Cerebral perfusion in posterior reversible encephalopathy syndrome measured with arterial spin labeling MRI

BACKGROUND AND PURPOSE

The pathophysiologic basis of posterior reversible encephalopathy syndrome (PRES) remains controversial. Hypertension (HTN)-induced autoregulatory failure with subsequent hyperperfusion is the leading hypothesis, whereas alternative theories suggest vasoconstriction-induced hypoperfusion as the underlying mechanism. Studies using contrast-based CT and MR perfusion imaging have yielded contradictory results supporting both ideas. This work represents one of the first applications of arterial spin labeling (ASL) to evaluate cerebral blood flow (CBF) changes in PRES.

MATERIALS AND METHODS

After obtaining Institutional Review Board approval, MRI reports at our institution from 07/2015 to 09/2020 were retrospectively searched and reviewed for mention of "PRES" and "posterior reversible encephalopathy syndrome." Of the resulting 103 MRIs (performed on GE 1.5 Tesla or 3 Tesla scanners), 20 MRIs in 18 patients who met the inclusion criteria of clinical and imaging diagnosis of PRES and had diagnostic-quality pseudocontinuous ASL scans were included. Patients with a more likely alternative diagnosis, technically non-diagnostic ASL, or other intracranial abnormalities limiting assessment of underlying PRES features were excluded. Perfusion in FLAIR-affected brain regions was qualitatively assessed using ASL and characterized as hyperperfusion, normal, or hypoperfusion. Additional quantitative analysis was performed by measuring average gray matter CBF in abnormal versus normal brain regions.

RESULTS

HTN was the most common PRES etiology (65%). ASL showed hyperperfusion in 13 cases and normal perfusion in 7 cases. A hypoperfusion pattern was not identified. Quantitative analysis of gray matter CBF among patients with visually apparent hyperperfusion showed statistically higher perfusion in affected versus normal appearing brain regions (median CBF 100.4 ml/100 g-min vs. 61.0 ml/ 100 g-min, p < 0.001).

CONCLUSION

Elevated ASL CBF was seen in the majority (65%) of patients with PRES, favoring the autoregulatory failure hypothesis as a predominant mechanism. Our data support ASL as a practical way to assess and noninvasively monitor cerebral perfusion in PRES that could potentially alter management strategies.

Apparent posterior cerebral artery territory perfusion asymmetry on arterial spin labeling MRI is a common non-pathologic finding in patients with a unilateral fetal posterior cerebral artery

Purpose

To determine the frequency of apparent posterior cerebral artery (PCA) territory asymmetry seen on arterial spin labeling (ASL) imaging in patients with a unilateral fetal PCA, but without underlying clinical or imaging pathology to suggest true hypoperfusion.

Methods

A search of radiology reports from 1/2017 through 6/2020 was performed with the inclusion term "fetal PCA.” Eighty patients were included with unilateral fetal PCA confirmed on MRA or CTA, with brain MRI including ASL imaging, and without conventional imaging abnormality or clinical symptoms referable to the PCA territories. Cases were evaluated by two independent readers for visually apparent PCA perfusion asymmetries. ASL imaging consisted of pseudocontinuous ASL with 1.5 s labeling duration and 2 s post-labeling delay adapted from white paper recommendations.

Results

Thirteen of 80 cases (16.2%) had apparent hypoperfusion in the PCA territory contralateral to the side of the fetal PCA. Agreement between readers was near perfect (97.5%, κ = 0.91). This finding was more common in patients who were older, scanned on a 3.0 T magnet, and who had non-visualization of the posterior communicating artery contralateral to the fetal PCA.

Conclusion

Apparent PCA hypoperfusion on ASL is not uncommon in patients with a contralateral fetal PCA who have no clinical or conventional imaging findings to suggest true hypoperfusion. This phenomenon is likely due to differential blood velocities between the carotid and vertebral arteries that result in differential arterial transit times and labeling efficiency. It is important for radiologists to know that apparent hypoperfusion may arise from variant circle of Willis anatomy.

What a difference a delay makes! CT urogram: a pictorial essay

PURPOSE

The aim of this pictorial essay is to demonstrate several cases where the diagnosis would have been difficult or impossible without the excretory phase image of CT urography.

