CT findings of secondary aorto-enteric fistulae

PURPOSE: The aim of our study was to review CT findings concerning secondary aorto-enteric fistulae (AEF). In particular, we aimed to evaluate signs of contrast medium extravasation from the aortic graft into the bowel (active bleeding), in correlation with clinical and surgical reports. MATERIALS AND METHODS: Clinical and CT findings were retrospectively evaluated in 13 surgically proven cases of AEF. All patients underwent spiral CT examination with biphasic contrast technique, before and 30 and 80 seconds after intravenous injection of 120-150 ml of contrast medium (Ultravist 370; flow rate 2.5-3 ml/sec). Late scans (240 seconds) were also acquired on surgical anastomoses. We used 3 mm (arterial phase) and 5 mm (venous phase) slices. RESULTS: At surgery, all 13 patients presented a communication between the bowel and the aortic graft. At CT examination, all 13 patients presented one or more CT signs indicating AEF (perigraft soft tissue, perigraft fluid, ectopic air or bowel wall thickening). Moreover, in 6 out of 13 patients, contrast medium extravasation from the aortic graft into the small bowel (active bleeding) was detected with CT. Detection of active bleeding was possible because CT examinations were performed without oral administration of contrast medium. CONCLUSIONS: CT is easily and readily available and provides an accurate evaluation of the aorta and surrounding retroperitoneal tissues. In our study we were able to identify the CT sign of active bleeding in more than a half of the patients with acute gastrointestinal bleeding (66%). Hence, we suggest that patients undergo CT examination without oral contrast medium administration in order to better appreciate the presence of active bleeding.     

CT of aortoenteric fistulas

We compared CT findings with endoscopic, angiographic and surgical results in ten patients suspected of having an aortoenteric fistula (AEF) because of gastrointestinal bleeding (seven) or recurrent sepsis (three). CT correctly diagnosed AEF in six patients and excluded it in the other four. CT findings of AEF consisted of perigraft fluid (PGF) (5/6) and/or gas within the bed of the graft (4/6) later than three months after graft surgery. All six patients with AEF had perigraft infections; PGF with gas was found in 50%, PGF alone in 33%, and in one patient perigraft gas alone was found. Angiography and endoscopy failed to identify AEF. Our findings indicate that CT should be the initial imaging procedure in patients with suspected AEF who do not require immediate surgical intervention.     

Aortic prosthetic graft infections: radiologic manifestations and implications for management.

Prosthetic graft infections are an uncommon complication of aortic bypass. These infections may have serious sequelae such as limb loss and can be lethal. They are hard to eradicate and, under certain circumstances, difficult to diagnose. Usually, computed tomography (CT) is the most efficacious imaging method for diagnosis of graft infections due to its quick availability. The sensitivity of magnetic resonance imaging in detection of perigraft infection has not been thoroughly investigated but is probably similar to that of CT. After the early postoperative period, persistent or expanding perigraft soft tissue, fluid, and gas are the CT findings of graft infection. Aortoenteric fistula should be considered a subset of aortic graft infection; however, perigraft air is more likely to be seen with an aortoenteric fistula. Other conditions associated with graft infection include pseudoaneurysm, hydronephrosis, and osteomyelitis. Adjunctive studies such as sinography, ultrasonography, gallium scanning, and labeled white blood cell scanning can be quite useful in diagnosis, determination of the extent of disease, and selection of the treatment modality. White blood cell scanning is an important complementary test to CT in ambiguous cases, such as in the early postoperative period, and may be more sensitive in detection of early graft infection.     

CT平扫对Bouveret综合征的诊断价值

目的探讨多层螺旋CT平扫对Bouveret综合征的诊断价值。资料与方法回顾性分析7例经手术证实的Bouveret综合征患者的CT表现及临床资料。结果 7例CT平扫均见肠腔内异位结石,结石上方肠梗阻,梗阻以下肠管空虚;胆道及胆囊积气2例,胆囊窝结构紊乱伴积气5例。结石位于空肠1例,位于回肠6例。1例随访可见胆石梗阻部位移动。结石呈圆形或类圆形,直径3～5 cm,高密度阳性结石4例,低密度阴性结石3例。7例术前CT平扫确诊为Bouveret综合征,准确率为100%。结论单纯CT平扫能对Bouveret综合征进行确诊,"肠袢扩张、胆系积气、异位结石"为Bouveret综合征三大重要的CT平扫表现。     

