Measurements of organ volume by ultrasonography

Ovarian Volume of Saudi Children and Adolescents in the Southern Region Based on Ultrasound Imaging

Introduction Sonography is a non-invasive and painless technique used for assessing pelvic anatomy and disorder in children and adolescents. Ovarian growth patterns during infancy and puberty are not completely understood. No consensus exists about the normal measures and morphologic appearance of the ovaries in the southern region of Saudi Arabia. Therefore, this study determined the pattern of ovarian and uterine sizes among Saudi girls and their correlation with age. Methods This study was conducted in the radiology department at Abha Maternity and Children Hospital among girls between 0-13 years. All the participants underwent transabdominal ultrasound, and we measured ovarian volume, uterine length, and endometrial thickness to correlate with chronologic age using the Chi-squared test. Results A Total of 152 females were included in this study. The median age was 72 months, with a minimum of one month and a maximum of 156 months. The Chi-squared test showed a significant correlation between age and ovarian measurement. Age was positively associated with ovarian volume, uterine length, and endometrial thickness (p<0.001).  Conclusion The study concluded that age strongly correlated with the size of the uterus and ovaries, which is crucial in interpreting ultrasound measurements of the pelvic organs correctly.

Sonographic Evaluation of the Gallbladder in Adult Patients With Type 2 Diabetes Mellitus

Introduction and aim: Diabetes mellitus (DM) is one of the most common non-communicable diseases worldwide. Diabetics with autonomic neuropathy tend to have larger gallbladder (GB) with poor contraction after fatty meals predisposing them to gallstones and cholecystitis. This may be prevented and treated if detected early using ultrasound. This study sonographically evaluated the GB in adults with type 2 diabetes and compared the findings with a non-diabetic age and sex-matched control group.

Methods: In this case-control study, 120 patients with type 2 diabetes and 120 non-diabetic controls between the ages of 18 and 80 years at National Hospital Abuja had their GB evaluated after eight hours of overnight fast using B-mode ultrasound. The data were analyzed using IBM SPSS version 20.0 (Armonk, NY: IBM Corp.) and presented in tables.

Result: There were 60 males and 60 females with mean ages of 53.3 and 52 years for the cases and controls, respectively. The average fasting gallbladder volume (FGBV) in diabetics (34.51 + 3.16cm³) was higher than that of controls (27.17 + 1.25cm³). Eleven (9.2%) diabetics had gallstone (GS), while none was detected in controls. The GB wall thickness was significantly higher in diabetics than in the controls (0.28 ± 0.06 cm vs 0.25 ± 0.04 cm).

Conclusion: A significant proportion of type 2 diabetics had higher FGBV, GB wall thickness, and presence of gallstone compared to the non-diabetic controls. B-mode ultrasound is a very important non-invasive and accurate tool for detecting these changes early.

Evaluation of low gradient severe aortic stenosis: should we change our outlook in the analysis of clinical data?

Nowadays, technological progress has equipped clinicians with new useful devices for the collection, analysis and presentation of data. As a consequence, many diseases and pathological conditions have been studied in a more detailed way, sometimes with remarkable results. In fact, they are not always validated by the old physiological models. In this respect, we present the case of low gradient severe aortic stenosis, a condition characterised by a small aortic valve area and a low-pressure gradient. According to the mathematical and physical assumptions these readings are contradictory whereas the Doppler-echocardiography shows clearly the existence of such a situation. In this work, we have described the physiological base of this phenomenon and discussed the limitations of the technology used. In this work, we are going to analyse some conditions commonly observed in daily clinical practice in order to prompt a critical outlook in both clinicians and technicians about the instrumentations used and the methods applied.

Analysis of ovarian volume of Korean children and adolescents at magnetic resonance imaging

BACKGROUND

Knowledge of ovarian volume is important for diagnostic evaluations; however, normal ovarian volume studies on children and adolescents are lacking.

OBJECTIVE

This study aimed to analyze age-specific ovarian volume and identify the diverse factors that contribute to ovarian diagnoses.

