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A 64-year-old man was referred to our department after a small pancreatic cystic lesion was discovered on computed tomography performed to assess choledocholithiasis. Multiple standard imaging modalities, including endoscopic ultrasound (EUS), failed to reveal pancreatic masses, wall thickening, or mural nodules. Consequently, a benign pancreatic cystic lesion was suspected, and the patient underwent biannual imaging studies including rotating magnetic resonance imaging and EUS. Six years after the initial detection of the pancreatic cyst, wall thickening was observed, leading to a shortened observation period of once every 3 months. After 6.5 years, hypoechoic area surrounding the cyst, which could be interpreted as thickening of the cyst wall was observed, prompting distal pancreatectomy due to the suspicion of malignant disease. The histopathological examination revealed a unilocular mucinous cyst with a single layer of cuboidal cells and low-grade dysplasia. A fibrous proliferation of the polycystic stroma and no ovarian-type stroma was observed. Malignant cells were absent from the cystic epithelium and stroma. The final histopathological diagnosis was a simple mucinous cyst of the pancreatic tail. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study was to assess the incremental value of myocardial wall motion and thickening compared with perfusion alone obtained from gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) in diagnosing myocardial viability in patients with ischemic heart failure. Methods: Eighty-three consecutive patients with ischemic heart failure who underwent both 99mTc-MIBI gated SPECT MPI and 18F-FDG positron emission tomography (PET) myocardial metabolic imaging were retrospectively enrolled. SPECT/PET myocardial viability was defined as the reference standard. Segmental myocardial perfusion, wall motion, and thickening were measured by an automated algorithm from gated SPECT MPI. Univariate and stepwise multivariate analysis were conducted to establish an optimal multivariate model for predicting hibernating myocardium and scar. Results: Among the 1411 segments evaluated, 774 segments had normal perfusion and 637 segments had decreased perfusion. The latter were classified by 18F-FDG PET into 338 hibernating segments and 299 scarred segments. The multivariate regression analysis showed that the model that combined myocardial perfusion uptake with wall motion and thickening scores had the optimal predictive efficiency to distinguish hibernating myocardium from scar in the segments with decreased perfusion. The model had the largest C-statistic (0.753 vs 0.666, P < 0.0001), and the global chi-square was increased from 53.281 to 111.234 when compared with perfusion alone (P < 0.001). Conclusions: Assessment of myocardial wall motion and thickening in addition to conventional perfusion uptake in the segments with decreased perfusion enables better differentiation of hibernating myocardium from scar in patients with ischemic heart failure. Considering wide availability and high cost-effectiveness, regional myocardial function integrated with perfusion on gated SPECT MPI has great promise to become a clinical tool in the assessment of myocardial viability. [ABSTRACT FROM AUTHOR]

Background: A low appropriate therapy rate indicates that a minority of patients will benefit from their implantable cardioverter defibrillator (ICD). Quantitative measurements from 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) may predict ventricular arrhythmia (VA) occurrence after ICD placement.Methods: We performed a prospective observational study and recruited patients who required ICD placement. Pre-procedure image scans were performed. Patients were followed up for VA occurrence. Associations between image results and VA were analyzed.Results: In 51 patients (33 males, 53.9 ± 17.2 years) analyzed, 17 (33.3%) developed VA. Compared with patients without VA, patients with VA had significantly larger values in scar area (17.7 ± 12.4% vs. 7.0 ± 7.9%), phase standard deviation (51.4° ± 14.0° vs. 34.0° ± 15.0°), bandwidth (172.9° ± 39.8° vs. 128.7° ± 49.9°), sum thickening score (STS, 29.5 ± 11.1 vs. 17.8 ± 13.2), and sum motion score (42.9 ± 11.5 vs. 33.0 ± 19.0). Cox regression analysis and receiver operating characteristic curve analysis showed that scar size, dyssynchrony, and STS were associated with VA occurrence (HR, 4.956, 95% CI 1.70-14.46).Conclusion: Larger left ventricular scar burden, increased dyssynchrony, and higher STS quantified by 18F-FDG PET may indicate a higher VA incidence after ICD placement. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether the assessment of regional wall thickening (WT) in addition to myocardial perfusion from stress supine acquisitions could compensate for the lack of prone acquisition and the corresponding decrease in the diagnostic performance of SPECT myocardial perfusion imaging (MPI) in patients with known or suspected coronary artery disease (CAD). Methods: The study group comprised 41 patients (123 vessels) with known or suspected CAD prospectively recruited for systematic prone and supine 201Tl stress SPECT MPI. The diagnostic performance of SPECT MPI was determined for various image sets including nongated supine images (supine NG), nongated combined prone and supine images (prone and supine NG) and gated supine images, allowing WT evaluation from NG images in addition to perfusion (supine NG + WT) using invasive coronary angiography and fractional flow reserve as the gold standards. Results: The rate of false positives was significantly higher among the supine NG images (20.8%) than among either the prone and supine NG or the supine NG + WT images (3.3% and 2.7%, respectively, P < 0.05 vs. supine NG). Consequently, specificity was higher for the prone and supine NG images than for the supine NG images (96.1% vs. 76.1%, P < 0.01) and was highest for the supine NG + WT images (96.8%, P not significant vs. prone and supine NG), without significant differences in sensitivity (80.0%, 86.6% and 73.3%, respectively, P not significant for all comparisons). Conclusion: The diagnostic performance of supine stress SPECT MPI is improved when WT assessment of ischaemic segments is used as an additional diagnostic criterion to values not significantly different from those with combined prone and supine acquisitions. [ABSTRACT FROM AUTHOR]