盆腔器官外软组织肿瘤的CT诊断

目的 探讨盆腔器官外软组织肿瘤的CT表现及其诊断价值。材料与方法 回顾性分析经手术病理证实的30例原发性盆腔器官外软组织良、恶性肿瘤的CT表现。其中间叶源性肿瘤15例,神经源性肿瘤8例,胚胎残余组织源性肿瘤5例,腹膜间皮细胞肿瘤2例。结果 原发于盆腔器官外软组织肿瘤较少见,CT表现为囊性肿块者均为良性,囊实性或实性者以恶性居多。虽然肿瘤来源于多种不同组织,但CT表现可各有其特征。结论 CT是诊断盆腔器官外肺瘤的重要影像学手段,能明确肿瘤范围以及肿瘤与周围组织的关系及其性质。     

胸壁肿块的CT诊断

目的分析胸壁肿块的CT表现,提高其诊断水平。方法 30例临床证实的胸壁肿块患者均经CT平扫,10例又经增强扫描。对所有患者的CT表现进行了回顾性分析。结果在CT像上,胸壁结核(5例)表现为胸壁内软组织密度肿块影;细菌性脓肿(4例),表现为局限性软组织肿块影,密度不均匀;脂肪瘤(4例)表现为胸壁内局限性脂肪密度肿块影;神经源性肿瘤(5例)表现为胸壁内密度均匀、边界清楚的软组织肿块影;血管瘤(1例)表现为左侧胸壁散在条状迂曲的软组织密度肿块影,增强后明显强化;胸膜间皮瘤(3例),其中良性者(2例)表现为局限性胸膜增厚,恶性者(1例)表现为弥漫性胸膜增厚伴胸腔积液;胸膜转移瘤(3例)表现为胸膜结节状增厚;肋骨转移瘤(4例)表现为胸膜结节状增厚;Askin瘤(1例)表现为右侧胸壁内及胸膜处软组织肿块影伴邻近肋骨骨质破坏。结论 CT对胸壁肿块的定位及良、恶性鉴别具有重要价值,尤其64排螺旋CT及其后处理技术更有利于其诊断与鉴别诊断。     

胸部腹外型侵袭性纤维瘤病的CT表现

目的：分析发生于胸部的腹外型侵袭性纤维瘤病的CT表现,提高对本病的诊断水平。方法：回顾性分析19例经手术病理证实的胸部侵袭性纤维瘤病患者的CT 表现。19例均行 CT 平扫,9例行增强扫描,1例行 CTA 检查。结果：19例共检出23个病灶,其中3例为多发病灶（发生于软组织1例、骨骼2例）。病变位于软组织15例共16个病灶（两侧和前胸壁8个、背部5个、肩部1个、腋窝1个）,位于骨骼4例共7个病灶（肋骨5个、胸肋关节1个、胸骨上段1个）。16个软组织肿块中呈类圆形或梭形13个,分叶形或不规则形3个;边界不清13个,边界清晰3个（其中2个有假包膜）;CT平扫表现为等或低密度肿块14个,囊实性肿块2个,3个病灶内可见钙化（分别呈点状、弧形和爆米花样）;增强扫描9例共10个病灶中,表现为轻度均匀强化2个,明显不均匀强化2个,边缘轻度强化1个,边缘明显强化2个,轻中度不均匀强化2个,多发小圆形轻中度环形强化1个;5个病灶可见肿瘤与骨质粘连伴骨质破坏。4例共7个骨骼病灶,CT 平扫6个表现为骨内软组织肿块、膨胀性骨质破坏（1个出现周缘硬化边）,1个表现为软组织肿块伴有局限性骨皮质压迫吸收;肿块呈较低密度3个,等或稍低密度3个,稍高密度1个;1例行增强扫描,肿瘤呈轻度～中度不均匀强化。结论：胸部侵袭性纤维瘤病的CT表现有一定特征性,CT对本病具有较高的诊断价值。     

肾上腺肿瘤的CT诊断(附46例分析)