MATERIALS AND METHODS

We retrospectively enrolled 180 patients (0-18 years of age) with normal ovaries who underwent magnetic resonance imaging (MRI) between 2010 and 2018. MRI sequences included coronal and axial T2-weighted turbo spin echo (TSE) images and coronal T1-weighted TSE images. Ovarian volume was calculated by the standard ellipsoid formula. Age-specific ovarian volume, height, weight, height-adjusted total ovarian volume and body mass index were obtained. Linear regression analysis was used to predict ovarian volume.

RESULTS

Six age groups (infant; early and late child, and early, middle and late adolescent) were described. The early adolescent group (10-12 years) had the highest rate of increase. In the middle adolescent period (13-15 years), the curve of ovarian volume appeared flat.

CONCLUSION

Our findings provide age-specific references for ovarian volume.

Versatile Low-Cost Volumetric 3-D Ultrasound Platform for Existing Clinical 2-D Systems

Ultrasound imaging has indications across many areas of medicine, but the need for training and the variability in skill and acquired image quality among 2-D ultrasound users have limited its wider adoption and utilization. Low-cost volumetric ultrasound with a known frame of reference has the potential to lower these operator-dependent barriers and enhance the clinical utility of ultrasound imaging. In this paper, we improve upon our previous research-scanner-based prototype to implement a versatile volumetric imaging platform for existing clinical 2-D ultrasound systems. We present improved data acquisition and image reconstruction schemes to increase quality, streamline workflow, and provide real-time visual feedback. We present initial results using the platform on a Vimedix simulator, as well as on phantom and in vivo targets using a variety of clinical ultrasound systems and probes.

Sonographic Measurement of Cervical Volume in Pregnant Women at High Risk of Preterm Birth Using a Geometric Formula for a Frustum Versus 3-Dimensional Automated Virtual Organ Computer-Aided Analysis

OBJECTIVES

To compare cervical volume measurements by 3-dimensional (3D) sonography using Virtual Organ computer-aided analysis (VOCAL; GE Healthcare, Milwaukee, WI) versus a manual method using a geometric formula for a frustum.

METHODS

We included 142 asymptomatic pregnant women at 16 to 24 weeks gestation at high risk for preterm birth. With a Voluson 730 Expert system (GE Healthcare), they underwent 2-dimensional (2D) transvaginal sonographic cervical length measurements and 3D cervical volume acquisition. The stored volumes were processed by VOCAL on a surface tablet. Cervical volume was manually calculated from the 2D images by using the formula V = 1/3 × π × h × (r1²  + r2²  + r1 × r2), where V represents cervical volume; π was approximated as 3.14159; h, cervical length; r1, radius at the internal os; and r2, radius at the external os.

RESULTS

Cervical volume was lower when obtained manually than by VOCAL, with a coefficient of variation of 30%, a mean difference of 10.1 ± 14.9 cm³ (P < .0001), and a poor interclass correlation coefficient of 0.62 (95% confidence interval [CI], 0.31 to 0.78). Both methods had good reproducibility; however, VOCAL had wider limits of agreement. A positive correlation was found between both methods (r = 0.63; P < .0001). No correlation was found between cervical length by 2D transvaginal ultrasound and cervical volume by the VOCAL technique (r = 0.06; 95% CI, -0.10 to 0.22) or cervical volume by the manual method (r = 0.2; 95% CI, 0.08 to 0.39).

CONCLUSIONS

The cervix represents a frustum (truncated cone, r1 is not equal to r2) in shape rather than a cylinder. Both methods are reproducible; VOCAL is less reliable but provides higher values of cervical volume.

The Age-Related Development of Maxillary Sinus in Children

INTRODUCTION

Paranasal sinuses are complex structures and show individual variation. Providing normative values for paranasal sinus size and their changes related to age could be helpful in evaluating the presence of some diseases related to sinonasal region. The purpose of the current study was to investigate the development of maxillary sinuses and evaluate the volume changes according to age and sex by using stereological and ellipsoidal formula methods after that to compare these approaches with each other in children.

MATERIALS AND METHODS

This retrospective volumetric computed tomography (CT) study was carried out on 361 individuals (180 females, 181 males) between 0 and 18 years old (10 females, 10 males in each group, only 14 age group includes 11 males) with no signs of sinus pathology volumetric estimations determined on CT images using point-counting approach of stereological methods and ellipsoid formula by using morphometric data.

