Laura L. Avery

Multidetector CT of Blunt Thoracic Trauma

Thoracic injuries are significant causes of morbidity and mortality in trauma patients. These injuries account for approximately 25% of trauma-related deaths in the United States, second only to head injuries. Radiologic imaging plays an important role in the diagnosis and management of blunt chest trauma. In addition to conventional radiography, multidetector computed tomography (CT) is increasingly being used, since it can quickly and accurately help diagnose a wide variety of injuries in trauma patients. Furthermore, multiplanar and volumetric reformatted CT images provide improved visualization of injuries, increased understanding of trauma-related diseases, and enhanced communication between the radiologist and the referring clinician.

Multidetector CT of Carpal Injuries: Anatomy, Fractures, and Fracture-Dislocations

Fractures and dislocations of the carpal bones are more common in young active patients. These injuries can lead to pain, dysfunction, and loss of productivity. Conventional radiography remains the primary imaging modality for evaluation of suspected carpal fractures and dislocations. However, multidetector computed tomography (CT) is playing an increasingly important role, especially in the following situations: (a) when results from initial radiographs are negative in patients with suspected carpal fractures, (b) when initial radiographic findings are indeterminate, and (c) when knowledge of the extent of carpal fractures or dislocations is required before surgical treatment. The advantages of multidetector CT include quick and accurate diagnosis with availability in most emergency centers. Multidetector CT can easily display the extent of carpal fractures and dislocations, often depicting fractures that are occult at radiography. In addition, with multiplanar (two-dimensional) and volumetric (three-dimensional) reformation, pathologic conditions and anatomic relationships are better perceived. This information can be easily conveyed to orthopedic and trauma surgeons and can be crucial for surgical treatment and planning.

Case records of the Massachusetts General Hospital. Case 6-2008. A 46-year-old woman with renal failure and stiffness of the joints and skin.

Dr. Nancy Cibotti-Granof (Medicine): A 46-year-old woman with end-stage renal disease was seen by a rheumatology consultant because of stiffness of her joints and skin. The patient had been well except for mild asthma until 7 years earlier, when group A streptococcal pneumonia developed, complicated by septic shock, with acute respiratory distress syndrome; septic emboli to the lungs, brain, and kidney; renal failure requiring dialysis; f laccid quadriplegia; and coma. On the 25th day after initial admission to another hospital, she was transferred to this hospital while she was receiving mechanical ventilation. As part of the evaluation during admission, computed tomography (CT) of the thorax, abdomen, and pelvis with intravenous contrast revealed cavitary lesions in the right lower lobe of the lung, with diffuse bilateral ground-glass opacities, small bilateral pleural effusions, and multiple prominent mediastinal lymph nodes. CT of the head revealed regions of cortical mineralization in the left posterior frontal lobe and the right parietal lobe, with surrounding hypodensity consistent with edema and minimal enhancement consistent with cerebritis. Magnetic resonance imaging (MRI) of the brain with gadolinium revealed regions of cortical enhancement with surrounding edema in the left posterior frontal lobe and right parietal lobe consistent with cerebritis and vasculitis, as well as a small infarct in the right corona radiata (Fig. 1A). Follow-up CT scans with contrast enhancement and MRI studies with gadolinium enhancement revealed regions of cerebritis and small infarcts, with no drainable abscesses. Transthoracic and transesophageal echocardiography showed a patent foramen ovale, normal left ventricular function, and no valvular vegetations. A filter was placed in the inferior vena cava. During the hospital stay, the blood pressure stabilized; the patient regained consciousness and recovered speech and motor strength, with residual right-sided weakness. Kidney function improved, and hemodialysis was discontinued. Weakness, sensory loss, and pain in both feet persisted, and treatment with gabapentin (300 mg twice daily) was begun. The patient was discharged on the 53rd hospital day, first to a rehabilitation facility for 2 months, and then to home. Follow-up MRI Case 6-2008: A 46-Year-Old Woman with Renal Failure and Stiffness of the Joints and Skin

