Micro-Computed Tomography Assessment of Apical Accessory Canal Morphologies.

INTRODUCTION: The morphologic features of accessory canals (ACs) were investigated by using micro-computed tomography technique with a centerline fitting algorithm. METHODS: Ninety-three 3-mm-long apical root segments with unobstructed ACs were scanned by micro-computed tomography at 2.5-µm scanning resolution. After automatic segmentation, a centerline of the reconstructed lateral canal was developed, and the diameter, length, shape, and undulation of ACs were analyzed along the centerline. RESULTS: Of 178 unobstructed ACs identified, the median diameter was 67.0 µm, the average length was 786.6 µm, the predominant shape was oval, and the undulation was tortuous rather than straight. CONCLUSIONS: The diameter, length, shape, and undulation may vary among ACs in particular from the pulpal space to the external root surface, which may complicate the debridement of the ACs.

Reliability and Limits of Agreement of the Supraspinatus Muscle Anatomical Cross-Sectional Area Assessment by Ultrasonography.

The purpose of this study was to evaluate the reliability and limits of agreement for assessment of the anatomical cross-sectional area (ACSA) of the supraspinatus muscle using B-mode ultrasonography. Sixteen participants were examined with two different protocols, on two different days. There were no statistically significant differences (p > 0.05) in ACSA values between days 1 and 2 or between protocols 1 and 2; the average intra-class correlation coefficient ranged from 0.93 to 0.96. The limits of agreement for supraspinatus ACSA were, in both protocols, about ± 1 cm(2). Our findings revealed that both protocols had high reliability in distinguishing differences of about 1 cm(2) between groups or after interventions and that ultrasonography can be used for experimental designs in which the expected changes in ACSA would be higher than 14%.

Rapid maxillary expansion effects: An alternative assessment method by means of cone-beam tomography

INTRODUCTION: This study aims to develop a method to assess the changes in palatal and lingual cross-sectional areas in patients submitted to rapid maxillary expansion (RME). METHODS: The sample comprised 31 Class I malocclusion individuals submitted to RME and divided into two groups treated with Haas (17 patients) and Hyrax (14 patients) expanders. Cone-beam computed tomography scans were acquired at T0 (before expansion ) and T1 (six months after screw stabilization). Maxillary and mandibular cross-sectional areas were assessed at first permanent molars and first premolars regions and compared at T0 and T1. Mandibular occlusal area was also analyzed. RESULTS: Maxillary cross-sectional areas increased in 56.18 mm2 and 44.32 mm2 for the posterior and anterior regions. These values were smaller for the mandible, representing augmentation of 40.32 mm2 and 39.91 mm2 for posterior and anterior sections. No differences were found when comparing both expanders. Mandibular occlusal area increased 43.99mm2 and mandibular incisors proclined. Increments of 1.74 mm and 1.7 mm occurred in mandibular intermolar and interpremolar distances. These same distances presented increments of 5.5 mm and 5.57 mm for the maxillary arch. CONCLUSION: Occlusal and cross-sectional areas increased significantly after RME. The method described seems to be reliable and precise to assess intraoral area changes. .