RESULTS

Maxillary sinus volume measurements that were obtained using 2 methods were increased with age in both sexes until 16 years old. There was a significant correlation determined between 2 methods (ICC 0.894-1.000 for right and 0.862-0.999 for left maxillary sinus measurements). According to the sex, the right and left mean maxillary sinuses volumes were determined at 8.30 ± 5.19 and 8.57 ± 5.53 cm(3) in male and at 7.60 ± 4.57 and 7.99 ± 4.73 cm(3) in female by using ellipsoid formula respectively. By the stereological method these values were 8.28 ± 5.26, 8.44 ± 5.35 cm(3) and 7.64 ± 4.55, 7.85 ± 4.73 cm(3) respectively. There was no statistically significant difference between the volume of maxillary sinuses with sex and side using both methods.

CONCLUSIONS

This study presents the basic data for studies relative to the development of the maxillary sinus in children according to 2 methods. The current study demonstrated that the point-counting method and ellipsoid formula are both effective in determining volume estimation of maxillary sinuses and are well suited for CT studies.

Validation of a Novel 3-Dimensional Sonographic Method for Assessing Gastric Accommodation in Healthy Adults

OBJECTIVES

A novel automated 3-dimensional (3D) sonographic method has been developed for measuring gastric volumes. This study aimed to validate and assess the reliability of this novel 3D sonographic method compared to the reference standard in 3D gastric sonography: freehand magneto-based 3D sonography.

METHODS

A prospective study with 8 balloons (in vitro) and 16 stomachs of healthy volunteers (in vivo) was performed. After a 500-mL liquid meal, 1 preprandial and 3 postprandial volume scans of the stomachs were performed by the novel 3D sonographic method and the current reference-standard 3D sonographic method.

RESULTS

The in vitro study showed a mean volume difference between the novel method and the true balloon volume of -1.3 mL; limits of agreement (LoA) were small (-39.3 to12.3 mL), with an intraclass correlation coefficient (ICC) of 0.998. The in vivo study showed a mean gastric volume of 321 mL between the novel method and the freehand magneto-based method, with a mean volume difference of -4.4 mL; LoA were -40.1 to 31.2 mL, and the ICC was 0.991. The intraobserver and interobserver variability rates were low, at 0.8 mL (LoA, -24.0 to 25.6 mL), with an ICC of 0.995, and 0.5 mL (LoA, of -26.8 to 27.8 mL), with an ICC of 0.999, respectively.

CONCLUSIONS

The novel 3D sonographic method with automated acquisition showed good agreement with the current reference-standard gastric 3D sonographic method, with low intraobserver and interobserver variability. This novel 3D sonographic method is a valid and reliable technique for determining gastric accommodation.

Correlation Between Liver Volumetric Computed Tomography Results and Measured Liver Weight: A Tool for Preoperative Planning of Liver Transplant

OBJECTIVES

Before liver transplant, it is necessary to know the size of the organ in advance of the procedure. We studied the correlation between liver volumetric computed tomography results and liver weight.

MATERIALS AND METHODS

Postmortem volumetric computed tomography was conducted on cadavers before autopsy, and 3-dimensional liver volume was estimated with semiautomated software. Liver weight was then determined at autopsy. Linear regression and univariate analysis of variance results were used to determine the accuracy of volumetric 3-dimensional computed tomography in estimating liver weight. We also used 2-dimensional liver sizes to design a 2-dimensional formula to estimate liver volume.

RESULTS

We found that 3-dimensional volumetric computed tomography was able to accurately estimate liver weight (standard error = 157 g) with a liver density of 0.99 g/mL. Intraobserver and interobserver variabilities were small. The 2-dimensional formula estimated liver weight slightly less accurately (standard error = 212 g).

CONCLUSIONS

We conclude that liver weight can be estimated accurately with 3-dimensional volumetric computed tomography; estimates were more precise than with the 2-dimensional formula-based liver volume estimation. Volumetric computed tomography can be an important tool during preoperative workup before transplant surgery.