目的:探讨肾上腺肿瘤在CT上的表现特点,以提高对该部位肿瘤的认识。方法:收集46例肾上腺肿瘤,回顾分析CT特征,对照病理结果进行讨论。结果:46例中,皮质腺瘤21例,多数较小,边缘光滑,轻度强化;转移瘤7例,单侧或双侧,密度均匀或不均匀;嗜铬细胞瘤6例,肿块一般较大,密度不均,增强后实质部分强化明显;髓性脂肪瘤6例,瘤内脂肪组织为其特征;皮质腺癌3例,较大肿块,直径一般大于7 cm,密度不均;肾上腺囊肿2例,边缘光滑,均匀水样密度的囊性占位,增强扫描无强化;非何杰金淋巴瘤1例,双侧发生,软组织密度肿块,强化较均匀。结论:肾上腺肿瘤CT表现各有特征,结合临床表现和生化检查可作出较为正确的诊断。     

Endovascular repair of the abdominal aortic aneurysm with the ancure endograft: CT follow-up of perigraft flow and aneurysm size at 6 months

PURPOSE: Perigraft flow--flow outside the graft lumen but contained within the abdominal aortic aneurysm (AAA)--is a potential complication after endovascular repair of AAA. Such flow may permit AAA growth and rupture. The purpose of this study is to evaluate with computed tomography (CT) the rate of spontaneous closure of perigraft flow and the effect of persistent flow on AAA diameter. MATERIALS AND METHODS: During a 30-month period, the authors evaluated all CT scans in 50 patients who underwent AAA repair using the Ancure endograft system. CT was performed at discharge, 6, 12, and 24 months, and at 3 months if there was perigraft flow at discharge. Scans were reviewed for the presence, size, and location of perigraft flow, and measurement of AAA diameter. Transcatheter embolization was performed on those patients with persistent leak at 6 months. RESULTS: Sixteen (32%) of 50 patients demonstrated perigraft flow on CT performed within 72 hours of placement. Resolution of perigraft flow by 6 months was found in nine (56%) of the 16 patients, in whom AAA size had decreased in five, had increased in none, and was unchanged in four. Seven patients had persistent leaks at 6-month CT; AAA size had decreased in one, had increased in one, and was unchanged in five. In 34 patients without leaks, AAA size had decreased in nine, had increased in one, and was unchanged on 24. There was no statistically significant difference for the relationship between resolution or persistence of perigraft flow and subsequent course of AAA diameter (P = .16). CONCLUSIONS: Although perigraft flow is frequently seen (32%) early after repair of AAA with the Ancure system, spontaneous resolution by 6 months occurs in 56% of cases. AAA size decreased in a larger percentage of patients in whom perigraft leak was absent or resolved by 6 months compared with those in whom perigraft leak persisted at 6 months.     

Descending thoracic aortic aneurysm: thoracic CT findings after endovascular stent-graft placement.

PURPOSE: To evaluate the usefulness of thoracic computed tomography (CT) after placement of an endovascular stent-graft for the treatment of descending thoracic aortic aneurysm. MATERIALS AND METHODS: From 1992 to 1996, 85 patients with thoracic aortic aneurysm underwent stent-graft placement. In 63 patients, thoracic CT scans were obtained both before and within 10 days after placement. The CT findings were retrospectively studied, and their clinical effect analyzed. In 20 of 63 patients, long-term follow-up CT findings were also evaluated. RESULTS: After stent-graft placement in the 63 patients, CT demonstrated an increase in pleural effusion in 46 (73%), periaortic changes in 21 (33%), perigraft leak in 13 (21%), atelectasis in six (10%), mural thrombus within the stent-graft in two (3%), and new aortic dissection in one (2%). The mean maximum diameter of the aneurysm was 58.8 mm before and 60.0 mm after stent-graft insertion. Sixty-two (98%) patients were successfully treated until discharge. Interventional procedures were performed to eliminate the leakage into the aneurysm sac in 10 patients with perigraft flow depicted at CT. Other complications were managed conservatively. CONCLUSION: Thoracic CT is useful in the treatment of patients after stent-graft insertion for the management of descending thoracic aortic aneurysm.     