INTRODUÇÃO: o presente estudo teve como objetivo desenvolver um método para avaliar as mudanças nas áreas transversais palatinas e linguais em pacientes submetidos à expansão rápida da maxila (ERM). MÉTODOS: a amostra foi composta por 31 indivíduos com má oclusão Classe I de Angle, submetidos a ERM e divididos em dois grupos, tratados com expansores tipo Haas (17 pacientes) e de Hyrax (14 pacientes). Tomografias computadorizadas de feixe cônico foram adquiridas em T0 e T1 (antes da expansão e seis meses após a estabilização do parafuso). Áreas transversais da maxila e mandíbula foram avaliadas nas regiões de primeiros molares permanentes e pré-molares e comparadas entre T0 e T1. A área oclusal mandibular também foi analisada. RESULTADOS: as áreas transversais maxilares aumentaram 56,18mm2 e 44,32mm2 para regiões posterior e anterior, respectivamente. Esses valores foram menores para mandíbula, representando aumentos de 40,32mm2 e de 39,91mm2 para as seções anterior e posterior. Não foram encontradas diferenças quando se comparam os dois expansores. A área oclusal mandibular aumentou 43,99mm2 e incisivos inferiores vestibularizaram. Incrementos de 1,74mm e 1,7mm ocorreram entre as distâncias intermolares e interpré-molares inferiores. Essas mesmas distâncias apresentaram incrementos de 5,5mm e de 5,57mm para maxila. CONCLUSÃO: as áreas transversais avaliadas e oclusal de mandíbula aumentaram significativamente após a ERM. O processo descrito parece ser um método confiável e preciso para avaliar as mudanças das área intrabucais propostas. .

Risk assessment of inferior alveolar nerve injury for immediate implant placement in the posterior mandible: a virtual implant placement study.

OBJECTIVES: To investigate the prevalence and morphological parameters of lingual concavity, and whether these factors are related to a higher risk of inferior alveolar nerve (IAN) injury when performing an immediate implant surgery in posterior mandible region. METHODS: The CBCT images from 237 subjects (1008 teeth) were analysed the shape of the mandibles (C, P, U type), dimensional parameters of lingual concavity (angle, height, depth), and its relation to inferior alveolar canal (IAC) (A, B, C zone), RAC (distance from root apex to IAC) and probability of IAN injury. Multiple logistic regression modelling to determine the odds ratio of variables that made an important contribution to the probability of IAN injury and to adjust for confounding variables. RESULTS: The U type ridge (46.7%) and the most concave point located at C zone (48.8%) are most prevalent in this region. The mandibular second molar presents highest risk for IAN injury than other tooth type (p<0.001), which were 3.82 times to occur IAN injury than the mandibular second premolar. The concave point located at A zone and B zone were 7.82 and 3.52 times than C zone to have IAN damage, respectively. The probability of IAN injury will reduce 26% for every 1mm increase in RAC (p<0.001). CONCLUSIONS: The tooth type, morphological features of lingual concavities, and RAC are associated with risks of IAN injury during immediate implant placement. CLINICAL SIGNIFICANCE: Pre-surgical mapping of the IAC and identification of its proximity relative to the lingual concavity in the posterior mandible regions may avoid unpleasant complications, specifically when performing immediate implant procedures.

Volumetric breast composition analysis: reproducibility of breast percent density and fibroglandular tissue volume measurements in serial mammograms.

BACKGROUND: Volumetric breast composition analysis represents a useful tool for assessing changes in breast composition over time. However, no data exist on the reproducibility of this method in serial mammograms. PURPOSE: To assess the reproducibility of two volumetric breast composition parameters, breast percent density (PD) and fibroglandular tissue volume (FTV), in consecutive mammograms. MATERIAL AND METHODS: Volumetric breast composition analysis to determine PD and FTV was performed in two consecutive unilateral mammograms of 211 patients. All mammograms were obtained on the same digital mammography unit within a maximum interval of 24 months. Volumetric data for analysis for both examinations were available for 174 patients. Thirty-two patients had successful volumetric analysis of additional consecutive examinations on a second digital mammography unit. Inter-examination correlation of measurements and absolute differences were analyzed. Bland-Altman analysis was performed to compare readings from different mammography units. RESULTS: Mean FTV remained constant over the study period. A reduction in PD of 0.5% and a mean increase in breast volume (BV) of 3% were observed. FTV measurements obtained on the same mammography unit were significantly more reproducible than PD measurements (Pearson correlation coefficients of 0.947 and 0.920, respectively; P < 0.05). A 15% difference between mean absolute volume measurements (FTV and BV) obtained on different mammography units was observed (P ≤ 0.001), while mean PD was close to the expected value. CONCLUSION: Volumetric breast composition analysis is highly reproducible in serial mammograms in normal women. FTV is a more reproducible parameter than PD, indicating that absolute quantification of breast parenchyma may be preferable to the measurement of relative parameters such as PD. However, a disadvantage of using FTV is that it is susceptible to systematic differences when measurements are obtained on different imaging platforms.

