Does motion analysis in postexercise gated sestamibi SPECT reflect rest left ventricular motion even in severe coronary artery disease?

PURPOSE: Evidence has suggested that postexercise gated Tc-99m sestamibi SPECT (GSPECT) provides combined information about resting wall motion and exercise perfusion. No data have been published about possible differences in wall motion analysis between postexercise and resting GSPECT. METHODS: Fifty patients underwent postexercise (symptom-limited bicycle stress) and rest GSPECT and cardiac catheterization with contrast ventriculography. In 35 patients, additional rest planar Tc-99m RBC radionuclide ventriculography (RNV) was performed. Four observers independently performed left ventricular ejection fraction (LVEF) calculations and visual analysis of regional wall motion (graded in four stages) for all studies. RESULTS: The LVEF calculations in GSPECT revealed a statistically significant difference between postexercise (45.8 +/- 15.7%) and rest (48.0 +/- 16.1%; P < 0.05) determination. Postrest GSPECT LVEF showed a better correlation with LVEF determination performed with contrast ventriculography and RNV than did postexercise GSPECT LVEF. The reduced postexercise wall motion could be shown in segments with exercise-induced ischemia and in those with normal regional perfusion but not in segments with irreversibly abnormal perfusion. CONCLUSIONS: Postexercise GSPECT provides reliable information regarding global wall motion even in severe coronary artery disease, but regional wall motion is underestimated compared with rest GSPECT, because of an imprecise surface detection algorithm in ischemic wall segments and possibly postexercise stunning in severe coronary artery disease.     

Right ventricular ejection fraction measured by multigated planar equilibrium radionuclide ventriculography is an independent prognostic factor in patients with ischemic heart disease

Background

The number of studies on the prognostic value of the right ventricular ejection fraction (RVEF) in patients with ischemic heart disease (IHD) is limited, whereas it is widely accepted that the left ventricular ejection fraction (LVEF) is a strong prognostic factor. We assessed whether RVEF measured by multigated planar equilibrium radionuclide ventriculography (RNV) is an independent prognostic factor in patients with IHD.

Methods and Results

We retrospectively identified 347 consecutive patients with IHD (mean age 71?±?11?years; 18% women) who underwent multigated planar equilibrium RNV between 2004 and 2008 to determine the LVEF, which also provided the RVEF (mean 44.7%?±?11.0%). We categorized patients according to RVEF in ??40% (n?=?240) and <40% (n?=?107). Patients were followed for a median of 826?days (range 3-2,400) for the occurrence of events [all-cause mortality (n?=?60), cardiac mortality (n?=?33), and cardiac hospitalization (n?=?78)]. Cox regression analysis with significant univariate predictors [coronary artery revascularization (P?=?.003), diuretics (P?=?.03), and statins (P?<?.001)] showed that an RVEF <40% was associated with a 2.90 (1.68-5.00)-fold higher risk of all-cause death. Accordingly, a decreased RVEF was associated with a 2.15 (1.34-3.43)-fold increase in the risk of cardiac hospitalization and a 5.11(2.32-11.23)-fold risk of cardiac death.

Conclusion

RVEF measured by multigated planar equilibrium RNV is an independent prognostic factor in patients with chronic IHD.     

Correlation of radionuclide ventriculography with roentgenological findings in chemotherapy patients

Radionuclide ventriculography (RNV) is a common method to evaluate cardiotoxic effects of drugs applied during chemotherapeutic treatment, whereas thoracic radiographs are used to detect morphologic alterations. Aim of this study was to identify radiographic signs, which correlate with RNV parameters and with RNV image quality. For this study, RNV data of 116 patients receiving chemotherapy acquired during 205 RNV studies (some patients underwent up to 7 follow-up examinations) were correlated to roentgenologic findings assessed by 176 thoracic radiographs. Isolated thoracic radiographic signs of cardiac failure showed only slight correlations to left ventricular ejection fractions measured with radionuclide ventriculography, but the orientation of correlation (positive or negative) could be confirmed well by clinical data. This fact matches clinical experience, that radiographic signs of heart insufficiency can surely predict heart damage only when several of them coincide. By the help of this study it was possible to detect radiographic findings, which are of relevance in patients with suspicion of cardiotoxic damage as side effect of high-dose chemotherapy. The clinical value of several radiologic findings should be reassessed to diagnose cardiac failure in chemotherapy patients.     

