CT cystography: radiographic and clinical predictors of bladder rupture

OBJECTIVE: Our goal was to identify radiographic and clinical variables that correlate with bladder rupture that may then be used as selection criteria for CT cystography in trauma patients. SUBJECTS AND METHODS: Hemodynamically stable trauma patients with hematuria were examined under standardized protocol with dynamic oral and i.v. contrast-enhanced CT of the abdomen and pelvis, followed immediately by CT cystography. CT cystography consisted of contiguous 5-mm axial scans of the pelvis after retrograde distention of bladder with 300-400 ml of 4% iodinated contrast material. Radiographic and clinical variables (pelvic fracture, pelvic fluid, intraabdominal visceral injury, degree of hematuria, hematocrit, units of blood transfused, base deficit, injury mechanism, seat belt use, sex, age) were assessed and statistically analyzed using the two-tailed Fisher's exact test and Wilcoxon's rank sum test. Positive and negative individual and multivariate predictors were analyzed. RESULTS: Of the 157 patients entered in our study, 12 (eight males and four females) had bladder rupture. One or more pelvic fractures were present in nine (75%) of the 12 patients (p < 0.001). Pubic symphysis diastasis, sacroiliac diastasis, and sacral, iliac, and pubic rami fractures were statistically associated with bladder rupture. Isolated acetabular fractures did not correlate with rupture. Eight (67%) of the 12 patients with bladder rupture revealed on CT cystography had gross hematuria (p < 0.001). No ruptures were seen in patients with <25 RBC/HPF (red blood cells per high-power field). All patients with rupture had pelvic fluid revealed on standard contrast-enhanced CT (p < 0.001). CONCLUSION: Gross hematuria, pelvic fluid, and specific pelvic fractures were highly correlated with bladder rupture; identification of these findings may help in selection of trauma patients for CT cystography.     

Comparison of computed tomography and conventional cystography for detection of traumatic bladder rupture

Computed tomography (CT) is the method of choice for evaluating patients with blunt abdominal and/or pelvic trauma. However, the sensitivity of CT for detecting bladder ruptures has been questioned. We reviewed both the conventional cystograms and the CT examinations of 25 patients who had both studies as the initial evaluation of blunt abdominal and pelvic trauma in the last 5 years. Five of these 25 patients had bladder ruptures, three extraperitoneal and two intraperitoneal. All five injuries were detected by both CT and conventional cystography. In one patient the conventional cystogram was falsely positive. In this case the correct diagnosis was made by CT, and a repeat cystogram confirmed that no bladder injury was present. Our results indicate that CT, if properly performed, is as sensitive for detection of bladder injuries as conventional cystography.     

Comparison of computed tomography and conventional cystography for detection of traumatic bladder rupture

Computed tomography (CT) is the method of choice for evaluating patients with blunt abdominal and/or pelvic trauma. However, the sensitivity of CT for detecting bladder ruptures has been questioned. We reviewed both the conventional cystograms and the CT examinations of 25 patients who had both studies as the initial evaluation of blunt abdominal and pelvic trauma in the last 5 years. Five of these 25 patients had bladder ruptures, three extraperitoneal and two intraperitoneal. All five injuries were detected by both CT and conventional cystography. In one patient the conventional cystogram was falsely positive. In this case the correct diagnosis was made by CT, and a repeat cystogram confirmed that no bladder injury was present. Our results indicate that CT, if properly performed, is as sensitive for detection of bladder injuries as conventional cystography.     

Contrast material in posterior vaginal fornix mimicking bladder rupture: CT features

Abdominopelvic CT of a 22-year-old woman who sustained blunt abdominal trauma revealed a collection of contrast material posterior to the bladder. This CT appearance was interpreted as evidence of bladder rupture, despite previously performed normal retrograde cystography. Subsequent urologic studies confirmed the absence of bladder injury. Retrospective review of CT revealed that collection was within the vagina. This case demonstrates an important false-positive CT diagnosis of bladder rupture and confirms the importance of retrograde cystography for the diagnosis of bladder rupture.     

CT cystography in the evaluation of major bladder trauma.