Rapid maxillary expansion effects: an alternative assessment method by means of cone-beam tomography.

INTRODUCTION: This study aims to develop a method to assess the changes in palatal and lingual cross-sectional areas in patients submitted to rapid maxillary expansion (RME). METHODS: The sample comprised 31 Class I malocclusion individuals submitted to RME and divided into two groups treated with Haas (17 patients) and Hyrax (14 patients) expanders. Cone-beam computed tomography scans were acquired at T0 (before expansion ) and T1 (six months after screw stabilization). Maxillary and mandibular cross-sectional areas were assessed at first permanent molars and first premolars regions and compared at T0 and T1. Mandibular occlusal area was also analyzed. RESULTS: Maxillary cross-sectional areas increased in 56.18 mm2 and 44.32 mm2 for the posterior and anterior regions. These values were smaller for the mandible, representing augmentation of 40.32 mm2 and 39.91 mm2 for posterior and anterior sections. No differences were found when comparing both expanders. Mandibular occlusal area increased 43.99mm2 and mandibular incisors proclined. Increments of 1.74 mm and 1.7 mm occurred in mandibular intermolar and interpremolar distances. These same distances presented increments of 5.5 mm and 5.57 mm for the maxillary arch. CONCLUSION: Occlusal and cross-sectional areas increased significantly after RME. The method described seems to be reliable and precise to assess intraoral area changes.

Assessment of tumor heterogeneity by CT texture analysis: can the largest cross-sectional area be used as an alternative to whole tumor analysis?

OBJECTIVE: To determine if there is a difference between contrast enhanced CT texture features from the largest cross-sectional area versus the whole tumor, and its effect on clinical outcome prediction. METHODS: Entropy (E) and uniformity (U) were derived for different filter values (1.0-2.5: fine to coarse textures) for the largest primary tumor cross-sectional area and the whole tumor of the staging contrast enhanced CT in 55 patients with primary colorectal cancer. Parameters were compared using non-parametric Wilcoxon test. Kaplan-Meier analysis was performed to determine the relationship between CT texture and 5-year overall survival. RESULTS: E was higher and U lower for the whole tumor indicating greater heterogeneity at all filter levels (1.0-2.5): median (range) for E and U for whole tumor versus largest cross-sectional area of 7.89 (7.43-8.31) versus 7.62 (6.94-8.08) and 0.005 (0.004-0.01) versus 0.006 (0.005-0.01) for filter 1.0; 7.88 (7.22-8.48) versus 7.54 (6.86-8.1) and 0.005 (0.003-0.01) versus 0.007 (0.004-0.01) for filter 1.5; 7.88 (7.17-8.54) versus 7.48 (5.84-8.25) and 0.005 (0.003-0.01) versus 0.007 (0.004-0.02) for filter 2.0; and 7.83 (7.03-8.57) versus 7.42 (5.19-8.26) and 0.005 (0.003-0.01) versus 0.006 (0.004-0.03) for filter 2.5 respectively (p ≤ 0.001). Kaplan-Meier analysis demonstrated better separation of E and U for whole tumor analysis for 5-year overall survival. CONCLUSION: Whole tumor analysis appears more representative of tumor heterogeneity.

Contribution of thin slice (1 mm) oblique coronal proton density-weighted MR images for assessment of anteromedial and posterolateral bundle damage in anterior cruciate ligament injuries.