Total and partial cardiac sympathetic denervation after surgical repair of ascending aortic aneurysm.

Sympathetic cardiopulmonary nerves arise from the cervical sympathetic trunks and travel alongside the great arteries to innervate the ventricles. Because of the proximity of the nerve and artery, cardiac sympathetic denervation may occur in patients who have just undergone surgery for the repair of an ascending aortic aneurysm. METHODS: To evaluate the cardiac sympathetic activity in aortic aneurysm, we performed cardiac 123I-metaiodobenzylguanidine (MIBG) imaging on 12 patients (mean age +/- SD, 47 +/- 17 y) before and after the surgical repair of an aneurysm. Seven patients scheduled for coronary artery bypass grafting also underwent 123I-MIBG imaging as controls for open-chest surgery. Planar images were obtained at 15 min (early) and 4 h (delayed) after injection of 111 MBq 123I-MIBG, and the cardiac 123I-MIBG uptake was graded quantitatively and visually. The quantitative evaluation was based on the heart-to-mediastinum ratio (H/M), and visual evaluation was performed by assigning a score of 0-3 (0 = absent, 1 = severely reduced, 2 = reduced, and 3 = normal). Heart rate variability using 24-h Holter electrocardiography was analyzed before and after the operation to generate a time-domain index of heart rate variability as an index of autonomic balance. RESULTS: In patients with aortic aneurysms, both early and delayed H/Ms were significantly decreased after the operation (early H/M: 1.84 +/- 0.16 before vs. 1.40 +/- 0.16 after, P = 0.001; delayed H/M: 1.79 +/- 0.38 before vs. 1.27 +/- 0.18 after, P = 0.004). Visual analysis of 123I-MIBG accumulation in early images showed absence of 123I-MIBG accumulation in 3 of 12 patients, a score of 1 in 7 patients, and a score of 2 in 2 patients. In contrast, no significant difference between H/M before surgery and H/M after surgery was seen in patients who underwent coronary artery bypass grafting. The time-domain index of heart rate variability was significantly lower after the operation than before (135 +/- 40 after vs. 96 +/- 27 before, P < 0.05). CONCLUSION: Cardiac sympathetic nerves are totally or partially denervated after the surgical repair of ascending aortic aneurysm.     

CT prior to second-look operation in ovarian cancer

Second-look surgery is used in restaging patients with ovarian cancer to define sites of recurrence, plan therapy, and perform tumor debulking. We evaluated the role of CT in detecting residual or recurrent tumor in 55 patients in whom 64 abdominopelvic CT scans were obtained. Forty-eight patients underwent a second-look operation, and eight of these patients had an additional third-look operation. CT correctly identified 17 (85%) of 20 cases with residual or recurrent pelvic disease and three (75%) of four cases with bulky abdominal disease. CT failed to detect tumor in any of the five cases with minimal abdominopelvic disease and was able to detect carcinomatosis in only two (8%) of 24 cases. In four cases, CT detected pelvic disease not identified on clinical pelvic examination. On the 56 scans in 48 patients with surgical proof (280 surgical findings), CT had a sensitivity of 40% (22/55) and a specificity of 99% (224/225). In seven additional patients, second-look laparotomy was canceled because of CT findings of extensive, unresectable tumor. We conclude that CT provided valuable information regarding residual or recurrent tumor prior to second- and third-look surgery. In selective cases, CT findings obviated unnecessary surgery. However, the CT's lack of sensitivity in identifying minimal abdominopelvic disease and carcinomatosis precludes its use as a substitute for second-look surgery.     

