Groote Schuur Hospital neurosurgical intensive care unit: A 2-year review of admission characteristics

Background

At Groote Schuur Hospital (GSH), the neurosurgical intensive care unit (NsICU) is a 6-bed unit headed by a specialist neurosurgeon with extensive experience in neurocritical care, working in close collaboration with intensivists from the Division of Critical Care. There is currently no detailed analysis of the demographics, diagnosis and management of patients admitted to the NsICU at GSH.

Objectives

To provide a detailed descriptive analysis of the demographics, diagnosis and management of patients admitted to the NsICU at GSH from 1 January 2020 to 31 December 2021.

Methods

A retrospective descriptive analysis was done of patients who received treatment in the NsICU from 1 January 2020 to 31 December 2021.

Results

A total of 685 patients were admitted to the unit over a 2-year period, with a male preponderance (68.2%). The average age was 42.5 (standard deviation (SD) 17.2) years. The most common neurosurgical diagnoses were traumatic brain injuries (39.6%), brain tumours (22.6%) and aneurysmal subarachnoid haemorrhages (9.9%). Emergency admissions comprised 76.6% of the total and 86.7% of patients were admitted postoperatively. Three hundred and seventy-two patients (54.3%) required mechanical ventilation, 132 (19.3%) required both an intracranial pressure (ICP) monitor and brain tissue oxygenation monitor, 86 (12.5%) needed placement of an external ventricular drain, 50 (7.3%) needed placement of a tracheostomy tube and 16 (2.3%) needed placement of an ICP monitor only. The average duration of stay was 5.5 (1.3) days and NsICU mortality over 2 years was 11.1%.

Conclusion

The NsICU at GSH manages predominantly male trauma patients and a significant number of admitted patients require specialised invasive intracranial monitoring.

Contribution of the study

This is the first in-depth analysis of patients managed in a dedicated neurosurgical intensive care unit in South Africa. The work defines the patient population, neurosurgical pathologies and service level requirements that would likely be encountered by teams building a similar service.

Core competencies in critical care for general medical practitioners in South Africa: A Delphi study

Background

Despite a high burden of disease that requires critical care services, there are a limited number of intensivists in South Africa (SA). Medical practitioners at district and regional public sector hospitals frequently manage critically ill patients in the absence of intensivists, despite these medical practitioners having had minimal exposure to critical care during their undergraduate training.

Objectives

To identify core competencies in critical care for medical practitioners who provide critical care services at public sector hospitals in SA where intensivists are not available to direct patient management.

Methods

A preliminary list of core competencies in critical care was compiled. Thereafter, 13 national and international experts were requested to achieve consensus on a final list of core competencies that are required for critical care by medical practitioners, using a modified Delphi process.

Results

A final list of 153 core competencies in critical care was identified.

Conclusion

The core competencies identified by this study could assist in developing training programmes for medical practitioners to improve the quality of critical care services provided at district and regional hospitals in SA.

Contribution of the study

The study provides consensus on a list of core competencies in critical care that non-intensivist medical practitioners managing critically ill patients in healthcare settings in South Africa, especially where intensivists are not readily available, should have. The list can form the core content of training programmes aimed at improving critical care competence of general medical practitioners, and in this way hopefully improve the overall outcomes of critically ill patients in South Africa.

South African guidelines on the determination of death

Summary

Death is a medical occurrence that has social, legal, religious and cultural consequences requiring common clinical standards for its diagnosis and legal regulation. This document compiled by the Critical Care Society of Southern Africa outlines the core standards for determination of death in the hospital context. It aligns with the latest evidence-based research and international guidelines and is applicable to the South African context and legal system. The aim is to provide clear medical standards for healthcare providers to follow in the determination of death, thereby promoting safe practices and high-quality care through the use of uniform standards. Adherence to such guidelines will provide assurance to medical staff, patients, their families and the South African public that the determination of death is always undertaken with diligence, integrity, respect and compassion, and is in accordance with accepted medical standards and latest scientific evidence. The consensus guidelines were compiled using the AGREE II checklist with an 18-member expert panel participating in a three-round modified Delphi process. Checklists and advice sheets were created to assist with application of these guidelines in the clinical environment (https://criticalcare.org.za/resource/death-determination-checklists/).

Key points

Brain death and circulatory death are the accepted terms for defining death in the hospital context.

Death determination is a clinical diagnosis which can be made with complete certainty provided that all preconditions are met.

The determination of death in children is held to the same standard as in adults but cannot be diagnosed in children <36 weeks’ corrected gestation.

Brain-death testing while on extra-corporeal membrane oxygenation is outlined.

Recommendations are given on handling family requests for accommodation and on consideration of the potential for organ donation.

The use of a checklist combined with a rigorous testing process, comprehensive documentation and adequate counselling of the family are core tenets of death determination. This is a standard of practice to which all clinicians should adhere in end-of-life care.

South African guidelines on the determination of death

Death is a medical occurrence that has social, legal, religious and cultural consequences requiring common clinical standards for its diagnosis and legal regulation. This document compiled by the Critical Care Society of Southern Africa outlines the core standards for determination of death in the hospital context. It aligns with the latest evidence-based research and international guidelines and is applicable to the South African context and legal system. The aim is to provide clear medical standards for healthcare providers to follow in the determination of death, thereby promoting safe practices and high-quality care through the use of uniform standards. Adherence to such guidelines will provide assurance to medical staff, patients, their families and the South African public that the determination of death is always undertaken with diligence, integrity, respect and compassion, and is in accordance with accepted medical standards and latest scientific evidence. The consensus guidelines were compiled using the AGREE II checklist with an 18-member expert panel participating in a three-round modified Delphi process. Checklists and advice sheets were created to assist with application of these guidelines in the clinical environment (https://criticalcare.org.za/resource/death-determination-checklists/). Key points • Brain death and circulatory death are the accepted terms for defining death in the hospital context. • Death determination is a clinical diagnosis which can be made with complete certainty provided that all preconditions are met. • The determination of death in children is held to the same standard as in adults but cannot be diagnosed in children <36 weeks' corrected gestation. • Brain-death testing while on extra-corporeal membrane oxygenation is outlined. • Recommendations are given on handling family requests for accommodation and on consideration of the potential for organ donation. • The use of a checklist combined with a rigorous testing process, comprehensive documentation and adequate counselling of the family are core tenets of death determination. This is a standard of practice to which all clinicians should adhere in end-of-life care.