PURPOSE: To evaluate the diagnostic efficacy of using additional oblique coronal 1 mm proton density-weighted (PDW) MR imaging of the knee for detection and grading anterior cruciate ligament (ACL), anteromedial bundle (AMB) and posterolateral bundle (PLB) injuries. MATERIALS AND METHODS: We prospectively assessed preoperative MR images of 50 patients (36 men, 14 women; age range, 18-62 years). First, we compared the diagnostic performance of routine sagittal (3 mm) and additional oblique coronal images (1 mm) for ACL tears. Then, we compared the tear types (AMB or PLB) and grade presumed from oblique coronal MR imaging with arthroscopy. RESULTS: Arthroscopy revealed ACL tear in 24 (48%) patients. There was significant difference between sagittal images and arthroscopy results for ACL tear recognition (p<0.001). No significant difference was detected for oblique coronal images when compared with arthroscopy results (p=0.180). Sensitivity and specificity values for ACL tear diagnosis were 37.04% and 95.65% for sagittal images; 74.07% and 91.30% for oblique coronal images. There was no significant difference between arthroscopy and oblique coronal MR images in grading AMB and PLB injuries (p>0.05). CONCLUSION: Addition of thin slice oblique coronal images to conventional sequences could better contribute to better verifying the presence of ACL tear and in determining its grade.

Subjective image quality assessment of cross sectional imaging methods for the symphyseal region of the mandible prior to dental implant placement.

OBJECTIVES: A three dimensional appreciation of the form of the anterior mandible is required to place dental implants safely in the region. This study compared the subjective image quality of four available methods of cross sectional imaging of the symphyseal region, the lateral cephalometric view, cone beam computed tomography (CBCT), spiral tomography and the transymphyseal X-ray view. METHODS: An experimental water phantom was developed to reproduce human soft tissue around the mandible. Images were taken of four mandibles by the four X-ray techniques. Three different CBCT machines were included. The source of each image was disguised by displaying all images in the same format on the same computer screen. A protocol was developed to process the images for viewing whilst preserving their image quality. A panel of observers of ten dentists viewed the images and rated their image quality by recording their agreement with six statements on a five point Likert scale. RESULTS: The results showed a statistically significant difference in image quality between imaging methods. There were clear differences in the ratings between the three cone beam computed tomography machines. Small volume, high resolution CBCT provided images with the highest scores for subjective image quality. CONCLUSIONS: Within the limitations of this study, significant differences in subjective image quality were found between imaging systems used for cross sectional imaging for the symphyseal region of the mandible prior to dental implant placement.

Reliability of computed tomography measurements in assessment of thigh muscle cross-sectional area and attenuation.

BACKGROUND: Advancement in technology of computer tomography (CT) and introduction of new medical imaging softwares enables easy and rapid assessment of muscle cross-sectional area (CSA) and attenuation. Before using these techniques in clinical studies there is a need for evaluation of the reliability of the measurements. The purpose of the study was to evaluate the inter- and intra-observer reliability of ImageJ in measuring thigh muscles CSA and attenuation in patients with anterior cruciate ligament (ACL) injury by computer tomography. METHODS: 31 patients from an ongoing study of rehabilitation and muscle atrophy after ACL reconstruction were included in the study. Axial CT images with slice thickness of 10 mm at the level of 150 mm above the knee joint were analyzed by two investigators independently at two times with a minimum of 3 weeks between the two readings using NIH ImageJ. CSA and the mean attenuation of individual thigh muscles were analyzed for both legs. RESULTS: Mean CSA and mean attenuation values were in good agreement both when comparing the two observers and the two replicates. The inter- and intraclass correlation (ICC) was generally very high with values from 0.98 to 1.00 for all comparisons except for the area of semimembranosus. All the ICC values were significant (p < 0,001). Pearson correlation coefficients were also generally very high with values from 0.98 to 1.00 for all comparisons except for the area of semimembranosus (0.95 for intraobserver and 0.92 for interobserver). CONCLUSION: This study has presented ImageJ as a method to monitor and evaluate CSA and attenuation of different muscles in the thigh using CT-imaging. The method shows an overall excellent reliability with respect to both observer and replicate.

