Bladder trauma: multidetector computed tomography cystography

Multidetector computed tomography (MDCT) cystography is rapidly becoming the most recommended study for evaluation of the bladder for suspected trauma. This article reviews the bladder trauma with emphasis on the application of MDCT cystography to traumatic bladder injuries using a pictorial essay based on images collected in our level I trauma center.     

Acute knee trauma: analysis of multidetector computed tomography findings and comparison with conventional radiography

Purpose: To evaluate the multidetector computed tomography (MDCT) findings of acute knee trauma and to compare radiography with MDCT in patients referred to a level 1 trauma center.

Material and Methods: During a 5-year period, a total of 415 MDCT examinations were performed on 409 patients with acute knee trauma to reveal complex fracture anatomy or rule out a fracture. MDCT and primary radiographs were re-evaluated with respect to fracture location and trauma mechanism. Tibial plateau fractures were further analyzed depending on anatomical location: anterior-medial, anterior-lateral, posterior-lateral, and posterior-medial regions. Maximal depression of the tibial articular surface was measured. Findings on the primary knee radiographs were compared with MDCT findings.

Results: Of the 409 patients, 356 (87%) had a knee fracture. A total of 451 fractures were found in all anatomic regions: distal femur (n = 49), proximal tibia (n = 307), patella (n = 23), and proximal fibula (n = 72). Primary radiographs were available in 316 (76%) cases. Of these, 225 (71%) had MDCT in order to reveal the fracture anatomy better, and 91 (29%) had a subsequent MDCT after negative plain radiographs. Overall sensitivity of radiography was 83%, while negative predictive value was 49%. On radiography, tibial plateau articular depression was underestimated in all regions except when the fracture consisted of the whole half of the anterior or posterior plateau. The three main injury mechanisms were traffic accident, a simple fall, and sport. In 49 cases (15%), primary radiographs were suboptimal due to positioning.

Conclusion: In severely injured patients, diagnostically sufficient radiographs are difficult to obtain, and therefore a negative radiograph is not reliable in ruling out a fracture. In these patients, MDCT is a fast and accurate examination and is also recommended in patients with tibial plateau fractures or complex knee injuries in order to evaluate the fracture adequately.     

Improved pelvicalyceal visualization with multidetector computed tomography urography; comparison with helical computed tomography

Our aim was to compare the quality of pelvicalyceal visualization on computed tomography (CT) urography using a small intravenous contrast material dose, hydration, and high-resolution multidetector CT (MDCT) with that of conventional helical CT. The test (MDCT) group (49 consecutive patients, 98 kidneys) was scanned 5 min following an intravenous bolus of 30 ml of iodinated contrast material. The control (helical CT) group (50 consecutive patients, 95 kidneys) was scanned 5 min following injection of 120–150 ml of intravenous contrast material. Enhancement and quality of calyceal detail were measured using a five-scale grading system (1 for no detail, 5 for cupped calyces). Calyceal attenuation was substantial in both groups (more than 220 Hounsfield units, HU) but less in the test group compared with the control group (mean 475 and 920 HU, respectively), p<0.0001. In the test group, the calyceal attenuation was less than 500 HU in the majority of cases (65/98 kidneys), while the opposite was true for the control group, where calyceal attenuation was more than 750 HU in 50/95 kidneys (p<0.001). The quality of calyceal detail was 3.4/5 in the test group compared with 1.8/5 in the control group (p<0.0001). The combination of hydration, low-contrast dose, and the high image resolution achieved with MDCT significantly improves calyceal visualization in CT urography.     

High-resolution computed tomography with single-slice computed tomography and 16-channel multidetector computed tomography: a comparison regarding visibility and motion artifacts

Background: High-resolution computed tomography is the image procedure of choice in the evaluation of interstitial lung disease. Multidetector-row computed tomography provides the possibility of simultaneous reconstruction of thin and thick slices from the same raw data, acquired from one single series. Thus, it may be tempting to exclude the step-and-shoot series.

Purpose: To compare high-resolution computed tomography (HRCT step-and-shoot) from single-slice CT (SSCT) and 16-channel multidetector CT (MDCT) in terms of visibility and motion artifacts, and to investigate whether thin images reconstructed from helical MDCT are equal to or better than conventional HRCT by SSCT in terms of visibility and motion artifacts.

Material and Methods: 20 patients underwent HRCT step-and-shoot by SSCT (SSCT step-and-shoot) and MDCT (MDCT step-and-shoot), and a helical MDCT acquisition (MDCT helical). Images from four anatomical levels were analyzed in random order regarding visibility and motion artifacts.

Results: Visibility using MDCT step-and-shoot was significantly better than or equal to SSCT step-and-shoot for segmental bronchi and fissures, but not for subsegmental bronchi. For MDCT helical, visibility was equal to or better than SSCT step-and-shoot for segmental bronchi, but not for fissures and subsegmental bronchi. Concerning motion artifacts, MDCT step-and-shoot and MDCT helical were significantly better than or equal to SSCT step-and-shoot.

Conclusion: The image quality (accounting for motion artifacts and visibility) of SSCT step-and-shoot and MDCT step-and-shoot is comparable. The visibility of anatomic structures in images from MDCT helical is inferior to HRCT step-and-shoot.     

Interruption of the aortic arch: diagnosis with multidetector computed tomography

Purpose

We investigated retrospectively the usefulness of multidetector computed tomography (MDCT) in the preoperative diagnosis of interruption of the aortic arch (IAA).

Materials and methods

Seven neonates with IAA underwent enhanced MDCT before a surgical repair operation between April 2006 and March 2010. The MDCT procedures were performed using either a 16- or 64-MDCT scanner without electrocardiographic gating or respiratory arrest.

Results

High-quality CT images were obtained in all cases. One patient was diagnosed to be IAA type A, and 6 were diagnosed to be IAA type B (Celoria and Patton classification). The Celoria and Patton classification of IAA types and subtype classification by MDCT were confirmed by surgery.

Conclusion

Our results show that the information from MDCT was sufficient for a preoperative diagnosis of IAA and allowed omission of a cardiac catheter examination before surgery.     

Violence-related facial trauma: analysis of multidetector computed tomography findings of 727 patients

Objectives

The multidetector CT (MDCT) findings of facial trauma in victims of interpersonal violence were assessed.

Methods

All MDCT requests for suspected facial injury during a 62 month period were retrieved; 727 cases met the inclusion criteria. Images were interpreted by two researchers by consensus.

Results

Of the 727 patients (aged 15–86 years old, mean 37), 583 (80.2%) were male and 144 (19.8%) female. Of all the patients, 74% had a fracture, and of these 44% had multiple non-contiguous fractures.

Conclusions

Violence is a very common cause of facial injury. Nasal and orbital fractures predominate. Males are more often involved; they are younger, sustain fractures more often and significantly more often present with high-energy fracture patterns. LeFort fractures are often unilateral or asymmetrical, and are frequently accompanied by other, clinically significant fractures. Up to 25% of patients with fractures do not have paranasal sinus effusions.     

Detection of hepatocellular carcinoma: comparison of dynamic three-phase computed tomography images and four-phase computed tomography images using multidetector row helical computed tomography

PURPOSE: The purpose of our study was to assess the value of additional early arterial phase computed tomography (CT) imaging in the detection of hepatocellular carcinoma (HCC) by comparing three-phase and four-phase imaging by using multidetector row helical CT. METHODS: Twenty-five patients with 33 HCCs underwent four-phase helical CT imaging. The diagnosis was established by pathologic examination after surgical resection in 19 patients and by biopsy in six. Four-phase CT imaging comprises early arterial, late arterial, portal venous, and delayed phase imaging obtained 25 seconds, 45 seconds, 75 seconds, and 180 seconds after the start of contrast material injection using multidetector row helical CT. Three-phase CT images (late arterial, portal venous, and delayed phase) and four-phase CT images (early arterial, late arterial, portal venous, and delayed phase) were interpreted independently for the detection of HCC by three blinded observers on a segment-by-segment basis. Sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve (Az) for three-phase CT images and four-phase CT images were calculated. The enhancement pattern of HCC was analyzed on early arterial and late arterial phase imaging. RESULTS: The mean sensitivity of three- and four-phase CT images was 94% and 93%, respectively. The differences between sensitivities were not statistically significant (all p > 0.05). The mean specificities of three- and four-phase CT images were 99% and 98%, respectively. The differences between the specificities were not statistically significantly (all p > 0.05). Neither were the mean areas under the ROC curve for four-phase CT images (Az = 0.976) and three-phase CT images (Az = 0.971) statistically significant (p > 0.05). On early arterial phase imaging, 16 HCCs were hyperattenuating and 17 HCCs were isoattenuating. On late arterial phase imaging, 24 HCCs were hyperattenuating and nine HCCs were isoattenuating. CONCLUSIONS: Additional early arterial phase imaging did not improve the detection of HCC compared with three-phase CT images, including late arterial, portal venous, and delayed phase imaging.     

Gastric volvulus through a Morgagni hernia: multidetector computed tomography diagnosis

Hernia through the foramen of Morgagni (HM) is uncommon in adults, accounting for only 3% of all treated diaphragmatic hernias. We report a very rare case of acute gastric volvulus producing within this type of hernia. It was found in an 81-year-old man presenting with symptoms of acute gastric outlet obstruction. The diagnosis was first suspected on plain abdominal and chest radiographs, but a safe and complete anatomic preoperative diagnosis was clearly achieved with multidetector computed tomography (MDCT). The paper refers to the basic anatomy, clinical symptoms, diagnostic, and therapeutic considerations for HM and emphasizes the major advantages of MDCT in acute surgical conditions implicating the thoracic abdominal junction.     

Anomalous origin of right coronary artery: diagnosis and dynamic evaluation with multidetector computed tomography

16 slice multidetector CT findings of an anomalous right coronary artery originating from the left sinus of Valsalva are presented. Multidetector CT depicted the malignant coronary anomaly in great anatomic detail as well as enabled dynamic evaluation through the cardiac cycle, documenting a substantial reduction in arterial diameter during peak systole. This case illustrates the full capabilities of multidetector cardiac CT in the evaluation of coronary artery pathology.     

Postoperative multidetector computed tomography angiography after aneurysm clipping: comparison with digital subtraction angiography

OBJECTIVES: To evaluate the usefulness of multidetector computed tomography angiography (MDCTA) as a noninvasive diagnostic modality for the detection of aneurysm remnants after clipping of intracranial aneurysms. METHODS: Thirty-eight patients who had aneurysm clipping and had undergone MDCTA and digital subtraction angiography (DSA) were enrolled in this study. In 16 of the 38 patients, MDCTA was performed with 16-channel MDCTA, in 20 patients with 4-channel MDCTA, and in 2 with both. Two neuroradiologists evaluated the image quality of MDCTA with a 3-point rating scale and the presence of the residual aneurysm sac with a 5-point rating scale. Receiver operating characteristic analysis was used to measure the diagnostic performance of MDCTA. RESULTS: Forty-nine surgically clipped aneurysms were evaluated in this study. The overall diagnostic accuracy of MDCTA was 88.1% (95% confidence interval: 0.761-0.954). The ability of 16-channel MDCTA to discriminate between surgical clips and parent vessels was superior to that of 4-channel MDCTA (P=0.005). CONCLUSION: Multidetector computed tomography angiography is a valuable noninvasive diagnostic modality for the assessment of aneurysm remnants in patients after aneurysm clipping.     

Liver imaging with multidetector helical computed tomography

The speed and flexibility of multidetector computed tomography (MDCT) have led to improvements in liver imaging, particularly related to the detection and characterization of focal lesions. This report discusses the different phase of liver enhancement following the bolus administration of iodinated contrast material, and the enhancement pattern of various liver lesions during these phases. We also propose guidelines for designing protocols for MDCT of the liver and discuss the principles of contrast media delivery.     

Diagnostic accuracy of multidetector computed tomography for patients with suspected scaphoid fractures and negative radiographic examinations

Purpose  

The aim of this prospective study was to evaluate the diagnostic accuracy of multidetector computed tomography (MDCT) in detecting occult scaphoid fractures.     

Preoperative staging of colorectal cancer: accuracy of single portal venous phase multidetector computed tomography

In this study, we aimed to investigate the accuracy of single portal venous phase multidetector computed tomography (MDCT) in preoperative staging of colorectal cancer. MDCT, surgery, and pathological results of 159 patients with pathologically proven colorectal adenocarcinoma were evaluated retrospectively. In T staging, the accuracy was 96% for ≤ T2 tumors, 92% for T3 tumors, and 96% for T4 tumors. In N staging, the accuracy was 68% for N0 tumors, 74% for N1 tumors, and 71% for N2 tumors. In conclusion, the accuracy of single portal venous phase MDCT is reasonably high in T staging, but it is not sufficiently high enough in N staging.     

Preoperative staging accuracy of multidetector row computed tomography for extrahepatic bile duct carcinoma

PURPOSE: This study sought to evaluate the accuracy of multidetector computed tomography (MDCT) for preoperative staging of extrahepatic bile duct (EHD) carcinoma and to assess the value of coronal reformations from isotropic voxels. MATERIALS AND METHODS: Thirty patients with surgically proven EHD cancer underwent dynamic MDCT with coronal reformation. Two experienced radiologists independently evaluated contrast-enhanced dynamic transverse CT images (axial approach) and combined transverse and coronal images (combined approach). The radial extent (TNM staging) and the vertical extent of tumors were assessed and correlated with pathological findings of surgical specimen. RESULTS: All of primary tumors were detected by axial and combined CT imaging (100%). Overall accuracy of the T staging was 73% (22/30) with axial and 77% (23/30) with combined CT imaging (P>0.05). The accuracy of N staging was 57% (17/30) with axial and 63% (19/30) with combined CT imaging (P>0.05). The accuracy of M staging was 97% (29/30) with both axial and combined CT imaging.Upper margin accuracy was 97% (29/30) for axial and 100% for combined CT imaging (P>0.05), whereas that of the lower margin was 90% (27/30) for axial and 93% (28/30) for combined CT imaging (P>0.05). CONCLUSIONS: Multidetector computed tomography was sufficiently accurate for evaluating the vertical extents, but radial extents of EHD cancer. The addition of coronal reformatted images did not improve the accuracy for staging of EHD cancer.     

钝性胸部伤早期救治中64排螺旋CT的应用

目的探讨64排螺旋CT在钝性胸部伤早期救治中的作用。方法回顾性分析2006年1月以来收治的170例钝性胸部伤，单纯胸部伤74例，多发伤96例，胸部伤AIS2—4分，平均3．2分；多发伤ISS11～34分，平均24．6分。其中到院后3小时内64排螺旋CT检查160例，平均8分钟。结果诊断肺挫伤117例，肺挫裂伤及肺内血肿19例，肺不张24例，血胸67例，气胸45例，血气胸52例，纵隔血肿7例，纵隔积气8例，皮下气肿25例，膈疝17例，肋骨骨折103例，连枷胸34例。143例（84．1％）经非手术处理，其中43例行胸腔闭式引流术，22例行机械呼吸支持。紧急剖胸手术27例（15．9％）。治愈161例，死亡9例（5．3％）。结论胸部钝性伤初次评价在有条件时应首选采用64排螺旋CT扫描。     

钝性胸部伤早期救治中64排螺旋CT的应用

目的 探讨64排螺旋CT在钝性胸部伤早期救治中的作用.方法 回顾性分析2006年1月以来收治的170例钝性胸部伤,单纯胸部伤74例,多发伤96例,胸部伤AIS 2～4分,平均3.2分;多发伤 ISS 11～34分,平均24.6分.其中到院后3小时内64排螺旋CT检查160例,平均8分钟.结果 诊断肺挫伤117例,肺挫裂伤及肺内血肿19例,肺不张24例,血胸67例,气胸45例,血气胸52例,纵隔血肿7例,纵隔积气8例,皮下气肿25例,膈疝17例,肋骨骨折103 例,连枷胸34例.143例(84.1%)经非手术处理,其中43例行胸腔闭式引流术,22例行机械呼吸支持.紧急剖胸手术27例(15.9%).治愈161例,死亡9例(5.3%).结论 胸部钝性伤初次评价在有条件时应首选采用64排螺旋CT扫描.     

Detection of intracranial aneurysms with 64 channel multidetector row computed tomography: comparison with digital subtraction angiography

PURPOSE: To compare the contribution of 64 channel multidetector row computed tomography angiography (64MDCT-angiography) with digital subtraction angiography (DSA) in the detection of intracranial aneurysms. METHODS AND MATERIALS: Twenty-nine patients (10 males and 19 females, age: 40-84 years; average: 61.9 years) with clinical and imaging findings strongly suggesting the presence of subaracnoid hemorrhage underwent 64MDCT-angiography and DSA with a short interval between the two examinations (less than 12 h-5 days). CT parameters were: 64 mm x 0.5 mm collimation, pitch-0.828 and helical pitch-53. DSA were performed with standard technique (four vessel catheterization) and multiple projections. Axial CT scans as well as maximum intensity projection, volume rendering and multiplanar reformations and angiographic views were independently reviewed by four readers (two for 64MDCT-angiography and two for DSA). Consensus was reached for discordant cases. DSA was considered as the standard of reference. RESULTS: In 29 patients, 28 aneurysms were found (14 patients had 1 aneurysm, 4 patients had 2 aneurysms and 2 patients had 3 aneurysms; in 9 patients no aneurysm were found). 64MDCT-angiography detected 26/28 aneurysms. No false-positive sites were recognized. The sensitivity, specificity, positive and negative predictive values and diagnostic accuracy were, respectively, 92.8, 100, 100, 99.4 and 99.5%. CONCLUSIONS: 64MDCT-angiography is helpful in detecting intracranial aneurysms with results similar to those of DSA but with less discomfort and risks for the patients and can be considered for the first line imaging technique. Conventional angiography is still needed in doubtful cases or negative MDCT-angiography associated with a strong clinical suspect.