previously validated imaging-based bowel-injury scoring systems, the CT-based Faget score and the clinically and radiologically based Mc Nutt score (BIPS), were compared by applying each to our trauma cohort. Student t-test, chi-squared, and logistic regression were used in analyses.

RESULTS

Twenty-one of 752 analysed patients (2.8 %) had confirmed sBBMI. Active mesenteric bleeding, mesenteric and free pneumoperitoneum, small haemoperitoneum, non-focal bowel wall thickening, mesenteric/pericolic fat stranding, and anterior abdominal wall injury were significantly correlated with sBBMI, as did the two evaluated scoring systems (p < 0.001). However, multivariate logistic regression revealed the superiority of the Faget score to the McNutt score.

CONCLUSION

The prevalence of sBBMI among polytrauma patients is low. Early diagnosis is necessary to avoid increased mortality. Certain CT features are pathognomic of sBBMI and must not be overlooked. Scoring systems are helpful, especially when they are based on radiological signs.

Association of Time of Day When Endovascular Therapy for Stroke Starts and Functional Outcome

OBJECTIVE

To investigate the association between endovascular therapy (EVT) start time in acute ischemic stroke (AIS) and midterm functional outcome.

METHODS

This retrospective cohort study included all patients with AIS treated with EVT from 2 stroke center registries from January 2012 to December 2018. The primary outcome was the score on the modified Rankin Scale (mRS) and the utility-weighted mRS (uw-mRS) at 90 days. A proportional odds model was used to calculate the common odds ratio (OR) as a measure of the likelihood that the intervention at a given EVT start time would lead to lower scores on the mRS (shift analysis).

RESULTS

A total of 1,558 cases were equally allotted into 12 EVT start time periods. The primary outcome favored EVT start times in the morning at 08:00-10:20 and 10:20-11:34 (OR, 0.53; 95% confidence interval [CI], 0.38 to 0.75; p < 0.001; OR, 0.62; 95% CI, 0.44 to 0.87; p = 0.006, respectively), while it disfavored EVT start times at the end of the working day at 15:55-17:15 and 18:55-20:55 (OR, 1.47; 95% CI, 1.03-2.09; p = 0.034; OR, 1.49; 95% CI, 1.03-2.15; p = 0.033). Symptom onset to EVT start time was significantly higher and use of IV tissue plasminogen activator significantly lower between 10:20 and 11:34 (p < 0.004 and p = 0.012, respectively).

CONCLUSION

EVT for AIS in the morning leads to better midterm functional outcome, while EVT at the end of the work day leads to poorer midterm functional outcome. Difference in baseline factors, standard workflow, and technical efficacy metrics could not be identified as potential mediators of this effect.

Patient respiratory-triggered quantitative T2 mapping in the pancreas

Background

Long acquisition times and motion sensitivity limit T₂ mapping in the abdomen. Accelerated mapping at 3 T may allow for quantitative assessment of diffuse pancreatic disease in patients during free‐breathing.

Purpose

To test the feasibility of respiratory‐triggered quantitative T₂ analysis in the pancreas and correlate T₂‐values with age, body mass index, pancreatic location, main pancreatic duct dilatation, and underlying pathology.

Study Type

Retrospective single‐center pilot study.

Population

Eighty‐eight adults.

Field Strength/Sequence

Ten‐fold accelerated multiecho‐spin‐echo 3 T MRI sequence to quantify T₂ at 3 T.

Assessment

Two radiologists independently delineated three regions of interest inside the pancreatic head, body, and tail for each acquisition. Means and standard deviations for T₂ values in these regions were determined. T₂‐value variation with demographic data, intraparenchymal location, pancreatic duct dilation, and underlying pancreatic disease was assessed.

Statistical Tests

Interreader reliability was determined by calculating the interclass coefficient (ICCs). T₂ values were compared for different pancreatic locations by analysis of variance (ANOVA). Interpatient associations between T₂ values and demographical, clinical, and radiological data were calculated (ANOVA).

Results

The accelerated T₂ mapping sequence was successfully performed in all participants (mean acquisition time, 2:48 ± 0:43 min). Low T₂ value variability was observed across all patients (intersubject) (head: 60.2 ± 8.3 msec, body: 63.9 ± 11.5 msec, tail: 66.8 ± 16.4 msec). Interreader agreement was good (ICC, 0.82, 95% confidence interval: 0.77–0.86). T₂‐values differed significantly depending on age (P < 0.001), location (P < 0.001), main pancreatic duct dilatation (P < 0.001), and diffuse pancreatic disease (P < 0.03).

Data Conclusion

The feasibility of accelerated T₂ mapping at 3 T in moving abdominal organs was demonstrated in the pancreas, since T₂ values were stable and reproducible. In the pancreatic parenchyma, T₂‐values were significantly dependent on demographic and clinical parameters.

Level of Evidence: 4

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2019;50:410–416.

Local recurrence rate in patients with colorectal cancer liver metastasis after wedge resection or percutaneous radiofrequency ablation

PURPOSE

To compare local recurrence (LR) rate in patients with colorectal cancer liver metastasis (CRCLM) after surgical wedge resection (WR) or radiofrequency ablation (RFA) and to investigate predictive factors of LR.

