Imaging of renal trauma: a comprehensive review.

Computed tomography (CT) is the modality of choice in the evaluation of blunt renal injury. Intravenous urography is used primarily for gross assessment of renal function in hemodynamically unstable patients. Selective renal arteriography or venography can provide detailed information regarding vascular injury. Retrograde pyelography is valuable in assessing ureteral and renal pelvic integrity in suspected ureteropelvic junction injury. Ultrasonography is useful in detecting hemoperitoneum in patients with suspected intraperitoneal injury but has limited value in evaluating those with suspected extraperitoneal injury. Occasionally, radionuclide renal scintigraphy or magnetic resonance imaging may prove helpful. Renal injuries can be classified into four large categories based on imaging findings. Category I renal injuries include minor cortical contusion, subcapsular hematoma, minor laceration with limited perinephric hematoma, and small cortical infarct. Category II lesions include major renal lacerations extending to the medulla with or without involvement of the collecting system and segmental renal infarct. Category III lesions are catastrophic renal injuries and include multiple renal lacerations and vascular injury involving the renal pedicle. Category IV injuries are ureteropelvic junction injuries. CT is particularly useful in evaluating traumatic injuries to kidneys with preexisting abnormalities and can help assess the extent of penetrating injuries in selected patients with limited posterior stab wounds. Integration of the imaging findings in renal injury with clinical information is critical in developing a treatment plan.     

CT在肾创伤诊断与分类中的价值

目的评价CT在肾损伤的诊断和分类中的价值。方法回顾性分析76例肾损伤的CT表现。结果76例中单纯性肾挫伤9例，单纯性肾内血肿7例，肾挫裂伤24例，单纯性肾包膜下血肿10例，肾撕裂伤21例，肾撕裂伴血肿及尿外渗2例，单纯性肾周血肿3例，合并腹内脏器伤41例，下位肋骨骨折18例。同时，所有患者的肾损伤是依据CT表现分为4大类型。结论螺旋CT能明确诊断肾损伤，并确定损伤类型，为临床制定治疗方案提供重要依据。     

Blunt diaphragmatic lesions: Imaging findings and pitfalls

Blunt diaphragmatic lesions (BDL) are uncommon in trauma patients, but they should be promptly recognized as a delayed diagnosis increases morbidity and mortality. It is well known that BDL are often overlooked at initial imaging, mainly because of distracting injuries to other organs. Sonography may directly depict BDL only in a minor number of cases. Chest X-ray has low sensitivity in detecting BDL and lesions can be reliably suspected only in case of intra-thoracic herniation of abdominal viscera. Thanks to its wide availability, time-effectiveness and spatial resolution, multi-detector computed tomography (CT) is the imaging modality of choice for diagnosing BDL; several direct and indirect CT signs are associated with BDL. Given its high tissue contrast resolution, magnetic resonance imaging can accurately depict BDL, but its use in an emergency setting is limited because of longer acquisition times and need for patient’s collaboration.     

<Emphasis Type="Bold">Multi-detector computed tomography findings of atypical blunt traumatic aortic injuries: a pictorial review</Emphasis>

Traumatic injuries to the aorta are a significant source of morbidity and mortality in trauma patients, which highlights the importance of rapid diagnosis and treatment. Multi-detector row computed tomography has become the primary imaging modality for the imaging assessment of the polytrauma patient because it is fast, noninvasive, and the data sets can be used to create tailored multi-planar reformatted images that optimally display the location and morphology of aortic trauma and its relationship to adjacent structures. Although the classic location of blunt injury to the aorta occurs just distal to the left subclavian artery, aortic injuries may occur at any location along the aorta and in any patient population. Radiologists should be prepared to evaluate these types of injuries in nontraditional planes that are tailored to each examination and to present the data to clinicians using commercially available 3D software for purposes of surgical planning. Here, we review in pictorial form atypical aortic injuries with emphasis on multi-planar reformations.     