Imaging of Penile and Scrotal Emergencies

Penile and scrotal emergencies are uncommon, but when they do occur, urgent or emergent diagnosis and treatment are necessary. Emergent conditions of the male genitalia are primarily infectious, traumatic, or vascular. Infectious conditions, such as epididymitis and epididymo-orchitis, are well evaluated at ultrasonography (US), and their key findings include heterogeneity and hyperemia. Pyocele and abscess may also be seen at US. Fournier gangrene is best evaluated at computed tomography, which depicts subcutaneous gas. Vascular conditions, such as testicular torsion, infarction, penile Mondor disease, and priapism, are well evaluated at duplex Doppler US. The key imaging finding of testicular torsion and infarction is a lack of blood flow in the testicle or a portion of the testicle. Penile Mondor disease is characterized by a lack of flow to and noncompressibility of the superficial dorsal vein of the penis. Clinical examination and history are usually adequate for diagnosis of priapism, but Doppler US may help confirm the diagnosis. Traumatic injuries of the penis and scrotum are initially imaged with US, which depicts whether the penile corpora and testicular seminiferous tubules are contained by the tunicae albuginea; herniation of contents and discontinuity of the tunica albuginea indicate rupture. In some cases, magnetic resonance imaging may be performed because of its ability to directly depict discontinuity of the tunica albuginea. Radiologists must closely collaborate with emergency physicians, surgeons, and urologists to quickly and efficiently diagnose or rule out emergent conditions of the male genitalia to facilitate prompt and appropriate treatment.

Case 6-2008

Dr. Nancy Cibotti-Granof (Medicine): A 46-year-old woman with end-stage renal disease was seen by a rheumatology consultant because of stiffness of her joints and skin. The patient had been well except for mild asthma until 7 years earlier, when group A streptococcal pneumonia developed, complicated by septic shock, with acute respiratory distress syndrome; septic emboli to the lungs, brain, and kidney; renal failure requiring dialysis; f laccid quadriplegia; and coma. On the 25th day after initial admission to another hospital, she was transferred to this hospital while she was receiving mechanical ventilation. As part of the evaluation during admission, computed tomography (CT) of the thorax, abdomen, and pelvis with intravenous contrast revealed cavitary lesions in the right lower lobe of the lung, with diffuse bilateral ground-glass opacities, small bilateral pleural effusions, and multiple prominent mediastinal lymph nodes. CT of the head revealed regions of cortical mineralization in the left posterior frontal lobe and the right parietal lobe, with surrounding hypodensity consistent with edema and minimal enhancement consistent with cerebritis. Magnetic resonance imaging (MRI) of the brain with gadolinium revealed regions of cortical enhancement with surrounding edema in the left posterior frontal lobe and right parietal lobe consistent with cerebritis and vasculitis, as well as a small infarct in the right corona radiata (Fig. 1A). Follow-up CT scans with contrast enhancement and MRI studies with gadolinium enhancement revealed regions of cerebritis and small infarcts, with no drainable abscesses. Transthoracic and transesophageal echocardiography showed a patent foramen ovale, normal left ventricular function, and no valvular vegetations. A filter was placed in the inferior vena cava. During the hospital stay, the blood pressure stabilized; the patient regained consciousness and recovered speech and motor strength, with residual right-sided weakness. Kidney function improved, and hemodialysis was discontinued. Weakness, sensory loss, and pain in both feet persisted, and treatment with gabapentin (300 mg twice daily) was begun. The patient was discharged on the 53rd hospital day, first to a rehabilitation facility for 2 months, and then to home. Follow-up MRI Case 6-2008: A 46-Year-Old Woman with Renal Failure and Stiffness of the Joints and Skin

Does Computed Tomographic Assessment of Inferior Alveolar Canal Cortical Integrity Predict Nerve Exposure During Third Molar Surgery

PURPOSE To evaluate the association between computed tomographic (CT) assessment of inferior alveolar nerve (IAN) canal cortical integrity and intraoperative IAN exposure. MATERIALS AND METHODS This was a retrospective cohort study. The study sample included patients considered at high risk for IAN injury based on panoramic findings. The primary predictor variable was IAN canal integrity (intact or interrupted) assessed on coronal CT images. The secondary predictor variable was length of the cortical defect, in millimeters. The primary outcome variable was intraoperative visualization of the IAN. Other variables were demographic and operative parameters. Bivariate and multiple logistic regression analyses were used to evaluate the unadjusted and adjusted associations between the cortical integrity and IAN exposure. Diagnostic test characteristics were computed for cortical integrity and threshold cortical defect size. A P value < or = 0.05 was statistically significant. RESULTS The sample consisted of 51 subjects (57% female) with a mean age of 35.2 +/- 12.8 years. Of the 80 third molars available for evaluation, 52 third molars (64.1%) had evidence of loss of cortical integrity. The mean cortical defect length was 2.9 +/- 2.6 mm. Loss of cortical integrity had a high sensitivity (> or = 0.88) but low specificity (< or = 0.49) as a diagnostic test for IAN visualization. A cortical defect size > or = 3 mm was associated with an increased risk for intraoperative IAN visualization with a high sensitivity and specificity (> or = 0.82). CONCLUSION Cortical defect size on a maxillofacial CT has a high sensitivity and specificity for predicting intraoperative IAN exposure during third molar removal.

