The Importance of Diet and Gut Health to the Treatment and Prevention of Mental Disorders

The departure from traditional lifestyles and the rising disease burden of mental disorders are increasing global health concerns. Changes in diet around the world mean that populations are now increasingly reliant on highly processed, poor quality foods, which have been linked to increased risk for mental disorder. Conversely, a nutrient-rich diet is understood to be protective of mental health, and researchers are now aiming to understand the biological underpinnings of this relationship. The gut microbiota has been proposed as a key mediator of this link, given its association with both diet and mental health. Importantly, several critical "windows of opportunity" for prevention and intervention have been identified, particularly early life and adolescence; these are periods of rapid development and transition that provide a foundation for future health. Strategies that promote overall diet quality, high in fiber and nutrients, have been linked to increased microbial diversity and gut health. Improving diet quality and subsequent gut health may have benefits for individuals' mental health, as well as the mental health of future generations. Here we discuss specific, targeted dietary and gut focused strategies for the prevention and treatment of mental disorder.

Evaluation of the genetic association of the PTPN22 R620W polymorphism in familial and sporadic systemic lupus erythematosus

OBJECTIVE

The R620W (1858C-->T) polymorphism in PTPN22 has been implicated in type 1 diabetes mellitus, rheumatoid arthritis, Graves' disease, Hashimoto thyroiditis, autoimmune thyroid disease, and systemic lupus erythematosus (SLE). The aim of this study was to evaluate this polymorphism in patients with familial SLE and in those with sporadic SLE.

METHODS

A total of 4,981 DNA samples were genotyped (from 1,680 SLE patients, 1,834 family members, and 1,467 controls). Both population-based case-control and family-based association designs were used for the analyses.

RESULTS

In the European American familial SLE cohort, the minor 1858T allele was more common in randomly selected patients compared with controls (chi2= 5.61, P = 0.018, odds ratio [OR] 1.46, 95% confidence interval [95% CI] 1.07-1.99). The heterozygous C/T genotype was also more common in these European American patients compared with controls (OR 1.63, 95% CI 1.15-2.30). Family-based association tests showed preferential transmission of the 1858T allele to affected offspring (chi2 = 5.87, P = 0.015). In contrast, the frequency of the 1858T minor allele was not significantly increased in the European American patients with sporadic SLE compared with controls, nor did these patients have preferential transmission of the 1858T allele. Indeed, the difference in the 1858T allele frequency between patients with familial SLE and those with sporadic SLE was measurable (allelic chi2= 4.22, P = 0.04, OR 1.51, 95% CI 1.02-2.24). Our data also showed that among patients with SLE, the 1858T allele was separately associated with type 1 diabetes mellitus and with autoimmune thyroid disease, confirming the findings of other investigators.

CONCLUSION

The 1858T allele of PTPN22 is associated with familial SLE but not with sporadic SLE in European Americans, thereby potentially explaining previous contradictory reports.

Carotid and vertebral artery dissection syndromes

Cervicocerebral arterial dissections (CAD) are an important cause of strokes in younger patients accounting for nearly 20% of strokes in patients under the age of 45 years. Extracranial internal carotid artery dissections comprise 70%-80% and extracranial vertebral dissections account for about 15% of all CAD. Aetiopathogenesis of CAD is incompletely understood, though trauma, respiratory infections, and underlying arteriopathy are considered important. A typical picture of local pain, headache, and ipsilateral Horner's syndrome followed after several hours by cerebral or retinal ischaemia is rare. Doppler ultrasound, MRI/MRA, and CT angiography are useful non-invasive diagnostic tests. The treatment of extracranial CAD is mainly medical using anticoagulants or antiplatelet agents although controlled studies to show their effectiveness are lacking. The prognosis of extracranial CAD is generally much better than that of the intracranial CAD. Recurrences are rare in CAD.

Computer-enhanced laparoscopic training system (CELTS): bridging the gap

BACKGROUND

There is a large and growing gap between the need for better surgical training methodologies and the systems currently available for such training. In an effort to bridge this gap and overcome the disadvantages of the training simulators now in use, we developed the Computer-Enhanced Laparoscopic Training System (CELTS).

METHODS

CELTS is a computer-based system capable of tracking the motion of laparoscopic instruments and providing feedback about performance in real time. CELTS consists of a mechanical interface, a customizable set of tasks, and an Internet-based software interface. The special cognitive and psychomotor skills a laparoscopic surgeon should master were explicitly defined and transformed into quantitative metrics based on kinematics analysis theory. A single global standardized and task-independent scoring system utilizing a z-score statistic was developed. Validation exercises were performed.

RESULTS

The scoring system clearly revealed a gap between experts and trainees, irrespective of the task performed; none of the trainees obtained a score above the threshold that distinguishes the two groups. Moreover, CELTS provided educational feedback by identifying the key factors that contributed to the overall score. Among the defined metrics, depth perception, smoothness of motion, instrument orientation, and the outcome of the task are major indicators of performance and key parameters that distinguish experts from trainees. Time and path length alone, which are the most commonly used metrics in currently available systems, are not considered good indicators of performance.

CONCLUSION

CELTS is a novel and standardized skills trainer that combines the advantages of computer simulation with the features of the traditional and popular training boxes. CELTS can easily be used with a wide array of tasks and ensures comparability across different training conditions. This report further shows that a set of appropriate and clinically relevant performance metrics can be defined and a standardized scoring system can be designed.

Estimating localized oscillatory tissue motion for assessment of the underlying mechanical modulus

The technique of harmonic motion imaging (HMI) uses the localized stimulus of the oscillatory ultrasonic radiation force as produced by two overlapping beams of distinct frequencies, and estimates the resulting harmonic displacement in the tissue in order to assess its underlying mechanical properties. In this paper, we studied the relationship between measured displacement and stiffness in gels and tissues in vitro. Two focused ultrasound transducers with a 100 mm focal length were used at frequencies of 3.7500 MHz and either 3.7502 (or 3.7508 MHz), respectively, in order to produce an oscillatory motion at 200 Hz in the gel or tissue. A 1.1 MHz diagnostic transducer (Imasonics, Inc.) was also focused at 100 mm and acquired 5 ms RF signals (pulse repetition frequency (PRF)=3.5 kHz) at 100 MHz sampling frequency during radiation force application. First, three 50x50 mm(2) acrylamide gels were prepared at concentrations of 4%, 8% and 16%. The resulting displacement was estimated using crosscorrelation techniques between successively acquired RF signals with a 2 mm window and 80% window overlap at 1260 W/cm(2). A normal 1-D indentation instrument (TeMPeST) applied oscillatory loads at 0.1-200 Hz with a 5 mm-diameter flat indenter. Then, 12 displacement measurements in 6 porcine muscle specimens (two measurements/case, as above) were made in vitro, before and after ablation which was performed for 10 s at 1260 W/cm(2). In all gel cases, the harmonic displacement was found to linearly increase with intensity and exponentially decrease with gel concentration. The TeMPeST measurements showed that the elastic moduli for the 4%, 8% and 16% gels equaled 3.93+/-0.06, 17.1+/-0.2 and 75+/-2 kPa, respectively, demonstrating that the HMI displacement estimate depends directly on the gel stiffness. Finally, in the tissues samples, the mean displacement amplitude showed a twofold decrease between non-ablated and ablated tissue, demonstrating a correspondence between the HMI response and an increase in stiffness measured with the TeMPeST instrument.