Serious horse-riding accidents: imaging findings and evaluation with multi-slice CT

Purpose: To assess acute phase multi-slice CT findings in horse-riding accidents in patients referred to a level one trauma center. Methods: Using PACS, we retrieved all CT requests during a time period of 19 months. Patients who had a horse-riding accident and were examined with multi-slice CT were included. The imaging findings of multi-slice CT were retrospectively evaluated by location and injury mechanism. Results: Forty-six patients (3 male, 43 female, age 16–55 years, mean age 30) were assessed. The injuries we found were five head, three facial, 13 spine, five body, two pelvic, and three lower extremity trauma. Multiple injuries were seen in five (11%) patients. In 21 patients (46%) the initial multi-slice CT examination(s) was normal. Three main injury mechanisms were established; falling off a horse (72%), a horse kick (11%), and crushing injury caused by a falling horse (13%). Fifteen (33%) patients had serious injuries, one lethal and they were associated more frequently with falling off a horse. Conclusion: Serious injuries with horse riding accidents are not uncommon. In two thirds of patients, the injury mechanism was falling off a horse. Multiple injuries were seen in 11% of cases. In the acute phase, multi-slice CT provided fast and valuable information in assessing these injuries. Electronic Publication     

Abdominal crush injury in the Sichuan earthquake evaluated by multidetector computed tomography

AIM:To investigate the features of abdominal crush injuries resulting from an earthquake using multidetector computed tomography(MDCT). METHODS:Fifty-one survivors with abdominal crush injuries due to the 2008 Sichuan earthquake underwent emergency non-enhanced scans with 16-row MDCT. Data were reviewed focusing on anatomic regions including lumbar vertebrae,abdominal wall soft tissue, retroperitoneum and intraperitoneal space;and types of traumatic lesions. RESULTS:Fractures of lumbar vertebrae and abdominal wall soft tissue injuries were more common than retro-and intraperitoneal injuries(P<0.05).With regard to the 49 lumbar vertebral fractures in 24 patients,these occurred predominantly in the transverse process(P<0.05),and 66.67%of patients(16/24) had fractures of multiple vertebrae,predominantly two vertebrae in 62.5%of patients(10/16),mainly in L1-3 vertebrae in 81.63%of the vertebrae(40/49). Retroperitoneal injuries occurred more frequently than intraperitoneal injuries(P<0.05),and renal and liver injuries were most often seen in the retroperitoneum and in the intraperitoneal space,respectively(all P< 0.05). CONCLUSION:Transverse process fractures in two vertebrae among L1-3 vertebrae,injury of abdominal wall soft tissue,and renal injury might be features of earthquake-related crush abdominal injury.     

Multi-detector row computed tomography and blunt chest trauma

Blunt chest trauma is a significant source of morbidity and mortality in industrialized countries. The clinical presentation of trauma patients varies widely from one individual to another and ranges from minor reports of pain to shock. Knowledge of the mechanism of injury, the time of injury, estimates of motor vehicle accident velocity and deceleration, and evidence of associated injury to other systems are all salient features to provide for an adequate assessment of chest trauma. Multi-detector row computed tomography (MDCT) scanning and MDCT-angiography are being used more frequently in the diagnosis of patients with chest trauma. The high sensitivity of MDCT has increased the recognized spectrum of injuries. This new technology can be regarded as an extremely valuable adjunct to physical examination to recognize suspected and unsuspected blunt chest trauma.     

An approach to medical imaging for sports-related injuries

Medical imaging plays a valuable role in the evaluation and management of sports-related injuries. Although most acute injuries can be evaluated satisfactorily by clinical assessment and standard radiographs, some types of injuries require additional imaging for localization and characterization. The more advanced technologies (bone scintigraphy, computed tomography [CT], and magnetic resonance imaging [MRI]) provide sensitive physiological or detailed anatomic information in evaluating the athletes complaints. Stress injuries are common sports-related injuries, and they are detected most frequently by bone scintigraphy. Pars interarticularis injuries of the spine are best identified by bone scintigraphy. Other anatomic regions of stress injury include upper extremity complaints from throwing sports and lower extremity symptoms from running and jumping activities.When the management of symptoms is uncertain based on clinical assessment and plain radiographs and the area of involvement is not well defined, bone scintigraphy is extremely sensitive to injuries causing increased bone turnover. To show detailed anatomy, the cross-sectional modalities (CT and MRI) are without equal. CT allows exquisite bone detail when subtle injuries, particularly in areas of complex anatomy, are suspected at a specific site. MRI is the procedure of choice when bone marrow and soft-tissue injuries are of concern in a specific anatomic region.     

The impact of magnetic resonance on the diagnostic evaluation of acute cervicothoracic spinal trauma

From 1984 to 1987 magnetic resonance (MR) imaging was performed on 100 patients suffering acute spinal trauma. MR demonstrated one or more injuries to the cervicothoracic region in 31 patients. It displayed a spectrum of spinal cord injury ranging from mild compression and swelling to complete transection. MR was also useful in evaluating alignment at the cervicothoracic junction, in depicting ligamentous injury, in establishing the presence of disc herniation, and in identifying unsuspected levels of injury. We present a diagnostic algorithm that incorporates the role of MR in evaluating acute cervicothoracic spinal trauma and emphasizes the replacement of myelography by MR in the initial assessment of neurologic deficit.     

Assessing potential spinal injury in the intubated multitrauma patient: does MRI add value?

The purpose of the study was to determine the role of magnetic resonance imaging (MRI) in intubated multitrauma patients with normal computed tomography (CT) in excluding unstable ligamentous injury to the cervical spine. A retrospective evaluation was done on those multitrauma patients admitted to the intensive care unit of a level 1 trauma centre who had normal single-slice helical CT cervical spine and underwent MRI for cervical spine clearance from 1/1/04 to 30/6/05. Fifty-five patients met the inclusion criteria. Ten of these patients had a discoligamentous injury identified on MRI; however, all these patients had injuries limited to only one of the three columns of the cervical spine. Single-slice helical CT with sagittal reformats had a negative predictive value of 82% for discoligamentous injury and 100% for unstable injury. A normal single-slice helical CT with sagittal reformats of the cervical spine in intubated trauma patients excluded unstable injuries at follow-up cervical spine MR imaging.     

MR imaging of the spine: trauma and degenerative disease

The purpose of this paper is to discuss the capabilities and drawbacks of MR imaging in patients with trauma to the spine and degenerative spinal conditions. In spinal trauma MR imaging is secondary to plain X-ray films and CT because of the greater availability and ease of performance of these techniques and their superior capability for detecting vertebral fractures. Magnetic resonance imaging is useful for detecting ligamentous ruptures and intraspinal mass lesions such as hematoma, and for assessing the state of the spinal cord and prognosis of a cord injury. In degenerative spinal disease the necessity is emphasized of critically evaluating the clinical relevance of any abnormal feature detected, as findings of degenerative pathology are common in individuals without symptoms. Magnetic resonance myelography permits rapid and accurate assessment of the state of the lumbar nerve roots (compressed or not). In the cervical region the quality of the myelographic picture is often degraded in patients with a narrow spinal canal.     

Reperfusion injury components and manifestations determined by cardiovascular MR and MDCT imaging

Advances in magnetic resonance (MR) and computed tomography (CT) imaging have improved visualization of acute and scar infarct. Over the past decade, there have been and continues to be many significant technical advancements in cardiac MR and multi-detector computed tomography (MDCT) technologies. The strength of MR imaging relies on a variety of pulse sequences and the ability to noninvasively provide information on myocardial structure, function and perfusion in a single imaging session. The recent technical developments may also allow CT technologies to rise to the forefront for evaluating clinical ischemic heart disease. Components of reperfusion injury including myocardial edema, hemorrhage, calcium deposition and microvascular obstruction (MO) have been demonstrated using MR and CT technologies. MR imaging can be used serially and noninvasively in assessing acute and chronic consequences of reperfusion injury because there is no radiation exposure or administration of radioactive materials. MDCT is better suited for assessing coronary artery stenosis and as an alternative technique for assessing viability in patients where MR imaging is contraindicated. Changes in left ventricular (LV) volumes and function measured on cine MR are directly related to infarct size measured on delayed contrast enhanced images. Recent MR studies found that transmural infarct, MO and peri-infarct zone are excellent predictors of poor post-infarct recovery and mortality. Recent MR studies provided ample evidence that growth factor genes and stem cells delivered locally have beneficial effects on myocardial viability, perfusion and function. The significance of deposited calcium in acute infarct detected on MDCT requires further studies. Cardiac MR and MDCT imaging have the potential for assessing reperfusion injury components and manifestations.     

Pelvic imaging in the stable trauma patient: is the AP pelvic radiograph necessary when abdominopelvic CT shows no acute injury?

The purpose of the study was to determine the utility of anteroposterior (AP) pelvic radiographs in stable trauma patients who will undergo or have undergone abdominopelvic CT as part of the initial trauma imaging evaluation. Radiology reports of all stable trauma patients who underwent both abdominopelvic CT and AP pelvic radiograph from 25 January through 30 April, 2003 were reviewed for findings of acute pelvic injuries. A total of 509 consecutive patients were included in this series. Of these, 449 patients (88.2%) had no acute pelvic injury revealed by abdominopelvic CT. CT showed 163 acute injuries in 60 patients. AP radiographs showed 132 acute injuries in 52 patients. No patients with a negative CT had an acute finding on the radiograph. There were eight false-negative pelvic radiographs (negative predictive value 98.25%). CT is highly accurate in excluding acute osseous pelvic injuries. In the stable trauma patient whose CT does not reveal an acute pelvic injury or who is scheduled to undergo an abdominopelvic CT as part of the initial imaging evaluation, the pelvic radiograph may be unnecessary.Comment Abstract originally presented at the American Society of Emergency Radiology 14th Annual Scientific Meeting, Las Vegas, Nevada, October 2003.     

Internal derangement of the knee after ipsilateral femoral shaft fracture: MR imaging findings

Objective. This study uses magnetic resonance (MR) imaging to delineate the types and frequencies of injuries seen in the knee after ipsilateral femoral shaft fracture. We also compare the results of the orthopedic knee examination with the MR findings. Design and patients. MR imaging of the ipsilateral knee was performed on 34 patients with closed femoral shaft fractures. Indications for knee MR imaging included knee pain at the time of fracture, soft tissue swelling or an effusion of the knee, or a positive knee examination under anesthesia. The patients had a mean age of 27 years and all were stabilized with intramedullary nails. Imaging was performed a mean time of 2.5 days after surgery. All patients had knee examinations done under anesthesia, and the MR results were compiled and compared with the clinical examinations. Results. Ninety-seven percent of patients demonstrated knee effusions. Twenty-seven percent of patients demonstrated meniscal tears, with the posterior horn of the medial meniscus most frequently torn. The medial collateral ligament was the most frequent site of ligamentous injury (38%) followed by the posterior cruciate ligament (21%). Fifty percent of patients had injuries of the extensor mechanism. Bone bruises were noted in 32% of patients. Articular cartilage injuries were confined to the patella in four cases. One occult tibial plateau fracture and one meniscocapsular separation were seen. Conclusions. There is a common incidence of both ligamentous and meniscal injury to the knee after ipsilateral femoral shaft fracture. MR imaging can be useful in assessing the extent of injury, and may reveal findings unsuspected after clinical examination of the knee.     

Review of Multidetector Computed Tomography Angiography as a Screening Modality in the Assessment of Blunt Vascular Neck Injuries

Blunt vascular neck injuries (BVNI), previously thought to be rare, have demonstrated increasing incidence rates in recent literature and are associated with significant mortality and morbidity. A radiologist needs to efficiently recognize these injuries on preliminary screening to enable initiation of early management. When initiation of accurate management is started promptly, decreased rates of postinjury complications, for example, stroke, have been demonstrated. This article reviews the incidence, pathophysiology, and rationale for screening for these BVNI injuries. The utility of computed tomography angiography (CTA) as the potential new criterion standard as the screening and follow-up imaging modality for BVNI will be discussed. The application of new multidetector CTA techniques available, such as dual-energy CT and iterative reconstruction, are also reviewed. In addition, the characteristic imaging findings on CTA and the associated Denver Grading scale for BVNI will be reviewed to allow readers to become familiar with the injury patterns and to understand the prognostic and clinical implications, respectively. Examples of the spectrum of injuries, potential injury mimics, and different artifacts on multidetector CTA are shown to help familiarize readers and allow them to successfully and confidently recognize a true BVNI.     

Computed tomography of ocular trauma

A wide variety of ocular (eyeball and related soft tissues) injuries resulting from concussive (blunt) and penetrating trauma can be diagnosed by computed tomography (CT). CT can show intraorbital and intraocular emphysema and themorrhage, lens dislocation and subluxation, globe rupture associated with corneal and scleral lacerations, retinal and choroidal detachment, optic nerve injury, and extraocular muscle injury. CT also can localize foreign bodies, and identify injuries caused by them and determine their nature. Not only may CT provide useful information when ocular trauma is clinically suspected, but trauma head and face CT scans may identify unsuspected ocular injuries in the multiple trauma patient. It is imperative that orbital contents be scrutinized carefully on both soft tissue and bone windows of all trauma head and face CT scans in order that clinically significantly ocular injuries not be overlooked.     

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.

Utility of contrast-enhanced computed tomography in forensic examination of a stab wound in living individuals

In cases of inflicted injury, the process of examining the patient for external injuries and documenting the findings is important for forensic assessment, including estimating or determining the type of weapon used and the circumstances of the violence. However, external examination is obviously limited in assessing internal injury. Here, we report the cases of two patients who survived stab wounds, where the findings of contrast-enhanced computed tomography (CT) performed for clinical diagnosis in the hospital were useful for forensic injury evaluation. In both cases, contrast-enhanced CT clearly displayed the injuries to the parenchymal organs and enabled the estimation of the direction and depth of the stab wounds by depicting the track and base of the wounds on acquired images. With the addition of the findings from examination of the external wound, the stab wounds in both victims were consistent with injury caused by the suspected weapon. Recently, imaging modalities including CT have become useful supplemental tools for precise forensic evaluation. Imaging findings obtained from these modalities could especially provide useful information for forensic assessment in clinical forensic medicine because examination of internal injury in the living body cannot generally be performed. Research on the precise diagnostic value of this method is required to utilize this method adequately in clinical forensic medicine.     

Dual-energy CT of the heart—Principles and protocols

The introduction of coronary CT angiography (cCTA) has reinvigorated the debate whether management of patients with suspected coronary artery disease (CAD) should be primarily based on physiological versus anatomical testing. Anatomical testing (i.e., cCTA or invasive catheterization) enables direct visualization and grading of coronary artery stenoses but has shortcomings for gauging the hemodynamic significance of lesions for myocardial perfusion. Conversely, rest/stress myocardial perfusion imaging (MPI) has been extensively validated for assessing the clinical significance of CAD by demonstrating fixed or reversible perfusion defects but has only limited anatomical information. There is early evidence that contrast medium enhanced dual-energy cCTA (DECT) has potential for the comprehensive analysis of coronary artery morphology as well as changes in myocardial perfusion. DECT exploits the fact that tissues in the human body and iodine-based contrast media have unique absorption characteristics when penetrated with different X-ray energy levels, which enables mapping the iodine (and thus blood) distribution within the myocardium. The purpose of this communication is to describe the practical application of this emerging technology for the comprehensive diagnosis of coronary artery disease in the context of the currently used tomographic imaging modalities (cCTA, nuclear MPI, MR MPI).