Congenital portosystemic shunts: Imaging findings and clinical presentations in 11 patients

OBJECTIVE To evaluate the clinical anatomy and presentations of congenital portosystemic shunts, and determine features that promote recognition on imaging. MATERIALS AND METHODS Institutional review board approval was obtained for this HIPAA-compliant study. The requirement for written informed consent was waived. Radiology reports were retrospectively reviewed from non-cirrhotic patients who underwent imaging studies from January 1999 through February 2009. Clinical sources reviewed included electronic medical records, archived images and histopathological material. RESULTS Eleven patients with congenital portosystemic shunts were identified (six male and five female; age range 20 days to 84 years). Seven patients had extrahepatic and four patients had intrahepatic shunts. All 11 patients had absent or hypoplastic intrahepatic portal veins, a feature detected by CT and MRI, but not by US. Seven patients presented with shunt complications and four with presentations unrelated to shunt pathophysiology. Three adult patients had four splenic artery aneurysms. Prospective radiological evaluation of five adult patients with cross-sectional imaging had failed prospectively to recognize the presence of congenital portosystemic shunts on one or more imaging examinations. CONCLUSIONS Congenital portosystemic shunts are associated with splenic artery aneurysms, a previously unrecognized association. Portosystemic shunts were undetected during prospective radiologic evaluation in the majority of adult patients, highlighting the need to alert radiologists to this congenital anomaly.

Multidetector and Three-Dimensional CT Evaluation of the Patient With Maxillofacial Injury

Interpretation of images associated with the traumatically injured face is challenging. The complexity of facial anatomy, coupled with the superimposition of numerous bony structures on plain radiographs, poses specific obstacles to accurate interpretation of facial injury. Although plain radiographs can be helpful in cases of isolated injuries, CT is the most useful modality for evaluating facial injury. This article reviews facial anatomy as it pertains to traumatic injury, emphasizes the clinical findings associated with various types of facial injury, and simplifies the diagnosis of facial injury on CT.

Acetabular Fractures: What Radiologists Should Know and How 3D CT Can Aid Classification

Correct recognition, description, and classification of acetabular fractures is essential for efficient patient triage and treatment. Acetabular fractures may result from high-energy trauma or low-energy trauma in the elderly. The most widely used acetabular fracture classification system among radiologists and orthopedic surgeons is the system of Judet and Letournel, which includes five elementary (or elemental) and five associated fractures. The elementary fractures are anterior wall, posterior wall, anterior column, posterior column, and transverse. The associated fractures are all combinations or partial combinations of the elementary fractures and include transverse with posterior wall, T-shaped, associated both column, anterior column or wall with posterior hemitransverse, and posterior column with posterior wall. The most unique fracture is the associated both column fracture, which completely dissociates the acetabular articular surface from the sciatic buttress. Accurate categorization of acetabular fractures is challenging because of the complex three-dimensional (3D) anatomy of the pelvis, the rarity of certain acetabular fracture variants, and confusing nomenclature. Comparing a 3D image of the fractured acetabulum with a standard diagram containing the 10 Judet and Letournel categories of acetabular fracture and using a flowchart algorithm are effective ways of arriving at the correct fracture classification. Online supplemental material is available for this article.

Intra-arterial Air Thrombogenesis after Cerebral Air Embolism Complicating Lower Extremity Sclerotherapy

BackgroundCerebral arterial gas embolism is a potentially life-threatening event. Intraarterial air can occlude blood flow directly or cause thrombosis. Sclerotherapy is an extremely rare cause of cerebral arterial gas embolism.MethodCase-report.ResultsA 38-year-old female suffered acute onset of a left middle cerebral artery (LMCA) syndrome with an NIH stroke score of 11 approximately ten minutes after lower extremity sclerotherapy. CT angiogram demonstrated LMCA intraarterial air. Patient fully recovered after hyperbaric oxygen treatment with complete resolution of intraarterial air. However, thrombus replaced intraarterial air despite anticoagulation with heparin.ConclusionWe provide radiological evidence of hyperbaric oxygen therapy resolving intraarterial air but also demonstrate the thrombogenic potential of this procedural complication.