Purpose: The present study aimed to assess CT and MR imaging findings of infection-free and benign second branchial cleft cysts (SBCCs).Methods: Eleven patients with histopathologically confirmed infection-free and benign SBCCs underwent preoperative contrast-enhanced CT (CECT) and/or MR imaging. We assessed qualitative (presence and extent of wall thickening, degree of contrast enhancement of the thickened wall on CECT images, and signal intensity of the thickened wall on T2-weighted images) and quantitative (maximum thickness of the thickened wall) imaging findings.Results: Eccentric and smooth wall thickening was observed in 11/11 (100%) patients. The wall thickening extent (percentage of the thickened wall to the circumference of the wall) was small (1%-25%) in 4/11 (36%), moderate (26%-50%) in 6/11 (54%), extensive (51%-75%) in 1/11 (9%), and diffuse (76%-100%) in 0/11 (0%) patients. Mild homogeneous enhancement of the thickened wall on CECT images was observed in 7/7 (100%) patients. The signal intensity of the thickened wall on T2-weighted images was isointense relative to that of normal lymph nodes in 7/8 (88%) and mildly hyperintense in 1/8 (12%) patient. The maximum thickness of the thickened walls ranged from 2 to 4 (mean 3.4) mm.Conclusions: Infection-free and benign SBCCs are identifiable as cysts with eccentric and smooth wall thickening on CECT and MR images. The wall thickness was almost always less than half of the wall circumference, isointense relative to normal lymph nodes, and showed mild homogeneous enhancement. [ABSTRACT FROM AUTHOR]

Our aim was to investigate wall thickening (WT) pattern of atherosclerotic basilar artery stenosis with three-dimensional volumetric isotropic turbo spin echo acquisition (3D VISTA), and the relationship with clinical characteristics. Twenty consecutive patients with atherosclerotic basilar artery stenosis were prospectively enrolled. All cross-sectional slices on VISTA images of basilar arteries were assessed, and classified as eccentric or concentric WT. Clinical characteristics and degree of stenosis were compared between the patients with different wall WT pattern. Wall abnormalities were identified in 568 cross-sectional slices in basilar arteries of 20 patients including eccentric WT in 497 (87.5 %) slices, and concentric WT in 71 (12.5 %) slices. In 11 of 20 patients, all the cross-sectional slices (293 slices) showed eccentric WT. In 9 of 20 patients, the cross-sectional slices (275 slices) showed both eccentric WT (204 slices, 74.2 %) and concentric WT (71 slices, 25.8 %). No lesion showed only concentric WT. At the slices of maximum luminal narrowing sites, only one patient showed concentric WT. Symptomatic stenosis was more common in the patients with mixed WT (eccentric and concentric), compared to patients with only eccentric WT (100 vs 54.5 %, p = 0.038). Atherosclerotic basilar artery stenosis could show both eccentric and concentric WT based on each slice analysis. Concentric WT was found in near half of the patients, but tended to locate in minimal slices. No lesion was entirely concentric. Lesions with mixed WT (concentric and eccentric) might represent advanced atherosclerosis with high risk of ischemic event. [ABSTRACT FROM AUTHOR]

Background: We evaluated gated-SPECT using a Cadmium-Zinc-Telluride (CZT) camera for assessing global and regional left ventricular (LV) function. Methods: A phantom study evaluated the accuracy of wall thickening assessment using systolic count increase on both Anger and CZT (Discovery 530NMc) cameras. The refillable phantom simulated variable myocardial wall thicknesses. The apparent count increase (%CI) was compared to the thickness increase (%Th). CZT gated-SPECT was compared to cardiac magnetic resonance (CMR) in 27 patients. Global and regional LV function (wall thickening and motion) were quantified and compared between SPECT and CMR data. Results: In the phantom study using a 5-mm object, the regression between %CI and %Th was significantly closer to the line of identity ( y = x) with the CZT ( R = 0.9955) than the Anger ( R = 0.9995, P = .03). There was a weaker correlation for larger objects ( P = .003). In patients, there was a high concordance between CZT and CMR for ESV, EDV, and LVEF (all CCC >0.80, P < .001). CZT underestimated %CI and wall motion (WM) compared to CMR ( P < .001). The agreement to CMR was better for WM than wall thickening. Conclusion: The Discovery 530NMc provided accurate measurements of global LV function but underestimated regional wall thickening, especially in patients with increased wall thickness. [ABSTRACT FROM AUTHOR]