Direct measurement of left ventricular outflow tract area using three-dimensional echocardiography in biplane mode improves accuracy of stroke volume assessment.

AIMS: The aim of the study was to investigate whether left ventricular stroke volume (LVSV) assessment using direct measurement of left ventricular outflow tract area (LVOT(A)) is superior to conventional methods for SV calculation. METHODS AND RESULTS: Thirty patients were included in the study (39 ± 12 years). LVSV was assessed by multiplying LVOT velocity time integral (VTI) by LVOT(A) provided by direct planimetrical measurements from real time three-dimensional echocardiography (RT3DE) in biplane mode (SV2). These measurements were compared to conventional methods using either the LVOT diameter for LVOT(A) multiplied with VTI (SV1) or biplane Simpson (SV3). Direct SV measurements by RT3DE were used as gold standard (SV(ref)). There was an excellent correlation and agreement between SV determined by SV2 and 3DE (r = 0.98, mean difference 0.5 ± 3.3 mL). However, the concordance of the traditional methods (SV1 and SV3) with 3DE was weaker (r = 0.38, mean difference -2.0 ± 17.6 mL, r = 0.84, mean difference -7.6 ± 8.7 mL, respectively). Furthermore, cardiac output (CO) measurements performed by the different modalities were not concordant with wide limits of agreement, except by SV2 the mean difference of CO by SV1 was -0.12 ± 1.05 L/min, 0.03 ± 0.20 L/min by SV2, and -0.45 ± 0.52 L/min by SV3. CONCLUSIONS: SV and CO calculations using direct measurement of LVOT area is a feasible, accurate and reproducible method and correlates extremely well with 3DE volume measurements. SV and CO calculation by LVOT(A) is therefore an appealing method for LVSV assessment in clinical routine.

Magnetic resonance imaging (MRI) for assessment of differences in geometrical parameters in muscles stabilizing vertebral column in young and older persons. Case study.

Today non-traumatic low back pain (LBP) is a social disease being attributed to weakening the function of abdominal and back muscles. Condition of deep muscles, inaccessible to non-invasive examinations, can be assessed by means of magnetic resonance imaging (MRI). The method allows for the assessment of cross-sections, muscle girths, as well as their intensity (brightness). The aim of the investigations was to determine the opportunities to employ MRI technique for assessing the geometry of muscles which stabilize spinal column. The study covered 4 women without LBP symptoms. The cross-sectional area, thickness and brightness of abdominal and back muscles were measured at the level of L3-L4. Measurement of geometrical parameters in the positions studied was aimed at setting such measurement conditions that would force higher isometric contraction in the muscles examined. As a result of measurements it can be inferred that other conditions of the experiment affect neither an increase in cross-sectional surface area nor the thickness of the muscles examined. The differences observed in geometrical parameters of the muscles testify to different coordination of muscle activation in the positions studied, both in young and older subjects, and to the purposefulness of continuing this type of measurements.

Assessment of the vessel lumen diameter and degree of stenosis in the superficial femoral artery before intervention: comparison of different algorithms.

PURPOSE: To determine which angiography-based algorithm delivers the most precise results in comparison with direct measurements at intravascular ultrasonography (US) and evaluate their influence on the resulting balloon size for treatment. MATERIALS AND METHODS: Thirty patients with untreated superficial femoral artery stenosis underwent digital subtraction angiography (DSA) and intravascular US before intervention. Two experienced radiologists measured twice the native vessel lumen diameter and the degree of stenosis with all algorithms and modalities in a predefined vessel segment that was perceived to be unaffected. On the basis of the measurements of the vessel lumen diameter, a suitable balloon size for treatment of the lesion was calculated. RESULTS: The mean vessel diameter was 5.7 mm for intravascular US, 6.6 mm for caliper calibration, 6.0 mm for calibration of the catheter tip, and 4.7 mm for visual estimation. Selected balloon sizes were 6.0 mm, 7.0 mm, 6.0 mm, and 5.0 mm, respectively. The mean percentage of stenosis was 78.8% for intravascular US, 81.6% for caliper calibration, 79.7% for catheter calibration, and 88.8% for visual estimation. Intermethod correlation was best for intravascular US and calibration of a catheter tip (0.881, P < .0001). CONCLUSIONS: Measurements on DSA equipment calibrated to a catheter tip correlate best with direct intravascular measurements. Visual estimation can lead to underestimation of the true vessel size and overestimation of stenosis.