Die interventionelle/endovaskuläre Therapie des infrarenalen abdominellen Aortenaneurysmas

The catheter-based interventional therapy (endovascular aortic repair EVAR) of abdominal aortic aneurysms (AAA) has gained an established place in the spectrum of therapeutic options. The procedure is characterized by low peri-interventional morbidity and mortality. Multislice computed tomography (CT) has a dominant role in defining the correct indications and in selecting an appropriate stent graft prior to the intervention. The rate of acute conversions could be reduced from 2.9 % to 0?% in our own elective patient population since 2010. In our vascular centre the proportion of patients treated by EVAR was 39.5?% (102 out of 258). The procedure is used routinely in patients who have an increased risk for general anesthesia or open surgery due to concomitant diseases. It is also used in patients with a reduced local operability due to prior surgery, abdominal diseases or radiation therapy. Arterial closure devices allow a completely percutaneous approach in a certain group of patients. However, after EVAR a life-long surveillance is mandatory because delayed therapy failure has been described. In younger patients who do not have a higher risk open surgery is still an option. The paper describes techniques, results und complications of EVAR.     

The additive values of left ventricular function and extent of myocardium at risk to dipyridamole perfusion imaging for optimal risk stratification prior to vascular surgery.

Although the increased risk of cardiac complications in surgical patients with diminished left ventricular ejection fraction (LVEF) is well-established, this method has been supplanted in recent years by assessment of ischaemic burden using myocardial perfusion imaging (MPI). This study was conducted to determine if MPI and LVEF determination provide complementary or redundant information in preoperative evaluation of vascular surgery patients. A total of 101 patients were studied with dipyridamole MPI and radionuclide ventriculography before surgery. Single photon emission tomographic MPI images were scored for defect severity and categorized as either fixed or reflecting ischaemia. Resting left ventricular cavity was also categorized as normal or dilated. LVEF was subdivided into normal (> or = 50%) and abnormal (< 50%). Seventeen patients had cardiac events. Events were more frequent in patients with ischaemia, in patients with a LVEF < 50% and in those with dilated left ventricular chambers. The mean number of ischaemic segments was also higher in the cardiac event group. Higher event rates were seen when a combination of these factors was present. A history of myocardial infarct, congestive heart failure or coronary artery disease was also a significant predictor of subsequent events. Thus, both abnormal left ventricular function and extent of ischaemic myocardium have independent and complementary predictive power for cardiac events in vascular surgery patients.     

Effects of AV delay programming on ventricular resynchronisation: role of radionuclide ventriculography

PURPOSE: Optimal atrioventricular delay (AVD) setting for cardiac resynchronisation therapy, i.e. biventricular pacing in patients with heart failure, remains a formidable challenge. Thus, the purpose of this study was to evaluate the effects of different AVD on inter- and intra-ventricular resynchronisation using phase histograms of radionuclide ventriculography (RNV). METHODS: In 17 consecutive patients (mean age 64 +/- 6 years), RNV was performed 236 +/- 350 days after pacemaker implantation for cardiac resynchronisation therapy. Images were acquired during atrial pacing at 80 bpm and during biventricular pacing with AVD ranging from 80 to 160 ms. Inter-ventricular dyssynchrony was measured by the delay between the mean phase angles of the left and right ventricles. Intra-ventricular dyssynchrony was measured by the standard deviation (SD) of left ventricular phase histograms. RESULTS: Left ventricular (LV) ejection fraction (EF) was inversely correlated to LV dyssynchrony (SD of LV phase histogram, R = -0.82, p < 0.0001). However, the increase in LVEF by biventricular pacing (mean +4.4 +/- 4%) showed only modest correlation to the resulting resynchronisation effect (characterised by a -13 +/- 8 degrees decrease in LV phase histogram SD, R = -0.38, p < 0.0001). CONCLUSION: RNV is helpful in optimising pacing parameters for resynchronisation therapy. Varying AVD did not have a major impact on intra- or inter-ventricular resynchronisation. Thus, the benefit of AVD-based LVEF optimisation seems to result from atrioventricular resynchronisation.     