Dynamic cerebral autoregulation and beat to beat blood pressure control are impaired in acute ischaemic stroke

OBJECTIVES

Hypertension and chronic cerebrovascular disease are known to alter static cerebral autoregulation (CA) but the effects of acute stroke on dynamic CA (dCA) have not been studied in detail. Those studies to date measuring dCA have used sympathetically induced blood pressure (BP) changes, which may themselves directly affect dCA. This study assessed whether dCA is compromised after acute stroke using spontaneous blood pressure (BP) changes as the stimulus for the dCA response.

METHODS

56 patients with ischaemic stroke (aged 70 (SD 9) years), studied within 72 hours of ictus were compared with 56 age, sex, and BP matched normal controls. Cerebral blood flow velocity was measured using transcranial Doppler ultrasound (TCD) with non-invasive beat to beat arterial BP levels, surface ECG, and transcutaneous CO(2) levels and a dynamic autoregulatory index (dARI) calculated.

RESULTS

Beat to beat BP, but not pulse interval variability was significantly increased and cardiac baroreceptor sensitivity (BRS) decreased in the patients with stroke. Dynamic CA was significantly reduced in patients with stroke compared with controls (strokes: ARI 3.8 (SD 2.2) and 3.2 (SD 2.0) for pressor and depressor stimuli respectively v controls: ARI 4.7 (SD 2.2) and 4.5 (SD 2.0) respectively (p<0.05 in all cases)). There was no difference between stroke and non-stroke hemispheres in ARI, which was also independent of severity of stroke, BP, BP variability, BRS, sex, and age.

CONCLUSION

Dynamic cerebral autoregulation, as assessed using spontaneous transient pressor and depressor BP stimuli, is globally impaired after acute ischaemic stroke and may prove to be an important factor in predicting outcome.

The home health aide. Scarce resource in a competitive marketplace

Direct-care staff--home health aides and personal care attendants--are the very point where home care "touches the client." Yet our system of care delivery has never been designed for the needs of the direct-care worker. Today we are paying the price: Across the country, our industry is experiencing the highest rates of direct-care vacancies and turnover in its history. The very future of our industry now rests on our ability to attract workers within an increasingly competitive labor market. In order to survive, let alone provide high-quality care, the home care industry must restructure paraprofessional employment.

Twenty-four hour systolic blood pressure predicts long-term mortality following acute stroke

OBJECTIVE

To assess the effects of acute blood pressure (BP) on long-term mortality following stroke.

DESIGN

Prospective observational study.

SETTING

Leicester Teaching Hospitals.

PATIENTS

Two hundred and nineteen consecutive patients were recruited within 24 h of acute stroke.

INTERVENTIONS

Clinic and 24 h BP levels were measured. Other risk factors previously associated with stroke mortality were recorded within 24 h of admission. No specific pharmacological interventions;were made.

MAIN OUTCOME MEASURES

The primary outcome measure was death over a median follow-up period of over 2.5 years. The hazards ratios associated with predefined variables were assessed using Cox's proportional hazards modelling, and Kaplan-Meier survival plots were also calculated.

RESULTS

On multiple variable analysis, 24 h systolic BP (> or = 160 mmHg) was associated with an increased hazards ratio of 2.41 (95% confidence intervals: 1.24-4.67) for death, compared to the reference group (140-159 mmHg). The addition of 24 h heart rate was significant, with increasing heart rate (> 83 bpm) associated with an increased mortality (P = 0.006), although this effect was not constant over time. Increasing age (> 80 years) at presentation was also associated with an increased hazards ratio of 2.53 (1.14-5.62) compared to age < or = 66 years.

CONCLUSIONS

This study provides evidence that elevated 24 h systolic BP in the acute stroke period is associated with increased long-term mortality. This may have implications in the therapeutic management of BP following stroke, though further research is required to determine the timing, nature and effect of such an intervention.

Cerebral blood flow velocity response to induced and spontaneous sudden changes in arterial blood pressure

The influence of different types of maneuvers that can induce sudden changes of arterial blood pressure (ABP) on the cerebral blood flow velocity (CBFV) response was studied in 56 normal subjects (mean age 62 yr, range 23-80). ABP was recorded in the finger with a Finapres device, and bilateral recordings of CBFV were performed with Doppler ultrasound of the middle cerebral arteries. Recordings were performed at rest (baseline) and during the thigh cuff test, lower body negative pressure, cold pressor test, hand grip, and Valsalva maneuver. From baseline recordings, positive and negative spontaneous transients were also selected. Stability of PCO2 was monitored with transcutaneous measurements. Dynamic autoregulatory index (ARI), impulse, and step responses were obtained for 1-min segments of data for the eight conditions by fitting a mathematical model to the ABP-CBFV baseline and transient data (Aaslid's model) and by the Wiener-Laguerre moving-average method. Impulse responses were similar for the right- and left-side recordings, and their temporal pattern was not influenced by type of maneuver. Step responses showed a sudden rise at time 0 and then started to fall back to their original level, indicating an active autoregulation. ARI was also independent of the type of maneuver, giving an overall mean of 4.7 +/- 2.9 (n = 602 recordings). Amplitudes of the impulse and step responses, however, were significantly influenced by type of maneuver and were highly correlated with the resistance-area product before the sudden change in ABP (r = -0.93, P < 0.0004). These results suggest that amplitude of the CBFV step response is sensitive to the point of operation of the instantaneous ABP-CBFV relationship, which can be shifted by different maneuvers. Various degrees of sympathetic nervous system activation resulting from different ABP-stimulating maneuvers were not reflected by CBFV dynamic autoregulatory responses within the physiological range of ABP.

