Persistent adrenal enhancement may be the earliest CT sign of significant hypovolaemic shock

Multidetector CT Imaging Biomarkers as Predictors of Prognosis in Shock: Updates and Future Directions

A severe mismatch between the supply and demand of oxygen is the common sequela of all types of shock, which present a mortality of up to 80%. Various organs play a protective role in shock and contribute to whole-body homeostasis. The ever-increasing number of multidetector CT examinations in severely ill and sometimes unstable patients leads to more frequently encountered findings leading to imminent death, together called "hypovolemic shock complex". Features on CT include dense opacification of the right heart and major systemic veins, venous layering of contrast material and blood, densely opacified parenchyma in the right hepatic lobe, decreased enhancement of the abdominal organ, a dense pulmonary artery, contrast pooling in dependent lungs, and contrast stasis in pulmonary veins. These findings are biomarkers and prognostic indicators of paramount importance which stratify risk and improve patient outcomes. In this review, we illustrate the various CT patterns in shock and review the spectrum and prognostic significance of thoraco-abdominal vascular and visceral alarming signs of impending death with the intention of increasing awareness among radiologists and radiographers to prepare for immediate resuscitation when required.

Iodine uptake of adrenal glands: A novel and reliable spectral dual-layer computed tomographic-derived biomarker for acute septic shock

OBJECTIVES

Septic shock is a potentially fatal condition. This study aims to assess whether iodine uptake and iodine density of abdominal organs on dual-layer spectral detector computed tomography (SDCT) could serve as a new imaging biomarker for patients in septic shock.

METHODS

Here, 95 patients who received contrast-enhanced abdominal CT examinations were included and separated into two groups: group A - septic shock; group B - no shock condition. Preselected abdominal (right and left adrenal gland, right and left kidney, infrarenal inferior vena cava (IVC), pancreas, spleen, and liver) localizations were independently evaluated by two radiologists, who measured iodine concentrations (mg/ml) and Hounsfield units (HU).

RESULTS

In all, 1520 measurements of iodine concentrations in mg/ml and HU were performed, with 27 patients in group A and 68 in group B. Iodine concentrations in mg/ml and HU correlated significantly in all organs measured. The corresponding correlation coefficient (r) ranged from 0.809 (pancreas) to 0.963 (right kidney). Inter-rater reliability (IRR) was very good for mg/ml (κ = 0.8; p < 0.01) and good for HU (κ = 0.773; p < 0.01) measurements. The mean iodine concentration and HU of the adrenal glands in septic and nonseptic patients was 4.88 ± 1.16 mg/ml/153 ± 36 HU and 2.67 ± 1.07 mg/ml/112 ± 41 HU, respectively. Iodine concentrations in the adrenal glands were significantly higher in group A than in group B patients (p < 0.01). The other organs remained unaffected and no significant difference was observed between patients in group A and B. Patients in group A presented significantly more often with an iodine uptake of >3.5 mg/ml of one adrenal gland (sensitivity = 0.926, specificity = 0.849, AUC = 0.951) or/and a combined concentration of >7 mg/ml of both adrenal glands (sensitivity = 0.889, specificity = 0.836, AUC = 0.928).

CONCLUSION

SDCT-derived iodine concentration of the adrenal glands could serve as a novel imaging biomarker for patients in acute septic shock. Our data suggest that an iodine uptake of >3.5 mg/ml of at least one adrenal gland or a combined iodine uptake of >7 mg/ml in both adrenal glands identifies patients in this condition.

Cross-sectional imaging features of unusual adrenal lesions: a radiopathological correlation

The detection rates of adrenal masses are increasing with the common and widespread use of cross-sectional imaging. Adrenal adenomas, myelolipomas, metastases, pheochromocytomas, and adrenocortical tumors are well-known and relatively common adrenal tumors. However, there are many less-known neoplastic and nonneoplastic adrenal diseases that might affect the adrenal glands in addition to these common lesions. These rare entities include, but are not limited to, hydatid cysts, congenital adrenal hyperplasia, Wolman disease, adrenal tuberculosis, primary adrenal lymphoma. This article aims to present imaging findings of these unusual lesions in accordance with their pathologic characteristics. We think that the simultaneous presentation of the pathological findings with the imaging features may facilitate the learning process and may potentially enhance the recognition of these entities.

Hyperlactatemia associated with diabetic ketoacidosis in pediatric intensive care unit

BACKGROUND

Children with diabetic ketoacidosis often have elevated lactate. In this study, we investigated the clinical variables associated with hyperlactatemia in children with diabetic ketoacidosis.