Prognostic value of serial cardiac 123I-MIBG imaging in patients with stabilized chronic heart failure and reduced left ventricular ejection fraction.

Many studies have shown that a one-time 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphic study during a stable period is useful for determining the prognosis of patients with chronic heart failure (CHF). However, the findings from this imaging modality are well known to be improved by medical treatment for heart failure. Accordingly, this study was performed to determine whether serial 123I-MIBG scintigraphic studies represent a reliable prognostic marker for patients with CHF. METHODS: A total of 208 patients with CHF (left ventricular ejection fraction [LVEF] < 45%) and with no cardiac events for at least 5 mo were identified on the basis of a history of decompensated acute heart failure requiring hospitalization. The delayed percentage of denervation (% denervation), delayed heart-to-mediastinum count (H/M) ratio, and washout rate (WR) were determined from the patients' 123I-MIBG images just before they left the hospital and after they had received 6 mo of treatment. The left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and LVEF were also determined by echocardiography at the same time points. RESULTS: Of the 208 patients, 56 experienced fatal cardiac events during the study. The mean follow-up period was 4.45 +/- 1.82 y. The baseline H/M ratio and WR; follow-up % denervation, H/M ratio, and WR; Delta-% denervation, H/M ratio, and WR; baseline LVEF; follow-up LVEDV, LVESV, and LVEF; and Delta-LVEDV, Delta-LVESV, and Delta-LVEF were significantly worse in the cardiac death group. A Cox regression analysis showed that the Delta-WR was an independent predictor of cardiac death. Moreover, sudden death occurred in 13 of the 56 patients with cardiac death. A Cox regression analysis also showed that the Delta-WR was an incremental predictor of sudden death. The cardiac death-free rate and sudden death-free rate were significantly higher in patients with Delta-WR less than -5% and Delta-WR less than -2% than in patients with Delta-WR greater than or equal to -5% and Delta-WR greater than or equal to -2%. CONCLUSION: Delta-WR obtained from serial 123I-MIBG scintigraphic studies can be useful for predicting cardiac death and sudden death in stabilized patients with CHF.     

二代双源CT MinDose技术与超声心动图在主动脉瓣狭窄术前评估中的对比研究

目的采用双源CT的MinDose技术（MD-DSCT）及二维超声心动图分别评价并比较主动脉瓣狭窄患者的冠状动脉、瓣环直径及心功能。方法回顾性分析33例欲行换瓣治疗的主动脉瓣狭窄患者。MD-DSCT检查仅于全RR间期的10%间期全剂量曝光,于70%RR间期双斜轴向图像重建。超声心动图及MD-DSCT采分别测量左室射血分数（LVEF）和主动脉瓣环直径（AVAD）。结果所有患者MD-DSCT检查评价冠状动脉均获得良好效果。LVEF-2D与LVEF-MD-DSCT有较强的相关性（r=0.96,P〈0.01）。AVAD-2D与AVAD-MD-DSCT有较强的相关性（r=0.91,P〈0.01）。结论 MD-DSCT可以于术前一站式评价主动脉瓣狭窄患者的冠状动脉、LVEF以及AVAD。     

Two-dimensional echocardiography in the diagnosis of intracardiac masses: A prospective study with anatomic validation