Designing a computer-based simulator for interventional cardiology training

Interventional cardiology training traditionally involves one-on-one experience following a master-apprentice model, much as other procedural disciplines. Development of a realistic computer-based training system that includes hand-eye coordination, catheter and guide wire choices, three-dimensional anatomic representations, and an integrated learning system is desirable, in order to permit learning to occur safely, without putting patients at risk. Here we present the first report of a PC-based simulator that incorporates synthetic fluoroscopy, real-time three-dimensional interactive anatomic display, and selective right- and left-sided coronary catheterization and angiography using actual catheters. Significant learning components also are integrated into the simulator.

ICTS, an interventional cardiology training system

In this article, we present an Interventional Cardiology Training System developed by the Medical Application Group at Mitsubishi Electric in collaboration with the Center for Innovative Minimally Invasive Therapy. The core of the ICTS is a computer simulation of interventional cardiology catheterization. This simulation integrates clinical expertise, research in learning, and technical innovations to create a realistic simulated environment. The goal of this training system is to augment the training of new cardiology fellows as well as to introduce cardiologists to new devices and procedures. To achieve this goal, both the technical components and the educational content of the ICTS bring new and unique features: a simulated fluoroscope, a physics model of a catheter, a haptic interface, a fluid flow simulation combined with a hemodynamic model and a learning system integrated in a user interface. The simulator is currently able to generate--in real-time--high quality x-ray images from a 3D anatomical model of the thorax, including a beating heart and animated lungs. The heart and lung motion is controlled by the hemodynamic model, which also computes blood pressure and EKG. The blood flow is then calculated according to the blood pressure and blood vessel characteristics. Any vascular tool, such as a catheter, guide wire or angioplasty balloon can be represented and accurately deformed by the flexible tool physics model. The haptics device controls the tool and provides appropriate feedback when contact with a vessel wall is detected. When the catheter is in place, a contrast agent can be injected into the coronary arteries; blood and contrast mixing is computed and a visual representation of the angiogram is displayed by the x-ray renderer. By bringing key advances in the area of medical simulation--with the real-time x-ray renderer for instance--and by integrating in a single system both high quality simulation and learning tools, the ICTS opens new perspectives for computer based training systems.

Dynamic but not static cerebral autoregulation is impaired in acute ischaemic stroke

It remains unclear as to whether dynamic and static cerebral autoregulation (CA) are impaired in acute ischaemic stroke, and whether these changes are related to stroke subtype. This could have important implications with regard to post-stroke prognosis and the management of blood pressure (BP) in the acute post-ictal period. Using transcranial Doppler ultrasonography and non-invasive manipulation of BP, we compared both mechanisms in 61 patients with ischaemic stroke within 96 h of ictus, and 54 age- and sex-matched controls. There was no difference in static and dynamic CA indices between the various stroke subtypes. Combining all stroke subtypes dynamic autoregulation, as measured using thigh cuff release, was significantly impaired in both the affected and non-affected stroke hemispheres compared to controls (mean autoregulation index 4.1 +/- 3.3, 4.8 +/- 3.1 and 6.2 +/- 2.3, respectively, p < 0.05). By comparison static autoregulation, assessed using isometric hand grip and thigh cuff inflation, was not significantly different. In conclusion, dynamic but not static CA appears to be globally impaired in acute ischaemic stroke. This deserves further study and may identify possibilities for therapeutic intervention.

Which parameters of beat-to-beat blood pressure and variability best predict early outcome after acute ischemic stroke?

BACKGROUND AND PURPOSE

In hypertensive populations, increasing blood pressure (BP) levels and BP variability (BPV) are associated with a greater incidence of target organ damage. After stroke, elevated 24-hour BP levels predict a poor outcome, although it is uncertain whether shorter-length BP recordings assessing mean BP levels and BPV have a similar predictive role. The objectives of this study were to compare the different measures of beat-to-beat BP and BPV on outcome after acute ischemic stroke and assess whether these parameters were affected by stroke subtype.

METHODS

Ninety-two consecutive admissions with a CT-confirmed diagnosis of acute ischemic stroke were recruited, of whom 54 had cortical infarction, 29 subcortical, and 9 posterior circulation infarction. Casual and two 5-minute recordings of beat-to-beat BP (Finapres, Ohmeda) were made under standardized conditions within 72 hours of ictus, with mean BP levels taken as the average of this 10-minute recording and BPV as the standard deviation. Outcome was assessed at 30 days as dead/dependent or independent (Rankin </=2). The effects of BP, BPV, and stroke subtype on outcome were studied with the use of logistic regression. Stroke subjects were subsequently divided by BP quartiles and within each quartile into low- and high-variability groups; the influence of high BPV on outcome was also assessed.

RESULTS

The odds ratio for death/dependency was significantly higher in cortical strokes compared with subcortical and posterior circulation strokes even after controlling for differences in BP and BPV (OR 4.19, P=0.002). Beat-to-beat systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP +/- SD) levels were higher in the dead/dependent group compared with the independent group (MAP 106+/-20.4 mm Hg vs 97+/-19.1 mm Hg, P<0.02), as was MAP variability: 6.1 (interquartile range 4.5 to 7.4 mm Hg) versus 4.9 (3.8 to 6.4 mm Hg, P=0.02). The odds ratio for a poor outcome was 1. 38 (P=0.014) for every 10-mm Hg increase in MAP and 1.32 (P=0.02) for every 1-mm Hg increase in MAP variability. Casual BP measurements had no prognostic significance. For the group as a whole when separated into BP quartiles, those with a high MAP and DBP but not SBP variability within each quartile had a worse prognosis compared with those with a low BPV.

CONCLUSIONS

A poor outcome at 30 days after ischemic stroke was dependent on stroke subtype, beat-to-beat DBP, and MAP levels and variability. Important prognostic information can be readily obtained from a short period of noninvasive BP monitoring in the acute stroke patient. These findings have important implications, particularly regarding the use of hypotensive agents in the acute stroke period.