Critical Care Society of Southern Africa adult patient blood management guidelines: 2019 Round-table meeting, CCSSA Congress, Durban, 2018

The CCSSA PBM Guidelines have been developed to improve patient blood management in critically ill patients in southern Africa. These consensus recommendations are based on a rigorous process by experts in the field of critical care who are also practicing in South Africa (SA). The process comprised a Delphi process, a round-table meeting (at the CCSSA National Congress, Durban, 2018), and a review of the best available evidence and international guidelines. The guidelines focus on the broader principles of patient blood management and incorporate transfusion medicine (transfusion guidelines), management of anaemia, optimisation of coagulopathy, and administrative and ethical considerations. There are a mix of low-middle and high-income healthcare structures within southern Africa. Blood products are, however, provided by the same not-for-profit non-governmental organisations to both private and public sectors. There are several challenges related to patient blood management in SA due most notably to a high incidence of anaemia, a frequent shortage of blood products, a small donor population, and a healthcare system under financial strain. The rational and equitable use of blood products is important to ensure best care for as many critically ill patients as possible. The summary of the recommendations provides key practice points for the day-to-day management of critically ill patients. A more detailed description of the evidence used to make these recommendations follows in the full clinical guidelines section.

The Critical Care Society of Southern Africa Consensus Guideline on ICU Triage and Rationing (ConICTri)

Background

In South Africa (SA), administrators and intensive care practitioners are faced with the challenge of resource scarcity as well as an increasing demand for intensive care unit (ICU) services. ICU services are expensive, and practitioners in low- to middle-income countries experience the consequences of limited resources daily. Critically limited resources necessitate that rationing and triage (prioritisation) decisions are routinely necessary in SA, particularly in the publicly funded health sector.

Purpose

The purpose of this guideline is to utilise the relevant recommendations of the associated consensus meeting document and other internationally accepted principles to develop a guideline to inform frontline triage policy and ensure the best utilisation of adult intensive care in SA, while maintaining the fair distribution of available resources.

Recommendations

An overall conceptual framework for the triage process was developed. The components of the framework were developed on the basis that patients should be admitted preferentially when the likely incremental medical benefit derived from ICU admission justifies admission. An estimate of likely resource use should also form part of the triage decision, with those patients requiring relatively less resources to achieve substantial benefit receiving priority for admission. Thus, the triage system should maximise the benefits obtained from ICU resources available for the community. Where possible, practical examples of what the consensus group agreed would be considered appropriate practice under specified South African circumstances were provided, to assist clinicians with practical decision-making. It must be stressed that this guideline is not intended to be prescriptive for individual hospital or regional practice, and hospitals and regions are encouraged to develop specified local guidelines with locally relevant examples. The guideline should be reviewed and revised if appropriate within 5 years.

Conclusion

In recognition of the absolute need to limit patient access to ICU because of the lack of sufficient intensive care resources in public hospitals, this guideline has been developed to guide policy-making and assist frontline triage decision-making in SA. This document is not a complete plan for quality practice, but rather a template to support frontline clinicians, guide administrators and inform the public regarding appropriate triage decision-making.

The Critical Care Society of Southern Africa Consensus Statement on ICU Triage and Rationing (ConICTri)

Background

In South Africa (SA), intensive care is faced with the challenge of resource scarcity as well as an increasing demand for intensive care unit (ICU) services. ICU services are expensive, and practitioners in low- to middle-income countries experience daily the consequences of limited resources. Critically limited resources necessitate that rationing and triage (prioritisation) decisions are frequently necessary in SA, particularly in the publicly funded health sector.

Purpose

The purpose of this consensus statement is to examine key questions that arise when considering the status of ICU resources in SA, and more specifically ICU admission, rationing and triage decisions. The accompanying guideline in this issue is intended to guide frontline triage policy and ensure the best utilisation of intensive care in SA, while maintaining a fair distribution of available resources. Fair and efficient triage is important to ensure the ongoing provision of high-quality care to adult patients referred for intensive care.

Recommendations

In response to 14 key questions developed using a modified Delphi technique, 29 recommendations were formulated and graded using an adapted GRADE score. The 14 key questions addressed the status of the provision of ICU services in SA, the degree of resource restriction, the efficiency of resource management, the need for triage, and how triage could be most justly implemented. Important recommendations included the need to formally recognise and accurately quantify the provision of ICU services in SA by national audit; actively seek additional resources from governmental bodies; consider methods to maximise the efficiency of ICU care; evaluate lower level of care alternatives; develop a triage guideline to assist policy-makers and frontline practitioners to implement triage decisions in an efficient and fair way; measure and audit the consequence of triage; and promote research to improve the accuracy and consistency of triage decisions. The consensus document and guideline should be reviewed and revised appropriately within 5 years.

Conclusion

In recognition of the absolute need to limit patient access to ICU because of the lack of sufficient intensive care resources in public hospitals, recommendations and a guideline have been developed to guide policy-making and assist frontline triage decision-making in SA. These documents are not a complete plan for quality practice but rather the beginning of a long-term initiative to engage clinicians, the public and administrators in appropriate triage decision-making, and promote systems that will ultimately maximise the efficient and fair use of available ICU resources.

Magnetic resonance elastography in the detection of hepatorenal syndrome in patients with cirrhosis and ascites

OBJECTIVE

Hepatorenal syndrome (HRS) is the most lethal cause of renal impairment in cirrhosis. Magnetic resonance elastography (MRE) is a diagnostic test that characterises tissues based on their biomechanical properties. The aim of this study was to assess the feasibility of MRE for detecting HRS in cirrhotic patients.

METHODS

A prospective diagnostic investigation was performed. Renal MRE was performed on 21 hospitalised patients with cirrhosis and ascites. Six patients had HRS, one patient had non-HRS renal impairment, and 14 patients had normal renal function. The MRE-measured renal stiffness was compared against the clinical diagnosis as determined by clinical review alongside laboratory and radiologic results.