METHODS

A brief discussion of CT urography technique and dose reduction is followed by several cases illustrating the utility of CT urography.

RESULTS

CT urography has become the primary imaging modality for evaluation of hematuria, as well as in the staging and surveillance of urinary tract malignancies. CT urography includes a non-contrast phase and contrast-enhanced nephrographic and excretory (delayed) phases. While the three phases add to the diagnostic ability of CT urography, it also adds potential patient radiation dose. Several techniques including automatic exposure control, iterative reconstruction algorithms, higher noise tolerance, and split-bolus have been successfully used to mitigate dose. The excretory phase is timed such that the excreted contrast opacifies the urinary collecting system and allows for greater detection of filling defects or other abnormalities. Sixteen cases illustrating the utility of excretory phase imaging are reviewed.

CONCLUSIONS

Excretory phase imaging of CT urography can be an essential tool for detecting and appropriately characterizing urinary tract malignancies, renal papillary and medullary abnormalities, CT radiolucent stones, congenital abnormalities, certain chronic inflammatory conditions, and perinephric collections.

Hospital Teaching Status and Readmission after Open Abdominal Aortic Aneurysm Repair

BACKGROUND

Readmission after abdominal aortic aneurysm (AAA) repair to a different (nonindex) hospital has been shown to be associated with high mortality rates. Factors influencing this association remain unknown. The objective of this study was to determine the impact of hospital teaching status on nonindex hospital readmission and mortality.

METHODS

An observational analysis of the longitudinally linked California Office of Statewide Health Planning and Development database was conducted from 1995 to 2009. Patients who were readmitted within 30 days after open AAA repair were included. The primary outcome measured was mortality on readmission.

RESULTS

Over the 15-year study period, 3,475 readmissions after AAA were analyzed, of which 1,020 (29.4%) were to a nonindex hospital. After adjusting for age, race, gender, insurance, comorbidities, perioperative factors, and reason for readmission, nonindex readmission for patients undergoing their initial operation at a teaching hospital did not impact mortality (odds ratio [OR] 0.78, 95% confidence interval [CI] 0.28-2.17, P = 0.63). Nonindex readmission for patients undergoing their initial operation at a nonteaching hospital, however, significantly increased mortality (OR 1.63, 95% CI 1.04-2.54, P = 0.03).

CONCLUSIONS

Readmission to a different hospital is associated with a higher mortality rate for patients undergoing AAA repair at nonteaching hospitals. This effect is not seen in patients having their initial operation performed at teaching hospitals, possibly due to infrastructure at these hospitals allowing for decreased impact from fragmentation of care. In cases where triage to an index hospital for readmission is not possible, communication at a high level between the index hospital and readmission hospital is paramount.

Treatment biases in traumatic neurosurgical care: a retrospective study of the Nationwide Inpatient Sample from 1998 to 2009

OBJECT

This study was designed to assess the relationship between insurance status and likelihood of receiving a neurosurgical procedure following admission for either extraaxial intracranial hemorrhage or spinal vertebral fracture.

METHODS

A retrospective analysis of the Nationwide Inpatient Sample (NIS; 1998–2009) was performed. Cases of traumatic extraaxial intracranial hematoma and spinal vertebral fracture were identified using International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes. Within this cohort, those patients receiving a craniotomy or spinal fusion and/or decompression in the context of an admission for traumatic brain or spine injury, respectively, were identified using the appropriate ICD-9 procedure codes.

RESULTS

A total of 190,412 patients with extraaxial intracranial hematoma were identified between 1998 and 2009. Within this cohort, 37,434 patients (19.7%) received a craniotomy. A total of 477,110 patients with spinal vertebral fracture were identified. Of these, 37,302 (7.8%) received a spinal decompression and/or fusion. On multivariate analysis controlling for patient demographics, severity of injuries, comorbidities, hospital volume, and hospital characteristics, uninsured patients had a reduced likelihood of receiving a craniotomy (odds ratio [OR] 0.76, 95% confidence interval [CI] 0.71–0.82) and spinal fusion (OR 0.67, 95% CI 0.64–0.71) relative to insured patients. This statistically significant trend persisted when uninsured and insured patients were matched on the basis of mortality propensity score. Uninsured patients demonstrated an elevated risk-adjusted mortality rate relative to insured patients in cases of extraaxial intracranial hematoma. Among patients with spinal injury, mortality rates were similar between patients with and without insurance.