Computed tomographic (CT) cystography has been advocated in lieu of conventional cystography in the initial work-up of patients with suspected urinary bladder trauma. CT cystography was applied to a classification scheme for bladder injury based on the degree of wall injury and anatomic location and demonstrated characteristic imaging features for each type of injury. In bladder contusion (type 1), findings are normal. In intraperitoneal rupture (type 2), CT cystography demonstrates intraperitoneal contrast material around bowel loops, between mesenteric folds, and in the paracolic gutters. Manifestations of interstitial injury (type 3) include intramural hemorrhage and submucosal extravasation of contrast material without transmural extension. In extraperitoneal rupture (type 4), the path of extravasated contrast material is variable: Extravasation is confined to the perivesical space in simple extraperitoneal ruptures, whereas in complex extraperitoneal ruptures, contrast material extends beyond the perivesical space and may dissect into a variety of fascial planes and spaces. Combined intra- and extraperitoneal rupture (type 5) usually demonstrates extravasation patterns that are typical for both types of injury. Familiarity with these CT cystographic features allows accurate classification of bladder injury and allows prompt, effective treatment with less radiation exposure than and without the added cost of conventional cystography.     

CT cystography in the evaluation of bladder trauma

At our trauma center we have replaced plain film cystography with CT cystography to evaluate trauma patients with hematuria sent for emergent CT of the abdomen and pelvis. Ten cases of ruptured bladders evaluated by CT are tabulated, and characteristic images are presented.     

Detection of pancreatic fluid and urine leakage after pancreas transplantation: value of CT and cystography

Leakage from the urinary bladder or duodenal stump after pancreas transplantation with urinary bladder drainage of the graft is difficult to diagnose clinically. We retrospectively reviewed our experience with fluoroscopic cystography and CT to determine their relative merit in the diagnosis of pancreatic fluid and urine leakage as documented by surgical exploration in pancreas transplant recipients. Thirteen leaks were diagnosed by fluoroscopic cystography or by CT in 11 patients after pancreas transplantation with urinary bladder drainage of pancreatic fluid. Conventional retrograde fluoroscopic cystography showed 11 leaks; CT with retrograde bladder opacification showed three leaks. Of the five CT studies that did not show a leak and that also were done within 7 days of a cystogram with abnormal findings, failure to use retrograde bladder opacification accounted for the majority (three cases) of missed diagnoses. Focal or free peritoneal abdominal fluid was seen in all CT examinations, with extravasation of contrast material seen into both walled-off collections and free ascites. Our experience suggests that retrograde bladder and duodenal stump opacification should be a routine part of the CT evaluation performed to detect leakage from the urinary bladder or duodenal stump after pancreas transplantation.     

Utility of routine trauma CT in the detection of bladder rupture

RATIONALE AND OBJECTIVES: The purpose of this study was to determine the frequency with which routine computed tomography (CT) fails to depict bladder rupture, the potential utility of delayed CT scans, and whether these findings might be useful in determining which patients may require subsequent cystography. MATERIALS AND METHODS: Cystograms and abdominal and pelvic CT scans of 54 patients with blunt trauma and in whom bladder rupture was clinically suspected were retrospectively reviewed. Blind readings of CT scans were performed by two genitourinary radiologists. Cystograms were used as the standard. RESULTS: Cystograms depicted bladder rupture in 10 patients. On CT scans, extravesical fluid was depicted in all three patients with intraperitoneal bladder rupture (although only a small amount of pelvic intraperitoneal fluid was present in two of these patients), in all seven patients with extraperitoneal bladder rupture, and in 32 of the 44 patients without bladder injury. Contrast material had been excreted into the bladder at the time of the initial or delayed CT in eight patients with bladder rupture; however, extravasation was identified in only four of the eight. In two of the four patients without extravasation, the bladder was distended at the time of CT. No bladder injuries were found in the 12 patients in whom pelvic fluid was not identified on CT scans. CONCLUSION: The absence of pelvic fluid on a trauma CT scan indicates that bladder rupture is unlikely. Even when a partially opacified bladder is passively distended, bladder injury may be present despite the absence of contrast material extravasation.     

Bladder injury in blunt pelvic trauma

Clinical and radiologic findings in 97 patients with bladder injury secondary to blunt pelvic trauma were reviewed. Fifty-five patients had extraperitoneal bladder rupture; 35, intraperitoneal rupture; two, interstitial bladder injury; and five, combined intraperitoneal and extraperitoneal bladder rupture. Of the 61 of 97 patients with film studies available for review, two patients with surgically proved intraperitoneal rupture had false-negative cystograms. In two other cases of intraperitoneal rupture, the diagnosis was established with cystography but was not demonstrated with urography. All cases of extraperitoneal rupture were demonstrated cystographically; in 15 cases in this group, the injury was complex, with extravasation of contrast material beyond the confines of the perivesical space. In two additional patients, incomplete bladder injury termed "interstitial bladder rupture" was identified. A classification of bladder injury based on cystographic patterns of extravasation is proposed.     