Linear and nonlinear analysis of human dynamic cerebral autoregulation

The linear dynamic relationship between systemic arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV) was studied by time- and frequency-domain analysis methods. A nonlinear moving-average approach was also implemented using Volterra-Wiener kernels. In 47 normal subjects, ABP was measured with Finapres and CBFV was recorded with Doppler ultrasound in both middle cerebral arteries at rest in the supine position and also during ABP drops induced by the sudden deflation of thigh cuffs. Impulse response functions estimated by Fourier transfer function analysis, a second-order mathematical model proposed by Tiecks, and the linear kernel of the Volterra-Wiener moving-average representation provided reconstructed velocity model responses, for the same segment of data, with significant correlations to CBFV recordings corresponding to r = 0.52 +/- 0.19, 0.53 +/- 0.16, and 0.67 +/- 0.12 (mean +/- SD), respectively. The correlation coefficient for the linear plus quadratic kernels was 0.82 +/- 0.08, significantly superior to that for the linear models (P < 10(-6)). The supine linear impulse responses were also used to predict the velocity transient of a different baseline segment of data and of the thigh cuff velocity response with significant correlations. In both cases, the three linear methods provided equivalent model performances, but the correlation coefficient for the nonlinear model dropped to 0.26 +/- 0.25 for the baseline test set of data and to 0.21 +/- 0.42 for the thigh cuff data. Whereas it is possible to model dynamic cerebral autoregulation in humans with different linear methods, in the supine position a second-order nonlinear component contributes significantly to improve model accuracy for the same segment of data used to estimate model parameters, but it cannot be automatically extended to represent the nonlinear component of velocity responses of different segments of data or transient changes induced by the thigh cuff test.

Older subjects show no age-related decrease in cardiac baroreceptor sensitivity

OBJECTIVE

To examine the relationship between age, blood pressure and cardiac baroreceptor sensitivity derived from spectral analysis, the Valsalva manoeuvre and impulse response function.

METHODS

We studied 70 healthy normotensive volunteers who were free from disease and not taking medication with cardiovascular or autonomic effects. We measured beat-to-beat arterial blood pressure and used standard surface electrocardiography to record pulse interval under standardized conditions with subjects resting supine as well as during three Valsalva manoeuvres. We performed single, multiple and stepwise regression of patient characteristics against cardiac baroreceptor sensitivity results.

RESULTS

There is a non-linear decline in cardiac baroreceptor sensitivity with advancing age, increasing systolic blood pressure and heart rate values (except for the Valsalva-derived result), but little further decline after the fourth decade. Only age significantly influenced values derived using the Valsalva manoeuvre and impulse response analysis. Using spectral analysis, age, systolic and diastolic blood pressure and heart rate influenced cardiac baroreceptor sensitivity, age contributing to 50% of the variability. Age also influenced the relationship between pulse interval and blood pressure, possibly indicating more non-baroreceptor-mediated changes with advancing age.

CONCLUSIONS

Although age is the dominant factor influencing cardiac baroreceptor sensitivity in this normotensive population, there is little change in mean values after 40 years of age. The differences in the relationship between pulse interval and blood pressure with advancing age have implications for the calculation of cardiac baroreceptor sensitivity using spectral analysis.

Critical closing pressure explains cerebral hemodynamics during the Valsalva maneuver

The Valsalva maneuver (VM), a voluntary increase in intrathoracic pressure of approximately 40 mmHg, has been used to examine cerebral autoregulation (CA). During phase IV of the VM there are pronounced changes in mean arterial blood pressure (MABP), pulse interval, and cerebral blood flow (CBF), but the changes in CBF are of a much greater magnitude than those seen in MABP, a finding to date attributed to either a delay in activation of the CA mechanism or the inability of this mechanism to cope with the size and speed of the blood pressure changes involved. These changes in CBF also precede those in MABP, a pattern of events not explained by the physiological process of CA. Measurements of CBF velocity (transcranial Doppler) and MABP (Finapres) were performed in 53 healthy volunteers (aged 31-80 yr). By calculating beat-to-beat values of critical closing pressure (CCP) during the VM, we have found that this parameter suddenly drops at the start of phase IV, providing a coherent explanation for the large increase in CBF. If CCP is included in the estimation of cerebrovascular resistance, a temporal pattern more consistent with an autoregulatory response to the MABP overshoot is also found. CCP is intricately involved in the control of CBF during the VM and should be considered in the assessment of CA.

Diurnal blood pressure change varies with stroke subtype in the acute phase

BACKGROUND AND PURPOSE

It is unclear whether acute stroke is associated with a loss of the normal diurnal blood pressure (BP) change and whether stroke type influences this. Some of this confusion results from the use of fixed time definitions of day and night, which can be overcome by the use of cumulative sums analysis (cusums).

METHODS

Ninety-eight stroke patients had 24-hour BP monitoring (Spacelabs 90207) performed within 48 hours of ictus. Three subgroups were identified: cortical infarct, n=50; subcortical infarct, n=29; and primary intracerebral hemorrhage [PICH], n= 19. An age-matched control group of 74 subjects was also studied. Diurnal change was assessed by both day-night differences (absolute and percentage) and cusums (cusums plot height [CPH] and circadian alteration magnitude [CDCAM]); ANCOVA was used to compare groups.

RESULTS

Compared with control subjects, cortical infarct and PICH subgroups had significantly reduced mean diurnal systolic changes using day-night differences (absolute, -12 and -17 mm Hg; percentage, -10 and -12, respectively; P < 0.0001) and cusums (CDCAM, -6.96 and -8.6 mm Hg; CPH, -32.05 and -46.04 mm Hg, respectively; P < 0.005), only the subcortical infarct subgroup demonstrated reduced percentage differences (-4.4%, P < 0.02). Mean diastolic differences were significantly reduced in all stroke subgroups(CPH, -24.84, -17.31, and -36.92 mm Hg; absolute, -8.26, -4.04, and -11.44 mm Hg; percentage, -10.65, -5.81, and -15.23%, for cortical infarct, subcortical infarct, and PICH subgroups, respectively; P < 0.05), except for CDCAM, which was not reduced in subcortical infarcts (-4.78 and -7.70 mm Hg for cortical infarct and PICH subgroups, respectively; P < 0.001).

CONCLUSIONS

Diurnal BP change was reduced in the 3 stroke subgroups studied, especially in patients with cortical infarcts and PICH. This may reflect damage to the central modulation of autonomic BP control. The implications in terms of prognosis and therapy in the acute period require further study.

Force interactions in laparoscopic simulations: haptic rendering of soft tissues

Research in the area of computer assisted surgery and surgical simulation has mainly focused on developing 3D geometrical models of the human body from 2D medical images, visualization of internal structures for educational and preoperative surgical planning purposes, and graphical display of soft tissue behavior in real time. Conveying to the surgeon the touch and force sensations with the use of haptic interfaces has not been investigated in detail. We have developed a set of haptic rendering algorithms for simulating "surgical instrument--soft tissue" interactions. Although the focus of the study is the development of algorithms for simulation of laparoscopic procedures, the developed techniques are also useful in simulating other medical procedures involving touch and feel of soft tissues. The proposed force-reflecting soft tissue models are in various fidelities and have been developed to simulate the behavior of elastically deformable objects in virtual environments. The developed algorithms deal directly with geometry of anatomical organs, surface and compliance characteristics of tissues, and the estimation of appropriate reaction forces to convey to the user a feeling of touch and force sensations.