METHODS

We designed a single-center retrospective descriptive study of children with diabetic ketoacidosis in a pediatric intensive care unit.

RESULTS

Of the 107 patients with diabetic ketoacidosis included in the analysis, 61 developed hyperlactatemia. Multivariate logistic regression analysis showed that heart rate (p = 0.003),diastolic blood pressure (p = 0.001) and stage of severity (p = 0.042) were independently associated with the development of hyperlactatemia in diabetic ketoacidosis. We found that lactate level was not significantly associated with length of hospital stay (p = 0.115) or the length of time to diabetic ketoacidosis resolution (p = 0.143).

CONCLUSIONS

Children with diabetic ketoacidosis presenting with severer stage, elevated heart rate and higher diastolic blood pressure may be prone to hyperlactatemia. Hyperlactatemia was not associated with length of time to DKA resolution and length of hospital stay.

Bilateral adrenal enhancement revised-adrenal-to-spleen ratio as an appropriate mortality predictor

Purpose

To investigate whether adrenal gland radiodensities alone or set in relation to either the inferior vena cava (IVC) or the spleen can predict hospital mortality in intensive care unit patients.

Methods

One hundred thirty-three intensive care patients (90 males, age: 66.3 ± 14.5 years) with an acute clinical deterioration were included in this retrospective analysis. CT attenuation (Hounsfield units) of adrenal glands, IVC, and spleen was evaluated by 2 radiologists separately. Adrenal-to-IVC and adrenal-to-spleen ratios were calculated. Receiver operating characteristic (ROC) analysis, combined with the Matthews correlation coefficient (MCC) as a classifier, was used to assess which parameter is the most suitable for short-term, intermediate-term, and overall mortality prediction. Interrater agreement was assessed using intraclass correlation coefficient (ICC).

Results

The highest discriminative power to distinguish between deceased and survivors was found for the adrenal gland-to-spleen ratio for the 72-h mortality. A threshold of > 1.4 predicted 72-h mortality with a sensitivity of 79.31% and a specificity of 98.08% (area und the curve (AUC) = 0.94; p < 0.0001; MCCs = 0.81). The positive likelihood ratio was 41; the positive predictive value was 92.20%. Adrenal gland-to-spleen ratio was also best suited to predict the 24-h and overall mortality. ICCs of HU measurements in adrenal gland, IVC, and spleen indicated a high interrater agreement (ICC 0.95–0.99).

Conclusions

To conclude, the adrenal-to-spleen ratio in CT in portal venous phase may serve as an imaged-based predictor for short, intermediate, and overall mortality and as reproducible prognostic marker for patient outcome.

Vascular changes of the superior mesenteric artery (SMA): A new component of the hypovolemic shock complex (HSC)

PURPOSE

To assess the type and frequency of vascular changes in the superior mesenteric artery (SMA) associated with the hypovolemic shock complex (HSC).

METHODS

Twenty-six patients (14 males, 70.6 ± 11.2 years) meeting the criteria for hypovolemic shock complex in computed tomography were examined for the presence of angiographic signs of non-occlusive mesenteric ischemia (NOMI) in the SMA: the string of sausages sign and spasms of the arcades of mesenteric arteries on coronal maximum intensity projection images (MIP). Interrater agreement was assessed using weighted kappa (κ).

RESULTS

Vascular changes of the SMA were visible in almost all of the patients with HSC with a frequency of 88.5 %-96.2 %. Intraclass correlation coefficients indicated a substantial to almost perfect interrater agreement.

CONCLUSIONS

Using computed tomography, it is possible to reliably and reproducibly detect vascular changes in SMA known from angiography in the context of hypoperfusion. The pathological vascular changes also occur more frequently than other classic signs of a CT hypoperfusion complex. Since the qualitative assessment of the SMA requires only a small amount of time, it is suitable as a further criterion for the presence of the CT hypoperfusion complex.

Adrenal glands enhancement in computed tomography as predictor of short-and intermediate term mortality in critically ill patients

PURPOSE

To investigate whether adrenal gland radiodensities alone or compared to the inferior vena cava (IVC) can correctly predict hospital mortality in patients in intensive care.

METHODS

One hundred thirteen intensive care patients (76 males, age: 67.2 ± 14.0 years) with an acute clinical deterioration were included in this retrospective analysis. For the venous and the arterial phase CT attenuation (Hounsfield units) of adrenal glands and IVC was ROI-based evaluated by two radiologists separately. ROC analysis, combined with the Matthews Correlation Coefficient (MCC) as a classifier, was used to assess whether one of the parameters is suitable for predicting short and medium-term mortality and, if so, which parameter is most appropriate. Interrater agreement was assessed using the intraclass correlation coefficient.