Ultrasonography in gastroenterology

Ultrasonography (US) is a safe and available real-time, high-resolution imaging method, which during the last decades has been increasingly integrated as a clinical tool in gastroenterology. New US applications have emerged with enforced data software and new technical solutions, including strain evaluation, three-dimensional imaging and use of ultrasound contrast agents. Specific gastroenterologic applications have been developed by combining US with other diagnostic or therapeutic methods, such as endoscopy, manometry, puncture needles, diathermy and stents. US provides detailed structural information about visceral organs without hazard to the patients and can play an important clinical role by reducing the need for invasive procedures. This paper presents different aspects of US in gastroenterology, with a special emphasis on the contribution from Nordic scientists in developing clinical applications.

Comparative analysis of 2-D versus 3-D ultrasound estimation of the fetal adrenal gland volume and prediction of preterm birth

OBJECTIVE

We aim to test the hypothesis that two-dimensional (2-D) fetal adrenal gland volume (AGV) measurements offer similar volume estimates as volume calculations based on 3-D technique.

METHODS

Fetal AGV was estimated by three-dimensional (3-D) ultrasound (VOCAL) in 93 women with signs/symptoms of preterm labor and 73 controls. Fetal AGV was calculated using an ellipsoid formula derived from 2-D measurements of the same blocks (0.523 × length × width × depth). Comparisons were performed by intraclass correlation coefficient (ICC), coefficient of repeatability, and Bland-Altman method. The corrected AGV (cAGV; AGV/fetal weight) was calculated for both methods and compared for prediction of preterm birth (PTB) within 7 days.

RESULTS

Among 168 volumes, there was a significant correlation between 3-D and 2-D methods (ICC = 0.979; 95% confidence interval [CI]: 0.971 to 0.984). The coefficient of repeatability for the 3-D was superior to the 2-D method (intraobserver 3-D: 30.8, 2-D:57.6; interobserver 3-D:12.2, 2-D: 15.6). Based on 2-D calculations, cAGV ≥ 433 mm3/kg was best for prediction of PTB (sensitivity: 75%, 95% CI = 59 to 87; specificity: 89%, 95% CI = 82 to 94). Sensitivity and specificity for the 3-D cAGV (cutoff ≥ 420 mm3/kg) was 85% (95% CI = 70 to 94) and 95% (95% CI = 90 to 98), respectively. In receiver-operating-curve curve analysis, 3-D cAGV was superior to 2-D cAGV for prediction of PTB (z = 1.99, p = 0.047).

CONCLUSION

2-D volume estimation of fetal adrenal gland using ellipsoid formula cannot replace 3-D AGV calculations for prediction of PTB.

Computer-aided diagnosis for contrast-enhanced ultrasound in the liver

Computer-aided diagnosis (CAD) has become one of the major research subjects in medical imaging and diagnostic radiology. The basic concept of CAD is to provide computer output as a second opinion to assist radiologists’ image interpretations by improving the accuracy and consistency of radiologic diagnosis and also by reducing the image-reading time. To date, research on CAD in ultrasound (US)-based diagnosis has been carried out mostly for breast lesions and has been limited in the fields of gastroenterology and hepatology, with most studies being conducted using B-mode US images. Two CAD schemes with contrast-enhanced US (CEUS) that are used in classifying focal liver lesions (FLLs) as liver metastasis, hemangioma, or three histologically differentiated types of hepatocellular carcinoma (HCC) are introduced in this article: one is based on physicians’ subjective pattern classifications (subjective analysis) and the other is a computerized scheme for classification of FLLs (quantitative analysis). Classification accuracies for FLLs for each CAD scheme were 84.8% and 88.5% for metastasis, 93.3% and 93.8% for hemangioma, and 98.6% and 86.9% for all HCCs, respectively. In addition, the classification accuracies for histologic differentiation of HCCs were 65.2% and 79.2% for well-differentiated HCCs, 41.7% and 50.0% for moderately differentiated HCCs, and 80.0% and 77.8% for poorly differentiated HCCs, respectively. There are a number of issues concerning the clinical application of CAD for CEUS, however, it is likely that CAD for CEUS of the liver will make great progress in the future.