Intrathoracic complications following allogeneic bone marrow transplantation: CT findings

The authors retrospectively reviewed computed tomographic (CT) scans of 18 patients who developed 21 episodes of intrathoracic complications after allogeneic bone marrow transplantation (BMT). Pathologic and/or microbiologic diagnoses were available for all patients. All patients were immunocompromised due to either graft-versus-host disease (GVHD), neutropenia, or recurrent malignancy after BMT. CT demonstrated diagnostically relevant findings that were not apparent at radiography in 12 of the 21 cases (57%). These included a ground-glass pattern in early pneumonia (n = 5); a peripheral distribution in GVHD, bronchiolitis obliterans organizing pneumonia, and eosinophilic drug reaction (n = 4); cavitating lesions in Pneumocystis carinii pneumonia (n = 1); hemorrhagic infarcts in aspergillosis (n = 1); and mediastinal adenopathy in recurrent Hodgkin disease (n = 1). The authors conclude that chest CT is superior to radiography in demonstrating the presence, distribution, and extent of intrathoracic complications developing in patients after allogeneic BMT. CT is useful in guiding procedures for tissue diagnosis.     

侵袭性肺曲菌病的CT表现

目的 探讨侵袭性肺曲菌病（ＩＰＡ）的ＣＴ表现。方法 经病理及临床证实的ＩＰＡ８例,均行常规ＣＴ扫描,２例４周后ＣＴ复查。结果 ＣＴ表现为肿块样浸润（３例）;炎症样病变（３例）;多发结节（２）。结论 ＩＰＡ的早期ＣＴ征象有肿块,多发结节,实变;ＣＴ“晕轮征”的出现强烈提示的早期诊断。     

Periportal lymphatic distension resulting from cardiac tamponade: CT findings and clinical-pathologic correlation

Purpose: To correlate computed tomography (CT) findings with clinical-pathologic results and discuss the possible significance of periportal hypodensity in patients with clinical cardiac tamponade secondary to acute proximal thoracic aortic dissection, aneurysm, or heart rupture. Materials and methods: In a retrospective review of thoracoabdominal CT scans and records of 17 consecutive patients with hemopericardium, 10 patients with clinical signs of cardiac tamponade associated with hypodensity around the portal vein were selected; at surgery or autopsy all 10 patients had a thoracic aortic aneurysm, dissecting aneurysm, and heart rupture. The ratio of transverse inferior vena cava diameter to the diameter of the aorta at the level of the right adrenal gland was determined. Results: Abdominal CT scans showed focal (n = 1) or diffuse (n = 9) areas of hypodensity around the portal vein associated with pericaval hypodensity in four cases. Other abdominal abnormalities included persistent enhancement of renal parenchyma (n = 5), and gallbladder wall edema (n = 2); in nine cases the inferior vena cava diameter was significantly increased compared with that of patients with normal findings on CT scans (P < 0.01). Pathologic correlation, available in nine cases by autopsy, showed evidence of periportal lymphatic vessel dilatation and lymphedema. Conclusions: Periportal hypodensity on CT scans corresponds to the histopathologic picture of dilated lymphatic vessels or hepatic lymphedema; a diagnosis of hepatic lymphedema may be considered on the basis of CT scans in patients with pericardial effusion.     

动脉瘤样骨囊肿的影像学诊断

目的：探讨动脉瘤样骨囊肿（ABC）的影像学特点。资料与方法：回顾性分析23例经手术病理证实的ABC的影像学表现，23例均摄X线平片和CT平扫。4例行MRI检查。结果：23例ABC发生于长骨18例，骨盆5例。ABC平片表现常为偏心性膨胀性骨破坏；CT平扫可见膨胀的骨壳内缘呈清晰弧形压迹，其中骨壳完整12例，断缺11例。病灶密度不均，19例可见蜂房样低密度影或液－液平面，15例出现软组织肿块；4例MRI主要表现为T1WI呈等低信号，T2WI呈大小不一高信号囊腔或液－液平面，3例增强扫描，2例无明显强化，1例轻度强化，囊间隔在T1WI、T2WI及增强后均为低信号。结论：X线平片简便经济，但对内部结构的显示有一定限度，CT和MR对内部结构及软组织的显示明显优于前者，对ABC具有很高的诊断价值。     

Incorporation versus infection of retroperitoneal aortic grafts: MR imaging features