MATERIALS AND METHODS

This single-centre, retrospective, institutional review board-approved study including 43 consecutive patients with 121 metastases treated by WR and 60 patients with 110 metastases treated by RFA between 2007 and 2014 with 23 and 18.5 months of follow-up, respectively. Demographics and tumour characteristics were compared using the unpaired t-test and chi-square test. Predictive factors for LR (lesion size, depth, relation to hepatic vessels, intervention, margin status) were investigated in uni- and multivariate analyses.

RESULTS

Patient and CRCLM characteristics were similar in both groups. Mean lesion size and depth in the WR and RFA groups were 18 mm and 15 mm (p = 0.03), and 19 mm and 26 mm (p < 0.001), respectively. LR showed a trend towards difference in favour of RFA (19% and 10% in the WR and RFA groups, respectively, p = 0.06). Positive margins and lesion depth were predictive factors of LR in the WR group (p = 0.03 and p = 0.02, respectively, on uni- and multivariable analyses). Lesion depth and proximity to a vein increased the risk of positive margins on pathology after WR (p = 0.04 and p < 0.001, respectively). Our analysis did not identify any predictive factors of LR following RFA.

CONCLUSION

Our study showed a trend towards a lower LR rate with RFA compared to WR. Lesions located deep in the liver and/or close to large vessels are at high risk of LR following WR, while curative treatment can be obtained with RFA.

Clinical significance of pneumatosis intestinalis - correlation of MDCT-findings with treatment and outcome

Objectives

To evaluate the clinical significance of pneumatosis intestinalis (PI) including the influence on treatment and outcome.

Method and Materials

Two radiologists jointly reviewed MDCT-examinations of 149 consecutive emergency patients (53 women, mean age 64, range 21-95) with PI of the stomach (n = 4), small (n = 68) and/or large bowel (n = 96). PI extension, distribution and possibly associated porto-mesenteric venous gas (PMVG) were correlated with other MDCT-findings, risk factors, clinical management, laboratory, histopathology, final diagnosis and outcome.

Results

The most frequent cause of PI was intestinal ischemia (n = 80,53.7 %), followed by infection (n = 18,12.1 %), obstructive (n = 12,8.1 %) and non-obstructive (n = 10,6.7 %) bowel dilatation, unknown aetiologies (n = 8,5.4 %), drugs (n = 8,5.4 %), inflammation (n = 7,4.7 %), and others (n = 6,4 %). Neither PI distribution nor extension significantly correlated with underlying ischemia. Overall mortality was 41.6 % (n = 62), mostly related to intestinal ischemia (p = 0.003). Associated PMVG significantly correlated with underlying ischemia (p = 0.009), as did the anatomical distribution of PMVG (p = 0.015). Decreased mural contrast-enhancement was the only other MDCT-feature significantly associated with ischemia (p p < 0.001). Elevated white blood count significantly correlated with ischemia (p = 0.03).

Conclusion

In emergency patients, ischemia remains the most common aetiology of PI, showing the highest mortality. PI with associated PMVG is an alerting sign. PI together with decreased mural contrast-enhancement indicates underlying ischemia.

Key Points

• In emergency patients, PI may be caused by various disorders.

• Intestinal ischemia remains the most common cause of PI in acute situations.

• PI associated with decreased mural contrast-enhancement indicates acute intestinal ischemia.

• PI associated with PMVG should alert the radiologist to possible underlying ischemia.

Metastasectomy or radiofrequency ablation for treatment for colorectal cancer liver metastasis: Comparison of recurrence rates and identification of risk factors for local recurrence

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Background: Metastasectomy and radiofrequency ablation (RFA) are currently use for treatment of colorectal cancer (CRC) liver metastasis aiming for total tumor ablation with sparing liver parenchyma. Literature is lacking of studies comparing results and risk of recurrence between both techniques. We aim to compare recurrence rate after RFA and metastasectomy for CRC liver metastasis and to define which lesion is the best candidate for each treatment. Methods: By a lesion-by-lesion analysis, we reviewed 121 metastases treated by metastasectomy (43 patients, median follow up 798 days) and 110 metastases treated by RFA (60 patients, median follow up 590 days). Rate of local recurrence (LR) and hepatic recurrence (HR) were compared. We analyzed patients and primary tumor characteristics, looked for predictive factors for recurrence in metastasis data: size, deepness in liver, distance to hepatic veins, pathological resection margins in case of surgery. Analysis were performed using Chi Square and logistic regression in uni and multivariate analysis. Results: Patients and primary tumor characteristics were similar. Metastasis size was larger in metastasectomy group (18mm, range 2-90mm and 15mm, range 3-55mm; p = 0.03). Lesions were located deeper in the liver parenchyma in RFA group (20mm, range 3-51mm and 26mm, range 6-59mm; p < 0.001). Rate of LR and HR were nearly statistically different in favor of RFA: LR was 19% for metastasectomy group and 10% for RFA group (p = 0.06, delay: 245 and 289 days, p = 0.56), HR were 78% for metastasectomy and 66% for RFA (p = 0.054, delay: 226 and 235 days, p = 0.81). Predictive factors for recurrence in metastasectomy group: R1 status (p = 0.03) and metastasis deepness (p = 0.02). Metastasis deepness and proximity to hepatic veins increased risk for R1 (p = 0.04 and p < 0.001 respectively). We found no predictive factor for recurrence in RFA group. Conclusions: Pending proper selection (small lesions visible under imaging guidance), RFA tends to have a lower recurrence rate than metastasectomy. Lesions localized in depth in the liver parenchyma, close to hepatic veins are at risk of LR after metastasectomy.