An assessment of the accuracy of hepatic and splenic size based upon a clinician's physical examination, a radiologist's impression and the actual liver and spleen volumes calculated by CT scanning

OBJECTIVES

In this study, a radiologist's impression of liver and spleen size based on computed tomography (CT) images, calculated liver and spleen volumes as determined radiologically, and findings of a hepatologist were compared.

METHODS

One hundred and ninety-four consecutive subjects seen by a hepatologist were evaluated clinically and radiologically. Liver and spleen volumes were calculated based on CT images and compared to radiologist's impression and to expected liver volume based on body weight. Covariate analysis was used to determine the relationships between different variables, and a value of P < 0.05 was considered to be significant.

RESULTS

Liver volume calculated on the basis of CT scans correlated to liver size based on the hepatologist's clinical exam but not to the radiologist's impression of liver size. In contrast, spleen volume based on CT scans, splenic size based upon radiologist's impression, and clinician's assessment all correlated well.

CONCLUSIONS

A variety of biases determine and/or affect the radiologist's assessment of liver size but not of splenic size.

Advanced imaging and visualization in gastrointestinal disorders

Advanced medical imaging and visualization has a strong impact on research and clinical decision making in gastroenterology. The aim of this paper is to show how imaging and visualization can disclose structural and functional abnormalities of the gastrointestinal (GI) tract. Imaging methods such as ultrasonography, magnetic resonance imaging (MRI), endoscopy, endosonography, and elastography will be outlined and visualization with Virtual Reality and haptic methods. Ultrasonography is a versatile method that can be used to evaluate antral contractility, gastric emptying, transpyloric flow, gastric configuration, intragastric distribution of meals, gastric accommodation and strain measurement of the gastric wall. Advanced methods for endoscopic ultrasound, three-dimensional (3D) ultrasound, and tissue Doppler (Strain Rate Imaging) provide detailed information of the GI tract. Food hypersensitivity reactions including gastrointestinal reactions due to food allergy can be visualized by ultrasonography and MRI. Development of multi-parametric and multi-modal imaging may increase diagnostic benefits and facilitate fusion of diagnostic and therapeutic imaging in the future.

Measurements of gastric emptying of low- and high-nutrient liquids using 3D ultrasonography and scintigraphy in healthy subjects

Scintigraphy represents the 'gold standard' for the measurement of gastric emptying. Recent studies suggest that three-dimensional (3D) ultrasonography may allow a precise measure of gastric emptying, given the capacity for accurate volume calculations of the stomach. The aim of this study was to compare measurements of gastric emptying of both low- and high-nutrient drinks by 3D ultrasonography with scintigraphy. Ten healthy young subjects (6M, 4F, age 23.5 +/- 1.5 years) were studied on 2 days. Concurrent measurements of gastric emptying by scintigraphy and 3D ultrasonography were performed after ingestion of 500 mL beef soup (12 kcal) or 300 ml dextrose (25% w/v) (314 kcal) labelled with 20 MBq (99m)Tc-sulphur colloid. There was no significant difference between scintigraphic and ultrasonographic 50% emptying times (T50s) (soup: 27.7 +/- 4.8 min vs 23.8. +/- 4.8 min; dextrose: 122.2 +/- 13.3 min vs 131.9 +/- 10.2 min). There was a close correlation between scintigraphic and ultrasonographic T50s for both soup (r = 0.92, P = 0.0005) and dextrose (r = 0.88, P = 0.0007). For the T50s, the limits of agreement were -15.2 min and +8.1 min for the soup (mean difference -3.6 min) and -35.3 min and +47.6 min for dextrose (mean difference +6.2 min). 3D ultrasonography provides a valid measure of gastric emptying of liquid meals in healthy subjects.