The sentinel clot sign: a useful CT finding for the evaluation of intraperitoneal bladder rupture following blunt trauma.

OBJECTIVE: To evaluate the frequency and relevance of the "sentinel clot" sign on CT for patients with traumatic intraperitoneal bladder rupture in a retrospective study. MATERIALS AND METHODS: During a recent 42-month period, 74 consecutive trauma patients (45 men, 29 women; age range, 12-84 years; mean age, 50.8 years) with gross hematuria were examined by the use of intravenous contrast-enhanced CT of the abdomen and pelvis, followed by retrograde cystography. Contrast-enhanced CT scanning was performed by using a helical CT scanner. CT images were retrospectively reviewed in consensus by two radiologists. The CT findings including the sentinel clot sign, pelvic fracture, traumatic injury to other abdominal viscera, and the degree of intraperitoneal free fluid were assessed and statistically analyzed using the two-tailed x(2) test. RESULTS: Twenty of the 74 patients had intraperitoneal bladder rupture. The sentinel clot sign was seen for 16 patients (80%) with intraperitoneal bladder rupture and for four patients (7%) without intraperitoneal bladder rupture (p < 0.001). Pelvic fracture was noted in five patients (25%) with intraperitoneal bladder rupture and in 39 patients (72%) without intraperitoneal bladder rupture (p < 0.001). Intraperitoneal free fluid was found in all patients (100%) with intraperitoneal bladder rupture, irrespective of an associated intraabdominal visceral injury, whereas 19 (35%) of the 54 patients without intraperitoneal bladder rupture had intraperitoneal free fluid (p < 0.001). CONCLUSION: Detection and localization of the sentinel clot sign abutting on the bladder dome may improve the accuracy of CT in the diagnosis of traumatic intraperitoneal bladder rupture, especially when the patients present with gross hematuria.     

MRI for the diagnosis of blunt abdominal trauma: a case report

Blunt abdominal trauma is a leading cause of trauma related mortality. Currently, the gold standard in the radiographic evaluation of intra-abdominal injury is computed tomography (CT) with iodinated contrast material. However, in the setting of renal failure or a previous anaphylactic reaction to contrast material, radiographic evaluation of the trauma patient may prove difficult. Without contrast material, the sensitivity of CT in the diagnosis of solid organ injury is diminished. We present a case report and literature review of magnetic resonance imaging in the evaluation of blunt abdominal trauma.     

Blunt abdominal trauma: utility of 5-minute delayed CT with a reduced radiation dose

PURPOSE: To retrospectively evaluate the utility of 5-minute delayed computed tomography (CT) of the abdomen and pelvis by using a reduced radiation dose in patients with blunt abdominal trauma. MATERIALS AND METHODS: Institutional review board consent was obtained, and written informed consent was waived. The study was HIPAA compliant. A total of 662 patients (497 men, 165 women; mean age, 40.5 years; range, 18-94 years) were identified who were evaluated with CT after blunt abdominal trauma during a 1-year period. Delayed CT scans were acquired 5 minutes after intravenous contrast material injection by using a decreased tube current of 100 mAs. Injury was identified in 106 patients. Two radiologists blinded to initial CT scan interpretation reviewed these cases to determine the quality and utility of delayed scans. Disagreement was settled by consensus. Delayed scans were considered useful when they aided in (a) characterizing initial CT findings, (b) identifying findings not present at initial CT, (c) excluding injury suggested at initial CT, and (d) increasing reader confidence with regard to initial CT findings. RESULTS: All delayed scans were diagnostic. Delayed scans were useful in 27% (12 of 44) of patients with solid organ injury, 5.9% (one of 17) of patients with bowel or mesenteric injury, 4.5% (one of 22) of patients with pelvic fractures, and in none of the patients with free fluid only. Overall, delayed CT was useful in 2.1% (14 of 662) of all patients (95% confidence interval: 1.0, 3.2) referred for evaluation following blunt abdominal trauma. Utility increased to 13.2% (14 of 106) (95% confidence interval: 6.8, 19.7) in the group of patients with injury or suspected of having injury after initial CT. CONCLUSION: If delayed CT scans are acquired when patients with blunt abdominal trauma are evaluated, selective, rather than routine, acquisition is recommended and a reduced radiation dose seems adequate.     

