Analysis of misses in imaging of head and neck pathology by attending neuroradiologists at a single tertiary academic medical centre.

AIM: To analyse errors in head and neck (H&N) pathology made by attending neuroradiologists at a single tertiary-care centre. MATERIALS AND METHODS: A neuroradiology quality assurance (QA) database of radiological errors was searched for attending physician errors in H&N pathology from 2014-2020. Data were limited to computed tomography (CT) and magnetic resonance imaging (MRI) reports. Data were collected on missed pathologies and study types. Misses were grouped into three categories: central neck (thyroid gland, aerodigestive tract), lateral neck (salivary glands, lymph nodes, soft tissues), and face/orbits (orbits, sinuses, masticator space). RESULTS: During the study period, a total of 283,248 CT and MRI neuroradiology examinations were interpreted (all indications). Seventy-four H&N misses were identified comprising 85.1% perceptual and 14.9% interpretive errors. The distribution of errors was face/orbits (37.8%), central neck (36.5%), and lateral neck (25.7%). Clinically significant errors were found most commonly in the aerodigestive tract (21%), orbits (17.7%), masticator space, and parotid glands (14.5% each). The majority (67.6%) of the misses were detected on examinations that were not performed for a primary H&N indication; MRI brain was the most common examination (27%). Clearly malignant or potentially malignant masses accounted for 48.6% of all misses. CONCLUSION: The majority of H&N misses were perceptual and were detected on examinations not performed for a H&N indication. Clearly malignant or potentially malignant masses represented half of all misses.

Unicentric Castleman's disease in the posterior cervical space mimicking a schwannoma.

INTRODUCTION: Castleman's disease (CD) is a benign and rare lymphoid tissue disease of undetermined origin. It affects the neck infrequently; therefore its preoperative diagnosis is difficult and can be confused with other hypervascular lesions. CASE REPORT: We present a case of unicentric hyaline-vascular CD in the posterior cervical space (PCS) evaluated by MRI and initially presumed to be a cervical schwannoma. DISCUSSION: As shown with our case, unicentric CD should be included in the differential diagnosis for masses in the PCS, especially when a hypervascular lesion like a schwannoma is suspected. The finding of central low intensity areas in a fissured and radial pattern in T2 sequences can help to consider CD when dealing with PCS masses as shown by previous cases and our reported experience.

Evaluation of hippocampus dose for patients undergoing intensity-modulated radiotherapy for nasopharyngeal carcinoma.

OBJECTIVE: To evaluate the dose received by the hippocampus among patients undergoing intensity-modulated radiotherapy (IMRT) for nasopharyngeal cancer. METHODS: 10 patients with biopsy-proven, locally advanced nasopharyngeal cancer constituted the study population. The total prescribed dose to the planning target volume (PTV) was 70 Gy (D95%) delivered in 2.12-Gy daily fractions using IMRT. Using established anatomical guidelines, MRI co-registration and the assistance of a board-certified neuroradiologist, the right and left hippocampi were delineated on axial imaging from the CT scan obtained at simulation for each patient beginning at the most anterior portion of the lateral ventricle. IMRT treatment plans were generated without dose-volume constraints to the hippocampus. A range of dose-volume statistics was calculated. RESULTS: The mean hippocampus volume was 6.01 ± 2.61 cm(3). The mean V20 was 72.2%; V40 was 22.0%; V50 was 10.2%; and V60 was 5.5%. The average mean, minimum and maximum hippocampus doses were 30.27 Gy (range, 19.08-47.99 Gy); 17.54 Gy (range, 11.66-33.17 Gy); and 54.95 Gy (range, 35.59-75.57 Gy), respectively. The hippocampus received a maximum dose exceeding 70 Gy in 30% of cases. CONCLUSION: Our dosimetric analysis suggests that, for patients undergoing IMRT for nasopharyngeal cancer, the hippocampus routinely receives significantly high doses. ADVANCES IN KNOWLEDGE: The hippocampus receives a fair amount of incidental radiation during treatment for nasopharyngeal cancer. Given the importance of this structure with respect to memory and neurocognitive function, consideration should be given to identifying the hippocampus as a critical organ at risk in the IMRT optimization process.

Intensity-modulated radiotherapy increases dose to the brachial plexus compared with conventional radiotherapy for head and neck cancer.