Relationships between gastric accommodation and gastrointestinal sensations in healthy volunteers. A study using the barostat technique and two- and three-dimensional ultrasonography

The origin of postprandial gastrointestinal sensations and their relation to gastric accommodation remain unclear. Our aim was to investigate the relation between antral and fundal accommodation and sensations. (A) In eight healthy volunteers fundus accommodation was measured using a barostat after a 200-ml (300-kcal) liquid nutrient. Antral area (AA) was measured using ultrasound. Data on bag volumes, AA, and sensations were assessed. (B) In another eight healthy volunteers gastric volume was measured after a 500-ml (300-kcal) liquid nutrient using 2-D/3-D ultrasound. Sensations were scored using VAS. Distal and proximal volumes were calculated from 3-D datasets. (A) Fullness was correlated with AA (r = 0.48, P = 0.002). Fullness and bag volume were not correlated. (B) Fullness was correlated with AA (r = 0.77, P < 0.001) and distal volume (r = 0.75, P < 0.001). Proximal volume was not correlated with fullness (r = 0.10, P = NS). We conclude that fullness is related to antral volume and area rather than proximal volume. The gastric antrum may play a key role in normal appetite regulation.

Clarifying the role of three-dimensional transvaginal sonography in reproductive medicine: an evidenced-based appraisal

This overview describes and illustrates the clinical applications of three-dimensional transvaginal sonography in reproductive medicine. Its main applications include assessment of uterine anomalies, intrauterine pathology, tubal patency, polycystic ovaries, ovarian follicular monitoring and endometrial receptivity. It is also useful for detailed evaluation of failed and/or ectopic pregnancy. Three-dimensional color Doppler sonography provides enhanced depiction of uterine, endometrial, and ovarian vascularity.

Gastric sensory and motor dysfunction in adolescents with functional dyspepsia

OBJECTIVES

Validated, noninvasive studies were used to compare sensation and motor function of the upper gastrointestinal tract in adolescents with functional dyspepsia (FD) and in control subjects.

STUDY DESIGN

Fifteen adolescents with FD and 15 healthy participants underwent standardized symptom assessment, a satiation nutrient drink test, and 13 C-Spirulina platensis breath test for gastric emptying of solids. Adolescents with FD also underwent measurements of fasting and postprandial gastric volume by means of single-photon emission computed tomography, and their results were compared with those from 15 healthy volunteers (age, 18 to 25 years).

RESULTS

Compared with control subjects, adolescents with FD had significantly higher postprandial symptoms 30 minutes after reaching maximum satiation with the nutrient drink test and significant delay in the T 1/2 for gastric emptying of solids. Compared with healthy 18- to 25-year-old adults, adolescents had a diminished postprandial gastric volume response. By means of single-photon emission computed tomography, frequent baseline dyspeptic symptoms were associated with prolonged T 1/2 for gastric emptying and higher postprandial aggregate symptom score. A baseline increased severity of dyspepsia symptoms was associated with prolonged T 1/2 for gastric emptying.

CONCLUSIONS

Adolescents with FD demonstrate increased postprandial symptoms after challenge, delayed gastric emptying, and a reduced gastric volume response to feeding.

Volume estimation of small phantoms and rat kidneys using three-dimensional ultrasonography and a position sensor

To evaluate the accuracy of small volume estimation, both in vivo and in vitro, measurements with a three-dimensional (3D) ultrasound (US) system were carried out. A position sensor was used and the transmitting frequency was 10 MHz. Balloons with known volumes were scanned while rat kidneys were scanned in vivo and in vitro. The Archimedes' principle was used to estimate the true volume. For balloons, the 3D US system gave very good agreement with true volumes in the volume range 0.1 to 10.0 mL (r = 0.999, n = 45, mean difference +/- 2SD = 0.245 +/- 0.370 mL). For rat kidneys in vivo (volume range 0.6 to 2.7 mL) the method was less accurate (r = 0.800, n = 10, mean difference +/- 2SD = -0.288 +/- 0.676 mL). For rat kidneys in vitro (volume range 0.3 to 2.7 mL) the results showed good agreement (r = 0.981, n = 23, mean difference +/- 2SD = 0.039 +/- 0.254 mL). For balloons, kidneys in vivo and in vitro, the mean percentage error was 9.3 +/- 4.8%, -17.1 +/- 17.4%, and 4.6 +/- 11.5%, respectively. This method can estimate the volume of small phantoms and rat kidneys and opens new possibilities for volume measurements of small objects and the study of organ function in small animals. (E-mail ).

