Grading Abdominal Trauma: Changes in and Implications of the Revised 2018 AAST-OIS for the Spleen, Liver, and Kidney.

According to the Centers for Disease Control and Prevention, trauma is the leading cause of fatal injuries for Americans aged 1-44 years old and the fourth leading overall cause of death. Accurate and early diagnosis, including grading of solid organ injuries after blunt abdominal trauma (BAT), is crucial to guide management and improve outcomes. The American Association for the Surgery of Trauma (AAST) Organ Injury Scale (OIS) is the most widely accepted BAT scoring system at CT both within the United States and internationally, and its uses include stratification of injury severity, thereby guiding management, and facilitation of clinical research, billing, and coding. Furthermore, this system also plays a role in the credentialing process for trauma centers in the United States. The newly revised 2018 OIS provides criteria for grading solid organ damage into three groups: imaging, operation, and pathology. The final grade is based on the highest of the three criteria. If multiple lower-grade (I or II) injuries are present in a single organ, one grade is advanced to grade III. The most substantial change in the revised 2018 AAST-OIS is incorporation of multidetector CT findings of vascular injury, including pseudoaneurysm and arteriovenous fistula. The authors outline the main revised aspects of grading organ injury using the AAST-OIS for the spleen, liver, and kidney after BAT, particularly the role of multidetector CT and alternative imaging in organ injury detection, the importance of vascular injuries in grade change, and the impact of these changes on patient management and in prediction of operative treatment success and in-hospital mortality. ©RSNA, 2023 Supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

Use of Multiphase CT Protocols in 18 Countries: Appropriateness and Radiation Doses.

PURPOSE: To assess the frequency, appropriateness, and radiation doses associated with multiphase computed tomography (CT) protocols for routine chest and abdomen-pelvis examinations in 18 countries. MATERIALS AND METHODS: In collaboration with the International Atomic Energy Agency, multi-institutional data on clinical indications, number of scan phases, scan parameters, and radiation dose descriptors (CT dose-index volume; dose-length product [DLP]) were collected for routine chest (n = 1706 patients) and abdomen-pelvis (n = 426 patients) CT from 18 institutions in Asia, Africa, and Europe. Two radiologists scored the need for each phase based on clinical indications (1 = not indicated, 2 = probably indicated, 3 = indicated). We surveyed 11 institutions for their practice regarding single-phase and multiphase CT examinations. Data were analyzed with the Student t test. RESULTS: Most institutions use multiphase protocols for routine chest (10/18 institutions) and routine abdomen-pelvis (10/11 institutions that supplied data for abdomen-pelvis) CT examinations. Most institutions (10/11) do not modify scan parameters between different scan phases. Respective total DLP for 1-, 2-, and 3-phase routine chest CT was 272, 518, and 820 mGy·cm, respectively. Corresponding values for 1- to 5-phase routine abdomen-pelvis CT were 400, 726, 1218, 1214, and 1458 mGy cm, respectively. For multiphase CT protocols, there were no differences in scan parameters and radiation doses between different phases for either chest or abdomen-pelvis CT (P = 0.40-0.99). Multiphase CT examinations were unnecessary in 100% of routine chest CT and in 63% of routine abdomen-pelvis CT examinations. CONCLUSIONS: Multiphase scan protocols for the routine chest and abdomen-pelvis CT examinations are unnecessary, and their use increases radiation dose.

Heterogeneous Pulmonary Perfusion on Dual-Energy Computed Tomography: Faulty Postprocessing or New Artifact?

Iodine uptake in the lungs and intrathoracic lesions on postcontrast dual-energy computed tomography is used for evaluation of pulmonary embolism-related perfusion defects and pulmonary infarctions. It has been applied in characterization and treatment response assessment of lung and mediastinal abnormalities. We report a new imaging artifact or faulty image postprocessing in a commercially available rapid kV switching technique of dual-energy computed tomography, which can confound its clinical utility for evaluation of iodine uptake.

Should Patients Be Counseled About Possible Recurrence of Perimesencephalic Subarachnoid Hemorrhage?

BACKGROUND: Isolated perimesencephalic subarachnoid hemorrhage (pSAH) is a distinct subtype of subarachnoid hemorrhage (SAH) seen in 5% of patients with SAH, with a relatively benign natural course and good outcome compared with diffuse, aneurysmal SAH. Traditionally, the prognosis of pSAH is believed to be excellent compared with aneurysmal SAH, with no risk of recurrent hemorrhage after long-term follow-up. We describe a case of pSAH in which the patient had a recurrent perimesencephalic bleed 8 years after the initial episode. There are 5 previous reports of recurrent pSAH in existing literature. CASE REPORT: A patient in sixth decade of life with no history of trauma presented in 2006 with acute-onset, severe headache, and "off-balance" gait. The patient was diagnosed with pSAH on the basis of computed tomography angiography and digital subtraction angiography. The patient was discharged, and follow-up computed tomography angiography over the next 2 years revealed no underlying vascular anomaly. The patient presented in 2014 with sudden onset of headache, similar to the previous episode with no new neurologic signs. Patient had repeated imaging over the succeeding 2 years, which were all negative for new blood or source of subarachnoid bleed. REVIEW AND DISCUSSION: There are only a couple of case reports of recurrent pSAH, some of which were defined questionably. We review the reported cases and discuss the imaging results and outcome. Considering the rarity, low risks of complications, as well as the good outcome even after recurrence, we do not recommend routinely counseling patients about possibility of recurrence of pSAH.