CONCLUSIONS

In this study, uninsured patients were consistently less likely to receive a craniotomy or spinal fusion for traumatic intracranial extraaxial hemorrhage and spinal vertebral fracture, respectively. This difference persisted after accounting for overall injury severity and patient access to high- or low-volume treatment centers, and potentially reflects a resource allocation bias against uninsured patients within the hospital setting. This information adds to the growing literature detailing the benefits of health reform initiatives seeking to expand access for the uninsured.

Survival trends of grade I, II, and III astrocytoma patients and associated clinical practice patterns between 1999 and 2010: A SEER-based analysis

Background

The survival trends and the patterns of clinical practice pertaining to radiation therapy and surgical resection for WHO grade I, II, and III astrocytoma patients remain poorly characterized.

Methods

Using the Surveillance, Epidemiology and End Results (SEER) database, we identified 2497 grade I, 4113 grade II, and 2755 grade III astrocytomas during the period of 1999-2010. Time-trend analyses were performed for overall survival, radiation treatment (RT), and the extent of surgical resection (EOR).

Results

While overall survival of grade I astrocytoma patients remained unchanged during the study period, we observed improved overall survival for grade II and III astrocytoma patients (Tarone-Ware P < .05). The median survival increased from 44 to 57 months and from 15 to 24 months for grade II and III astrocytoma patients, respectively. The differences in survival remained significant after adjusting for pertinent variables including age, ethnicity, marital status, sex, tumor size, tumor location, EOR, and RT status. The pattern of clinical practice in terms of EOR for grade II and III astrocytoma patients did not change significantly during this study period. However, there was decreased RT utilization as treatment for grade II astrocytoma patients after 2005.

Conclusion

Results from the SEER database indicate that there were improvements in the overall survival of grade II and III astrocytoma patients over the past decade. Analysis of the clinical practice patterns identified potential opportunities for impacting the clinical course of these patients.

Long-term follow-up of unruptured intracranial aneurysms repaired in California

Object

Using a database that enabled longitudinal follow-up, the authors assessed the long-term outcomes of unruptured cerebral aneurysms repaired by clipping or coiling.

Methods

An observational analysis of the California Office of Statewide Health Planning and Development (OSHPD) database, which follows patients longitudinally in time and through multiple hospitalizations, was performed for all patients initially treated for an unruptured cerebral aneurysm in the period from 1998 to 2005 and with follow-up data through 2009.

Results

Nine hundred forty-four cases (36.5%) were treated with endovascular coiling, 1565 cases (60.5%) were surgically clipped, and 76 cases were treated with both coiling and clipping. There was no significant difference in any demographic variable between the two treatment groups except for age (median: 55 years for the clipped group, 58 years for the coiled group, p < 0.001). Perioperative (30-day) mortality was 1.1% in patients with coiled aneurysms compared with 2.3% in those with clipped aneurysms (p = 0.048). The median follow-up was 7 years (range 4–12 years). At the last follow-up, 153 patients (16.2%) in the coiled group had died compared with 244 (15.6%) in the clipped group (p = 0.693). The adjusted hazard ratio for death at the long-term follow-up was 1.14 (95% CI 0.9–1.4, p = 0.282) for patients with endovascularly treated aneurysms. The incidence of intracranial hemorrhage was similar in the two treatment groups (5.9% clipped vs 4.8% coiled, p = 0.276). One hundred ninety-three patients (20.4%) with coiled aneurysms underwent additional hospitalizations for aneurysm repair procedures compared with only 136 patients (8.7%) with clipped aneurysms (p < 0.001). Cumulative hospital costs per patient for admissions involving aneurysm repair procedures were greater in the clipped group (median cost $98,260 vs $81,620, p < 0.001) through the follow-up.