Emergency excretory urography in blunt abdominal trauma

In a prospective study the authors correlated the degree of hematuria and of blunt abdominal trauma with the results of emergency excretory urography. Urograms were obtained for 37 patients who presented with blunt abdominal trauma, no gross hematuria and at least five erythrocytes per high-power field (hpf) on microscopic urinalysis. Microscopic hematuria was defined as an erythrocyte count of more than 5 and fewer than 50 per hpf. Major trauma was defined as shock (systolic blood pressure of less than 90 mm Hg), fracture of the lumbar spine, the pelvis or the lower ribs, ecchymosis in the flank or acute abdominal injury. Contusions and small subcapsular hematomas were defined as nonsignificant renal injuries; all other renal injuries were defined as significant. Of 17 patients with minor blunt abdominal trauma 14 had fewer than 50 erythrocytes per hpf; none of these had a significant renal injury, whereas 1 of the 3 with more than 50 erythrocytes per hpf did have a significant injury. Of 20 patients with major trauma 5 had a significant renal injury. The authors conclude that microscopic hematuria associated with blunt abdominal trauma but without shock or major nongenitourinary injury does not warrant routine excretory urography.     

Blunt abdominal trauma: screening us in 2,693 patients

PURPOSE: To evaluate the accuracy of screening abdominal ultrasonography (US) in patients with blunt abdominal trauma. MATERIALS AND METHODS: Patients with blunt abdominal trauma underwent US. The abdomen and pelvis were scanned for free fluid, the visceral organs were assessed for heterogeneity, and duplex US was performed if necessary. Empty bladders were filled with 200-300 mL of sterile saline through a Foley catheter. US findings were considered positive if free fluid was present or if parenchymal abnormalities that could be consistent with trauma were detected. Screening US results were compared with findings of diagnostic peritoneal lavage, repeat US, computed tomography (CT), cystography, surgery, and/or autopsy and/or the clinical course. RESULTS: Findings from 2,693 US examinations were evaluated and were positive in 145 of 172 patients with injuries (sensitivity, 84%) and 64 (89%) of 72 patients who ultimately underwent laparotomy with surgical repair of injuries. False-negative findings were retroperitoneal injury, bowel injury, and intraperitoneal solid organ injury without hemoperitoneum. No patient with false-negative findings died. Specificity of US was 96% (2,429 of 2,521 patients), and overall accuracy was 96% (2,574 of 2,693 patients). Positive predictive value was 61% (145 of 237 patients), and negative predictive value was 99% (2,429 of 2,456 patients). CONCLUSION: Abdominal US is useful in screening for injury in patients with blunt abdominal trauma, and its use represents a notable change in institutional practice. Diagnostic peritoneal lavage is rarely performed, and CT is used when screening US findings are positive, when injury is clinically suspected despite negative US findings, or when US is not available.     

Screening US for blunt abdominal trauma: objective predictors of false-negative findings and missed injuries

PURPOSE: To determine the risk for missed injury in patients with blunt abdominal trauma and negative findings at screening ultrasonography (US) and with coexistent hematuria or fracture of the sixth through 12th ribs, lumbar spine, or pelvis. MATERIALS AND METHODS: From a database of 4,000 patients screened with US for blunt abdominal trauma at a level 1 trauma center, the 3,679 patients with negative US findings were retrospectively classified by consensus of two authors into high-risk (n = 494) and low-risk (n = 3,185) groups based on the presence of hypothetical predictors of missed injury: hematuria (n = 96) or fracture of the sixth through 12th ribs (n = 216), lumbar spine (n = 105), or pelvis (n = 174). Outcome in each patient was determined by the same two authors consensually after retrospective review of the trauma registry and all radiologic, surgical, and autopsy reports. The risk for missed abdominal injury was determined for each patient risk group and for each hypothetical predictor. Risks were statistically compared by using the Pearson chi2, Fisher exact, or Fisher-Freeman-Halton exact test, depending on expected frequencies. RESULTS: High-risk patients were 24 times more likely to have abdominal injuries after negative US findings (30 [6.1%] of 494) than were low-risk patients (eight [0.25%] of 3,185) (P <.001). Among high-risk patients, the absolute risks for missed abdominal injury associated with specific predictors were 15.6% (15 of 96 patients) for hematuria, 6.0% (13 of 216) for lower rib fractures, 7.6% (eight of 105) for lumbar spine fractures, and 5.2% (nine of 174) for pelvic fractures. Each of these risks was significantly higher for patients in the high-risk group than for those in the low-risk group (P <.001). CONCLUSION: Hematuria and fracture of the lower ribs, lumbar spine, or pelvis are objective predictors of missed abdominal injury in patients with blunt abdominal trauma and negative US findings, and such patients may benefit from additional screening with computed tomography.     