The magnetic resonance (MR) imaging characteristics of normal aortic graft healing were compared with those of perigraft infection in 57 patients after aortic graft implantation. Thirty-three patients without postoperative complications underwent MR imaging in a 0.35-T unit 1 week after graft implantation, and 13 of those patients were reexamined 2-3 months after graft implantation. Twenty-four patients with clinically suspected perigraft infection underwent MR imaging 6 weeks to 18 years after graft implantation. Early normal postoperative changes were characterized by a perigraft collar of low to medium signal intensity on T1-weighted images and of high intensity on T2-weighted images in all 33 cases, consistent with perigraft fluid collection. In 10 of 13 patients reexamined 2-3 months postoperatively, the MR images demonstrated a collar of tissue consistent with perigraft fibrosis. In cases of clinical suspicion of retroperitoneal graft infection, MR imaging showed eccentric fluid collections of low to medium signal intensity on T1-weighted images and high intensity on T2-weighted images at more than 3 months after surgery. The MR findings were diagnostic of retroperitoneal perigraft infection in 17 of 20 patients shown to be infected at surgery. Retroperitoneal infection was correctly excluded on the basis of MR findings in four patients. Thus, MR imaging is an accurate imaging method for the diagnosis of aortic graft infection. In the early postoperative phase, resolving perigraft fluid cannot be differentiated from perigraft infection.     

Pleuropulmonary paragonimiasis: radiologic findings in 71 patients.

Pleuropulmonary paragonimiasis is a disease caused by lung flukes characterized by migration of a juvenile worm in the early stage and by formation of cysts around the worm later on. The purpose of this study was to describe the radiologic manifestations of pleuropulmonary paragonimiasis, with special emphasis on the worm cyst and worm migration track. We retrospectively studied 71 patients who had evidence of pleuropulmonary paragonimiasis on chest radiographs (n = 71) and CT scans (n = 17). The diagnosis was based on the detection of eggs or on positive antibody tests. On chest radiographs, 59 patients (83%) had pulmonary lesions and 43 patients (61%) had pleural lesions. Pulmonary findings included patchy air-space consolidation (n = 37) with or without cystic changes; ring shadows (n = 16); and peripheral linear opacities (n = 29), which were more prominent in patients with pleural effusion. Twelve patients (17%) had bilateral pleural effusions or pneumothoraces. On CT scans, round low-attenuation cystic lesions (5-15 mm), filled either with fluid (n = 5) or gas (n = 5), were characteristically seen within the consolidation. Peripheral linear opacities seen on radiographs were suggestive of worm migration tracks on CT scans. CT may reveal an intracystic worm. Although the findings vary depending on the stage of the disease, findings on chest radiographs are usually typical of paragonimiasis. CT provides more specific information about the worm cyst and the worm migration track.     

Bronchopulmonary sequestration: CT assessment

Computed tomographic (CT) scans of 24 bronchopulmonary sequestrations in 23 patients were reviewed. Seventeen sequestrations were diagnosed at surgery, three at angiography, and four on the basis of radiographic or CT findings combined with appropriate history. Sixteen sequestrations were intralobar, and eight were extralobar; 21 were posterobasal. Seventeen occurred on the left side and seven on the right. Anomalous systemic arterial supply was demonstrated by CT in 16 sequestrations. In the others, a systemic artery was not shown, presumably because of unfavorable orientation or small size of the vessel. The lung abnormalities shown by CT were classified into three types: A = cysts containing air or fluid (n = 8), or soft-tissue masses (n = 2); B = emphysematous lung surrounding cysts, and/or soft-tissue nodules (n = 13); and C = lung hypervascularity (n = 2). In only three cases did the chest radiograph show the emphysematous lung tissue. Such emphysematous lung has rarely before been reported as a CT finding, and lung hypervascularity has not, to the authors' knowledge, been reported. The authors conclude that CT can be helpful in the diagnosis and evaluation of bronchopulmonary sequestration. Characteristic manifestations are (a) a complex lesion containing solid or fluid components combined with emphysematous lung or (b) any basal lesion supplied by a systemic artery.     