Conclusions

For unruptured cerebral aneurysms, an observed perioperative survival advantage for endovascular coiling relative to that for surgical clipping was lost on long-term follow-up, according to data from an administrative database of patients who were not randomly allocated to treatment type. A cost advantage of endovascular treatment was maintained even though endovascularly treated patients were more likely to undergo subsequent hospitalizations for additional aneurysm repair procedures. Rates of aneurysm rupture following treatment were similar in the two groups.

Incidence and predictors of 30-day readmission for patients discharged home after craniotomy for malignant supratentorial tumors in California (1995–2010)

Object

Hospital readmission within 30 days of discharge is a major contributor to the high cost of health care in the US and is also a major indicator of patient care quality. The purpose of this study was to investigate the incidence, causes, and predictors of 30-day readmission following craniotomy for malignant supratentorial tumor resection.

Methods

The longitudinal California Office of Statewide Health Planning & Development inpatient-discharge administrative database is a data set that consists of 100% of all inpatient hospitalizations within the state of California and allows each patient to be followed throughout multiple inpatient hospital stays, across multiple institutions, and over multiple years (from 1995 to 2010). This database was used to identify patients who underwent a craniotomy for resection of primary malignant brain tumors. Causes for unplanned 30-day readmission were identified by principle ICD-9 diagnosis code and multivariate analysis was used to determine the independent effect of various patient factors on 30-day readmissions.

Results

A total of 18,506 patients received a craniotomy for the treatment of primary malignant brain tumors within the state of California between 1995 and 2010. Four hundred ten patients (2.2%) died during the index surgical admission, 13,586 patients (73.4%) were discharged home, and 4510 patients (24.4%) were transferred to another facility. Among patients discharged home, 1790 patients (13.2%) were readmitted at least once within 30 days of discharge, with 27% of readmissions occurring at a different hospital than the initial surgical institution. The most common reasons for readmission were new onset seizure and convulsive disorder (20.9%), surgical infection of the CNS (14.5%), and new onset of a motor deficit (12.8%). Medi-Cal beneficiaries were at increased odds for readmission relative to privately insured patients (OR 1.52, 95% CI 1.20–1.93). Patients with a history of prior myocardial infarction were at an increased risk of readmission (OR 1.64, 95% CI 1.06–2.54) as were patients who developed hydrocephalus (OR 1.58, 95% CI 1.20–2.07) or venous complications during index surgical admission (OR 3.88, 95% CI 1.84–8.18).

Conclusions

Using administrative data, this study demonstrates a baseline glioma surgery 30-day readmission rate of 13.2% in California for patients who are initially discharged home. This paper highlights the medical histories, perioperative complications, and patient demographic groups that are at an increased risk for readmission within 30 days of home discharge. An analysis of conditions present on readmission that were not present at the index surgical admission, such as infection and seizures, suggests that some readmissions may be preventable. Discharge planning strategies aimed at reducing readmission rates in neurosurgical practice should focus on patient groups at high risk for readmission and comprehensive discharge planning protocols should be implemented to specifically target the mitigation of potentially preventable conditions that are highly associated with readmission.

Long-term outcomes of patients with nonsurgically managed uncomplicated appendicitis

BACKGROUND

Emerging literature has supported the safety of nonoperative management of uncomplicated appendicitis.

STUDY DESIGN

Patients with emergent, uncomplicated appendicitis were identified by appropriate ICD-9 diagnosis codes in the California Office of Statewide Health Planning and Development database from 1997 to 2008. Rates of treatment failure, recurrence, and perforation after nonsurgical management were calculated. Factors associated with treatment failure, recurrence, and perforation were identified using multivariable logistic regression. Mortality, length of stay, and total charges were compared between treatment cohorts using matched propensity score analysis.