CT cystography and virtual cystoscopy in the assessment of new and recurrent bladder neoplasms

OBJECTIVE: To determine if CT cystography and virtual cystoscopy have a role in the assessment of neoplasms of the urinary bladder. MATERIAL AND METHODS: Twenty five adults suspected of having bladder tumours underwent CT cystography. Twenty three had subsequent virtual cystoscopic reconstructions from the axial data. The examinations were reviewed by two radiologists and the findings were correlated with those at conventional cystoscopy. RESULTS: Seventeen masses larger than 0.5 cm were identified by CT cystography in 16 patients. Two patients had normal CT cystography, but one had small recurrent neoplasms on conventional examination. Seven patients had nodular mucosal irregularities which were subsequently shown to be neoplastic in three. Accuracy for diagnosis of neoplasm in all patients was 88%. CONCLUSION: CT cystography is very accurate at identifying masses larger than 0.5 cm and can show mucosal abnormalities as small as 2 mm. It is minimally invasive and can be diagnostic when conventional cystoscopy is inconclusive. It can indicate appropriate areas for assessment and biopsy at conventional examination. Virtual cystoscopy gave comparable views to conventional cystoscopy, but did not add diagnostic information. It is not likely to replace conventional cystoscopy, but may be helpful in occasional circumstances where the latter is inconclusive, or can not be performed.     

Evaluation of blunt abdominal trauma using PACS-based 2D and 3D MDCT reformations of the lumbar spine and pelvis

OBJECTIVE: The purpose of this study was to show the value of 2D and 3D reformations of CT data from abdominal and pelvic CT performed immediately at the workstation using a PACS-based software program to evaluate the lumbar spine and pelvis in patients with blunt abdominal trauma. MATERIALS AND METHODS: We reviewed the abdominopelvic CT scans and conventional radiographs of the lumbar spine or pelvis of 156 consecutive patients with blunt abdominal trauma. The CT data were compared with the radiographic findings and also with the findings of dedicated repeat CT of the spine or pelvis, when performed. RESULTS: CT depicted 80 fractures of the lumbar spine and 178 pelvic fractures. Radiography showed 40 fractures of the lumbar spine and 138 pelvic fractures. No additional fractures were identified on dedicated repeat CT. CONCLUSION: Conventional radiographs to clear the lumbar spine are no longer required when abdominopelvic CT data are available. CT and reformatted CT data show more fractures than radiography and miss no fractures compared with dedicated CT of the lumbar spine or pelvis. Having these images immediately available through the PACS workstation saves time for the trauma team in the management of critically ill patients.     

腹部闭合性创伤的急诊CT评价

目的：探讨急诊CT扫描在腹部闭合性创伤中的应用价值。方法：收集整理经手术或临床证实的腹部闭合性创伤65例急诊CT检查的影像资料,进行回顾性分析,所有病例均行CT平扫。结果：腹部闭合性创伤的急诊CT扫描主要表现为混杂高密度影像,多伴腹腔出血。本组65例腹部闭合性创伤中,肝脏损伤15例、脾26例、肾13例,肠系膜与肠管损伤2例,膀胱破裂2例,复合性实质性脏器损伤7例。其中51例伴腹腔出血,22例合并肋骨骨折。结论：急症CT扫描对诊断腹部闭合性创伤具有很大的价值,能明确腹部脏器损伤的部位、程度及复合性脏器损伤等信息,以指导临床医师制定有效的治疗方案。     

Role of multi-detector computerized tomography in diagnosis of traumatic urinary bladder injuries

Background

Urinary tract injuries occur in 3–10% of abdominal trauma. Early recognition and diagnosis of ruptured bladder is essential to lower this mortality rate. CT is the method of choice for the evaluation of patients with blunt or penetrating abdominal and/or pelvic trauma. Imaging in patients with suspected bladder injury with CT cystography may be performed using either an intravenous or retrograde technique.

CT evaluation of pediatric abdominal trauma: pitfalls and quandaries

CT of the pediatric abdomen after blunt trauma has become a widely accepted technique for evaluation of hepatic and splenic injury. However, detection of hollow viscus and pancreatic injury remains challenging and controversial. Detection of bowel rupture (extravasated oral contrast, bowel discontinuity), pancreatic injury (laceration, separation of fragments) and bladder rupture may be difficult, particularly with inadequate technique and lack of vigilance. This article reviews findings associated with several injuries which may present diagnostic pitfalls as well as technical factors relating to the administration of enteric contrast and CT cystography.