Mesenteric inflammatory veno-occlusive disease (MIVOD) is a rare cause of inflammatory enterocolitis whose clinical and imaging presentation can be confused with mesenteric venous thrombosis and inflammatory bowel disease. We report two cases of histologically proven MIVOD in patients presenting with abdominal pain and describe potentially useful distinguishing features at contrast-enhanced CT, including prominent small pericolonic arteries and veins but a diminutive or absent inferior mesenteric vein. Alerting referring clinicians to the possibility of this diagnosis may help avoid unnecessary anticoagulation and reduce diagnostic delay. Treatment of MIVOD is surgical resection, which is typically curative. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to assess the correlation between global wall thickening (GWT) obtained by gated-single photon emission computed tomography (SPECT) and echocardiographic measures [ejection fraction (EF), global longitudinal strain (GLS), and strain rate (GLSR)] and to compare their prognostic value for all-cause mortality. Methods and Results: Seventy-four patients with referral for dipyridamole myocardial perfusion SPECT were prospectively included and underwent transthoracic echocardiography to measure left ventricular EF, GLS, and GLSR. The strongest correlation with GWT was for EF ( R = 0.63, P < .001), followed by GLSR ( R = −0.57, P < .001) and GLS ( R = −0.53, P < .001). There were ten deaths over a period of 14.6 ± 5.7 months. Using the multivariate Cox analysis, summed stress score (HR 1.108; P = .023), EF (HR 1.01, P = .031), GLS (HR 1.593, P = .001), and GWT (HR 0.898, P = .034) remained independent predictors of mortality. Mean survival rate evaluated by Kaplan-Meier analysis was longer in patients with GWT ≥ 24% (21.9 ± 0.6 months) than those with GWT < 24% (13.6 ± 2.7 months; P < .001). Conclusions: GWT assessed is a highly sensitive tool to detect early myocardial systolic dysfunction and may bring additional prognostic information. [ABSTRACT FROM AUTHOR]

Process parameters, such as clearance, friction, boosting displacement, bending velocity, and centerline radius/tube diameter ratio, have a significant and complicated influence on wrinkling of circular tubes during rotary draw bending process. To explore the effects of these parameters on the wrinkling, a 3D elastic–plastic finite element (FE) model based on eta/DYNAFORM has been built and validated by experiments. Then, relevant simulation and analysis of the process have been performed. The results show that: (1) the wrinkling increases with the accretion of the clearance. A reasonable clearance of mold groove (less than 0.2 mm) can alleviate the severity of the wrinkling; (2) when the boosting velocity of the pressure die is larger than or equal to the linear velocity of the bend die in the X-axis direction, the wrinkling relieves as the friction between the pressure die and the tube decreases; conversely, when the boosting velocity is smaller than the linear velocity, the wrinkling reduces with the increase of the friction between the two contacted components; (3) the wrinkling is negatively correlated with the centerline radius/tube diameter ratio and positively correlated with the bending velocity of the bend die; and (4) the boosting displacement of the pressure die dominates the direction of frictional force exerted by the pressure die in the bending process. The wrinkling tendency becomes more obvious as the displacement increases. [ABSTRACT FROM AUTHOR]

Small bowel wall thickening detected on computed tomography is a frequent finding in patients referring to emergency room with acute abdominal pain. In this pictorial review, we aim to discuss patterns of small bowel wall thickening and to explain hints for differential diagnosis with imaging findings. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the role of multidetector computed tomography (MDCT) in detecting and classifying the large bowel lesions. A prospective study of 100 adult patients was conducted from June 2007 to October 2009. Rectal and IV contrast were used for three dimensional reconstruction. Angiography was performed in cases of suspected ischemic pathology. CT colongraphy was done to evaluate adenomas. CT findings were correlated and confirmed by either colonoscopy, biopsy, postoperative findings or follow-up CT. The pathologies were common in 50-70 yrs (44%). M: F ratio was 2:1. Malignant lesions were seen in (55%) followed by inflammatory lesions in 26%, diverticulitis and ischemic colitis in 6% each. Miscellaneous conditions like polyps, volvulus and intussusceptions were seen in 7%. Adenocarcinoma was the common malignancy (81.2%). Present study showed that adenocarcinomas were associated with marked thickening of bowel wall (>1.5 cm) in 85.4% of patients, asymmetrical wall thickening (96.4%), focal involvement (length <10 cm) in 85.5% with heterogeneous post contrast enhancement (96.3%). Inflammatory lesions showed mild thickening (69%),segmental or diffuse involvement (77%), symmetrical wall thickening (89%) and homogenous post contrast enhancement (81%). Ischemic lesions showed marked thickening (83.4%), symmetrical thickening (100%) and homogenous enhancement (100%). Diverticulitis showed marked thickening (100%), asymmetrical wall thickening (66.7%) with heterogeneous post contrast enhancement (100%), with pericolic fluid. Arterial/venous thrombosis was diagnosed in 66.66%. Three per cent had benign adenomatous polyps on CT colonographic studies. MDCT was accurate in 98.2% cases for differentiating between benign and malignant etiology and is the modality of choice. [ABSTRACT FROM AUTHOR]