The accuracy of two-dimensional echocardiography in the detection of intracardiac masses was verified in 334 patients who underwent cardiac catheterization in our laboratory over 21 consecutive months. A complete two-dimensional echocardiographic (2DE) examination was performed a day before catheterization. The presence or absence of a mass was verified at surgery in 77 patients who successively underwent mitral or aortic valve replacement (51), left ventricular aneurysmectomy with or without myocardial revascularization (25), and resection of atrial myxoma (2). In 32 patients 2DE revealed the presence of a mass-left or right atrial thrombi in 12, left atrial myxoma in 2, left ventricular thrombi in 16, and endocardial vegetations in 2. The other 45 patients were free of intracardiac masses on 2DE. Anatomic verification at surgery revealed the presence of an intracardiac mass in 34 patients. In 30 (true positives) of these, 2DE revealed the mass as well, and in 4 (false negatives) the presence of a mass had not been identified by 2DE. In 2 patients (false positives) the predicted mass was not found at surgery. Absence of a mass was correctly predicted by 2DE in 41 patients (true negatives). Thus 2DE detected intracardiac masses with sensitivity of 88.2% and a specificity of 95.3%. We recommend that 2DE be performed in all patients prior to hemodynamic study and/or cardiac surgery to enable safer management of patients with intracardiac masses during cardiac catheterization and/or cardiac surgery.     

Benefits of quantitative gated SPECT in evaluation of perioperative cardiac risk in noncardiac surgery

Objective Gated single-photon emission computed tomography (G-SPECT) was used to evaluate cardiac risk associated with noncardiac surgery and determine the benefits and indications of this technique for this type of surgery. Materials and methods Patients scheduled to undergo noncardiac surgery under the supervision of anesthesiologists and subjected to preoperative cardiac evaluation using G-SPECT during the 26-month period between June 2000 and August 2002 were followed for the presence/absence of cardiac events (i.e., cardiac death, myocardial infarction, unstable angina, congestive heart failure, or fatal arrhythmia) during surgery and the postoperative period until discharged. Relationships between the occurrence of cardiac events and preoperative G-SPECT findings were evaluated. Results A total of 39 patients underwent G-SPECT; 6 of the 39 exhibited abnormal ejection fraction (left ventricular ejection fraction, LVEF ≤ 50%) and end-systolic volume (ESV ≥ 50 ml). Surgery was suspended for three of these six patients and cardiac events developed in the remaining three patients. Both abnormal perfusion images (PI) and abnormal wall thickening (WT) were observed in all six patients. All six patients exhibited abnormal LVEF and/or ESV. Three patients had either abnormal PI or WT, and a cardiac event occurred in one of them. Of the five patients who experienced cardiac events during or after surgery, two exhibited a short run of ventricular tachycardia requiring a continuous administering of antiarrhythmic drugs, whereas the remaining three patients exhibited cardiac failure requiring inotropic support following surgery. Conclusions The results of this study indicate that the occurrence of perioperative cardiac events can be predicted by considering the severity of expected surgical stress and preoperative G-SPECT findings for LVEF, PI, and WT. We conclude that G-SPECT is quite useful for cardiac risk assessment in patients undergoing noncardiac surgery.     

The utility of urgent abdominal computed tomography in the elderly patient

The purpose of this study was to assess the utility of urgent abdominal computed tomography (CT) performed in a nontrauma setting on a predominantly elderly population. We retrospectively reviewed abdominal CT images of 170 patients (average age, 64 years); CT was performed on a “stat” basis to evaluate suspected acute abdominal pathology at a typical urban Veterans’ Affairs hospital. Imaging results were correlated with subsequent clinical intervention. Abdominal CT was most commonly ordered to assess abdominal pain (119 cases, 71%), suspected abdominal abscess (11 cases, 6.5%), suspected leaking abdominal aortic aneurysm (11 cases, 6.5%), and suspected acute pancreatitis (8 cases, 5%). Clinically relevant findings were recorded in 96 abdominal CT cases (56%), only 23 (13.5%) of which depicted acute pathology. This included nine patients with abscesses, four with diverticulitis, two with nonspecific enteric inflammation, and two with cholecystitis. Only 16 patients (9%) required urgent therapy. The most common clinically relevant findings not requiring prompt intervention were cholelithiasis (11 cases), chronic pancreatitis (9 cases), and liver metastases (6 cases). Of 13 patients with abdominal aortic aneurysm diagnosed on abdominal CT, 11 presented with abdominal pain, but none showed signs of rupture. Although, in a predominantly elderly population, urgent abdominal CT often reveals significant chronic disease, it seldom depicts pathology requiring prompt therapy. Therefore, a more focused use of this examination is warranted.     