Multiprobe laser reflectometry in imaging and characterization of biological tissues.

Laser backscattered radiation from human forearm and foot were measured by multi-probe reflectometer, which consisted of one input probe and three output probes placed at distances of 2, 4 and 6 mm from the input probe. The normalized backscattered intensity (NBI) signals from the tissue surface, measured by the output probes, after digitization, were used to reconstruct the reflectance images of tissues in various layers below the skin surface. From NBI profiles measured at various locations of the tissues on the forearm the corresponding optical parameters, the scattering (mu(s)) and absorption (mu(a)) coefficients and the anisotropy parameter g, by matching these with profiles as simulated by Monte Carlo procedure were determined. From these data the optical parametric images of forearm were reconstructed which show the variation of these parameters at various locations. Similarly, the NBI data were collected from the foot sole region of healthy and diabetes subjects and their images reconstructed. These images showed the variation in the NBI in the diabetic foot sole compared to that of healthy subject, indicating the tissue structural changes. These procedures could be useful for diagnostic and therapeutic applications of lasers.

Estimating whole body intermuscular adipose tissue from single cross-sectional magnetic resonance images.

Intermuscular adipose tissue (IMAT), a novel fat depot linked with metabolic abnormalities, has been measured by whole body MRI. The cross-sectional slice location with the strongest relation to total body IMAT volume has not been established. The aim was to determine the predictive value of each slice location and which slice locations provide the best estimates of whole body IMAT. MRI quantified total adipose tissue of which IMAT, defined as adipose tissue visible within the boundary of the muscle fascia, is a subcomponent. Single-slice IMAT areas were calculated for the calf, thigh, buttock, waist, shoulders, upper arm, and forearm locations in a sample of healthy adult women, African-American [n = 39; body mass index (BMI) 28.5 +/- 5.4 kg/m2; 41.8 +/- 14.8 yr], Asian (n = 21; BMI 21.6 +/- 3.2 kg/m2; 40.9 +/- 16.3 yr), and Caucasian (n = 43; BMI 25.6 +/- 5.3 kg/m2; 43.2 +/- 15.3 yr), and Caucasian men (n = 39; BMI 27.1 +/- 3.8 kg/m2; 45.2 +/- 14.6 yr) and used to estimate total IMAT groups using multiple-regression equations. Midthigh was the best, or near best, single predictor in all groups with adjusted R2 ranging from 0.49 to 0.84. Adding a second and third slice further increased R2 and reduced the error of the estimate. Menopausal status and degree of obesity did not affect the location of the best single slice. The contributions of other slice locations varied by sex and race, but additional slices improved predictions. For group studies, it may be more cost-effective to estimate IMAT based on one or more slices than to acquire and segment for each subject the numerous images necessary to quantify whole body IMAT.

Comprehensive examination of sentinel lymph node in breast cancer: a solution without a problem?