Left ventricular myofibers are connected by an extensive extracellular collagen matrix to form myolaminar sheets. Histological cardiac tissue studies have previously observed a pleated transmural distribution of sheets in the ovine heart, alternating sign of the sheet angle from epicardium to endocardium. The present study investigated temporal variations in myocardial fiber and sheet architecture during the cardiac cycle. End-diastolic histological measurements made at subepicardium, midwall, and subendocardium at an anterior-basal and a lateral-equatorial region of the ovine heart, combined with transmural myocardial Lagrangian strains, showed that the sheet angle but not the fiber angle varied temporally throughout the cardiac cycle. The magnitude of the sheet angle decreased during systole at all transmural depths at the anterior-basal site and at midwall and subendocardium depths at the lateral-equatorial site, making the sheets more parallel to the radial axis. These results support a previously suggested accordion-like wall-thickening mechanism of the myocardial sheets. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare semi-quantitative visual scores of perfusion, motion and thickening with an automated hypoperfusion index (HI) in patients with suspected acute inferolateral perfusion defects. In the absence of perfusion defects motion and thickening abnormalities were assessed. Sixty-eight patients with chest pain at rest and either ST depression ≥0.1 mV in ≥1 of leads I, aVL, V1-V6 on 12-lead ECG or ST elevation ≥0.05 mV in ≥1 posterior lead on the body surface map comprised the study population. A rest gated perfusion scan was performed within 24 h of symptoms. Scans were scored for perfusion, motion and thickening semi-quantitatively. The scores were compared to the automated HI. A 12 h Troponin T >0.09 ng/ml indicated myocardial infarction (MI). Sixty-five patients (96%, 65/68) had MI. The summed perfusion score correlated well with the HI (ρ = 0.90, P < 0.01) and agreement between scorers was good (κ = 0.77, 95% CI = 0.57-0.94). The summed motion score correlated with the HI (ρ = −0.61, P < 0.01) and agreement between scorers was moderate (κ = 0.65, 95% CI = 0.52-0.79). Summed thickening score correlated with HI (ρ = −0.67, P < 0.01) and agreement between scorers was good (κ = 0.74, 95% CI = 0.64-0.88). Of the 1156 segments assessed (68 × 17), 542 had normal perfusion. Of these normally perfused segments, 113 (21%, 113/542) had a motion abnormality and 102 (19%, 102/542) had a thickening abnormality. Three patients with proven myocardial infarction had normal myocardial perfusion (HI ≤ 5) but exhibited wall motion and thickening abnormalities. In conclusion, assessment of wall motion and thickening in addition to perfusion in acute myocardial perfusion imaging may improve the diagnostic sensitivity for acute MI. Of the scores addressing motion and thickening, interobserver agreement was better for the summed thickening score. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to compare global and regional left ventricular function in patients with coronary artery disease (CAD), obtained by use of Cedars-Sinai quantitative gated single photon emission computed tomography (QGS), for gated nitrogen 13 ammonia (NH3) positron emission tomography (PET) and technetium 99m sestamibi (MIBI) single photon emission computed tomography (SPECT). Methods and Results: Fifty-one patients with CAD underwent gated N-13 NH3 PET and gated MIBI SPECT. The end-diastolic volume, end-systolic volume, and ejection fraction were calculated by use of QGS. The quantitative regional wall motion (WM) and wall thickening (WT) scores for 20 segments in the myocardium were also measured by QGS. The end-diastolic volume, end-systolic volume, and ejection fraction measured by N-13 NH3 PET showed highly significant correlation with those measured by MIBI SPECT (r = 0.97, r = 0.97, and r = 0.84, respectively). The mean correlation of WM and WT on an individual patient basis between N-13 NH3 PET and MIBI SPECT was 0.81 and 0.84, respectively. The circumferential variation of WM and WT in 20 segments showed a similar pattern with N-13 NH3 PET and MIBI SPECT. Conclusion: Gated N-13 NH3 PET combined with QGS provides information on both global and regional left ventricular function comparable to that obtained by gated Tc-99m perfusion myocardial SPECT in CAD patients. [Copyright &y& Elsevier]

Objective: Because thickening of the gallbladder wall is observed not only in patients with gallbladder cancer but also in those with benign diseases such as chronic cholecystitis and gallbladder adenomyosis, it is difficult to distinguish between benign and malignant gallbladder wall thickening by conventional techniques of diagnostic imaging such as computed tomography (CT), magnetic resonance imaging (MRI), and abdominal ultrasonography (US). In the present study, we attempted to distinguish between benign and malignant gallbladder wall thickening by means of fluorine-18-fluorodeoxyglucose (FDG)-Positron emission tomography (PET).Methods: FDG-PET was performed in 12 patients with gallbladder wall thickening detected by CT or US, to determine whether it was benign or malignant. Emission scans were taken, beginning 45 minutes after intravenous administration of FDG, and SUV was calculated as an indicator of glucose metabolism.Results: Of the 12 patients, 4 showed positive uptake of FDG in the gallbladder wall. Of these 4 patients, 3 had gallbladder cancer. The remaining one, who had chronic cholecystitis, had false-positive findings. The other 8 patients had negative uptake of FDG in the gallbladder wall. Two of these 8 underwent surgical resection, which yielded a diagnosis of chronic cholecystitis. The other 6 patients exhibited no sign of gallbladder malignancy and have been followed without active treatment.Conclusions: FDG-PET appears able to distinguish between benign and malignant gallbladder wall thickening. [ABSTRACT FROM AUTHOR]