The reproducibility of cardiac baroreceptor activity assessed non-invasively by spectral sequence techniques

Baroreceptor sensitivity (BRS) is increasingly used as a prognostic indicator in cardiovascular disease. Traditionally it has been measured using invasive techniques with pharmacological manipulation of blood pressure (BP). With the advent of newer methods to measure pulse interval and beat-to-beat changes in BP it is now possible, using sophisticated mathematical modelling techniques, to calculate cardiac BRS non-invasively. However, there are virtually no data on the reproducibility of these newer techniques and what factors may affect the repeatability of these measurements. We studied 39 subjects, aged 22-82 years, with a supine systolic BP range 97-160 mmHg and a diastolic BP range 57-94 mmHg on two occasions between 1 week and 6 months apart. Cardiac BRS was measured by power spectral analysis using Fast Fourier Transformation (FFT), sequence analysis (using up, down and combined sequences) and from phase IV of the Valsalva manoeuvre. There was no significant difference between visits for any of the methods for measuring cardiac BRS. Mean BRS values were similar for FFT (16.7 +/- 11.2 ms/mmHg) and sequence analysis (15.8 +/- 11.4 ms/mmHg); however, results using phase IV of the Valsalva manoeuvre were significantly lower (8.1 +/- 2.9 ms/mmHg, p < 0.0001). The coefficient of variation for the five measures of cardiac BRS varied from 16.8% for Valsalva-derived values to 26.1% for 'down' sequence analysis. However, in ten subjects BRS could not be calculated from the Valsalva manoeuvre. None of the independent variables tested (including age, BP levels and time between testing) significantly influenced the degree of repeatability. In summary, there appears to be little difference between these non-invasive methods in their degree of reproducibility. These techniques would seem suitable for longitudinal studies of changes in cardiac BRS and overcome many of the problems associated with the invasive pharmacological methods.

Transluminal radiofrequency tissue ablation with use of metallic stents

PURPOSE

To determine if transluminal coagulative necrosis can be induced by applying radiofrequency (RF) energy to indwelling metallic stents.

MATERIALS AND METHODS

RF energy was applied to metallic alloy stents (20-68 mm length, 5-16 mm diameter) in tissue phantom (n = 31), ex vivo bovine liver (n = 10), and in vivo porcine hepatic veins (n = 4). For ex vivo and in vivo liver experiments, RF was applied for 5-6 minutes, titrating generator output to produce 85 degrees-95 degrees C temperatures at the stent surface. Local and remote temperature sensing was performed. Imaging and pathologic studies documented the extent of coagulation necrosis.

RESULTS

Phantom studies demonstrated uniform temperature distribution along the entire stent length for all Elgiloy stents powered for 2 minutes with a minimum of 120 watts. Shorter stents required less power or reduced time to achieve uniform temperature. In ex vivo liver, 25-mm stents (n = 5) showed 8-10 mm of uniform circumferential coagulation necrosis along the entire stent length. Fifty-millimeter stents showed less uniform coagulation necrosis. For the in vivo stents (20 mm), 8-10 mm of uniform circumferential coagulation necrosis surrounded the stent along its entire length.

CONCLUSION

Metallic stents can be used to deliver transluminal RF energy from an external source, inducing heat deposition with resultant circumferential tissue coagulation. Clinical applications might include reduction of intimal proliferation in vascular diseases and/or treatment of periluminal tumors compressing the bile ducts, the urethra, or other luminal structures.

Peptide-derived self-assembled monolayers: adsorption of N-stearoyl L-cysteine methyl ester on gold

The work reported herein concerns the assembly of N-stearoyl L-cysteine methyl ester [CH3(CH2)16COCysOMe, 1] on the surface of gold. This compound serves as a simple model of a related polypeptide, which has been designed to adopt a beta-sheet architecture on metallic and oxide surfaces. We describe the preparation of monolayers of 1, and characterization of these layers via ellipsometry, vibrational spectroscopy and X-ray photoelectron spectroscopy. The results are most consistent with a disordered array of the alkyl chains, in which close packing is frustrated by a mismatch in the cross-sectional areas of the cysteinyl ester head group and the stearoyl chains of the thiol. Despite the disorder, the alkyl chains form a hydrophobic surface layer, with an advancing contact angle for water comparable to that observed for octadecanethiol on gold.

Attenuation effects of biliary endoprostheses on therapeutic radiation

Seven commercially available biliary stents were tested to determine if they caused any clinically important attenuation of therapeutic radiation. Attenuation effects were evaluated in models of brachytherapy (iridium-192 source) and external beam radiation therapy (cobalt-60 source), with use of parameters that mimicked those used in patient treatment for biliary neoplasms. No stent demonstrated clinically important attenuation or scatter of therapeutic radiation, so local dosimetry was not affected.

Evaluation of the abdomen in sepsis of unknown origin

The radiologic evaluation of sepsis of unknown origin has changed dramatically since the introduction of cross-sectional imaging. Interventional procedures such as abscess drainage, cholecystostomy, biliary drainage, nephrostomy, and fluid aspiration have reduced the morbidity and mortality associated with occult sources of sepsis. This article examines some of the common etiologies and treatments of sepsis in the hospitalized patient.

Tissue ablation with radiofrequency using multiprobe arrays

RATIONALE AND OBJECTIVES

We studied the feasibility of increasing the volume of tissue destroyed by radiofrequency tissue coagulation using multiprobe arrays and defined parameters that determine lesion size and shape.

METHODS

Radiofrequency was applied to ex vivo calf liver using arrays of two to five 18-gauge probes for 6 min at 70-90 degrees C. Probe spacing (1-3 cm) and arrangement, as well as the method of radiofrequency application (simultaneous or sequential), were varied. The resulting areas of tissue coagulation were measured and compared.

RESULTS

Uniform tissue necrosis was observed with simultaneous radiofrequency application for probes 1.5 cm or less apart. At 1.5 cm, arrays of three equidistant probes produced spheroid lesions approximately 3.0 +/- 0.2 cm in diameter. Arrays of four equidistant probes produced cuboid lesions of 3.2 +/- 0.1 cm per side. However, probes placed 2 cm or more apart produced independent lesions 1.4 cm in diameter, with incomplete necrosis between probes. In the trials using five-probe arrays, a central region 4mm in diameter showed no visible evidence of tissue necrosis. With each array, lesion size varied less than 3 mm in any direction. Greater necrosis was accomplished when radiofrequency was applied simultaneously rather than sequentially.