RESULTS

The MRE-measured renal stiffness was significantly lower in patients with HRS (median stiffness of 3.30 kPa at 90 Hz and 2.62 kPa at 60 Hz) compared with patients with normal renal function (median stiffness of 5.08 kPa at 90 Hz and 3.41 kPa at 60 Hz) (P ≤ 0.014). For the detection of HRS, MRE had an area under the receiver operating characteristic curve of 0.94 at 90 Hz and 0.89 at 60 Hz. MRE had excellent inter-rater agreement, as assessed by Bland-Altman and intraclass correlation coefficient (> 0.9).

CONCLUSION

MRE shows potential in the detection of HRS.

KEY POINTS

• Magnetic resonance elastography (MRE) shows promise in the detection of hepatorenal syndrome. • MRE has the potential to track renal disease in a clinical population. • MRE is a reliable diagnostic test with excellent inter-rater agreement.

Reliability of magnetic resonance elastography using multislice two-dimensional spin-echo echo-planar imaging (SE-EPI) and three-dimensional inversion reconstruction for assessing renal stiffness

BACKGROUND

To evaluate the reliability of MRE using a spin-echo echo-planar imaging (SE-EPI) renal MRE technique in healthy volunteers.

METHODS

Institutional review board approved prospective study in which all participants provided written informed consent. Sixteen healthy volunteers comprising seven males and nine females with a median age of 35 years (age range: 23 to 59 years) were included. Coronal 90 Hz and 60 Hz MRE acquisitions were performed twice within a 30-min interval between examinations. Renal MRE reliability was assessed by (i) test-retest repeatability, and (ii) inter-rater agreement between two independent readers. The MRE-measured averaged renal stiffness values were evaluated using: intraclass correlation coefficient (ICC), Bland-Altman and the within-subject coefficient of variation (COV).

RESULTS

For test-retest repeatability, Bland-Altman showed a mean stiffness difference between examinations of 0.07 kPa (95% limits of agreement: -1.41, 1.54) at 90 Hz and 0.01 kPa (95% limits of agreement: -0.51, 0.53) at 60 Hz. Coefficient of repeatability was 1.47 kPa and 0.52 kPa at 90 Hz and 60 Hz, respectively. The within-subject COV was 13.6% and 7.7% at 90 Hz and 60 Hz, respectively. ICC values were 0.922 and 0.907 for test-retest repeatability and 0.998 and 0.989 for inter-rater agreement, respectively (P < 0.001).

CONCLUSION

SE-EPI renal MRE is a reliable technique.

Interactive neonatal gastrointestinal magnetic resonance imaging using fruit juice as an oral contrast media

BACKGROUND

The objective was to evaluate the use of fruit juice with an interactive inversion recovery (IR) MR pulse sequence to visualise the gastrointestinal tract.

METHODS

We investigated the relaxation properties of 12 different natural fruit juices in vitro, to identify which could be used as oral contrast. We then describe our initial experience using an interactive MR pulse sequence to allow optimal visualisation after administering pineapple juice orally, and suppressing pre-existing bowel fluid contents, with variable TI in three adult and one child volunteer.

RESULTS

Pineapple juice (PJ) had both the shortest T1 (243 ms) and shortest T2 (48 ms) of the fruit juices tested. Optimal signal differentiation between pre-existing bowel contents and oral PJ administration was obtained with TIs of between 900 and 1100 ms.

CONCLUSION

The use of an inversion recovery preparation allowed long T1 pre-existing bowel contents to be suppressed whilst the short T1 of fruit juice acts as a positive contrast medium. Pineapple juice could be used as oral contrast agent for neonatal gastrointestinal magnetic resonance imaging.

Interactive magnetic resonance imaging for paediatric vesicoureteric reflux (VUR)

OBJECTIVES

The current gold standard for diagnosing vesicoureteric reflux in unsedated infants is the X-ray-based Micturating CystoUrethroGram (MCUG). The aim of this study was to assess the diagnostic performance of interactive MRI for voiding cysto-urethrography (iMRVC).

METHODS

25 infants underwent conventional MCUG followed by iMRVC. In iMRVC, patients were examined using a real-time MR technique, which allows interactive control of image contrast and imaging plane location, before, during and after micturition. Images were assessed for presence and grade of VUR. Parental feedback on both procedures was evaluated.

RESULTS

iMRVC gave a sensitivity of 100%, specificity of 90.5% (95% CI: 81.6-99.4%), PPV of 66.7% and NPV of 100% in this population. There was 88% concordance (44/50 renal units) according to the presence of VUR between the two methods, with iMRVC up-grading VUR in 6 units (12%). There was very good agreement regarding VUR grade: Kappa=0.66±0.11 (95% CI 0.43-0.88). 60% of parents preferred the MRI, but did not score the two tests differently.

CONCLUSION

Interactive MRI allows dynamic imaging of the whole urinary tract without ionising radiation exposure. iMRVC gives comparable results to the MCUG, and is acceptable to parents.

Repeatability of edited lactate and other metabolites in astrocytoma at 3T

PURPOSE

To assess the repeatability of measurement of lactate and other metabolites in tumors using magnetic resonance spectroscopy (MRS).

MATERIALS AND METHODS

MRS with spectral editing for lactate was performed on 10 patients with astrocytoma (two Grade III, eight Grade IV) using an 8-channel receive coil at 3T. Lactate, lipid, choline, creatine, and N-acetyl aspartate (NAA) signals were measured in regions of tumor and contralateral white matter. Metabolites were quantified relative to unsuppressed water using LCModel fitting software.

RESULTS

The within-patient coefficients of variation were ≈16% (tumor lactate), 6%-8% (tumor choline and contralateral choline, creatine, and NAA), and 22% (tumor lipid). As expected due to their low concentration in normal tissue, lactate and lipid were not reliably detected in white matter but were found at high levels in most tumors. NAA and creatine were lower in tumors than in normal white matter, and choline varied between above- and below-normal values. No consistent short-term variation in metabolite levels was observed, despite differences in the time elapsed since administration of contrast agent.

CONCLUSION

MRS appears repeatable enough to provide longitudinal measures of metabolite content in tumors and contralateral tissue in the brain in vivo.