OBJECTIVE: The preferential use of intensity-modulated radiotherapy (IMRT) over conventional radiotherapy (CRT) in the treatment of head and neck cancer has raised concerns regarding dose to non-target tissue. The purpose of this study was to compare dose-volume characteristics with the brachial plexus between treatment plans generated by IMRT and CRT using several common treatment scenarios. METHOD: The brachial plexus was delineated on radiation treatment planning CT scans from 10 patients undergoing IMRT for locally advanced head and neck cancer using a Radiation Therapy Oncology Group-endorsed atlas. No brachial plexus constraint was used. For each patient, a conventional three-field shrinking-field plan was generated and the dose-volume histogram (DVH) for the brachial plexus was compared with that of the IMRT plan. RESULTS: The mean irradiated volumes of the brachial plexus using the IMRT vs the CRT plan, respectively, were as follows: V50 (18±5 ml) vs (11±6 ml), p = 0.01; V60 (6±4 ml) vs (3±3 ml), p = 0.02; V66 (3±1 ml) vs (1±1 ml), p = 0.04, V70 (0±1 ml) vs (0±1 ml), p = 0.68. The maximum point dose to the brachial plexus was 68.9 Gy (range 62.3-78.7 Gy) and 66.1 Gy (range 60.2-75.6 Gy) for the IMRT and CRT plans, respectively (p = 0.01). CONCLUSION: Dose to the brachial plexus is significantly increased among patients undergoing IMRT compared with CRT for head and neck cancer. Preliminary studies on brachial plexus-sparing IMRT are in progress.

Endovascular treatment of traumatic injuries of the vertebral artery.

BACKGROUND AND PURPOSE: There are a few reports regarding the treatment of traumatic vertebral arteriovenous fistulas and pseudoaneurysms. Our aim was to describe the clinical and angiographic results of endovascular therapy for traumatic injuries of the vertebral artery. MATERIALS AND METHODS: The clinical and angiographic features of 18 traumatic injuries of the vertebral artery during an 8-year period were reviewed. There were 14 male (78%) and 4 female patients (22%). The average age was 28 years (range, 11-49 years). Of the 18 lesions of the vertebral artery, 17 (95%) were the result of penetrating trauma (gunshot or stab wound injury) and 1 (5%) was iatrogenic (jugular vein catheter). In 16 (89%) instances, the injury resulted in an arteriovenous fistula, and in the other 2 (11%), in a pseudoaneurysm. All patients were treated with an endovascular approach by using different techniques (balloon occlusion, coil embolization, and/or stent deployment). RESULTS: Endovascular therapy resulted in immediate lesion total occlusion in 16 (89%) patients. Delayed total occlusion was demonstrated angiographically during follow-up in the 2 remaining patients. Clinical improvement was documented in all patients, and there were no clinically symptomatic complications. CONCLUSION: In this small series, endovascular techniques were a safe and effective method of treatment and were not associated with significant morbidity or mortality.

Value of the vertebrogram in predicting cement filling patterns with unipedicular percutaneous vertebroplasty.

BACKGROUND: Unipedicular vertebroplasty can be successful in selected patients to decrease procedure time, sedation amounts, and cost. PURPOSE: To evaluate the value of the antecedent unipedicular vertebrogram in predicting patterns of cement deposition to decide whether unipedicular vertebroplasty will be successful, or if a bipedicular vertebroplasty is needed. MATERIAL AND METHODS: 75 fractured vertebral levels were injected by a unipedicle approach with iodinated contrast material (vertebrogram). This filling pattern was then compared to the cement deposition pattern, via the same pedicle, of the percutaneous vertebroplasty. RESULTS: 35 levels showed excellent cross-filling and matched pattern by vertebrogram and cement deposition (47%). Twelve levels (16%) showed cross-filling by both techniques, with less than 100% matched pattern, but cement deposition was considered adequate for fracture treatment. Four levels (5%) showed predominantly matched central filling, considered adequate for fracture treatment. Twenty-one levels (28%) showed only matched filling of half of the vertebral body with both techniques, necessitating a bipedicle approach for treatment with cement. The remaining three levels (4%) demonstrated mismatched patterns between the vertebrogram and the cement deposition, necessitating a bipedicular approach. CONCLUSION: The unipedicular vertebrogram was helpful in predicting adequate cement deposition, using a single pedicle, in 51 of 75 cases (68%). The vertebrogram was also accurate in predicting the need for a double-pedicle technique in an additional 21 cases (28%). Therefore, the vertebrogram was very helpful in predicting the route of cement deposition in 72 of 75 (96%) cases, and should be considered as an adjunct to percutaneous vertebroplasty.

Delayed diffusion-weighted MR abnormality in a patient with an extensive acute cerebral hypoxic injury.

Diffusion-weighted (DW) MR imaging usually identifies acute cerebral infarction injury in symptomatic patients. We report a patient with severe hypoxic brain injury following suicide attempt by hanging, but with normal DW MR imaging 5-6 h after the event. Follow-up DW MR imaging 3 days after the event, and subsequent autopsy, revealed extensive cerebral anoxic injury.

One-year follow-up evaluation of magnetic resonance imaging of the brain in dogs with pituitary-dependent hyperadrenocorticism.