CONCLUSION

Multiprobe radiofrequency arrays permit the destruction of more tissue in a single treatment session than is possible with multiple individual probes operating alone. Probes spaced 1.5 cm or less apart act synergistically, producing a total volume of coagulated tissue that is greater than when the individual probes are operated sequentially.

Percutaneous drainage of subphrenic fluid collections that occur after splenectomy: efficacy and safety of transpleural versus extrapleural approach

OBJECTIVE

The purpose of this study was to compare the safety and efficacy of transpleural and extrapleural approaches for draining left subphrenic abscesses in patients who have had splenectomy.

MATERIALS AND METHODS

Twenty-five patients who had percutaneous catheter drainage (28 drainages) of postsplenectomy fluid collections were studied. Twenty drainages were transpleural and eight were extrapleural. In eight of the 20 transpleural drainages, it was elected to place the catheter transpleurally. In the remaining 12 patients, catheter drainage was judged to be transpleural on review, despite efforts to use an extrapleural approach.

RESULTS

Sixteen of 18 patients who had transpleural percutaneous drainage and six of seven patients who had true extrapleural (subcostal) percutaneous drainage were cured by catheter drainage requiring no further intervention. The mean number of days of drainage was not significantly different (p > .05) for the group drained transpleurally (mean, 18 days; range, 1-90 days) versus the group drained extrapleurally (mean, 20 days; range, 6-43 days). Complications (pneumothorax) requiring treatment were seen in two patients in whom a transpleural approach was used and in none of the patients in whom an extrapleural approach was used. Complications that did not require treatment were seen in four further patients drained transpleurally. These were inadvertent placement of catheter into pleural space (two patients) and pneumothorax not requiring treatment (two patients). No patient had an empyema.

CONCLUSION

Transpleural drainage of left subphrenic collections occurring after splenectomy is associated with a slightly increased complication rate but has a success rate similar to that of extrapleural drainage.

Tissue ablation with radiofrequency: effect of probe size, gauge, duration, and temperature on lesion volume

RATIONALE AND OBJECTIVES

We evaluated the parameters affecting the size and distribution of thermal tissue damage produced by radiofrequency electrodes.

METHODS

Thermal lesions were produced by electrodes connected to a radiofrequency generator in specimens of liver (n = 143) and muscle (n = 20). Various combinations of probe tip exposure (0.5-8 cm), gauge (12-24 gauge), duration of treatment (0.5-12 min), and temperature (80-90 degrees C) were studied. The resulting volumes of tissue coagulation were measured and compared.

RESULTS

Lesions equal to or less than 1.6 cm in diameter were symmetrically distributed around the electrode. Lesion diameter (but not length) increased with probe gauge and duration of treatment to a maximum of 6 min. However, lesions with mean diameters larger than 1.6 cm could not be produced using a single probe with any technique. Lesion length correlated with probe tip exposure from 1 to 8 cm (r2 = .996). Over the limited range investigated, increased temperature had minimal effects, except for tip exposures greater than 5 cm, in which larger and more uniform lesions resulted. Lesions varied equal to or less than 3 mm in diameter and equal to or less than 5 mm in length for each combination of variables.

CONCLUSION

Radiofrequency ablation can accurately and reproducibly cause coagulative tissue necrosis. Necrosed tissue volume increases with length of exposed probe tip, larger probes, and sessions lasting at least 6 min.

Percutaneous ethanol injection for the treatment of hepatic tumors: indications, mechanism of action, technique, and efficacy

Percutaneous injection of ethanol for treatment of hepatic tumors was first described by Sugiura et al. [1] in 1983. To date, reported experience with the procedure has focused mainly on therapy of hepatocellular carcinoma (HCC) [2-15], with little information available regarding its use in treating metastatic liver lesions [16]. Interest in this technique has grown recently as a possible means of treating patients with metastatic liver disease. The purpose of this perspective is to review the indications, mechanism of action, technique, complications, and efficacy of percutaneous ethanol injection for liver tumor treatment.

Failed metallic biliary stents: causes and management of delayed complications

OBJECTIVE

To describe the incidence, management and long-term outcome of metal stent failure in patients with malignant biliary obstruction.

SUBJECTS AND METHODS

Sixty-nine patients received a total of 93 metallic biliary stents for relief of malignant biliary obstruction. Twenty-nine patients had hilar tumours; 40 had common bile duct tumours.

RESULTS

Ten of 69 patients (14%) presented with stent occlusion at a mean interval of 4 months after stent insertion. Five of 29 patients (17%) with hilar lesions and five of 40 patients (12%) with common bile duct lesions had stent occlusion. Occlusion was due to tumour overgrowth in eight patients and to occlusion by debris in two. The eight patients with tumour overgrowth were treated with internal/external catheters (5 patients), no therapy (2 patients), and further metal stents (1 patient). These eight patients with tumour overgrowth had a limited lifespan after tumour overgrowth occurred with a mean survival of 2.6 months. The two patients with occlusion due to debris were treated by sweeping the stent with a balloon catheter and these patients survived 26 and 27 months, respectively.

CONCLUSION

Adequate peripheral purchase in the biliary tree and overstenting are necessary to prevent tumour overgrowth when stenting hilar lesions. The development of stent occlusion due to tumour overgrowth heralds a limited survival and internal/external catheters are preferred over further metal stents for palliation.

Pleural seeding from hepatocellular carcinoma: a complication of percutaneous alcohol ablation

The authors present a case of proved seeding of the pleural space secondary to alcohol ablation of a primary hepatocellular carcinoma. The patient underwent alcohol ablation for a 6.5-cm-diameter tumor in the right lobe of the liver; approximately 20 needle punctures were required to ensure complete or almost complete destruction of the tumor. Six months after the original ablation, a hypervascular pleural metastasis was noted adjacent to the original lesion at computed tomography. Percutaneous biopsy of the pleural lesion showed hepatocellular carcinoma.

