Partially recanalized chronic dural sinus thrombosis: findings on MR imaging, time-of-flight MR venography, and contrast-enhanced MR venography.

BACKGROUND AND PURPOSE: The imaging appearance of chronic, partially recanalized dural sinus thrombosis has been incompletely described. We sought to more fully characterize the imaging findings of this entity on MR imaging, time-of-flight MR venography (TOF-MRV), and elliptic centric-ordered contrast-enhanced MR venography (CE-MRV). MATERIALS AND METHODS: From a data base of patients with cerebral venous thrombosis, 10 patients were identified with imaging and clinical findings consistent with the diagnosis of chronic, partially recanalized, dural sinus thrombosis. All patients had MR imaging of the brain without and with contrast. Nine patients underwent MRV, and 6 had both CE-MRV and TOF-MRV. Thirty-four venous segments were thrombosed and were assessed in detail for multiple imaging features. RESULTS: Most thrombosed segments were isointense to gray matter on T1-weighted images (85%), and hyperintense to gray matter on T2-weighted images (97%). Visible serpiginous intrathrombus flow voids were visible in 23 segments (8/10 patients) corresponding with areas of flow signal intensity on TOF-MRV and enhancing channels on contrast MRV. Eighty-four percent of thrombosed segments enhanced equal to or greater than venographically normal venous sinuses. TOF-MRV and CE-MRV were abnormal in all patients, and CE-MRV more completely characterized the thrombosed segments. The imaging appearance did not change in those patients with follow-up imaging (average 13.6 months). CONCLUSION: Chronic, partially recanalized, venous thrombosis has a characteristic appearance on MR and MRV. CE-MRV was abnormal in all cases, despite the intense enhancement of the thrombosed segments. Because of the highly selected nature of the cases reported, further study is required to determine whether these findings are present in all cases of this condition.

Cerebral venous thrombus signal intensity and susceptibility effects on gradient recalled-echo MR imaging.

BACKGROUND AND PURPOSE: Cerebral venous thrombus (CVT) signal intensity is variable on MR imaging, and the appearance of CVT on gradient recalled-echo (GRE) sequences has been incompletely assessed. This study was performed to evaluate the GRE imaging appearance of CVT in different stages of thrombus evolution and its relationship to signal intensity on other MR pulse sequences. MATERIALS AND METHODS: The clinical and MR imaging findings in 18 patients with CVT and GRE imaging were reviewed. Sixty-nine thrombosed venous segments were evaluated, and the signal intensity of thrombus relative to gray matter was determined. The degree of thrombus susceptibility effect (SE) was assessed and related to time of imaging after onset of symptoms (clinical thrombus age) and appearance on other pulse sequences. Segments were classified as SE+ (demonstrating susceptibility effect) or SE- (no susceptibility effect). RESULTS: Thirty-six venous segments exhibited visible SE. SE+ segments had a clinical thrombus age that was less than that in SE- segments (8.1 versus 24.6 days, P=.003). Sixty-three percent (23/36) of SE+ segments exhibited hypointensity on T2-weighted images (T2WI) versus 12% (4/33) of SE- segments (P<.001). Twenty-nine of 32 (90.6%) segments with clinical thrombus age of 0-7 days were SE+, versus 7 of 30 (23.3%) segments with a thrombus age of 8 days or greater. CONCLUSION: SEs from CVT can be detected with GRE imaging and are most prevalent in patients with hypointense thrombus on T2WI within 7 days after the symptom onset. This correlates with the paramagnetic effects of deoxyhemoglobin in acute stage thrombus. GRE imaging may be useful in detecting thrombus in this stage when difficult to detect on other pulse sequences.

Overnight preliminary head CT interpretations provided by residents: locations of misidentified intracranial hemorrhage.