Although several methods have been devised to examine sentinel lymph node (SLN) specimens in breast cancer, the extent of examination and whether it should routinely include multilevel sectioning to detect micrometastases (MM) (<2.0 mm) is still debated. In this study all "positive'' SLN biopsies from 67 consecutive patients with breast carcinoma and evaluated by means of an extended protocol were reviewed. Abnormal findings included micrometastases (MM) between 0.2 and 1.0 mm (14 cases), (MM) between 1.0 and 2.0 mm (8 cases), metastases>2.0 mm (22 cases), and isolated tumor cells (ITCs) (23 cases). The likelihood of finding metastatic deposits was comparable if sections were carried out at 100-, 150-, 200-, 250-, and 500-microm intervals. No metastatic foci>2.0 mm would have been missed. 1 MM (1.1 mm focus) was missed within the 250- and 500-microm levels on hematoxylin-eosin, but not complementary cytokeratin staining. Our data show that SLN step sectioning does not add significant yield if compared to standard examination carried on initial levels, if the minimal target of 1.0 mm micrometastatic deposit is sought.

Automated software supported versus manual aorto-iliac diameter measurements in CT angiography of patients with abdominal aortic aneurysms: assessment of inter- and intraobserver variation.

BACKGROUND: Open surgical or endovascular abdominal aortic aneurysm (AAA) relies on precise preprocedual imaging. Purpose of this study was to assess inter- and intraobserver variation of software-supported automated and manual multi row detector CT angiography (MDCTA) in aortoiliac diameter measurements before AAA repair. PATIENTS AND METHODS: Thirty original MDCTA data sets (4 x 2mm collimation) of patients scheduled for endovascular AAA repair were studied on a dedicated software capable of creating two-dimensional reformatted planes orthogonal to the aortoiliac center-line. Measurements were performed twice with afour-week interval between readings. Data were analysed by two blinded readers at random order Two different measurement methods were performed: reader-assisted freehand wall-to-wall measurement and semi-automatic measurement. RESULTS: Aortoiliac diameters were significantly underestimated by the semi-automatic method as compared to reader-assisted measurements (p < 0.0031). Intraobserver variability of AAA diameter calculation was not significant (p > 0. 15) for reader-assisted measurements except for the diameter of the left common iliac artery in reader 2 (p = 0.0045) and it was not significant (p > 0. 14) using the semi-automatic method. Interobserver variability was not significant for AAA diameter measurements using the reader-assisted method and for proximal neck analysis with the semiautomatic method (p > 0.27). Relevant interobserver variation was observed for semi-automatic measurement of maximum AAA (p = 0.0007) and iliac artery diameters (p = 0.024). CONCLUSIONS: Dedicated MDCTA software provides a useful tool to minimize aortoiliac diameter measurement variation and to improve imaging precision before AAA repair. For reliable AAA diameter analysis the reader-assisted freehand measurement method is recommended to be applied to a set of reformatted CT data as provided by the software used in this study.

Detection rate and efficiency of lymph node assessment with axial and coronal image reading based on 16 row multislice CT of the neck.

PURPOSE: Multislice CT (MSCT) has the advantage of isotropic volumetric data acquisition which allows high resolution data reconstruction in the axial and coronal plane. We evaluate the accuracy and efficiency of coronal reconstruction compared to axial reconstructions of a routinely performed CT scan exemplary in neck lymph node assessment performed on a 16 row MSCT. MATERIAL AND METHODS: Contrast enhanced neck MSCT of 24 patients with known lymphoma were evaluated prospectively for lymph node assessment. 4 blinded readers evaluated the axial and coronal reconstructions of the same patient. Neck lymph nodes larger than 10 mm were evaluated by their anatomical region (deep jugular chain, submandibular, nuchal). Time for axial and coronal image evaluation was assessed. Detection rate was compared with consensus reading as gold standard. RESULTS: In consensus reading 169 enlarged lymph nodes in the deep jugular chain were found. Detection rate for axial image interpretation was 36.1 % with 54.9 % in coronal reading. Assessing the submandibular lymph nodes (n = 45) axial interpretation revealed 53.9 % with 36.1 % in coronal reading. Evaluation time for axial reading was in all but one reader significantly longer (mean 176 seconds) than in coronal reading (mean 129 seconds). CONCLUSION: Coronal image reading improves the detection rate of cranio-caudal oriented structures. Considering representatively neck lymph nodes in the deep jugular chain the image interpretation time is significantly reduced. Still axial reading remains necessary for assessing axially oriented structures such as the submandibular region in the neck.