Background: Traditionally, cardiac fluorodeoxyglucose (FDG) uptake is combined with regional perfusion for optimal evaluation of viability. Gated FDG-positron emission tomography (PET) may be an alternative technique for detection of viability because it permits combined assessment of glucose metabolism uptake and wall thickening (WT). In this study the value of FDG uptake and WT (analyzed from a stand-alone gated FDG-PET study) for the prediction of recovery of regional and global left ventricular (LV) function in patients with coronary artery disease undergoing revascularization is studied.Methods and Results: Thirty-eight patients with chronic coronary artery disease and LV dysfunction were included. Patients underwent gated FDG-PET to assess viability. Magnetic resonance imaging was performed before and 6 months after revascularization to assess regional and global LV function and LV volumes. Of the 213 revascularized dysfunctional segments, 133 (62%) exhibited functional recovery on follow-up magnetic resonance imaging. Receiver operating characteristic curve analysis indicated that a cutoff level for FDG uptake of 50% or greater yielded a sensitivity and specificity of 93% and 85%, respectively, on gated FDG-PET for prediction of improvement in regional function. Similarly, a cutoff level of 10% or greater for WT was optimal with a sensitivity and specificity of 89% and 78%, respectively. Improvement in LV ejection fraction was best predicted by the number of viable segments. Reverse LV remodeling could be predicted with a sensitivity and specificity of 89% and 65%, respectively, by use of FDG uptake of 50% or greater and 78% and 70%, respectively, by use of WT of 10% or greater.Conclusion: Accurate prediction of outcome after revascularization (including improvement in regional and global LV function and reverse remodeling) is possible with gated FDG-PET by use of a threshold of 50% or greater for FDG uptake or a threshold of 10% or greater for WT. [ABSTRACT FROM AUTHOR]

The aim of this study was to correlate MR findings of gallbladder wall thickening with pathologic findings on the basis of the layered pattern and to evaluate the diagnostic value of MR imaging in gallbladder disease. We retrospectively evaluated the source images of HASTE sequences for MR cholangiography in 144 patients with gallbladder wall thickening. The layered pattern of thickened wall was classified into four patterns. Type 1 shows two layers with a thin hypointense inner layer and thick hyperintense outer layer. Type 2 has two layers of ill-defined margin. Type 3 shows multiple hyperintense cystic spaces in the wall. Type 4 shows diffuse nodular thickening without layering. MR findings of a layered pattern of thickened gallbladder were well correlated with histopathology. Chronic cholecystitis matched to type 1, acute cholecystitis corresponded to type 2, adenomyomatosis showed type 3, and the gallbladder carcinomas showed type 4. All four layered patterns were associated with PPV of 73% or greater, sensitivity of 92% or greater and specificity of 95% or greater. Our results indicate that MR findings of gallbladder wall thickening are characteristic in each entity and correlate well with pathologic findings. The classification of the layered pattern may be valuable for interpreting thickened gallbladder wall. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate whether wall thickening analysis by gated perfusion single-photon emission computed tomography (SPECT) is useful in predicting functional recovery after revascularization. Methods: Forty-one patients with previous myocardial infarction and left ventricular (LV) dysfunction (ejection fraction, EF, 36±6%) who were scheduled for revascularization underwent rest 99mTc-sestamibi gated SPECT. Results: Of 131 akinetic or dyskinetic segments at baseline echocardiography, 82 (63%) recovered after revascularization. Compared with wall thickening analysis, perfusion imaging provided higher sensitivity (78% vs 50%, P<0.0001) and specificity (80% vs 71%, P<0.0005). Among segments with ≥55% sestamibi uptake (viable), those with detectable wall thickening had a higher likelihood of functional recovery than those with absent wall thickening (95% vs 77%, P<0.05). In segments with improved function, the absence of wall thickening was associated with lower sestamibi activity than was observed when detectable wall thickening was present (58±14% vs 71±13%, P<0.0005). An increase in EF of ≥5% was detectable in 22 (54%) patients. For the prediction of EF improvement, perfusion imaging provided a higher sensitivity than wall thickening analysis (68% vs 41%, P<0.05), while specificity was not significantly different (68% vs 74%). The prevalence of patients with functional recovery did not change when wall thickening analysis was considered in addition to perfusion status (73% in patients with detectable wall thickening and 70% in those without; P=NS). Conclusion: In patients with coronary artery disease, wall thickening analysis by gated perfusion SPECT provides additional information compared with perfusion data for the prediction of segmental functional recovery. However, on a patient basis, wall thickening assessment seems to be of more limited value than perfusion status. [ABSTRACT FROM AUTHOR]

