CT findings in a patient with bilateral metachronous carotidynia.

Carotidynia is a self-limiting, idiopathic clinical syndrome characterized by acute unilateral neck pain and tenderness of the carotid artery. We describe a unique case of bilateral carotidynia that occurred metachronously, with each incident resolving without long-term sequelae. Knowledge of this entity is important to properly interpret the imaging findings and to not mistake this finding as an ill-defined tumor, thus avoiding unnecessary biopsy.

Preoperative imaging of sensorineural hearing loss in pediatric candidates for cochlear implantation.

Cochlear implantation is the only U.S. Food and Drug Administration-approved treatment for children with marked bilateral sensorineural hearing loss. It provides auditory benefits that range from simple sound detection to substantial word understanding. Improved hearing through cochlear implantation has been demonstrated to enhance the rate of language acquisition, enable development of spoken language, and advance literacy in deaf children. Magnetic resonance imaging and computed tomography both have roles in the preoperative assessment of inner-ear abnormalities, cochlear nerve deficiency, and variant anatomy that may affect the decision to implant and the prognosis for auditory improvement and increase the risk for complications. Most cochlear abnormalities may be successfully treated with cochlear implantation, but the presence of a cochlear malformation may increase the risk for intraoperative cerebrospinal fluid leakage and postoperative bacterial meningitis. Eighth-nerve deficiency correlates with poor auditory outcomes and may affect eligibility for cochlear implantation. Another important consideration for implantation is the presence of labyrinthitis ossificans in some children with deafness resulting from bacterial meningitis, which may cause obstruction that limits electrode insertion. Anatomic variations of the facial nerve or middle-ear cavity, which are more common in syndromic patients, may also affect the surgical approach and make implantation difficult.

Radiation dose limits and liver toxicities resulting from multiple yttrium-90 radioembolization treatments for hepatocellular carcinoma.

PURPOSE: To assess the relationship between cumulative hepatic lobar radiation dose and liver toxicities in patients with hepatocellular carcinoma (HCC) treated with multiple sessions of yttrium-90 radioembolization. MATERIALS AND METHODS: Forty-one patients with HCC (age range, 46-82 years) underwent radioembolization with 90Y. Patients were classified according to the Okuda scoring system. All patients received single liver lobar treatments on two or more occasions according to standard clinical 90Y embolization protocol. Cumulative radiation dose to each liver lobe was measured and patients were followed to assess liver toxicities. Statistical analysis was performed with the Student t test and Kaplan-Meier analysis. RESULTS: Patients with Okuda stage I disease received more treatments than those with Okuda stage II disease (mean, 2.65 vs 2.24; P<.05). For average cumulative radiation dose, patients with Okuda stage I disease received 247 Gy (range, 88-482 Gy) and those with Okuda stage II disease received 198 Gy (range, 51-361 Gy; P<.05). A total of 13 toxicities occurred in seven patients (16%). Patients with Okuda stage I disease were given a greater cumulative dose than patients with Okuda stage II disease before worsening of liver function: 390 Gy versus 196 Gy (P<.005). For patients with Okuda stage I disease, a higher cumulative radiation dose was associated with occurrence of one or more toxicities: 222 Gy (no toxicities) versus 390 Gy (>or=1 toxicity; P<.005). No correlation between cumulative radiation dose and liver toxicities existed in patients with Okuda stage II disease. The maximum tolerated dose was between 222 and 390 Gy. Median survival times were 660 and 431 days for patients with Okuda stage I and stage II disease, respectively. CONCLUSIONS: Patients with HCC can tolerate high cumulative radiation doses with 90Y therapy. Compared with patients with Okuda stage II disease, patients with Okuda stage I disease tolerate a higher cumulative radiation dose without liver toxicity, but liver toxicities increase with increasing cumulative radiation doses.

Effect of transcatheter arterial embolization on levels of hypoxia-inducible factor-1alpha in rabbit VX2 liver tumors.

PURPOSE: To test the hypothesis that transcatheter arterial embolization (TAE) of VX2 rabbit liver tumors increases the expression of hypoxia-inducible factor-1alpha (HIF-1alpha), a transcription factor that regulates the expression of pro-angiogenic genes. MATERIALS AND METHODS: VX2 tumors were implanted in the livers of eight New Zealand white rabbits. Once tumor growth was seen at T2-weighted turbo spin-echo magnetic resonance (MR) imaging, four of the eight rabbits underwent TAE with 45-150-mum polyvinyl alcohol particles. The remaining four rabbits served as non-TAE controls. The TAE end point was stasis of antegrade blood flow. All rabbits were sacrificed for tumor harvest 2 hours after TAE. Tumor tissue and corresponding normal liver tissue in each rabbit liver were stained with anti-human HIF-1alpha monoclonal antibody and reviewed with light microscopy. Percentages of stained viable tumor and normal liver cells were compared by using the Mann-Whitney U test (alpha=0.05). RESULTS: In eight rabbits with 24 discrete liver tumors, the mean percentage (+/-standard deviation) of positive HIF-1alpha-stained cells in the TAE group was greater than that in the control group (19%+/-7.0 vs 12%+/-8.0, respectively) (P=.05). Normal liver tissue in both the TAE and control groups showed no HIF-1alpha staining. CONCLUSION: Although HIF-1alpha is not expressed in normal rabbit liver parenchyma-even after TAE-HIF-1alpha expression is present in implanted VX2 rabbit liver tumors and significantly increased in lesions that have undergone embolization.