BACKGROUND AND PURPOSE: Our aim was to determine the patterns of error of radiology residents in the detection of intracranial hemorrhage on head CT examinations while on call. Follow-up studies were reviewed to determine if there was any adverse effect on patient outcome as a result of these preliminary interpretations. MATERIALS AND METHODS: Radiology residents prospectively interpreted 22,590 head CT examinations while on call from January 1, 2002, to July 31, 2006. The following morning, the studies were interpreted by staff neuroradiologists, and discrepancies from the preliminary report were documented. Patients' charts were reviewed for clinical outcomes and any imaging follow-up. RESULTS: There were a total of 1037 discrepancies identified, of which 141 were due to intracranial hemorrhage. The most common types of intracranial hemorrhage that were missed were subdural and subarachnoid hemorrhage occurring in 39% and 33% of the cases, respectively. The most common location for missed subdural hemorrhage was either parafalcine or frontal. The most common location of missed subarachnoid hemorrhage was in the interpeduncular cistern. There was 1 case of nontraumatic subarachnoid hemorrhage that was not described in the preliminary report. Fourteen patients were brought back to the emergency department for short-term follow-up imaging after being discharged. We did not observe any adverse clinical outcomes that resulted from a discrepant reading. CONCLUSION: Discrepancies due to intracranial hemorrhage are usually the result of subdural or subarachnoid hemorrhage. A more complete understanding of the locations of the missed hemorrhage can hopefully help decrease the discrepancy rate to help improve patient care.

Sacroplasty by CT and fluoroscopic guidance: is the procedure right for your patient?

BACKGROUND AND PURPOSE: Sacral insufficiency fractures are an infrequent but often disabling cause of severe low back pain. We report our results of a sacroplasty technique, using CT for needle placement and fluoroscopy to monitor the polymethylmethacrylate injection in a group of patients with sacral insufficiency fractures. METHODS: All patients had a history of chronic back pain and had an osteoporotic sacral insufficiency fracture documented by imaging before the procedure. With the patient under conscious sedation, a bone biopsy needle was placed under CT guidance; the patient was then transferred to the fluoroscopy suite, where a polymethylmethacrylate mixture was injected into the sacrum under real-time fluoroscopy. Clinical outcome was assessed by telephone. RESULTS: The procedure was performed on 13 female patients with an average age of 76 years (range, 60-88 years). A bilateral procedure was performed in 11 patients and a unilateral procedure was performed in 2 patients. An average of 4.1 mL of cement was injected for each treatment. There were no instances of cement extravasation into the central canal or sacral foramina. Long-term follow-up, averaging 15 months, was available in 6 patients. Five patients (83%) reported no symptoms of pain at all. The final patient, in whom a bilateral procedure was performed, was completely asymptomatic on the left side but reported persistent unilateral pain on the right. CONCLUSION: Sacroplasty is a safe and effective procedure in the treatment of sacral insufficiency fractures that can provide substantial pain relief and lead to a better quality of life.

Left vertebral artery origin from the thyrocervical trunk: a unique vascular variant.

The vertebral artery normally arises from the subclavian artery, and variations in its origin have been described. We describe a unique case of the left vertebral artery arising from the thyrocervical trunk.

The effect of surgical timing on the perioperative complications of treatment of supracondylar humeral fractures in children.

BACKGROUND: The purpose of this study was to evaluate the perioperative complication rates associated with early surgical treatment (eight hours or less following injury) and delayed surgical treatment (more than eight hours following injury) of displaced supracondylar humeral fractures in children. METHODS: Fifty-two patients had early surgical treatment and 146 patients had delayed surgical treatment of a displaced supracondylar humeral fracture. The perioperative complication rates of the two groups were compared with the use of bivariate and multivariate statistical methods. RESULTS: There was no significant difference between the two groups with respect to the need for conversion to formal open reduction and internal fixation (p = 0.56), pin-track infection (p = 0.12), or iatrogenic nerve injury (p = 0.72). No compartment syndromes occurred in either group. Power analysis revealed that our study had an 86% power to detect a 20% difference between the two groups if one existed. CONCLUSIONS: We were unable to identify any significant difference, with regard to perioperative complication rates, between early and delayed treatment of displaced supracondylar humeral fractures. Within the parameters outlined in our study, we think that the timing of surgical intervention can be either early or delayed as deemed appropriate by the surgeon.