Background: Electrocardiography (ECG)-gated scintigraphy demonstrates promising results for the simultaneous assessment of myocardial glucose metabolism and contractile function. In this study a method was evaluated for absolute quantitation of left ventricular wall and cavity parameters with the use of fluorine 18 fluorodeoxyglucose (FDG) ECG-gated positron emission tomography (PET).Methods and Results: A previously developed 2-dimensional mathematical model was implemented for computer-automated identification of endocardial and pericardial borders. The accuracy and precision were tested in a heart phantom and in healthy subjects. Twelve healthy men aged 64 +/- 8 years were studied by use of cine magnetic resonance imaging (MRI) and ECG-gated FDG-PET during euglycemic glucose-insulin clamp. At increasing image noise levels, the estimated cavity volume of the heart phantom was within 2 mL of the actual volume, and no significant difference was found between actual and estimated wall thicknesses. Endocardial wall motion as assessed by ECG-gated PET in the healthy subjects was systematically underestimated compared with MRI. This underestimation correlated linearly with endocardial excursion during PET end diastole as measured by MRI. Myocardial end-diastolic wall thickness was systematically overestimated by PET, whereas end-systolic thickness deviated less than 1 mm from MRI. Cavity volumes measured by PET correlated linearly with MRI, with a tendency toward an underestimation of end-diastolic cavity volumes by PET.Conclusions: Absolute measures of cardiac structure and function may be obtained with a reasonable degree of accuracy by use of ECG-gated PET imaging. However, a high ECG-gating frequency appears to be required to obtain measurements comparable to what may be achieved by MRI. [ABSTRACT FROM AUTHOR]

Objectives: Septal wall motion abnormalities are frequently observed in patients with left bundle branch block (LBBB). However, septal wall thickening in LBBB patients has not been thoroughly evaluated.Methods and Results: To investigate the relationship between septal wall motion and wall thickening, we studied 31 normal control subjects, 24 LBBB patients with normal wall motion (LBBB-NWM), and 24 LBBB patients with septal dyssynchrony (LBBB-SDS), all with a low likelihood (<15%) of coronary artery disease. The septal and lateral quadrants of the left ventricle were analyzed in stress 8-frame gated technetium 99m sestamibi tomograms. The percent wall thickening was calculated by use of a 25-segment polar map with the p-FAST software program by two independent methods: the regional count density increase from end diastole to end systole (CD method) and the geometric increase in the distance between the 50% thresholded endocardial and epicardial borders from end diastole to end systole (GD method). In addition, the ratio of septal/lateral percent wall thickening was calculated. The relative septal wall thickening in the entire LBBB population was decreased as compared with the normal control subjects (0.35 +/- 0.37 vs 0.81 +/- 0.17, P <.001). Decreased wall thickening was observed in not only LBBB-SDS patients but also to a lesser degree in LBBB-NWM patients (0.12 +/- 0.35, P <.001; 0.57 +/- 0.24, P =.005, respectively). This abnormality was most apparent when the CD method was used.Conclusions: Septal wall thickening is decreased in patients with LBBB even with normal wall motion. LBBB per se may compromise septal wall thickening, and dyssynchronous wall motion results in further deterioration of wall thickening. [ABSTRACT FROM AUTHOR]

Object: This study was designed to assess the value of gated SPECT Tc-99m-tetrofosmin (TF) wall thickening (WT) in addition to TF exercise (Ex)/rest myocardial SPECT, in comparison with F-18 fluorodeoxyglucose (FDG)-PET.Methods: The study population consisted of 33 patients with old myocardial infarction (27 men and 6 women; mean age, 62 +/- 8 years old). All patients underwent Ex/rest TF SPECT and glucose loading FDG-PET. Polar map images of Ex/rest TF were generated and divided into 24 segments for further analysis. We classified LV segments according to the exercise-rest perfusion scintigraphy. LV segments with less than 70% of the maximum TF activity on the exercise image were defined as stress-induced defects. Among these, the segments whose TF activity increased by 10% from exercise to rest images or exceeded 70% of the maximum uptake were defined as reversible (viable) defects. The remaining defects on the rest image were irreversible (non-viable) defect segments, and were considered for viability study on the basis of %WT. %WT was calculated according to the standard method: [(counts ES - counts ED)/counts ED] x 100. A viable segment on gated SPECT was defined as a segment whose %WT exceeded the lower limit of the normal value (mean - SD). PET viability was defined as FDG uptake exceeding 50% of the maximum count.Results: Among the 792 segments evaluated in the 33 patients studied, there were 689 PET viable segments. Of the 689 segments analyzed, 198 (29%) were identified as having defects on Ex images. Among these defects, 55 (8%) were reversible or partially reversible, as evidenced by rest images, and 143 (21%) were irreversible. Of the irreversible segments on Ex/rest images, 106 (15%) demonstrated no apparent WT by gated TF SPECT, whereas 37 (6%) segments with irreversible defects did have apparent WT. Overall, the sensitivity of Ex/rest TF perfusion imaging was 79%. Sensitivity was improved from 79% to 85% by combining %WT and perfusion data, but specificity was reduced from 70% to 56%.Conclusion: %WT evaluated from gated TF imaging enhanced myocardial viability assessment in comparison with FDG-PET. [ABSTRACT FROM AUTHOR]