Advanced ovarian cancer: multiparametric MR imaging demonstrates response- and metastasis-specific effects

PURPOSE

To investigate the role of multiparametric magnetic resonance (MR) imaging in the evaluation of response to platinum-based neoadjuvant chemotherapy in advanced ovarian cancer and to compare imaging parameters between primary ovarian mass and metastatic disease.

MATERIALS AND METHODS

Evaluable patients suspected of having advanced ovarian carcinoma were enrolled in a prospective protocol-driven study. Research ethics committee approval and written informed consent were obtained. Multiparametric MR imaging (diffusion-weighted MR imaging, dynamic contrast material-enhanced [DCE] MR imaging, and hydrogen 1 MR spectroscopy) was performed with a 3.0-T wholebody MR imaging system. Three marker lesions-primary ovarian mass, omental cake, and peritoneal deposit-were outlined by a radiologist on apparent diffusion coefficient (ADC) and vascular signal fraction (VSF) maps and on DCE MR images. Comparisons of mean ADC, mean VSF, DCE MR imaging parameters, and choline concentration between responders and nonresponders were based on Response Evaluation Criteria in Solid Tumors and CA-125 criteria.

RESULTS

Twenty-two patients were evaluable. The mean ADC for peritoneal metastases was lower than that for ovarian (P = .015) and omental (P = .006) sites. There were no differences in pretreatment DCE MR imaging parameters between tumor sites. After treatment, responders showed a significantly larger increase in ADC (P = .021) and fractional volume of the extravascular extracellular space (v(e)) (P = .025) of ovarian lesions compared with nonresponders, but there was no change in ADC at other sites. Pre- and posttreatment values of choline concentration of ovarian lesions were lower in responders (P = .025) than in nonresponders (P = .010).

CONCLUSION

The significant differences in baseline ADCs among primary ovarian cancer, omental cake, and peritoneal deposits indicate that diffusivity profiles may be tumor-site dependent, suggesting biologic heterogeneity of disease. ADC and v(e) parameters correlated with the cytotoxic effects of platinum-based therapy and may be useful response markers, while choline concentration predicted but did not reflect response.

DCE and DW MRI in monitoring response to androgen deprivation therapy in patients with prostate cancer: a feasibility study

Androgen deprivation therapy (ADT) is a key primary treatment for advanced and metastatic prostate cancer and is an important neoadjuvant before radiotherapy. We evaluated 3.0 T dynamic contrast-enhanced MRI and diffusion-weighted (DW) MRI in monitoring ADT response. Twenty-three consecutive patients with prostate cancer treated by primary ADT were included. Imaging was performed at baseline and 3 months posttreatment with ADT. After 3 months therapy there was a significant reduction in all dynamic contrast-enhanced MRI parameters measured in tumor regions of interest (K(trans), k(ep), v(p), IAUGC-90); P < 0.001. Areas of normal-appearing peripheral zone showed no significant change; P = 0.285-0.879. Post-ADT, there was no significant change in apparent diffusion coefficient values in tumors, whilst apparent diffusion coefficient values significantly decreased in areas of normal-appearing peripheral zone, from 1.786 × 10(-3) mm(2) /s to 1.561 × 10(-3) mm(2) /s; P = 0.007. As expected the median Prostate-Specific Antigen (PSA) significantly reduced from 30 ng/mL to 1.5 ng/mL posttreatment, and median prostate volume dropped from 47.6 cm(3) to 24.9 cm(3) ; P < 0.001. These results suggest that dynamic contrast-enhanced MRI and diffusion-weighted MRI offer different information but that both could prove useful adjuncts to the anatomical information provided by T2-weighted imaging. dynamic contrast-enhanced as a marker of angiogenesis may help demonstrate ADT resistance and diffusion-weighted imaging may be more accurate in determining presence of tumor cell death versus residual tumor.

Evaluation of depth of myometrial invasion and overall staging in endometrial cancer: comparison of diffusion-weighted and dynamic contrast-enhanced MR imaging

PURPOSE

To compare the diagnostic performance of diffusion-weighted (DW) magnetic resonance (MR) imaging with that of dynamic contrast material-enhanced (DCE) MR imaging in evaluating the depth of myometrial invasion and overall stage in patients with endometrial cancer.

MATERIALS AND METHODS

The institutional review board approved this retrospective study; patient consent was not required. From May 2008 to February 2010, 48 women with endometrial cancer underwent preoperative MR imaging, including T1- and T2-weighted imaging, DW MR imaging (b=0 and 800 sec/mm2) and DCE MR imaging. Two radiologists independently interpreted the depth of myometrial invasion, overall stage, and presence of pitfalls associated with inaccurate assessment of myometrial invasion at T1- and T2-weighted imaging, DW MR imaging, and DCE MR imaging. Myometrial invasion and overall stage were compared by using the McNemar test, and κ statistics were used for reader agreement.

RESULTS

For assessing the depth of myometrial invasion, diagnostic accuracy, sensitivity, and specificity, respectively, were as follows: DW MR imaging-reader 1, 90%, 84%, and 100%; reader 2, 85%, 84%, and 88%; DCE MR imaging-reader 1, 71%, 61%, and 88%; reader 2, 79%, 77%, and 82%. The improvement in diagnostic accuracy for reader 1 was significant (P=.035). For myometrial invasion, κ values were 0.75 with DW MR imaging and 0.26 with DCE MR imaging. There was no association between inaccurate assessment of myometrial invasion and standard pitfalls with DW MR imaging. Readers 1 and 2 correctly staged more patients by using DW MR imaging (39 and 38 patients, respectively) than by using DCE MR imaging (29 and 30 patients, respectively) (P<.05). For overall stage, κ values were 0.74 with DW MR imaging and 0.22 with DCE MR imaging.

CONCLUSION

DW MR imaging has superior diagnostic accuracy in the assessment of myometrial invasion and significantly higher staging accuracy compared with DCE MR imaging.

Interactive magnetic resonance voiding cystourethrography (iMRVC) for vesicoureteric reflux (VUR) in unsedated infants: a feasibility study

OBJECTIVES

The current reference standard for diagnosing vesicoureteric reflux is the X-ray-based Micturating CystoUrethroGram (MCUG). The aim of this study was to evaluate the feasibility of performing interactive Magnetic Resonance voiding cysto-urethrography (iMRVC) in un-sedated infants.