Interventional radiology in the management of bile duct injuries

The advent of laparoscopic cholecystectomy has brought an increased number of bile duct injuries to the attention of surgeons and interventional radiologists. The spectrum of injury ranges from cystic duct stump leakage to partial obstruction to complete occlusion of the ducts and common hepatic or common bile duct ischemic strictures. The proper therapy for any given patient may be surgical or nonsurgical. Frequently, interventional radiologic techniques permit successful nonoperative drainage of postoperative fluid collections and percutaneous management of bile duct injury and stricture. In some patients in whom radiologic techniques are not successful or in whom the extent of injury requires surgical repair, interventional radiologic techniques can provide preoperative anatomic definition of the extent of injury as well as catheter localization of intrahepatic duct strictures before proximal hepaticojejunostomy.

Gallstones in critically ill patients with acute calculous cholecystitis treated by percutaneous cholecystostomy: nonsurgical therapeutic options

OBJECTIVE

Patients with acute calculous cholecystitis require removal of gallstones (generally cholecystectomy), as acute cholecystitis is likely to recur if gallstones are left in situ. The purpose of this study was to assess the role of nonsurgical techniques for treating gallstones in critically ill patients with acute calculous cholecystitis managed by percutaneous cholecystostomy.

MATERIALS AND METHODS

Twenty-six critically ill patients with complex medical and surgical problems who were in intensive care units underwent emergent percutaneous cholecystostomy for acute calculous cholecystitis. Seven of the 26 patients subsequently died of multiple organ failure. Curative gallstone therapies were tried in the surviving 19 patients, seven of whom underwent elective surgical cholecystectomy. Nonsurgical management was attempted in 12 of 19 patients, including six with terminal disease who were treated with long-term gallbladder drainage, three who were treated with methyl tert-butyl ether for stone dissolution, two who had percutaneous cholecystolithotomy, and one who had a gallbladder stone that had passed into the common bile duct and was retrieved endoscopically.

RESULTS

Long-term gallbladder drainage was successful in all six patients with terminal disease in whom it was attempted; they experienced no further episodes of cholecystitis. In four of the other six patients treated with nonsurgical therapies (percutaneous cholecystolithotomy, stone dissolution with methyl tert-butyl ether, and endoscopic removal), gallstones were successfully removed and no further therapy was required. Percutaneous therapies failed in two patients, who then had cholecystectomy.

CONCLUSION

Nonsurgical gallstone therapies should be attempted in high-risk patients with acute calculous cholecystitis. Some patients may benefit from long-term catheter drainage of the gallbladder.

Efficacy of sonographically guided biopsy of thyroid masses and cervical lymph nodes

OBJECTIVE

We performed a prospective study in 96 patients to determine accuracy of sonographically guided fine-needle aspiration biopsy of thyroid masses and cervical lymph nodes.

MATERIALS AND METHODS

Real-time sonography was used to guide biopsy of 112 cervical masses in 96 patients (71 patients with impalpable masses, 16 with failed unguided attempts, patient's or physician's preference in nine). The diameters of all masses were less than 3 cm, with a mean of 1.5 cm and a median of 1.5 cm. Twenty-nine masses measured 1 cm or less in diameter, 60 masses between 1.1 and 2.0 cm, and 23 masses between 2.1 and 3.0 cm. Cervical masses that were sampled by biopsy included 75 thyroid masses and 37 lymph nodes.

RESULTS

Diagnostic specimens were obtained in 102 (91%) of 112 masses sampled. Sixty-eight (91%) of 75 biopsies of thyroid tissue and 34 (92%) of 37 biopsies of lymph nodes were diagnostic. Nondiagnostic thyroid biopsies included four of complex cysts and three of solid nodules. Sonographic follow-up (1 year) revealed no change or decrease in size of those seven lesions. Sixty of 68 diagnostic thyroid biopsies showed benign processes: 42 macrofollicular adenomas, six colloid adenomas, five microfollicular adenomas, four probable cases of thyroiditis, and three hemorrhagic cysts. The remaining eight diagnostic thyroid biopsies showed malignant processes: seven papillary carcinomas and one metastatic small-cell carcinoma. Of 34 diagnostic biopsies of lymph nodes, 26 showed malignant processes and eight showed benign processes. Surgery in the three patients with nondiagnostic biopsies of lymph nodes revealed two recurrent medullary cancers and one benign node.

CONCLUSION

Sonographically guided fine-needle aspiration biopsy of neck masses has a high sensitivity (91%) and should be routinely used to evaluate indeterminate masses in the neck.

Percutaneous management of hilar biliary malignancies with metallic endoprostheses: results, technical problems, and causes of failure

Malignant obstruction at the biliary hilum is a challenging problem for percutaneous management because of the anatomy of the biliary hilum, which facilitates spread of tumor into multiple biliary radicles. Metallic self-expanding stents were used in 22 patients with hilar malignancies. Sixteen patients had focal common hepatic duct strictures, and six had multisegmental disease. Stents were placed in the biliary system with a single transhepatic approach in 16 patients with common hepatic duct strictures; stent placement in the right and left biliary ducts was performed with a bilateral transhepatic approach in five patients and with a single transhepatic approach in one patient. Metal stent occlusion occurred in six patients (27%) at a mean of 2.5 months after initial insertion. Stent occlusion was due to inspissated debris in two of these patients and to tumor overgrowth in four. The key to successful long-term treatment is to "overstent" to ensure adequate purchase above hilar tumors and insertion in a balanced position. Thus, the prevalence of tumor overgrowth is decreased.

CT-guided celiac ganglion block with alcohol

Celiac ganglion block has been performed without radiologic guidance by surgeons or anesthetists since it was first described by Kappis [1] in 1914. Radiographic guidance for celiac block was first reported in the 1950s [2], and more recently, radiologists have used CT to guide needle placement [3-5]. With CT guidance, more directed positioning of the needle is possible, allowing alcohol to be deposited in the specific ganglion areas. This article reviews our collective experience with CT-guided celiac ganglion block.

Case report: combined conservative and percutaneous management of a perforated duodenal ulcer

A case is presented of perforated duodenal ulcer with associated abscesses treated by percutaneous drainage in a patient with markedly impaired respiratory function. The potential role of conservative management in such patients is discussed.