Background: We reported previously that mean quantified cardiac functional parameters computed by one gated single photon emission computed tomography (SPECT) technique were not significantly altered by common gating errors. However, it is not known to what extent other gated SPECT approaches that are based on different ventricular modeling assumptions are influenced by arrhythmias, nor are the effects of gating errors on visual analyses and their subsequent clinical implications known.Methods: Projection data for 50 patients (aged 64 +/- 12 years; 68% men; 76% with myocardial perfusion defects) undergoing technetium-99m sestamibi gated SPECT who were in sinus rhythm during data acquisition were altered to simulate common arrhythmias. To determine quantitative effects, we performed calculations for original control and altered images by Gaussian myocardial detection (Quantitative Gated SPECT [QGS] program) and by wall thickening derived from gated perfusion polar maps (Emory Cardiac Toolbox program). To evaluate visual assessment in control and simulated-arrhythmia tomograms, 2 experienced blinded observers independently interpreted perfusion from polar maps and wall motion and thickening from tomographic cines, using a 4-point scale.Results: Although mean functional parameters were scarcely altered, paired t tests showed ejection fraction fluctuations to be significantly different from control values, causing patients to change between abnormal and normal ejection fraction categories (2% of patients by QGS and 14% by Emory Cardiac Toolbox). Visual examination of QGS polar perfusion and function maps showed changes for 72% of cases, although in only 4% were these considered to have potential clinical consequences. The kappa statistic for visual analysis of concordance between control and arrhythmia readings showed that agreement was "excellent" for perfusion, "good" for motion, and "marginal" for thickening.Conclusions: As with quantitative measurements, thickening is the parameter most prone to error in the presence of arrhythmias. It is important to test data for gating errors to avoid potentially erroneous measurements and visual readings. [ABSTRACT FROM AUTHOR]

This study was performed to evaluate regional wall motion (WM) and wall thickening (WT) using gated myocardial perfusion single photon emission computed tomography (SPECT) and to determine their similarity and disparity in patients with coronary artery disease (CAD). A total of 44 patients underwent 1 day stress/rest (MIBI) gated SPECT. Commercially available quantitative analysis of gated SPECT (QGS) software was used to generate 3D surface display and cine-mode SPECT display. Left ventricle was divided into nine segments to score WM and WT from 0 (no abnormality) to 4 (severe abnormality) by six independent observers. Finally a mean score was calculated for each segment from the scores of six observers. There was fairly good correlation between WM and WT of individual segments ( r = 0.62, p < 0.0001). Concordance rate (|WM − WT|≤1) was 85%. A large difference between WM and WT (WM − WT≥2) was observed in 15 segments, including 12 segments with greater WM abnormalities and 3 segments with greater WT abnormalities (lateral and inferior walls). Greater WM abnormalities were most commonly observed in anteroseptal segments especially in post coronary artery bypass grafting (CABG) patients. In conclusion, WM and WT showed similarity on QGS studies. However, these two parameters may be determined separately in gated SPECT studies for comprehensive and robust evaluation of the functional status of myocardium. Analyses based on WM assessment alone may lead to erroneous results especially in septal regions. [ABSTRACT FROM AUTHOR]

Hemophagocytic lymphohistiocytosis, a variant of histiocytosis, is characterized by an uncontrolled activation of the cellular immune system, including hepatic mononuclear phagocytic cells. Abdominal ultrasound findings in children are evaluated in this disease. We present six pediatric cases, two with familial and four with sporadic hemophagocytic lymphohistiocytosis, examined by abdominal sonography. Three signs were frequently observed: thickening of the gallbladder wall (all cases), increased periportal echogenicity (four cases), and enlarged lymph nodes in the porta hepatis (four cases). Hepatomegaly, splenomegaly, and ascitic fluid may also be found. These imaging findings are not specific and may be seen in viral hepatitis. However, once hepatitis is excluded, they may suggest the diagnosis of hemophagocytic lymphohistiocytosis in a critically ill child. A bone smear must be done to establish the diagnosis. [ABSTRACT FROM AUTHOR]

With technetium-99m 2-methoxy-isobutyl-isonitrile (Tc-MIBI), regional wall thickening in a patient with dilated cardiomyopathy was analyzed by the first component Fourier method. The regional wall thickening was compared with thallium-201 andTc-MIBI SPECT imaging. Thallium-201 SPECT images showed mildly reduced perfusion in the posterior wall and redistribution in the septum, whereasTc-MIBI images showed heterogeneous accumulation around the left ventricular circumference. By means of phase analysis, diffusely decreased wall thickening and discontinuity of percent wall thickening in neighboring segments were observed throughout the left ventricle. Regional wall motion and wall thickening correlated roughly. However, discrepancies between the mechanical function and myocardial perfusion, and discrepancies in regional myocardial perfusion between thallium-201 andTc-MIBI were observed. [ABSTRACT FROM AUTHOR]

Regional wall thickening was assessed by ECG-gated SPECT using technetium-99m 2-methoxy-isobutyl-isonitrile (Tc-MIBI). For myocardial segments with an optimal short axis, regional count changes from end-diastole to end-systole were used to calculate the regional wall thickening. Functional images displaying amplitude, % wall thickening (% WT), and phase were generated by a fundamental Fourier analysis. In the control subjects, %WT analysis showed heterogeneous contraction among the left ventricular wall segments. The amplitude values showed a similar pattern to the %WT values. Phase images demonstrated that the timing of ventricular contraction was almost homogenous between the various wall segments. In the CAD patients, regional decreases in amplitude and % WT corresponding to zones of reduced perfusion were shown in the ischemic segments. Phase images also indicated asynchronous contraction in these segments. Phase analysis of regional wall thickening inTc-MIBI scintigraphy seems to be useful for understanding regional myocardial function in combination with perfusion scanning. [ABSTRACT FROM AUTHOR]