RESULTS

Of 231,678 patients with uncomplicated appendicitis, the majority (98.5%) were managed operatively. Of the 3,236 nonsurgically managed patients who survived to discharge without an interval appendectomy, 5.9% and 4.4% experienced treatment failure or recurrence, respectively, during a median follow-up of more than 7 years. There were no mortalities associated with treatment failure or recurrence. The risk of perforation after discharge was approximately 3%. Using multivariable analysis, race and age were significantly associated with the odds of treatment failure. Sex, age, and hospital teaching status were significantly associated with the odds of recurrence. Age and hospital teaching status were significantly associated with the odds of perforation. Matched propensity score analysis indicated that after risk adjustment, mortality rates (0.1% vs 0.3%; p = 0.65) and total charges ($23,243 vs $24,793; p = 0.70) were not statistically different between operative and nonoperative patients; however, length of stay was significantly longer in the nonoperative treatment group (2.1 days vs 3.2 days; p < 0.001).

CONCLUSIONS

This study suggests that nonoperative management of uncomplicated appendicitis can be safe and prompts additional investigations. Comparative effectiveness research using prospective randomized studies can be particularly useful.

Gross-total resection outcomes in an elderly population with glioblastoma: a SEER-based analysis

Object

There is limited information on the relationship between patient age and the clinical benefit of resection in patients with glioblastoma. The purpose of this study was to use a population-based database to determine whether patient age influences the frequency that gross-total resection (GTR) is performed, and also whether GTR is associated with survival difference in different age groups.

Methods

The authors identified 20,705 adult patients with glioblastoma in the Surveillance, Epidemiology, and End Results (SEER) registry (1998–2009). Surgical practice patterns were defined by the categories of no surgery, subtotal resection (STR), and GTR. Kaplan-Meier and multivariate Cox regression analyses were used to assess the pattern of surgical practice and overall survival.

Results

The frequency that GTR was achieved in patients with glioblastoma decreased in a stepwise manner as a function of patient age (from 36% [age 18–44 years] to 24% [age ≥ 75]; p < 0.001). For all age groups, glioblastoma patients who were selected for and underwent GTR showed a 2- to 3-month improvement in overall survival (p < 0.001) relative to those who underwent STR. These trends remained true after a multivariate analysis that incorporated variables including ethnicity, sex, year of diagnosis, tumor size, tumor location, and radiotherapy status.

Conclusions

Gross-total resection is associated with improved overall survival, even in elderly patients with glioblastoma. As such, surgical decisions should be individually tailored to the patient rather than an adherence to age as the sole clinical determinant.

Hormone receptor-negative breast cancer: undertreatment of patients over 80

PURPOSE

Patients older than 80 years represent a significant breast cancer population but are underrepresented in clinical trials. It is established that estrogen receptor (ER)/progesterone receptor (PR)-negative status confers a worse prognosis in patients under 70, but this is not well studied in those over 80. We examined the prognosis of patients over 80 with ER/PR-negative disease to determine whether these patients are more likely to die of breast cancer than cardiovascular disease and to study treatment patterns.

METHODS

We queried the Surveillance Epidemiology and End Results (SEER) database between 1992 and 2009 for patients with invasive breast carcinoma. Primary outcomes were breast cancer or cardiovascular death; secondary outcomes were radiotherapy and surgery. Cox proportional hazard analysis and logistic regression were used to determine adjusted outcomes over time. Subset analysis was performed comparing mortality rates by stage.

RESULTS

There were 502,807 patients, 6,933 over 80 with ER/PR-negative disease. ER/PR-negative patients over 80 faced decreased 10-year survival compared to ER/PR-positive patients (61.5, 81.4 %; p < 0.05). ER/PR-negative patients were more likely to die of breast cancer than of cardiovascular disease (25.6, 12.2 %). Adjusting for confounders, ER/PR-negative patients over 80 were more likely to die from breast cancer specifically than patients aged 50-79 years [hazards ratio (HR) 1.53, 95 % confidence interval (CI) 1.43-1.64]. This finding was consistent across all stages. Compared to younger cohorts, elderly patients with ER/PR-negative disease received less radiotherapy [odds ratio (OR) 0.42, 95 % CI 0.39-0.46] and had a trend for less surgery (OR 0.86, 95 % CI 0.69-1.07).

CONCLUSIONS

Elderly ER/PR-negative patients are more likely to die of their breast disease than cardiovascular disease. Standard treatment regimens, especially radiotherapy, should be considered for elderly patients.