Possible small-bowel neoplasms: contrast-enhanced and water-enhanced multidetector CT enteroclysis

PURPOSE: To prospectively evaluate the sensitivity and specificity of contrast material-enhanced and water-enhanced multidetector computed tomographic (CT) enteroclysis in depicting small-bowel neoplasms in symptomatic patients, with endoscopic, tissue, and follow-up findings as reference standards. MATERIALS AND METHODS: The study protocol was approved by the Human Research Committee of the institution, and all patients gave written informed consent. Two hundred nineteen patients (108 male, 111 female; age range, 17-98 years; mean, 53.1 years) with clinical suspicion of small-bowel neoplasm underwent contrast- and water-enhanced multidetector CT enteroclysis after normal findings of upper and lower gastrointestinal endoscopy. The prospective interpretations of CT enteroclysis results include evaluation of focal bowel wall thickening, small-bowel masses, small-bowel stenosis, mesenteric stranding, enlarged mesenteric lymph nodes, and visceral metastasis. Positive enteroclysis findings were compared with results of pathologic examination after surgical (n = 35) or endoscopic (n = 20) procedures. Negative results were compared with results of surgery (n = 8), enteroscopy (n = 15), capsule endoscopy (n = 14), and clinical follow-up (n = 127). Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated on a per-patient basis with 95% confidence intervals. RESULTS: Findings of CT enteroclysis were positive in 55 cases and negative in 164. The overall sensitivity and specificity in identifying patients with small-bowel lesions were 84.7% and 96.9%, respectively. The negative and positive predictive values were 94.5% and 90.9%, respectively. Findings of pathologic examination confirmed small-bowel tumor in 50 patients with carcinoid tumor (n = 19), adenocarcinoma (n = 7), lymphoma (n = 5), jejunal adenoma (n = 9), stromal tumor (n = 5), ectopic pancreas (n = 2), angiomatous mass (n = 2), or metastasis (n = 1). Five examinations resulted in false-positive findings. CONCLUSION: Contrast- and water-enhanced multidetector CT enteroclysis had an overall accuracy of 84.7% for depiction of small-bowel neoplasms.     

AEF值评估肝硬化门静脉高压TIPS术疗效的应用价值

目的探讨常规CT三期类灌注参数动脉增强分数(AEF)值在肝硬化门静脉高压(PHT)行TIPS术后疗效评价中的应用价值。方法回顾性分析行TIPS术的30例PHT患者术前1周内、术后4~6周内的常规CT三期类灌注扫描图像。按照术后患者临床表现,分为治疗有效组和无效组。应用软件计算AEF值,AEF值为(动脉期CT值-平扫期CT值)/(门静脉期CT值-平扫期CT值),将结果与术后患者临床表现相结合并进行统计学分析。结果术后较术前AEF值明显增高(0.521±0.093 vs 0.446±0.057,Z=-4.214,P<0.05);有效组25例(出血治疗有效23例,腹腔积液治疗有效2例),无效组5例(出血治疗无效2例,腹腔积液治疗无效3例),有效组较无效组AEF值明显增高(0.533±0.098 vs 0.463±0.021,Z=-2.198,P<0.05),差异有统计学意义。以术后AEF值0.501为临界值预测TIPS术后短期内疗效,敏感性和特异性分别为60%和100%,曲线下面积为0.816(P<0.001)。结论常规CT三期类灌注扫描参数AEF值可能能定量评估肝硬化门静脉高压行TIPS术后短期内的疗效。     

螺旋CT在肝脓肿诊断中的应用

目的：评价螺旋CT、双期扫描对肝脓肿的诊断价值。方法：回顾性分析经临床或病理证实的28例肝脓肿的螺旋CT表现，所有病例均行平扫及螺旋CT双期增强扫描，其中5例经薄层重建后在工作站行表面遮盖重建(SSD)，并经切割处理，显示其冠、矢状位图像。结果：28例中，平扫表现为类圆形边缘不清楚的低密度灶17例，多房或簇状9例，不规则形1例，脓腔内积气1例。增强扫描动脉期28例均表现为病灶边缘极轻或轻度环状强化，其中有15例(53．5％)出现灶周楔形或片状一过性强化；门脉期显示簇状征9例，边缘强化10例，环靶征8例；另1例平扫为不规则形，增强扫描动脉期灶周出现明显楔形一过性强化，门脉期病灶内呈不规则强化，为较特殊表现。5例三维图像直观地显示了脓肿的立体形态和位置。结论：螺旋CT双期扫描对肝脓肿诊断有重要应用价值。动脉期的灶周楔形或片状一过性强化是肝脓肿又一重要CT表现，对诊断有指导意义。