Cross-sectional imaging combined with 3D-MR angiography (3D-MRA): diagnostic tool for preoperative vascular assessment of head and neck tumors.

BACKGROUND: Head and neck cancer accounts for 5% of all malignancies worldwide. The presence of lymph node metastases and vascular infiltration influence patient outcome. This prospective study describes the preoperative morphologic assessment of the vascular status of patients with head and neck tumors by means of high spatial resolution and extended coverage of the arterial and venous system reaching from the supra-aortic region to the skull base. PATIENTS AND METHODS: Cross-sectional imaging combined with contrast-enhanced 3D-maximum intensity projection MR angiography (3D-MRA) was applied using a dedicated head and neck coil with a 4-channel panorama array system interface to assess vascular involvement in patients with suspected head and neck cancer. 32 patients underwent preoperative assessment by magnetic resonance imaging (MRI). The results were then correlated with surgical and histological findings. RESULTS: 3 of the 32 patients (9%) demonstrated involvement of the arterial system. In 2 of these 3 cases, MRA correctly predicted the arterial status, while in 1 case it gave a false negative result. 11 of the 32 patients (34%) presented with involvement of the venous system. 10 cases showed complete concordance between the findings of the MR venography and the intraoperative status, while in 1 case a false negative result was produced. CONCLUSION: In patients with suspected head and neck tumors, 3D-MRA in combination with cross sectional imaging is a valuable diagnostic tool for the detection of vascular involvement.

Simultaneous assessment of gastric accommodation and emptying: studies with liquid and solid meals.

UNLABELLED: The aim of this study was to develop a scintigraphic test to measure gastric emptying and accommodation simultaneously. METHODS: Gastric emptying and accommodation were measured in healthy subjects. To determine gastric accommodation, the stomach was imaged with SPECT 20 min after intravenous administration of 185 MBq (5 mCi) (99m)Tc-pertechnetate. After ingestion of 11 MBq (300 micro Ci) (111)In-diethylenetriaminepentaacertic acid in a liquid nutrient drink or an (111)In-oxine-labeled egg sandwich, dual-isotope imaging assessed SPECT gastric dimensions and gastric emptying every 20 min up to 240 min. Gastric accommodation was calculated as the percentage change in planar (2-dimensional) gastric cross-sectional area (CSA) using a left anterior oblique planar projection and the percentage change in total SPECT gastric voxel counts (3-dimensional) compared with the baseline image. RESULTS: With the liquid nutrient drink (9 subjects), maximal mean CSA (158% +/- 12% of baseline; P < 0.05) occurred 40 min after meal ingestion, when only 69% +/- 3% of the radiolabeled liquid nutrient drink remained in the stomach. At 120 min, mean CSA was 125% +/- 8% of baseline, but only 35% +/- 3% of the liquid nutrient drink remained in the stomach. Using SPECT to measure 3-dimensional volumes, maximal gastric volume occurred 20 min after meal ingestion (189% +/- 25% of baseline). With the solid egg meal (10 subjects), maximal total CSA (159% +/- 13% of baseline) occurred immediately after meal ingestion; total CSA remained significantly increased above baseline for the first 3 h after ingestion of the egg meal, despite only 12% +/- 4% gastric retention at 3 h. Using SPECT to measure 3-dimensional volumes, maximal gastric volume occurred immediately after the meal (184% +/- 19% of baseline). CONCLUSION: This method permits simultaneous measurement of gastric emptying and accommodation. In healthy subjects, the gastric accommodation response is prolonged and persists despite nearly complete emptying of a liquid or solid meal.