OBJECTIVE: To evaluate magnetic resonance imaging (MRI) brain scans of dogs with pituitary-dependent hyperadrenocorticism (PDH) and no signs of CNS dysfunction 1 year after diagnosis and initial MRI. DESIGN: Prospective study of surviving dogs from a previous study. ANIMALS: 13 dogs underwent MRI of the brain at the time that PDH was diagnosed and prior to treatment. At that time, none of the dogs had clinical signs suggestive of an intracranial mass. Approximately 1 year after diagnosis and MRI, the brain was again evaluated by MRI. RESULTS: On the initial MRI scan, 5 of the 13 dogs had normal findings, and 8 had evidence of a mass (tumor) in the area of the pituitary gland. Of the 5 dogs that had no visible pituitary mass on the initial MRI scan, 3 had a normal MRI brain scan 1 year later. Of the 5 dogs that had no visible pituitary mass on initial MRI scan, 2 had a visible pituitary mass at 1 year. The 8 dogs that had a visible mass on the initial MRI brain scan had easily identified pituitary masses on the second MRI scan. Of these 8 dogs, 4 had no apparent change in pituitary mass size, and 4 had obvious increase in vertical height of the pituitary mass. Of the 4 dogs, 2 developed signs of neurologic dysfunction within 1 year after diagnosis of PDH, presumably attributable to that mass. Of the 13 dogs, 12 were treated with mitotane soon after completion of the initial MRI scan. Sensitivity to mitotane and initial pituitary mass size or growth were not correlated. Of the 13 dogs evaluated initially and 1 year after diagnosis, 10 had pituitary masses identified on MRI brain scans. CLINICAL IMPLICATIONS: The incidence of visible pituitary masses among dogs with PDH at the time of or within a year of diagnosis was > 75%. In 2 dogs, signs of CNS dysfunction developed within 1 year of PDH diagnosis when pituitary masses were > or = 10 mm.

Magnetic resonance imaging of the brain in dogs with recently diagnosed but untreated pituitary-dependent hyperadrenocorticism.

Magnetic resonance imaging was used to determine the prevalence of visible pituitary masses in 21 dogs with recently diagnosed and untreated pituitary-dependent hyperadrenocorticism. All dogs had clinical signs and routine database values (CBC, serum biochemical panel, and urinalysis) consistent with a diagnosis of hyperadrenocorticism, and none had clinical signs suggestive of an intracranial mass. Each dog had plasma cortisol concentrations after adrenocorticotropic hormone administration or low-dose dexamethasone administration consistent with hyperadrenocorticism. Pituitary-dependent hyperadrenocorticism was confirmed by the finding of 2 equal-size adrenal glands on abdominal ultrasonography and by results of plasma endogenous adrenocorticotropic hormone concentration and high-dose dexamethasone suppression testing. Sagittal and transverse T1-weighted magnetic resonance images of the brain were obtained before and after IV administration of gadopentenate dimeglumine. Eleven dogs had visible masses, ranging in size from 4 to 12 mm at greatest vertical height. Mean age and body weight of dogs with a visible pituitary mass was not significantly different from dogs without a visible mass. There was no significant difference in endocrine test results when comparing dogs with a visible pituitary mass to dogs without. The prevalence of visible pituitary masses in dogs with pituitary-dependent hyperadrenocorticism was greater than suggested by the prevalence of clinical neurologic signs.

Magnetic resonance imaging for diagnosis of pituitary macrotumors in dogs.

The value of magnetic resonance imaging (MRI) for the evaluation of dogs with pituitary-dependent hyperadrenocorticism (PDH) and CNS signs was assessed. Magnetic resonance imaging of the brain was performed in 13 dogs with PDH and neurologic signs. The diagnosis of PDH was made on the basis of results of adrenocortical function tests and abdominal ultrasonography, in conjunction with appropriate history, clinical signs, and clinicopathologic alterations. Eight dogs had been treated with the adrenocorticolytic agent, mitotane, for 1 to 30 months before the development of neurologic signs. Prior to MRI, each dog had progressive neurologic signs that could not be attributed to hypocortisolism or mitotane toxicosis. The neurologic signs most frequently detected were disorientation and ataxia. Mean age of dogs at the time neurologic signs developed was 9.5 years. Sex predilection was not detected; however, most were large-breed dogs, with 11 of the 13 dogs weighing more than 20 kg. A large mass in the pituitary gland, suprasellar region, or both was easily identified on the magnetic resonance images of each dog. The masses ranged from 8 to 24 mm in size. Expansion of tumors into the suprasellar region and compression of structures adjacent to the pituitary gland were readily detected by MRI. Contrast enhancement did not improve tumor identification, but did enable better delineation between tumor and surrounding structures. After the diagnosis of a macrotumor was made by MRI, radiotherapy was initiated in 9 dogs and was successfully completed in 6. Three dogs had a relapse of neurologic signs 8, 11, and 26 months after radiotherapy was completed.(ABSTRACT TRUNCATED AT 250 WORDS)

Dural and carotid cavernous sinus fistulas. Diagnosis, management, and complications.

Carotid cavernous sinus fistulas (CCSFs) are a rare entity occurring as a result of head trauma and also spontaneously. The major threat from these fistulas is loss of vision. The authors reviewed 18 cases of direct and dural CCSFs seen over the last 10 years and compared our results with 553 cases treated in the literature. