Bony ankylosis in rheumatoid arthritis. Associations with longer duration and greater severity of disease

Hand and wrist radiographs of 203 patients with rheumatoid arthritis were examined for bony ankylosis. Forty-eight patients (23.6%) showed ankylosis, including 34 with more than one joint fused. The distribution of ankylosed joints was 32.4% midcarpal, 29.5% common carpometacarpal, 15.8% radiocarpal, 15.8% proximal interphalangeal, and 6.5% metacarpophalangeal. Patients with ankylosis had significantly higher radiographic erosion, joint space narrowing, and malalignment scores than those without ankylosis (all P less than .001). Patients with ankylosis had significantly longer duration of disease (P less than .001) and physical examinations showed more limited motion and deformity (both P less than .001). More patients with ankylosis had subcutaneous nodules (P less than .05). Functional testing with grip strength and the button test revealed poorer performance in patients with ankylosis (both P less than .001). Questionnaires revealed patients with ankylosis had more difficulty with activities of daily living (P less than .001) and had more limited activity (P less than .01); physicians estimated more limited functional capacity (P less than .001). Thus, radiographic bony ankylosis was a relatively common feature of rheumatoid arthritis, and a marker of patients whose disease was clinically, radiographically, and functionally more severe.     

Primary tuberculosis in childhood: radiographic manifestations.

The aim of the study was to review the radiologic features of primary tuberculosis in childhood and to determine whether differences in patterns of disease occur among age and ethnic groups. Chest radiographs of 191 children with pediatric primary tuberculosis were reviewed by two observers. Lymphadenopathy, present in 92% of cases, was the most common abnormality identified on the initial chest radiograph and typically involved the hilar and paratracheal regions. Parenchymal abnormalities, identified in 70% of cases, occurred more commonly in the right lung (P less than .001). Children 0-3 years of age had a higher prevalence of lymphadenopathy (P less than .01) and a lower prevalence of parenchymal abnormalities (P less than .001) than older children. A lower prevalence of lymphadenopathy was found in whites than in nonwhites (P less than .02). The radiologic abnormalities often progressed in the initial follow-up. Lymphadenopathy, with or without concomitant parenchymal abnormality, is the radiologic hallmark of primary tuberculosis in childhood. However, distinct age-related and racial differences in presenting patterns of disease exist and should be recognized.     

Anemia in swimmers: fact or fiction? Study of hematologic and iron status in male and female top-level swimmers

The aim of the project was to examine the hematologic and iron status of a group of top-level male and female swimmers compared with a control group composed of fit, physically active subjects. The following parameters were examined: red blood cells (RBC), hemoglobin concentration (Hb), hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), serum iron (S I), total iron-binding capacity (TIBC), transferrin saturation (Sat), and serum ferritin concentration (S F). The male swimmers had higher values than the control men for RBC (5364 vs. 5163, P less than .01), Hb (15.4 vs 14.8, P less than .01), Hct (49 vs 46.6, P less than .01), TIBC (341 vs 297, P less than .001), and S I (107 vs 86.3, P less than .01). The female swimmers had higher values than the control women for MCV (91.2 vs 88.5, P less than .01), Hb (14 vs 12.8, P less than .01), Hct (44.2 vs 40.4, P less than .001), S F (58.65 vs 42.17, P less than .01), S I (106 vs 75.6, P less than .01), and TIBC (336 vs 278, P less than .001). The differences between men and women were smaller between the men and women of the swimmers group with respect to the men and women of the control group, for Hb: 15.4 vs 14 (P less than .01) and 14.8 vs 12.8 (P less than .001) and S F: 97.24 vs 58.65 (P less than .001) and 99.89 vs 42.17 (P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Fetal omphalocele: prenatal US detection of concurrent anomalies and other predictors of outcome

Forty-six consecutive fetuses with an identified omphalocele were examined with prenatal ultrasound (US) to determine the accuracy of detecting concurrent malformations and to evaluate other possible indicators of fetal outcome. In 43 fetuses with adequate follow-up, 29 (67%) had additional malformations, including 23 with major malformations and six with minor malformations. Thirty-six fetuses (78%) died at termination of pregnancy (n = 23) or spontaneously (n = 13). With the exclusion of pregnancy terminations, fetal mortality was strongly associated with the presence of concurrent malformations, (P less than .001). In 10 surviving fetuses, only three had concurrent malformations, and all were minor. Fetal mortality was also found to be statistically associated with anomalies detected at US (P = .01) and abnormal amniotic fluid volume but was not associated with fetal ascites (P = .64) or omphalocele size (P = .65). Chromosome abnormalities correlated with the absence of liver in the omphalocele sac (P less than .001) and with abnormal amniotic fluid volume (P = .02). Prenatal US can help predict the outcome in fetuses with an omphalocele.     

Chronic diffuse infiltrative lung disease: comparison of diagnostic accuracy of CT and chest radiography

The accuracies of chest radiography and computed tomography (CT) in the prediction of specific diagnoses in 118 consecutive patients with chronic diffuse infiltrative lung disease (DILD) were compared. The radiographs and CT scans were independently assessed by three observers without knowledge of clinical or pathologic data. The observers listed the three most likely diagnoses in order of probability and recorded the degree of confidence they felt in their first-choice diagnosis on a three-point scale. Confidence level 1 (definite) was reached with 23% of radiographic and 49% of CT scan readings, and the correct diagnosis was made with 77% and 93% of those readings, respectively (P less than .001). The correct first-choice diagnosis regardless of the level of confidence was made with 57% of radiographic and 76% of CT scan readings (P less than .001). The CT scan interpretations were most accurate in silicosis (93%), usual interstitial pneumonia (89%), lymphangitic carcinomatosis (85%), and sarcoidosis (77%). Observers correctly predicted whether a transbronchial or open lung biopsy was indicated with 65% of radiographs and 87% of CT scans (P less than .001). It is recommended that CT be performed before lung biopsy in all patients with chronic DILD.     

Obstructive sleep apnea: MR imaging volume segmentation analysis

PURPOSE: To retrospectively determine airway wall motion with volume segmentation of transverse cine magnetic resonance (MR) images in children with obstructive sleep apnea (OSA). MATERIALS AND METHODS: Transverse fast gradient-echo cine MR images of the hypopharynx were obtained at 1.5 T in 31 children with OSA (eight girls, 23 boys; mean age, 11.3 years) and 21 children free of airway symptoms who underwent MR imaging for other clinical indications (11 girls, 10 boys; mean age, 3.5 years). Volume segmentation with a k-means clustering algorithm was applied to transverse cine MR images to quantify airway volumes at each time. Airway wall motion for each child was described with standard deviation and range. Coefficient of variance and normalized range, which are independent of airway size, were used to compare groups (Kruskal-Wallis test). RESULTS: Plots of airway volume over time demonstrated large fluctuations during respiration in children with OSA and minimal fluctuations in controls; findings were consistent with airway distention and airway collapse in OSA. Average airway transverse volume was larger in the group with OSA than in the control group (OSA group, 2.52 mL; control group, 0.936 mL; P <.001). Mean standard deviation (OSA group, 0.840 mL; control group, 0.17 mL; P <.001) and mean range of airway cross section (OSA group, 3.552 mL; control group, 0.864 mL; P <.001) were larger in the group with OSA. Coefficient of variance (OSA group, 0.32; control group, 0.17; P <.001) and normalized range (OSA group, 1.42; control group, 0.96; P <.001) indicate statistically significant difference in airway dynamics in children with OSA. CONCLUSION: Volume segmentation of transverse cine MR images of the hypopharynx aids in quantification of increased airway wall motion in children with OSA. Transverse MR imaging demonstrates both airway distention and collapse in children with OSA.     

Sonographic detection of uterine and ovarian abnormalities in female survivors of Wilms' tumor treated with radiotherapy

OBJECTIVE: The purpose of this study was to use sonography to evaluate the size of the ovaries and uterus in survivors of Wilms' tumor who underwent radiotherapy. SUBJECTS AND METHODS: Eighteen survivors of Wilms' tumor had their ovaries and uterus measured on sonography. Their ages at diagnosis and treatment ranged from 14 months to 6 years. Four girls were prepubertal (age, 5-9 years), 11 were postpubertal (age, 11-30 years), and three had primary ovarian failure (age, 15-23 years) at the time of imaging. Findings were compared with those of a control group of 25 prepubertal and 25 postpubertal girls and women. Gonadotropin levels were measured. RESULTS: Three patients who underwent whole abdomen radiotherapy had elevated levels of gonadotropin and primary ovarian failure. Neither ovary was seen in two of the three patients and both ovaries were abnormally small (< or = 1 cm3) in the third patient. The uterus was abnormally small (length, < or = 4 cm) in all three of these patients even though two were being treated with hormone replacement therapy. Ten postpubertal patients who underwent hemiabdomen radiotherapy had normal gonadotropin levels and a normal-sized uterus on sonography; the ovary on the side that received radiotherapy was not seen in three of the 10 patients or was abnormally small (< or = 1.4 cm3) in two of the 10 patients compared with all normal ovaries in the postpubertal control group (p < .0001). One postpubertal patient with bilateral renal bed radiotherapy had normal ovaries and a normal-sized uterus. Significantly more patients in the postpubertal and ovarian failure radiotherapy group (5 [36%] of 14 patients) had one or both ovaries not seen than the control group (none [0%] of 25 patients; p = .0014). The uterus was significantly smaller than normal in three (23%) of the 13 patients in the postpubertal hemiabdomen and ovarian failure radiotherapy group versus none of the 25 patients in the postpubertal control group (p = .0339). CONCLUSION: Postpubertal female survivors of Wilm's tumor who underwent radiotherapy as children may have one or two small or absent ovaries and a small uterus that can be detected by sonography. The response of the uterus to hormone replacement therapy can also be assessed on sonography.     

Chest injury in children with blunt abdominal trauma: evaluation with CT

One or more significant chest injuries were identified in 62 of 512 children (12%) examined with computed tomography (CT) after blunt abdominal trauma. Thirty-eight percent of all abnormalities identified on CT scans were underestimated or missed on the initial chest radiograph. Pleural and parenchymal abnormalities were missed in 50% and 34% of initial chest radiographs, respectively. Chest injuries occurred more frequently in children less than 7 years of age than in older children (62% vs 38%, P less than .02). Children with chest injuries tended to be more physiologically unstable than children without, as determined with lower (worse) mean trauma scores (P less than .001). Both the presence and severity of chest injuries strongly affected outcome. Mortality was 1.3% in children with no chest injury, 10.8% in children with significant unilateral chest injury, and 40% in children with significant bilateral or mediastinal chest injury (P less than .0001). Significant unsuspected or underestimated thoracic injuries are relatively common in children, and CT scans of the chest obtained while examinations of the upper abdomen are being performed can be helpful in the early recognition of such injuries.     

Vertebral bone density in children: effect of puberty

To determine changes in bone density during growth, trabecular vertebral density and an index of spinal cortical bone were measured with quantitative computed tomography in 101 children. The children were divided by age into three groups: prepubertal, indeterminate, and pubertal. Compared with prepubertal children, pubertal adolescents had significantly higher trabecular bone density and more compact bone in the spine (P less than .001). After controlling for puberty, vertebral bone density failed to correlate significantly with age, sex, weight, height, surface area, and body mass index. The results indicate that bone density increases markedly during puberty.     

Comparison of hemodynamic and left ventricular responses to increased after-load in healthy males and females

Hemodynamic and left ventricular responses were studied echocardiographically in 20 males (31.5 +/- 4.5 yrs) and 20 females (30.4 +/- 4.3 yrs) at rest and during 3 min of isometric deadlift exercise at 30% of maximum voluntary contraction. Maximal tension exerted was significantly (P less than .001) lower in the female group (87.4 +/- 8.1 kg) compared with the male group (127.3 +/- 15 kg). Significant (P less than .001) increases in heart rate and contractility index were noted in both groups during exercise compared to the resting values. Mean arterial blood pressures were significantly (P less than .05) higher in the males at rest and during exercise. Ejection fraction and fractional shortening, both at rest and during exercise, differed significantly (P less than .05) between the two groups. It was raised by exercise only in the males (from 62 +/- 5% to 65 +/- 5% and 32 +/- 4% to 35 +/- 4%, respectively) but remained unchanged in the females. No significant changes in end diastolic dimension and stroke volume were observed in either group during exercise. End systolic dimension was significantly (P less than .001) lower during exercise in females and males (from 3.25 +/- .23 to 3.1 +/- .26 and 3.12 +/- .33 to 3.00 +/- .32 cm, respectively). These data indicate that hemodynamic and left ventricular function in normal male and female subjects were augmented during submaximal isometric exercise. However, females do so with lower after-load than males.     

Angiographic assessment of arterial outflow: predictive value of a new classification system.

A prospective study with 4 years of follow-up involving 127 consecutive symptomatic patients (60.6% with claudication, 39.4% with critical ischemia) who underwent aortobifemoral bypass surgery is described. A new grading system for the classification of arterial outflow was applied to determine its usefulness in predicting the outcome of surgery. Preoperative angiograms were numerically scored according to the arterial outflow status at the level of main segmental involvement. Higher scores corresponded to worse outflows. Outflow scores ranged between 1 and 10 with a mean of 3.6 +/- 0.24. The main comparison was between patients with scores of less than 5 (group A, n = 80) and patients with scores of 5 or more (group B, n = 47). Better outflow was associated with higher postoperative mean increases in the ankle-brachial index (ABI) (group A, 0.35 +/- 0.03; group B, 0.17 +/- 0.04; P less than .001) and transcutaneous oximetry (PtcO2) (group A, 15.4 mm Hg +/- 1.8; group B, 8.4 mm Hg +/- 3.0; P = .01). At 4-year follow-up, group A had higher cumulative rates of patency (98.3% vs 78.0%, P less than .001), symptomatic relief (84.0% vs 23.3%, P less than .001), and palliation (67.0% vs 19.9%, P less than .001). In conclusion, angiographic outflow, as evaluated with the system described, successfully helped predict postoperative increases in ABI and PtcO2 and the cumulative rates of graft patency, symptomatic relief, and palliation.     

The incidence and importance of renal duplication.

The excretory urograms performed on 1716 children and 3480 adults have been examined to find the incidence and complications of renal duplication. Ninety-five patients with duplication were found, unilateral in 79 and bilateral in 16 patients. It was equally common on each side and twice as common in females as in males. Non-duplex kidneys had a mean of 9.4 calyces and duplex kidneys had a mean 3.7 upper and 7-6 calyces in lower moieties. In patients without renal disease and with unilateral duplication the two kidneys were equal in size in 39%, and the duplex was smaller in 10%. Twenty-seven per cent of the duplex kidneys examined showed evidence of disease compared to 3% of the non-duplex kidneys-a significant difference (P less than 0-001). Saddle reflux is the only abnormality unique to duplication and was seen in one patient. Extravesical ectopic ureter and ureterocoeles are known to be associated with renal duplication, but in this series ureterocoeles were found only on the non-duplex side. The duplex kidney in children is more susceptible to reflux than is the non-duplex kidney, and this leads to both ureteric and pelvi-calyceal dilation, and to chronic pyelonephritis in the duplex side in those children who develop urinary tract infections. Chronic pyelonephritis was found in 22% of patients under 15, significantly more often than in adults (P less than 0-001), although the incidence of duplication was unchanged. It is concluded that there is no real increase in the number of children with duplex kidneys having urinary tract infections, and the vast majority of duplex kidneys do not become diseased.     

Myelination in children with partial deletions of chromosome 18q

BACKGROUND AND PURPOSE: We compared myelin levels in white matter (WM) in typically developing children with those of children with partial deletions of chromosome 18q (18q-). METHODS: Conventional spin-echo MR imaging at 1.9T was used to acquire T1-, T2-, and proton density-weighted images of the brain. From these images, a three-pool model was used to estimate the fraction of water in myelin, myelinated axon, and mixed water compartments (or pools) in six WM regions. A model curve was fit to the pool fractions to model the trend of myelin development by age in each region. Water-pool fractions in children with 18q- aged 5 months to 13 years were compared with those of age-matched, typically developing children. RESULTS: In children with 18q-, the model predicted later onset of myelination (P <.02), lower myelination rates (P <.001), and smaller equilibrium myelin pool fractions (P <.001). Significant differences were seen between the two groups for all three water pool fractions (P <.001). The mixed pool fraction was larger in children with 18q-. Although the myelin pool fraction was significantly smaller, the myelinated axon pool fraction was only slightly smaller, leading to a significantly smaller estimate of myelin per myelinated axon in children with 18q- (P <.001). CONCLUSION: Myelination modeling in 18q- children indicated delayed onset, a lower rate of myelination, and equilibrium myelin levels less than 50% those of age-matched, typically developing children.     

Assessment of myocardial infarction in humans with (23)Na MR imaging: comparison with cine MR imaging and delayed contrast enhancement

PURPOSE: To demonstrate the feasibility of sodium 23 ((23)Na) magnetic resonance (MR) imaging for assessment of subacute and chronic myocardial infarction and compare with cine, late enhancement, and T2-weighted imaging. MATERIALS AND METHODS: Thirty patients underwent MR imaging 8 days +/- 4 (subacute, n = 15) or more than 6 months (chronic, n = 15) after myocardial infarction by using a (23)Na surface coil with a double angulated electrocardiogram-triggered three-dimensional gradient-echo sequence at 1.5 T. In addition, cine, inversion-recovery gradient-echo, and, in the subacute group, T2-weighted images (n = 9) were obtained. Myocardial infarction mass was depicted as elevated signal intensity or wall motion abnormalities and expressed as a percentage of total left ventricular mass for all modalities. Correlations were tested with correlation coefficients. RESULTS: All patients after subacute infarction and 12 of 15 patients with chronic infarction had an area of elevated (23)Na signal intensity that significantly correlated with wall motion abnormalities (subacute; r = 0.96, P <.001, and chronic; r = 0.9, P <.001); three patients had no wall motion abnormalities or elevated (23)Na signal intensity. Only 10 patients in the subacute and nine in the chronic group revealed late enhancement; significant correlation with (23)Na MR imaging occurred only in subacute group (r = 0.68, P <.05). Myocardial edema in subacute infarction correlated (r = 0.71, P <.05) with areas of elevated (23)Na signal intensity but was extensively larger. CONCLUSION: (23)Na MR imaging demonstrates dysfunctional myocardium caused by subacute and chronic myocardial infarction.     

Acceleration of thrombolysis with a high-dose transthrombus bolus technique

The rate of complication and the time necessary to achieve thrombolysis remain major disadvantages of regional thrombolytic therapy. By lacing the entire length of arterial or arterial bypass graft occlusions in the lower extremities of 49 patients with one of two different bolus doses of urokinase (mean, 52,000 International U in 35 infusions = low-dose group [28 patients]; mean, 230,000 U in 23 infusions = high-dose group [21 patients]) prior to identical continuous infusions, it was possible to demonstrate a decrease in the time needed to complete thrombolysis from 33.6 hours in the low-dose group to 10.4 hours in the high-dose group (P less than .001). The total urokinase dose necessary for successful thrombolysis was also significantly less in the high-dose group (P less than .001). The major complication rate was 22.9% in the low-dose group and 8.7% in the high-dose group, although the difference was not statistically significant. The use of urokinase and a high-dose transthrombus bolus injection technique significantly accelerates thrombolysis, decreases the total urokinase dose needed, and may lower the major complication rate.     

Abnormal testicular function: potential of P-31 MR spectroscopy in diagnosis

Phosphorus-31 MR spectroscopy of the human testis was performed on healthy volunteers (n = 17) and oligospermic (n = 7) and azoospermic patients (n = 4). All patients in the latter group had the Sertoli-cell-only syndrome. Determination of the ratios of phosphomonoesters (PMs) to adenosine triphosphate (ATP), phosphodiesters (PDs) to ATP, and inorganic phosphate (Pi) to ATP made it possible to discriminate among these three groups. The testicular PM/ATP ratio was 1.71 +/- 0.03 (mean +/- standard deviation) in the healthy volunteers and dropped to 1.41 +/- 0.06 (P less than .001 in comparison with healthy volunteers) in the oligospermic patients and to 1.22 +/- 0.07 (P less than .001) in the azoospermic patients. The testicular PD/ATP ratio did show a slight increase from 0.52 +/- 0.10 in healthy volunteers to 0.68 +/- 0.09 (not significant) for oligospermic patients and to 0.83 +/- 0.10 (P less than .01) for azoospermic patients. The Pi/ATP ratio did not show significant differences between healthy volunteers (0.12 +/- 0.07) and oligospermic patients (0.23 +/- 0.08) but was elevated in the azoospermic patients (0.79 +/- 0.12) (P less than .001).     

Compensatory mechanisms in children with idiopathic lower extremity internal rotational malalignment during walking and running

BackgroundNoticeable in-toeing gait is present in most children with internal rotational malalignment and often a reason to consult an orthopedic specialist. The risk of tripping may be higher for these patients.Research QuestionThe aim of this study was to determine compensatory mechanisms adopted by children with internal rotational deformities to avoid tripping and falling during walking and running.MethodsSixty-nine patients between 5–18 years with idiopathic internal rotational malalignment were retrospectively included and subdivided into three groups: 18 patients with internal tibial torsion (ITT), 25 patients with internal femoral torsion (ITF) and 26 patients with both (ITB). Twenty-two typically developing age-matched children (TD) were analyzed for comparison. Three-dimensional gait data were evaluated. ANOVA’s on two factors, group (ITT, ITF, ITB, TD) and movement (walking, running) with post-hoc t-tests were used to identify significant differences between groups.ResultsAll groups had significantly greater step width than TD during walking (P ≤ .002) and all torsional groups had significantly greater step width during running (P ≤ .001). Similarly, all torsional groups showed greater peak ankle dorsiflexion in swing during running than TD (P ≤ .006). Only the ITT group showed significantly greater external hip rotation than TD. When compared to TD, the ITF and ITB group had a significantly lower hip abduction moment in stance during running, but not for walking (P ≤ .032).SignificanceCompensatory mechanisms in children with internal rotational deformities were mostly dependent on the location of rotational malalignment. All children with internal rotational malalignment had greater ankle dorsiflexion and greater step width during running. Especially in active patients, this greater ankle dorsiflexion during running may result in overuse of the ankle dorsiflexor muscles, while greater step width may have beneficial effects in normalizing knee adduction moments.     

The incidence of gastro-oesophageal reflux in children with exogenic and endogenic asthma tested by a new radiological method

24 asthmatic children and 15 children without any respiratory or gastrointestinal signs of symptoms were investigated for gastro-oesophageal reflux (GER) by a new radiological test in which the child swallowed a piece of rye bread with liver paté after intake of a glass of Mixobar (600 mg/ml barium sulphate). The asthmatic children were divided into an exogenic and an endogenic group. 62.5% of the endogenically asthmatic children had GER (p less than 0.01) and 19% in the exogenic group. In normal children only one child had GER (7%). Furthermore, GER was more frequent in asthmatic children with nightly cough compared to asthmatic children without nightly cough (p less than 0.02). It is concluded that GER reflux occurred significantly more often in patients with endogenic asthma and/or nightly cough when compared to normal children.     

Chronic diffuse interstitial lung disease: diagnostic value of chest radiography and high-resolution CT

The diagnostic value of chest radiography and high-resolution computed tomography (CT) in chronic diffuse interstitial lung disease (CDILD) was assessed in 140 consecutive patients with diffuse infiltration of the lung visible at radiography. Radiographs and CT scans were separately read by three independent observers without knowledge of clinical and pathologic data. The observers listed the three most likely diagnoses and recorded the degree of confidence they had in their choice on a 0%-100% probability scale. Findings at radiography and high-resolution CT were recorded by each observer and were used for a stepwise discriminant analysis between diagnoses. First-choice diagnoses of all three observers that were made with a high level of confidence (probability, greater than or equal to 75%) were more accurate with CT than with radiography (P less than .001). The superiority of high-resolution CT over radiography was most obvious for histiocytosis X and sarcoidosis; in cases of pulmonary fibrosis, CT was not significantly different from radiography. The interobserver agreement for the proposed diagnosis was significantly better with high-resolution CT (P less than .001). Twenty-one of 26 radiographic findings and 21 of 25 CT findings were discriminant. Stepwise discriminant analysis revealed the superiority of CT over radiography, since the ranking of all findings showed that the four most discriminant findings, and eight of the first 12 findings, were revealed with CT.     

Relationship of transient ischemic dilation in dipyridamole myocardial perfusion imaging and stress-induced changes of functional parameters evaluated by Tl-201 gated SPECT

BACKGROUND: This study assessed whether transient ischemic dilation (TID) of the left ventricle is related to ischemic stunning, manifested by stress-induced decrease of left ventricular ejection fraction (LVEF) and worsening of wall motion, by use of dipyridamole-stress and redistribution thallium 201 gated single photon emission computed tomography (SPECT). METHODS AND RESULTS: Ninety-two consecutive patients undergoing dipyridamole Tl-201 gated SPECT were included. Patients with a TID ratio in the highest quartile were defined as having TID. In patients with TID, end-diastolic volume (EDV) and end-systolic volume (ESV) were both significantly greater on dipyridamole-stress images than on redistribution images (P < .001). The degree of enlargement was much greater for ESV than EDV. In patients without TID, EDV and ESV were both decreased after stress (P < .001). Patients with TID had a lower mean LVEF on dipyridamole-stress images than on redistribution images (P < .001). Patients without TID had a higher mean LVEF on dipyridamole-stress images than on redistribution images (P < .001). Patients with TID had a significant worsening of global wall motion on dipyridamole-stress images than on redistribution images (P < .001), but patients without TID did not. CONCLUSION: TID was significantly correlated with ischemic stunning, and the enlargement of ESV was an important factor resulting in TID.