METHODS

Twelve infants underwent conventional single-cycle MCUG followed by iMRVC. In iMRVC, patients were examined using an in-house developed fluoroscopic pulse sequence, which allows on-the-fly control of image contrast and geometry. A single acquisition was performed during bladder filling, during and after micturition, with interactive control over imaging parameters. Images were assessed for diagnostic quality and presence of VUR.

RESULTS

Every case of reflux identified with MCUG was identified on iMRVC (100% sensitivity). Over 24 renal units, there was 88% concordance (21/24) according to the presence of reflux between the two methods. There were three "false positives" detected by MRI, giving a specificity of 83.3%, PPV of 66.7% and NPV of 100%.

CONCLUSION

iMRVC is a feasible method for evaluating the renal tract in infants without the need for radiation or sedation. A formal evaluation is required to establish its diagnostic potential.

Prostate cancer metabolite quantification relative to water in 1H-MRSI in vivo at 3 Tesla

(1)H magnetic resonance spectroscopic imaging was performed on 16 men with suspected prostate cancer using an 8-channel external receive coil at 3 T. Choline and citrate (Cit) signals were measured in prostate lesions and normal-appearing peripheral zone as identified on T(2)-weighted images. Metabolites were quantified relative to unsuppressed water from a separately acquired magnetic resonance spectroscopic imaging dataset using LCModel. Validation experiments were also performed in a phantom containing physiological concentrations of choline, Cit, and creatine. In vitro, fair agreement between measured and true concentrations was observed, with the greatest discrepancy being a 35% underestimation of Cit. In vivo, one dataset was rejected for failure to meet the quality criterion of linewidth <15 Hz, and in 6 of 15 subjects, insufficient normal-appearing peripheral zone tissue was identified for study. Lesions were found to have higher choline and choline/Cit, and lower Cit, than normal-appearing peripheral zone. The smaller skew of data obtained using water normalization in comparison with metabolite ratios suggests potential usefulness in longitudinal tumor monitoring and in studies of treatment effects.

Minimally-invasive fetal autopsy using magnetic resonance imaging and percutaneous organ biopsies: clinical value and comparison to conventional autopsy

OBJECTIVES

Autopsy is an important investigation following fetal death or termination for fetal abnormality. Postmortem magnetic resonance imaging (MRI) can provide macroscopic information of comparable quality to that of conventional autopsy in the event of perinatal death. It does not provide tissue for histological examination, which may limit the quality of counseling for recurrence risks and elucidation of the cause of death. We sought to examine the comparability and clinical value of a combination of postmortem MRI and percutaneous fetal organ biopsies (minimally invasive autopsy (MIA)) with conventional fetal autopsy.

METHODS

Forty-four fetuses underwent postmortem MRI and attempted percutaneous biopsy (using surface landmarks) of major fetal organs (liver, lung, heart, spleen, kidney, adrenal and thymus) following fetal death or termination for abnormality, prior to conventional autopsy, which was considered the 'gold standard'. We compared significant findings of the two examinations for both diagnostic information and clinical significance. Ancillary investigations (such as radiographs and placental histology) were regarded as common to the two forms of autopsy.

RESULTS

In 21 cases conventional autopsy provided superior diagnostic information to that of MIA. In two cases the MIA provided superior diagnostic information to that of conventional autopsy, when autolysis prevented detailed examination of the fetal brain. In the remaining 21 cases, conventional autopsy and MIA provided equivalent diagnostic information. With regard to clinical significance, however, in 32 (72.7%) cases, the MIA provided information of at least equivalent clinical significance to that of conventional autopsy. In no case did the addition of percutaneous biopsies reveal information of additional clinical significance.

CONCLUSIONS

Although in some cases MRI may provide additional information, conventional perinatal autopsy remains the gold standard for the investigation of fetal death. The utility of adding percutaneous organ biopsies, without imaging guidance, to an MRI-based fetal autopsy remains unproven. Postmortem MRI, combined with ancillary investigations such as placental histology, external examination by a pathologist, cytogenetics and plain radiography provided information of equivalent clinical significance in the majority of cases.

Validity of a new abdominal bioelectrical impedance device to measure abdominal and visceral fat: comparison with MRI

Abdominal fat, and in particular, visceral adipose tissue (VAT), is the critical fat depot associated with metabolic aberrations. At present, VAT can only be accurately measured by computed tomography or magnetic resonance imaging (MRI). This study was designed to compare a new abdominal bioelectrical impedance (BIA) device against total abdominal adipose tissue (TAAT) and VAT area measurements made from an abdominal MRI scan, and to assess its reliability and accuracy. One-hundred twenty participants were recruited, stratified by gender and BMI. Participants had triplicate measures of abdominal fat and waist circumference (WC) with the AB-140 (Tanita, Tokyo, Japan) and WC measurements using a manual tape measure. A single abdominal MRI scan was performed as the reference method. Triplicate measures with the AB-140 showed excellent precision for "visceral fat level," trunk fat %, and WC. AB-140 "visceral fat level" showed significantly stronger correlations with MRI TAAT area than with MRI VAT area (r = 0.94 vs. 0.65 in men and 0.92 vs. 0.64 in women). AB-140 WC showed good correlation with manual WC measurements (r = 0.95 in men and 0.90 in women). AB-140 and manual WCs showed comparable correlations with MRI TAAT area (r = 0.92 and 0.96 in men and 0.88 and 0.88 in women). AB-140 is a simple, quick, and precise technique to measure abdominal fat and WC in healthy adults. It provides a useful proxy for TAAT measured by MRI, comparable to the correlation obtained with manual WC measurements. Neither the AB-140 abdominal fat measures nor WC measurement appear to provide a useful proxy measure of VAT.