[Transrectal ultrasound of the prostate. Current status and prospects]

In recent years the role of ultrasound in the diagnosis of prostate carcinoma has increased in importance. In view of the increasing incidence of prostate cancer, which is the most frequent malignant neoplasm in men, TRUS (transrectal ultrasound) is an important imaging method in the diagnosis of various prostate diseases. This paper provides a basic overview of physical and technical bases of TRUS investigation of the prostate. It concerns technical developments and modern techniques designed to improve its value in diagnosis. Impressive innovations in ultrasound equipment, particularly in the area of colour-coded Doppler sonography in association with microbubble-enhanced colour Doppler ultrasound, have given rise to justifiable hope of improvements in the early diagnosis of prostate cancer.

Noninvasive measurement of gastric accommodation in patients with idiopathic nonulcer dyspepsia

OBJECTIVES

Postprandial symptoms are associated with impaired postprandial gastric accommodation. The aims of this study were to apply a noninvasive method to measure accommodation of the entire stomach in healthy subjects and in patients with idiopathic dyspeptic symptoms, and to assess the frequency of abnormal gastric accommodation and emptying of solids in these patients.

METHODS

In 20 healthy volunteers and 32 tertiary referral patients, we used i.v. 99mTc-single photon emission computed tomography (SPECT) to measure fasting and postprandial gastric volumes; we expressed the volume response to feeding ("accommodation") as the change in gastric volume and the ratio of postprandial/fasting volumes. The stomach was identified in transaxial SPECT tomographic images using a semiautomated, intensity-based extraction algorithm. Whole gastric volumes were measured using AnalyzeAVW software. Gastric emptying in patients was measured by scintigraphy. We also assessed dyspeptic symptoms and the association with normal or reduced accommodation.

RESULTS

SPECT imaging detects the postprandial change in gastric volume ("accommodation") in health and disease. Among healthy subjects (eight men, 12 women), the postprandial/fasting gastric volume ratio was 4.9+/-1.7 (mean +/- SD; fifth through 95th percentiles 3-8, median 4.6). Thirteen (41%) patients with idiopathic nonulcer dyspepsia had reduced postprandial "accommodation." Gastric emptying was fast in four (13%), normal in 25 (78%), and slow in three (9%) patients. Both tests were normal in 50% of patients. Weight loss of >10 pounds tended to be more frequently observed in those with reduced "accommodation" (62% vs 32%, p = 0.09).

CONCLUSIONS

SPECT imaging noninvasively measures fasting and postprandial gastric volumes in humans. Half the patients with idiopathic nonulcer dyspepsia had impaired gastric accommodation or emptying. Reduced gastric "accommodation" was observed in 41% of a group with idiopathic nonulcer dyspepsia. Abnormal gastric emptying is less frequent (22%).

[A testing device for quality assurance of 3D-ultrasound equipment]

A test object for 3D-ultrasound (US) imaging equipment was constructed, that could be used for various purposes: For training of the correct technical setup procedures and practical handling of a 3D-US equipment, as well as for various quality assurance procedures. The size and volume of these structures were known precisely (+/- 0.1 mm resp. +/- 0.06 mL, respectively; smallest volume: 0.1 mL). The stability of the structures was in agreement with guideline IEC 854 and allowed to quantify exactly the imaging and measurement errors of size and volume measurements performed with commercial 3D-equipment. The test object is well suited to validate measured volume data, as well as to perform procedures of technical quality assurance in a reproducible manner.

Three-dimensional ultrasound in obstetrics and gynecology

Three-dimensional ultrasound is a new modality finding its way into clinical practice. Most of the major ultrasound vendors are now developing three-dimensional ultrasound capabilities. We expect that although three-dimensional ultrasound will not replace two-dimensional ultrasound, many additional benefits will be identified and its use will continue to grow. The ability to evaluate anatomy and pathology with multiplanar and surface-rendered images provides physicians additional valuable clinical information. Volume data allows for a specific point in space to be evaluated from many different orienta tions by rotating, slicing, and referencing the slice to other orthogonal slices. It also allows for new volume-rendering displays that show depth, curvature, and surface images not available with conventional methods. The current limitations of image resolution, intuitive interfaces for obtaining and displaying optimal images, and technologic limitations for data storage and manipulation (including real-time three-dimensional ultrasound) will surely be overcome in the near future.