Treatment of Zea mays seedlings with a 5 mM caffeine solution inhibits cytokinesis in guard cell mother cells (GMCs), producing unicellular, binucleate aberrant stomata (a-stomata). Ventral wall (VW) strips of limited length, which usually meet the wall portions of GMCs adjoining the cortical zone of the preprophase microtubule band (PMB), are laid down in many a-stomata. In a-stomata with or without VW-strips, the periclinal walls are lined by numerous microtubules (Mts) converging on their mid-region, where local wall thickenings are deposited. When the VW-strips reach the mid-region of the periclinal walls, thickenings lined by numerous Mts rise at their free margins. In certain a-stomata an anticlinal wall column, surrounded by a dense Mt bundle, grows centripetally from either or both of the periclinal wall thickenings. In wall thickenings, the cellulose microfibrils are co-aligned with the adjacent Mts. Pore formation is initiated in all a-stomata. Deposition of an electron dense intra-wall material followed by lysis precedes 'pore' opening. This process is closely related to the a-stornata morphogenesis. These observations show that the primary morphogenetic phenomenon in a-stomata is the establishment of an intense and stable polarity in the cytoplasm abutting on the mid-region of the periclinal walls and/or the adjacent plasmalemma area. Prime morphogenetic factor(s), including microtubule organizing centres (MTOCs), seem to function in these sites. Morphogenesis in a-stomata is a Mt-dependent process that is carried out as in normal stomata but in the absence of a VW. [ABSTRACT FROM AUTHOR]

The appearance of gastrointestinal wall thickening of various entities is demonstrated on magnetic resonance imaging (MRI). The entities include benign gastric ulcer, gastric carcinoma, pancreatic carcinoma with direct invasion of stomach, duodenal leiomyoma, radiation enteritis, peritonitis, colonic carcinoma, recurrent carcinoma at the gastrojejunal anastomosis with direct extension to the transverse colon, colocolic intussusception, sigmoid diverticulitis with pericolonic abscess and fistula into the urinary bladder, and lymphoma of the stomach, duodenum, small bowel, and colon. Air was introduced antegradedly or retrogradedly into the alimentary tract to act as a contrast agent. When the bowel was distended by air, the normal bowel wall was barely visible or even invisible. Abnormal focal or segmental wall thickening was outlined between the intraluminal air and extraluminal fat. In some instances, the thickenings were better demonstrated on coronal or sagittal sections. The proper muscular layer of the bowel has a low-signal intensity and was delineated between the thickened mucosa-submucosa and extramural fat. Interruption of this low-intensity zone might represent tumor invasion through the muscular layer. [ABSTRACT FROM AUTHOR]

The regenerative differentiation of xylem, both around a wound in the stem and at the root junction was studied in seedlings of maize. The regeneration of vessels around a wound was very small, being limited to the very young internodes and sharply declining basipetally. There were more regenerative vessel elements and they differentiated faster above the wound than below it. The regenerative vessel elements around the wound were characterized by helical or annular pattern of secondary wall thickenings. Wounding also resulted in the development of additional vascular anastomoses in the leaf immediately above the wound, and in differentiation of discontinuous vessels in adjacent bundles. Regenerative vessel elements were very common where the adventitious roots connected with the stem internodes, and exhibited pitted or reticulated secondary wall thickenings. [ABSTRACT FROM AUTHOR]

Interactions between an isolate of the ectomycorrhizal fungus Pisolithus sp. and Afzelia africana Sm. seedlings were studied at the structural and ultrastructural levels. Several different conditions were tested with or without sugar and in a sterile or nonsterile medium. In the growth cabinet, the A. africana/Pisolithus sp. interactions did not produce ectomycorrhizas. A fungal sheath was formed but no Hartig net, and an unusual host epidermal cell wall was observed. Hyphae of Pisolithus sp. induced modifications of epidermal cells of 15-day-old A. africana seedlings indicative of non-mycorrhizal interactions, such as wall thickening, wall ingrowth, papillae formation, degraded host wall material and the presence of intracellular hyphae. Wall ingrowth consisted of depositions of host cell wall materials giving a positive reaction for polysaccharides; however, wall thickenings and papillae showed no homogeneous reactions for polysaccharides. In glasshouse conditions, inocula of Pisolithus sp. in the form of spores or mycelia entrapped in peat-vermiculite added to sterilized soil produced typical ectomycorrhizae only with 6-month-old A. africana seedlings. Under these conditions, no conspicuous cell wall reactions occurred on A. africana roots. The results demonstrate that the establishment of an association between an ectomycorrhizal fungus and a potential host plant is strongly influenced by seedling age and/or environmental conditions. Therefore, in vitro synthesis is not a conclusive demonstration of a symbiotic relationship. [ABSTRACT FROM AUTHOR]