Primary Self-Expandable Nitinol Stent Placement in Focal Lesions of Infrarenal Abdominal Aorta: Long Term Results

Purpose To evaluate the technical and clinical success, safety and long term results of percutaneous transluminal angioplasty/self-expandable nitinol stent placement of infrarenal abdominal aorta focal lesions. Materials and Methods Eighteen patients underwent PTA of focal atherosclerotic occlusive disease of distal abdominal aorta. Two symptomatic occlusions and 16 stenoses in 10 male and 8 female patients (mean age 68.2 years) were treated with primary self-expandable nitinol stent placement. Results Primary self-expandable nitinol stent placement was technically successful in all 18 procedures; clinical success was achieved in 100% of patients. No complications associated with the procedure occurred. During the 49.4 months of mean follow up (range 3–96, 4 months) all treated aortic segments remained patent. Conclusions Endovascular treatment (primary self-expandable nitinol stent placement) of focal atherosclerotic lesions of distal abdominal aorta is a safe method with excellent primary technical and clinical success rates and favourable Long term results.     

Immediate postgadolinium spoiled gradient-echo MRI for evaluating the abdominal aorta in the setting of abdominal MR examination

To assess the reproducibility and image quality of immediate postgadolinium chelate spoiled gradient-echo MRI in demonstrating disease of the abdominal aorta. All patients (27 patients: 21 men, 6 women) with substantial disease of the abdominal aorta, who underwent abdominal MR examinations at 1.5 T between 1991 and 1995, were entered in the study. Patients were referred for evaluation of suspected aortic disease (14 patients) or other abdominal diseases (13 patients). Three experienced investigators manually measured luminal and external aortic wall diameters and rated image quality, definition of inner and outer walls, extent of disease, and presence of other abdominal abnormalities, in an independent fashion. A cardiovascular surgeon then rated all studies to determine whether clinical management could be based on the MR findings alone. There was 98 to 99% agreement in measurements of luminal and external wall diameter between the three investigators. Overall image quality was rated as good in 77.8 to 88.9% of patients. A total of 31 additional nonaortic abdominal abnormalities were detected by all observers. The cardiovascular surgeon rated 25 of 27 studies as adequate to determine clinical management based on MR findings alone. Immediate postgadolinium spoiled gradient-echo MRI is a reproducible technique for the demonstration of abdominal aortic disease and possesses good image quality. Advantages of this technique include simultaneous evaluation of other nonvascular diseases of the abdomen, short examination time, and easy implementation as part of routine abdominal MRI scanning protocol.     

Einsatz der Dual-source-Computertomographie in der prä- und postoperativen kardiochirurgischen Diagnostik