RESULTS

Twenty-one patients (18.6%) died within three days in the ICU. Measurements of the adrenal glands in the portal venous phase yielded the highest discriminative power (=AUC) to distinguish between deceased and survivors. A threshold ratio of >95.5 predicted 72-hour mortality with a sensitivity of 76.19% and a specificity of 92.39% (AUC = 0.84; p < 0.0001). The positive likelihood ratio was 10.1; the positive predictive value was 69%. The predictive power for 24-hour mortality was slightly lower. Venous adrenal-to-IVC ratios and arterial measurements as a whole were substantially less suitable. All intraclass correlation coefficients indicated a high interrater agreement.

CONCLUSIONS

In the portal venous phase, hyperattenuating of the adrenal glands on contrast-enhanced CT can predict short and intermediate ICU mortality quite well and may serve as a reproducible prognostic marker for individual patient outcomes.

Hepatic Heterogeneity and Attenuation on Contrast-Enhanced CT in Patients With the Hypovolemic Shock Complex: Objective Classification Using a Contemporary Cohort

OBJECTIVE

When objectively measured on computed tomography (CT), does hepatic heterogeneity or overall liver attenuation predict the presence of shock?

METHODS

This retrospective study included 73 patients (mean age 33 years) with the hypoperfusion shock complex (HSC) on CT (cases) and 100 patients (mean age 43 years) with negative trauma CT scans (controls). Liver heterogeneity was calculated by using consistently sized regions of interest (ROIs) to measure the 2 highest and the 2 lowest areas of hepatic density (in Hounsfield units [HU]). The difference between the means of the 2 highest and 2 lowest ROIs was considered the heterogeneity. Attenuation was calculated using the mean of 3 randomly placed ROIs. Both heterogeneity and attenuation were then compared between cases and controls.

RESULTS

Median hepatic heterogeneity was 16.8 HU (IQR: 10.7-23.4) for the HSC group and 9.0 HU (IQR: 7.0-10.4) for the controls (P < 0.001). The area under the curve was 0.79, and a threshold of 30 HU yielded a specificity of 100%. Median hepatic attenuation was not significantly different between the HSC and the control groups, with an area under the curve of 0.56.

CONCLUSIONS

Increased hepatic heterogeneity may represent an objective marker of the HSC that performs in a similar manner to other established signs. By comparison, overall hepatic hypoattenuation is a poor indicator of the HSC.

Splenic contraction: a new member of the hypovolemic shock complex

OBJECTIVE

The objective of the article is to assess changes in splenic volume in the setting of hypovolemic shock; splenic enhancement in hypovolemic shock is also assessed.

MATERIALS/METHODS

71 consecutive adult patients with the hypovolemic shock complex on computed tomography (CT) were identified. Spleen volume and enhancement were compared to a baseline CT scan (without shock) or to height- and sex-corrected normal values and a control population when a comparison CT was unavailable.

RESULTS

Splenic volume was significantly lower in the setting of shock. Average splenic volume in adult patients with shock was 107 ± 63 cm³ compared to 220 ± 164 cm³ in the control population (P < 0.001). All shock patients with a comparison CT (n = 35) had decreased splenic volume in the setting of shock. The area under the receiver operating characteristic (ROC) curve for spleen volume predicting shock was 0.83. Splenic enhancement was also significantly lower in the setting of shock. Mean splenic attenuation value in our shock population was 105 ± 34 HU compared to 134 ± 25 HU in the control population (P < 0.001). Decreased splenic enhancement was present in 25 of 71 shock patients and in none of the control patients (P < 0.001).

CONCLUSION

Decreased splenic volume is a ubiquitous and reliable sign of hypovolemic shock and should be considered a member of the hypovolemic shock complex. It is of particular utility when a prior study is available. Splenic hypoenhancement has high specificity and a high positive predictive value for hypovolemic shock in the correct patient population.

Contrast-Enhanced Computed Tomography in Intensive Care Unit Patients With Acute Clinical Deterioration: Impact of Hyperattenuating Adrenal Glands

PURPOSE

The study sought to assess the frequency and prognostic value of hyperattenuating adrenal glands on contrast-enhanced computed tomography (CT) scans of surgical intensive care unit (ICU) patients with acute clinical deterioration.