Fine-needle biopsy of cervical lymph nodes in patients with thyroid cancer: a prospective comparison of cytopathologic and tissue marker analysis

Tissue levels of thyroglobulin (Tg) or calcitonin were compared with specimens from neck lymph node biopsy in patients with suspected recurrent differentiated (papillary or follicular) or medullary thyroid cancer. Thirty-six neck lymph node biopsies were performed in 29 patients. Tissue Tg levels were obtained from 31 specimens from patients with differentiated thyroid cancers, and tissue calcitonin levels were obtained from five specimens from patients with medullary cancer. Thirteen nodes were diagnosed as negative for cancer at surgery (n = 3) or follow-up sonography (n = 10). Malignant disease was confirmed at surgery in 23 of the 36 lymph nodes. Cytopathologic examination had a sensitivity of 91% and a specificity of 100%. Tissue Tg levels ranged from 0 to 3.5 ng/mL (mean, 1.5 ng/mL; median, 1.2 ng/mL) in 12 of the 13 benign lymph nodes and from 21 to 247,500 ng/mL (mean, 30,600 ng/mL; median, 2,330 ng/mL) in the 23 malignant nodes. Tissue calcitonin levels were elevated (range, 850-703,125 pg/mL; mean, 184,762 pg/mL; median, 17,538 pg/mL) in four malignant nodes and were normal (3.0 pg/mL) in one benign node. Diagnostic sensitivity of tissue markers was 91%. Specificity was 91%. The combined diagnostic sensitivity and specificity of tissue marker analysis and cytopathologic examination was 100%.

Gastrostomy conversion to transgastric jejunostomy: technical problems, causes of failure, and proposed solutions in 63 patients

Sixty-three radiologically guided conversions of gastrostomy to transgastric jejunostomy performed over a 4-year period were reviewed. Conversions succeeded in 31 of 38 surgically placed gastrostomies (82%), in 14 of 18 endoscopically placed gastrostomies (78%), and in seven of seven radiologically placed gastrostomies, for an overall success rate of 83%. Almost all failures (10 of 11 gastrostomies) were primarily the result of unfavorable fundal angulation of the surgical or endoscopic tract; unfavorable angulation was also the most common technical problem encountered in the successful conversions. Of the 52 successful conversions, 23 (44%) necessitated tube replacement: eight for spontaneous proximal migration of the tube, 11 for accidental tube dislodgment, and four for tube blockage. While most gastrostomy to transgastric jejunostomy conversions are simple to perform, in many cases the unfavorable angle of the original transcutaneous tract precludes jejunal intubation and may be a cause for early recoil of a successfully placed jejunal catheter back into the stomach. With early recognition of an unfavorable tract, a fresh transgastric jejunostomy through a new, properly angled puncture may be the preferred approach.

Fine-needle biopsy: prospective comparison of aspiration versus nonaspiration techniques in the abdomen

A prospective study was designed to compare the aspiration (suction method) and nonaspiration (nonsuction method) techniques of fine-needle biopsy (FNB) in 50 consecutive patients with abdominal pathologic conditions. Sites of biopsy included liver (n = 24), retroperitoneum (n = 9), adrenal gland (n = 5), pancreas (n = 4), omentum (n = 4), and miscellaneous sites (n = 4). Aspiration and nonaspiration FNBs were performed in each lesion with 22-gauge needles, and results were interpreted by a single cytopathologist. Cytologic specimens obtained with each technique were analyzed for diagnostic accuracy, total number of cell clusters per biopsy (graded 0-10, 10-20, 20-30, and > 30), presence of crush artifact, and amount of blood present (graded from 0 to +3). No significant differences were seen between the aspiration and nonaspiration techniques with regard to number of cell clusters per biopsy (44 of 50 specimens vs 42 of 50) (P < .0003), amount of blood present (grade 2.3 vs 2.2) (P < .0003), and amount of crush artifact. The positive predictive value for the aspiration technique was 91.5% versus 74% for the nonaspiration technique. The aspiration technique of FNB appears superior to the nonaspiration technique in the abdomen.

Palliation of malignant bile duct obstruction with metallic biliary endoprostheses: technique, results, and complications

Expandable metallic stents were placed in 34 patients with pathologically proved malignant bile duct obstruction to determine ease of insertion, benefits of a one-stage insertion, and cost-effectiveness relative to conventional plastic stents. Thirty-eight strictures, ranging in length from 1 to 7 cm (mean, 3.2 cm), were present in the 34 patients. Strictures were located in the lower common bile duct (n = 22), middle of the common bile duct (n = 6), and hilar confluence (n = 10). In 13 patients (38%) metallic stents were placed at the time of initial biliary drainage (one-stage procedure), while the remaining patients underwent stent placement within 1-7 days of biliary drainage (two-stage procedure). Biliary obstruction was relieved in 31 of 34 patients (91%). Three patients died within 14 days of stent insertion of unrelated causes, without any change in biliary status. Mean duration of follow-up for all patients was 5.3 months (range, 0.5-14 months). Four episodes of stent occlusion occurred in three patients (12% occlusion rate); each episode was treated successfully. The average length of hospital stay for patients who underwent a one-stage procedure was 13 days (range, 3-33 days) and was 20 days (range, 9-42 days) for patients who underwent a two-stage procedure. The facility of one-step insertion, low occlusion rate, and the many strategies available for treatment of occluded stents make metallic stents an attractive alternative to conventional plastic stents in palliating patients with malignant biliary obstruction.

Wallstent metallic biliary endoprosthesis: MR imaging characteristics

Image quality and safety of magnetic resonance (MR) imaging were evaluated in vitro and in eight patients with the most commonly employed metallic biliary endoprosthesis. In vitro, the stent produced no tip deflection at 0.6 or 1.5 T. Trace magnetic susceptibility artifact, similar to artifact from a column of air, paralleled the stent. In patients, image degradation was minimal with conventional pulse sequences. Middle-field-strength spin-echo images revealed minimal artifacts indistinguishable from those produced by pneumobilia.

Measurement of tissue carcinoembryonic antigen levels from fine-needle biopsy specimens: technique and clinical usefulness

Levels of tissue carcinoembryonic antigen (CEA) in 54 abdominal fine-needle biopsy specimens from 50 patients were measured to ascertain the use of tissue CEA levels in diagnosis of malignancy. Biopsy was performed in the following sites: liver (n = 34), retroperitoneum (n = 8), adrenal gland (n = 3), pancreas (n = 2), omentum (n = 2), pelvis (n = 2), spleen (n = 2), and stomach (n = 1). Histologic findings proved malignancy in 39 patients and benign disease in 11 patients. In these 11 patients, the mean levels of tissue CEA were lower than the normal level of serum CEA (3 ng/mL). Tissue CEA levels were higher than serum CEA levels in nine patients with colonic carcinoma and in 12 of 16 patients with noncolonic CEA-secreting malignancies. Four patients with noncolonic CEA-secreting malignancies had tissue CEA levels within the normal range (less than 3 ng/mL). Tissue CEA levels were also normal in 13 patients with various non-CEA-secreting tumors. Tissue CEA levels may prove useful in biopsy of necrotic or cystic lesions and assessment of response to ablative therapy for colon metastases.