PURPOSE: The aim of this study was to evaluate the clinical potential of dual-source computed tomography (DSCT) in pre- and postsurgical diagnostics in the field of cardiac surgery. MATERIAL AND METHODS: A total of 20 patients underwent DSCT of the heart. This CT system with two rotating X-ray tubes (Somatom Definition, Siemens Medical Solutions, Forchheim, Germany) achieves a temporal resolution of 83 ms and a spatial resolution of 0.4 x 0.4 x 0.4 mm. The patient cohort consisted of two subgroups. In a group of ten patients with known coronary artery disease (CAD), scheduled for bypass surgery (i.e., high pretest likelihood for having significant CAD), the results of DSCT coronary angiography (CTA) and invasive quantitative catheter angiography (QCA) were compared to assess the diagnostic accuracy of DSCT in the detection of significant coronary artery stenoses (>50%). In a second group of ten patients with previous aortic valve replacement (homografts), the valve opening area of the transplanted aortic valve graft was measured by DSCT and compared with echocardiography as a standard of reference to exclude postsurgical restenosis of the valve. RESULTS: Of 150 coronary artery segments depicted by CT, 144 (96%) were classified as "assessable." A significant CAD was known in all patients, and altogether 43 significant stenoses were present according to the results of QCA. Blinded to these results, DSCTA reached a sensitivity and specificity of 95% (41/43) and 93% (103/111), yielding a positive and negative predictive value (PPV, NPV) of 79% (31/39) and 98% (103/105), respectively. In patients with aortic valve homografts, all DSCT datasets were considered as being of diagnostic image quality concerning valve depiction. The planimetric evaluation of the CT data as compared to results of echocardiography showed a significant correlation of the results (r=0.64, p=0.0467). A high-grade valve stenosis (opening area <1.0 cm(2)) could be correctly excluded by DSCT in all patients. CONCLUSIONS: Dual-source CT shows great diagnostic potential in patients before or after cardiac surgery. DSCT provides a high diagnostic accuracy for detection of coronary artery stenosis before bypass surgery. DSCT also proved to be accurate in the assessment of patients who received aortic valve replacement.     

The usefulness of dipyridamole thallium-201 single photon emission computed tomography for predicting perioperative cardiac events in patients undergoing non-cardiac vascular surgery

The aim of this study was to evaluate the usefulness of dipyridamole Tl-201 myocardium single photon emission computed tomography (201Tl-SPECT) for predicting perioperative cardiac events in patients with arteriosclerosis obliterans (ASO) and abdominal aortic aneurysm (AAA) undergoing non-cardiac vascular surgery. METHODS: Preoperative dipyridamole 201Tl-SPECT imaging in association with clinical risk assessment was performed in 224 consecutive patients (97 ASO and 127 AAA). RESULTS: The patients were classified into three groups, including low-risk (n = 173, 77%), intermediate-risk (n = 39, 18%), and high-risk (n = 12, 5%) groups according to the clinical risk stratification. The prevalence of reversible Tl-201 defect was significantly higher in the high-risk group than that in the low-risk group (83% vs. 14%, p < 0.001). In 180 patients who underwent vascular surgery, 9 patients (5.0%) had perioperative cardiac events, including heart failure (n = 1), unstable angina (n = 2), and other cardiac events such as arrhythmias (n = 6). The clinical variables including the clinical risk stratification did not significantly correlate with the perioperative cardiac events. In contrast, the reversible defect on 201Tl-SPECT was the only variable to predict perioperative cardiac events by a stepwise logistic regression analysis (odds ratio 7.0, 95% confidence interval 1.7-28.0, p = 0.007). It was also a significant predictor of perioperative cardiac events in a subgroup of low risk patients (odds ratio 11.6, 95% confidence interval 2.3-57.4, p = 0.004). The sensitivity and specificity of the reversible defect for predicting perioperative cardiac events were 55.6% and 84.8% in all operated patients, and 57.1% and 89.7% in low risk patients, respectively. CONCLUSIONS: The preoperative dipyridamole 201Tl-SPECT was useful for predicting perioperative cardiac events in patients with vascular diseases, even in patients identified as having a low risk based on the clinical risk assessment.     