METHODS

Eighty-eight consecutive ICU patients (63.2 ± 14.5 years of age) were included in this retrospective analysis. All patients underwent biphasic contrast-enhanced CT due to an acute clinical deterioration. Hyperattenuation of the adrenal glands was assessed subjectively and objectively. Subjective presence or absence of hyperattenuating adrenal glands was assessed by 2 blinded radiologists (J.B. and R.S.L.) in consensus. Hounsfield units (HU) were measured in the adrenal glands and in the inferior vena cava. Objective hyperattenuation was defined as HU (adrenal glands) > HU (inferior vena cava) with a 15-HU threshold. Death within 14 days following CT was set as endpoint and acquired from electronic patient data.

RESULTS

Thirty-eight patients (43.2%, Group A_subj) exhibited hyperattenuation of the adrenal glands, whereas 50 patients (56.8%, Group B_subj) did not. Concerning the objective analysis, 31 patients (35.2%, Group A_obj) exhibited hyperdense adrenal glands, whereas 53 patients (64.8%, Group B_obj) did not. Overall 27 of 88 patients (30.6%) died within 14 days following the CT examination. Lethal outcome was significantly more frequent among patients in Group A_subj and A_obj (19 of 38 patients [50.0%] and 15 of 31 patients [48.4%]) as compared with patients in Group B_subj (8 of 50 patients [16.0%]) and Group B_obj (12 of 57 patients [21.1%]; P < .05). Subjective and objective analysis correlated significantly (P < .05).

CONCLUSIONS

Hyperattenuation of adrenal glands on contrast-enhanced CT of ICU patients with acute clinical deterioration is associated with a high mortality and might serve as a prognostic marker for patients' outcome.

Intense Adrenal Enhancement: A CT Feature of Cardiogenic Shock

In this report, images of intense adrenal enhancement in a 79-year-old female patient with right-sided heart failure and severe tricuspid insufficiency are presented. Only two cases of intense adrenal enhancement as a sign of cardiogenic shock were previously reported in the literature. Intense adrenal enhancement could be one of the earliest CT signs of cardiogenic shock. Its presence should be immediately reported to the referring physician as a sign of significant hemodynamic instability warranting early critical-care management.

Dynamic contrast-enhanced CT of the abdomen to predict clinical prognosis in patients with hypovolemic shock

OBJECTIVE

The objective of our study was to investigate the value of dynamic contrast-enhanced CT (DCE-CT) findings in predicting the clinical prognosis of patients with hypovolemic shock.

MATERIALS AND METHODS

This study included 33 patients with hypovolemic shock who underwent DCE-CT of the abdomen due to trauma. The CT attenuation values of several abdominal organs (spleen, liver, pancreas, kidneys [cortex and medulla], adrenal gland) in patients with hypovolemic shock were measured in the early phase and delayed phase to compare the differences in contrast enhancement effects between the survival group and the deceased group.

RESULTS

Among the 33 patients with hypovolemic shock, 15 patients died (deceased group) within 5 weeks (mean, 6 days). The remaining 18 patients survived and recovered (survival group). The mean CT attenuation values of the renal medulla in the delayed phase CT in the deceased group (155.4 ± 60.1 [SD] HU) were significantly lower (p = 0.001) than those in the survival group (227.3 ± 47.3 HU). The mean CT attenuation values of the renal medulla in the early phase CT did not show a significant difference between the two groups (102.4 ± 61.7 vs 113.9 ± 43.5 HU, respectively). The mean CT values of the spleen in the early phase CT in the deceased group (90.8 ± 26.0 HU) were significantly lower (p = 0.015) than those in the survival group (119.9 ± 33.9 HU). Regarding other CT measurements, there were no other significant differences between the deceased group and survival group.

CONCLUSION

Decreased enhancement of the renal medulla in the delayed phase and decreased enhancement of the spleen in the early phase are useful CT findings to predict a poor clinical prognosis in patients with hypovolemic shock.

Intense adrenal enhancement in patients with acute pancreatitis and early organ failure

Intense adrenal enhancement has previously been reported in patients with hypovolemic and septic shock. The purpose of this study was to assess whether this computed tomography (CT) finding is also observed in patients presenting with severe acute pancreatitis and early organ failure. A retrospective analysis of a prospectively collected database was performed. Out of 38 consecutive patients with predicted severe acute pancreatitis, 3 patients showed intense bilateral adrenal enhancement on early CT. All patients had early multiple organ failure and subsequently died. In two cases, pathologic correlation was obtained. Intense adrenal enhancement may be a new prognostic indicator in patients with acute pancreatitis, particularly when organ failure is present at the time of CT examination. Further studies are necessary to confirm this observation.