Dynamic contrast-enhanced MRI in ovarian cancer: Initial experience at 3 tesla in primary and metastatic disease

The aim of this study was to develop and demonstrate a methodology for dynamic contrast-enhanced MRI at 3 T in patients with advanced ovarian cancer and to report the results from pharmacokinetic modeling of the data. Nineteen patients with suspected advanced ovarian carcinoma (FIGO stage 3 or higher) were enrolled in this prospective study. Up to three marker lesions were identified: primary ovarian mass, omental ''cake'', and peritoneal deposits. Dynamic contrast-enhanced MRI was performed using a three-dimensional T(1)-weighted gradient-echo acquisition with a temporal resolution of 1.6 sec, following intravenous administration of 0.1 mmol/kg gadobutrol. Precontrast T(1) mapping, using an inversion-recovery fast gradient-echo sequence, was also performed. Imaging was completed in 18/19 patients, although two were subsequently excluded based on pathology results. Pharmacokinetic modeling of the data was performed according to the extended Kety model, using an arterial input function formed by concatenation of the Fritz-Hansen and Weinmann curves. No statistically significant differences were found between the results for the three marker lesions. In the future, this work will allow kinetic modeling results from ovarian dynamic contrast-enhanced MRI to be correlated with response to treatment. The high temporal resolution allows good characterization of the rapid contrast agent uptake in these vascular tumors.

Apparent diffusion coefficient and vascular signal fraction measurements with magnetic resonance imaging: feasibility in metastatic ovarian cancer at 3 Tesla: technical development

This prospective study aims to evaluate the feasibility of DWI at 3 Tesla in patients with advanced ovarian cancer and investigate the differences in vascular signal fraction (VSF) and apparent diffusion coefficient (ADC) values between primary ovarian mass and metastatic disease. Twenty patients with suspected advanced ovarian carcinoma were enrolled in the study. High-resolution T2W FRFSE images were used to confirm the position of three marker lesions: primary ovarian mass, omental cake and peritoneal deposit. Multislice DWI was acquired in a single breath-hold using multiple b-values. The three marker lesions were outlined by an experienced radiologist on ADC and VSF maps. Ovarian lesions showed the highest ADC values. The mean ADC value for peritoneal deposits was significantly lower than for both ovarian lesions (p = 0.03) and omental cake (p = 0.03). The VSF for omental cake was significantly higher than for ovarian lesions (p = 0.01) and peritoneal deposits (p = 0.04). There was a significant positive correlation between ADC and VSF for peritoneal deposits (p = 0.04). DWI in advanced ovarian cancer is feasible at 3 T. There are significant differences in baseline ADC and VSF values between ovarian cancer, omental cake and peritoneal deposits that may explain the mixed treatment response that occurs at different disease sites.

Metabolic characterization of primary and metastatic ovarian cancer by 1H-MRS in vivo at 3T

(1)H-MRS was performed on 12 women (age range 45-72) with ovarian cancer of FIGO stage 3 or above using a 3T MRI system with an 8-channel cardiac receive coil. Respiratory-triggered PRESS-localized spectra (TE = 144 ms) were obtained separately from an ovarian mass and from metastatic disease. Peak areas were quantified relative to unsuppressed water using LCModel and spectra were discarded if LCModel reported signal-to-noise ratio (SNR) < 3 or if no metabolites were reported with standard deviation (SD) < 30%. The cystic fraction of each voxel was estimated by thresholding T(2)-weighted images, and this was used both to correct the reported metabolite concentrations and to calculate an expected SNR of choline using the measured SNR of water. Choline was detected in 10/12 primary tumors and 5/11 metastatic lesions (range 2.0-16.6 mM). Of the 8/23 failures, 7 had a predicted choline SNR < 2, confirming that the failure to detect choline could be explained by technical problems. Glycine was observed in one benign lesion. (1)H-MRS can be used to quantify choline in primary and metastatic masses in ovarian cancer, but the moderately high rate of failure to detect choline necessitates careful recording of data quality parameters to discriminate true from false negatives.

Added Value of Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Predicting Advanced Stage Disease in Patients With Endometrial Carcinoma

Aim:

To assess the added value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in predicting advanced stage disease in patients with endometrial carcinoma.

Materials and Methods:

Fifty patients with endometrial carcinoma underwent preoperative MRI assessment in a single gynecological cancer center during a 2-year period. Magnetic resonance imaging examinations included high-resolution sagittal, axial, and axial-oblique T2-weighted images (T2WI) of the pelvis, and axial T1-weighted images (T1WI) of the pelvis and upper abdomen followed by DCE-MRI using a multiphase 3-dimensional gradient refocused echo T1WI sequence. The T2W images were evaluated initially, and local and overall staging was assigned according to the FIGO classification. An identical scoring system was used to evaluate the combination of DCE-MRI and T2WI. The presence of potential pitfalls in the accurate assessment of depth of myometrial invasion (leiomyoma, adenomyosis, loss of junctional zone definition, polypoid tumor, poor tumor-to-myometrium contrast, and tumor extension to uterine cornu) was also recorded. Surgical histology constituted the standard of reference.

Results:

The depth of myometrial invasion was correctly determined in 78% (39/50) of the cases on T2WI alone, increasing to 92% (46/50) with the addition of DCE-MRI (95% confidence interval for improvement, 4.4%-23.6%, P = 0.016). The addition of DCE-MRI led to the correct detection of deep myometrial invasion in all cases. Tumor extension to uterine cornu was the only variable significantly associated (P = 0.014) with incorrect estimation of depth of myometrial invasion.

Conclusions:

The addition of multiphase 3-dimensional DCE-MRI to T2WI can effectively assess the depth of myometrial invasion in endometrial carcinoma and may be a useful tool to guide the surgical approach.

Use of a confidence scale in reporting postmortem fetal magnetic resonance imaging

OBJECTIVES

Postmortem magnetic resonance imaging (MRI) may be an alternative to conventional autopsy. However, it is unclear how confident radiologists are in reporting such studies. We sought to determine the confidence with which radiologists report on various fetal organs by developing a scale to express their confidence of normality and abnormality, and to place this in the context of a pathological diagnosis of whether the organ was in fact normal or abnormal.

METHODS

Thirty fetuses, aged 16-39 gestational weeks and weighing 61-3270 g, underwent postmortem MRI prior to conventional autopsy. MRI studies were reported by two radiologists with access to the clinical and sonographic history: a neuroradiologist, reporting head and neck, and a pediatric radiologist, reporting thorax, abdomen and pelvis. Radiologists used a scale (0 = definitely abnormal, 100 = definitely normal, 50 = unable to comment) to indicate their confidence of anatomical structures being normal or abnormal, using a checklist. Conventional autopsies were performed by pediatric pathologists blinded to the MRI findings, and these were considered the reference standard.

RESULTS

Most normal fetal organs had high scores on postmortem MRI, with median confidence scores above 80. However, the atrioventricular valves, duodenum, bowel rotation and pancreas proved more difficult to assess, with median scores of 50, 60, 60 and 62.5, respectively. Abnormal cardiac atria and ventricles, kidneys, cerebral hemispheres and corpus callosum were always detected with high or moderate degrees of confidence (median scores of 2.5, 5, 0, 0 and 30 respectively). However, in two cases with abnormal cardiac outflow tracts, both cases scored 50. Kappa values, assessing agreement between MRI diagnoses of abnormality and autopsy, were high for the brain (0.83), moderate for the lungs (0.56) and fair for the heart (0.33).

CONCLUSIONS

This scoring system represents an attempt to define the confidence of radiologists to report varying degrees of normality and abnormality following z ex-utero fetal MRI. While most fetal anatomy is clearly visualized on postmortem MRI, radiologists may lack confidence reporting such studies and there are particular problems with assessment of some cardiac and gastrointestinal structures, both normal and abnormal.

Low-carbohydrate diet induced reduction of hepatic lipid content observed with a rapid non-invasive MRI technique

Low carbohydrate diets are currently fashionable for inducing weight loss, but the metabolic effects at organ level are not well understood, especially the effect on liver fat storage. Such studies require serial hepatic fat measurements, for which liver biopsy is impractical. In 10 healthy volunteers we demonstrate the use of rapid (total 2 min acquisition time, 10 min magnet room time), non-invasive, quantitative MRI to serially measure hepatic fat changes induced by following a low carbohydrate diet for 10 days. A significant (p<0.01) reduction in hepatic fat after 3 days of dieting was observed in 5 subjects. All subjects demonstrated significant (p<0.01) reductions in hepatic fat by day 10. A strong correlation (kappa = 0.81) existed between the initial fat content and the percentage fat content reduction in the first 3 days of the diet. All subjects lost weight (average 1.7 kg at day 3 and 3.0 kg at day 10), but this was not correlated with hepatic fat loss after 3 days or 10 days of dieting. The results presented illustrate the potential value of MR hepatic fat quantification in longitudinal studies of hepatic fat content.

Utility of an ultrafast magnetic resonance imaging protocol in recent and semi-recent strokes

OBJECTIVE

To evaluate the technical feasibility of an integrated ultrafast head magnetic resonance (MR) protocol using a sensitivity encoding (SENSE) technique for depicting parenchymal ischaemia and vascular compromise in patients with suspected recent stroke.

METHODS

23 patients were evaluated with the ultrafast MR protocol using T2, T1, fluid attenuated inversion recovery (FLAIR), 3D time of flight magnetic resonance angiography (MRA), and diffusion weighted imaging (DWI) sequences. These were compared with routine conventional MR sequences.

RESULTS

One patient could not tolerate conventional imaging, although imaging using the three minute head SENSE protocol was diagnostic. Both conventional and ultrafast protocols were of similar diagnostic yield in the remaining patients. There were no significant differences in clinical diagnostic quality for the T1, T2, FLAIR, and DWI sequences. One MRA examination was of better quality when SENSE was used, owing to reduced motion artefacts and shorter imaging time.

CONCLUSIONS

It is possible to undertake a comprehensive MR examination in stroke patients in approximately three to five minutes. Ultrafast imaging may become a useful triage tool before thrombolytic therapy. It may be of particular benefit in patients unable to tolerate longer sequences. Further work is necessary to confirm these findings in hyperacute stroke.

Measuring Carotid Stenosis on Contrast-Enhanced Magnetic Resonance Angiography

BACKGROUND AND PURPOSE

The aim of this study was to compare diagnostic performance and reproducibility of 3 different methods of quantifying stenosis on contrast-enhanced magnetic resonance angiography (CEMRA), with intra-arterial digital subtraction angiography (DSA) as the reference standard.

METHODS

167 symptomatic patients scheduled for DSA, after screening Doppler ultrasound, were prospectively recruited to undergo CEMRA. Severity of stenosis was measured according to the North American Symptomatic Trial Collaborators (NASCET), European Carotid Surgery Trial (ECST), and the common carotid (CC) methods. Measurements for each method were made for 284 vessels (142 included patients) on both CEMRA and DSA in a blinded and randomized manner by 3 independent attending neuroradiologists.

RESULTS

Significant differences in prevalence of severe stenosis were seen with the 3 methods on both DSA and CEMRA, with ECST yielding the least and NASCET the most cases of severe stenosis. Overall, all 3 methods performed similarly well in terms of intermodality correlation and agreement. No significant differences in interobserver agreement were found on either modality. With CEMRA, however, we found a significantly lower sensitivity for detection of severe stenosis with ECST (79.8%) compared with NASCET (93.0%), with DSA as reference standard.

CONCLUSIONS

Uniformity of carotid stenosis measurement methods is desirable because patient management may otherwise differ substantially. All 3 methods are adequate for use with DSA. With CEMRA, however, this study supports use of the NASCET method because of improved sensitivity for detecting severe stenosis.

In vivo detection of macrophages in human carotid atheroma: temporal dependence of ultrasmall superparamagnetic particles of iron oxide-enhanced MRI

Background- It has been suggested that inflammatory cells within vulnerable plaques may be visualized by superparamagnetic iron oxide particle-enhanced MRI. The purpose of this study was to determine the time course for macrophage visualization with in vivo contrast-enhanced MRI using an ultrasmall superparamagnetic iron oxide (USPIO) agent in symptomatic human carotid disease.

METHODS

Eight patients scheduled for carotid endarterectomy underwent multisequence MRI of the carotid bifurcation before and 24, 36, 48, and 72 hours after Sinerem (2.6 mg/kg) infusion.

RESULTS

USPIO particles accumulated in macrophages in 7 of 8 patients given Sinerem. Areas of signal intensity reduction, corresponding to USPIO/macrophage-positive histological sections, were visualized in all 7 of these patients, optimally between 24 and 36 hours, decreasing after 48 hours, but still evident up to 96 hours after infusion.

CONCLUSIONS

USPIO-enhanced MRI of carotid atheroma can be used to identify macrophages in vivo. The temporal change in the resultant signal intensity reduction on MRI suggests an optimal time window for the detection of macrophages on postinfusion imaging.

Small bowel MRI: comparison of a polyethylene glycol preparation and water as oral contrast media

PURPOSE

To compare water and a polyethylene glycol (PEG) preparation as potential oral contrast media for magnetic resonance imaging (MRI) of the small bowel.

MATERIALS AND METHODS

Twenty-two healthy volunteers underwent separate MRI examinations after drinking up to two liters of water or PEG preparation. Small bowel images were obtained every 10 minutes for at least two hours using breath-hold single shot half-Fourier imaging, including both thick section projection and thin section images. Examinations were evaluated by two radiologists in consensus, blinded to the volunteer and contrast details, for arrival at the terminal ileum, transit time, and demonstration of small bowel segments.

RESULTS

The PEG preparation was significantly better than water at reaching the terminal ileum (PEG 21/22 volunteers [95.45%], water 14/22 volunteers [63.6%], P = 0.04). There was no significant difference in the mean transit time (water 51 +/- 48 minutes, PEG 37.7 +/- 22 minutes) or in the demonstration of the stomach, duodenum, and jejunum, but the PEG preparation was significantly better at demonstrating the ileum (P = 0.005) and terminal ileum (P = 0.002).

CONCLUSION

A PEG preparation is significantly better than water as an oral contrast medium for demonstrating the distal small bowel during breath-hold T2-weighted MRI.

Atovaquone-proguanil versus chloroquine-proguanil for malaria prophylaxis in non-immune travellers: a randomised, double-blind study. Malarone International Study Team

BACKGROUND

Chloroquine plus proguanil is widely used for malaria chemoprophylaxis despite low effectiveness in areas where multidrug-resistant malaria occurs. Studies have shown that atovaquone and proguanil hydrochloride is safe and effective for prevention of falciparum malaria in lifelong residents of malaria-endemic countries, but little is known about non-immune travellers.

METHODS

In a double-blind equivalence trial, 1083 participants travelling to a malaria-endemic area were randomly assigned to two treatment groups: atovaquone-proguanil plus placebos for chloroquine and proguanil, or chloroquine, proguanil, and placebo for atovaquone-proguanil. Follow-up was by telephone 7 and 60 days after travel and at a clinic at 28 days. Serum samples were tested for antibodies to a malaria circumsporozoite protein. Blood and serum samples of participants with a potential malaria diagnosis were tested in a reference laboratory.

FINDINGS

7 days after travel, at least one adverse event was reported by 311 (61%) of 511 participants who received atovaquone-proguanil and 329 (64%) of 511 who received chloroquine-proguanil. People receiving atovaquone-proguanil had a lower frequency of treatment-related gastrointestinal adverse events (59 [12%] vs 100 [20%], p=0.001), and of treatment-related adverse events of moderate or severe intensity (37 [7%] vs 56 [11%], p=0.05). There were fewer treatment-related adverse events that caused prophylaxis to be discontinued in the atovaquone-proguanil group than in the chloroquine-proguanil group (one [0.2%] vs ten [2%], p=0.015).

INTERPRETATION

Overall the two preparations were similarly tolerated. However, significantly fewer adverse gastrointestinal events were observed in the atovaquone-proguanil group in than in the chloroquine-proguanil group.

Structural analysis of the human nov proto-oncogene and expression in Wilms tumor

We have cloned and sequenced the nov gene (novH) which is the homolog of the chicken nov proto-oncogene overexpressed in avian nephroblastomas. The novH gene is highly conserved and encodes a putative IGF-binding protein similar to that of chicken. We report that relative to autologous normal kidney expression of novH is elevated in Wilms tumors containing predominantly stromal elements and is inversely correlated in these tumors to the expression of WT1. Our results suggest that the regulation of IGFII expression by WT1 and increase of novH in Wilms tumors might be interrelated and represent a key element in tumor development in human.

Cloning and characterization of the Ewing's sarcoma and peripheral neuroepithelioma t(11;22) translocation breakpoints

Ewing's sarcoma (ES) and peripheral neuroepithelioma (PN) are related tumors, possibly of neural crest origin, which are cytogenetically characterized by the specific translocation t(11;22)(q24;q12). The cos5 locus, previously identified in the vicinity of the chromosome 22 breakpoint of this translocation, was shown by in situ hybridization on interphase nuclei to lie between VIIIF2 and LIF, two loci located on either side of the breakpoint and at a distance of less than 2,000 kb. The progressive expansion of this locus by chromosome walking led to the construction of a 300 kb contig, which finally crossed the breakpoint. The subsequent cloning of the two translocation junction fragments of a PN, followed by the molecular characterization of the translocation breakpoints of 20 ES and PN, showed that most chromosome 22 breakpoints are clustered within a small, 2 kb region. In contrast, the chromosome 11 breakpoints are scattered over a region of at least 40 kb. The translocation leads to the synthesis of chimeric transcript that links sequences from chromosomes 22 and 11. Finally, no evidence was found of any specific difference in the position of ES and PN translocation breakpoints.

Gene fusion with an ETS DNA-binding domain caused by chromosome translocation in human tumours

Ewing's sarcoma and related subtypes of primitive neuroectodermal tumours share a recurrent and specific t(11;22) (q24;q12) chromosome translocation, the breakpoints of which have recently been cloned. Phylogenetically conserved restriction fragments in the vicinity of EWSR1 and EWSR2, the genomic regions where the breakpoints of chromosome 22 and chromosome 11 are, respectively, have allowed identification of transcribed sequences from these regions and has indicated that a hybrid transcript might be generated by the translocation. Here we use these fragments to screen human complementary DNA libraries to show that the translocation alters the open reading frame of an expressed gene on chromosome 22 gene by substituting a sequence encoding a putative RNA-binding domain for that of the DNA-binding domain of the human homologue of murine Fli-1.