Bowel and mesenteric injury following blunt abdominal trauma: evaluation with CT

Computed tomography (CT) used in cases of blunt abdominal trauma has been found sensitive in detection of bowel and mesenteric injuries and discrimination of operable from nonoperable candidates. In 51 patients with suspected bowel or mesenteric injury following blunt abdominal trauma, CT correctly depicted bowel hematoma or mesenteric injury in 17 of 19 nonoperable patients (89%) and severe injuries in one patient who died preoperatively. In 26 of 28 patients who underwent therapeutic laparotomy (93%), initial CT enabled identification of surgically confirmed injuries. In two cases, initial scan misinterpretation delayed diagnosis of serious bowel injuries. The correct interpretation was rendered preoperatively and at blind retrospective review. CT findings that correlated with bowel or mesenteric injury requiring surgery were free peritoneal fluid (27 of 28, 96%), mesenteric infiltration (24 of 28, 86%), thick-walled bowel (17 of 28, 61%), associated abdominal injuries (12 of 28, 43%), and free air (nine of 28, 32%). In nonoperable cases, CT scans demonstrated bowel thickening (84%) but less frequently peritoneal fluid (21%), mesenteric infiltration (26%), or associated injuries (5%). In three of four patients who underwent nontherapeutic laparotomy, preoperative CT correctly imaged the limited abdominal injuries.     

Preoperative MR imaging of anal fistulas: Does it really help the surgeon?

PURPOSE: To evaluate the accuracy of magnetic resonance (MR) imaging with a quadrature phased-array coil for the detection of anal fistulas and to evaluate the additional clinical value of preoperative MR imaging, as compared with surgery alone. MATERIALS AND METHODS: Fifty-six patients with anal fistulas underwent high-spatial-resolution MR imaging. Twenty-four had a primary fistula; 17, a recurrent fistula; and 15, a fistula associated with Crohn disease. MR imaging findings were withheld from the surgeon until surgery ended and verified, and surgery continued when required. RESULTS: MR imaging provided important additional information in 12 (21%) of 56 patients. In patients with Crohn disease, the benefit was 40% (six of 15); in patients with recurrent fistulas, 24% (four of 17); and in patients with primary fistulas, 8% (two of 24). The difference between patients with or without Crohn disease and between patients with a simple fistula versus the rest was significant (P <.05). The sensitivity and specificity for detecting fistula tracks were 100% and 86%, respectively; abscesses, 96% and 97%, respectively; horseshoe fistulas, 100% and 100%, respectively; and internal openings, 96% and 90%, respectively. CONCLUSION: High-spatial-resolution MR imaging is accurate for detecting anal fistulas. It provides important additional information in patients with Crohn disease-related and recurrent anal fistulas and is recommended in their preoperative work-up.     

Gunshot wounds of abdomen: evaluation of stable patients with triple-contrast helical CT

PURPOSE: To assess helical computed tomography (CT) with contrast material administered intravenously, orally, and rectally (triple contrast helical CT)) in the prospective evaluation of stable patients with abdominal gunshot wounds in whom there is no clinical indication for immediate exploratory laparotomy. MATERIALS AND METHODS: The study was conducted for 19 months. All patients met the following inclusion criteria: age of 16 years or older, hemodynamic stability, no clinical signs of peritoneal irritation, and signed consent to participate. Patients with obvious indications for laparotomy, such as gastrointestinal bleeding or evisceration, were excluded from the study. Forty-seven patients fulfilled the criteria and underwent abdominal triple-contrast helical CT. CT findings were evaluated by one of four radiologists for evidence of peritoneal penetration and injury to solid organs or hollow viscera. Patients were followed up clinically for 13 weeks. CT findings were compared with those at surgery and/or clinical follow-up. RESULTS: CT demonstrated abnormalities in 27 (57%) patients. Laparotomy was performed in 11 (23%) patients; 10 procedures were therapeutic and one was nontherapeutic. The remaining 20 patients had a negative CT scan. These patients were treated conservatively. One injury was missed at CT. For prediction of the need for laparotomy, sensitivity of CT was 96%; specificity, 95%; positive predictive value, 96%; negative predictive value, 95%; and accuracy, 96%. CONCLUSION: In stable patients with gunshot wounds to the abdomen in whom there is no indication for immediate surgery, triple-contrast helical CT can help reduce the number of cases of unnecessary or nontherapeutic laparotomy (negative laparotomy) and can help identify patients with injuries that may be safely treated without surgery.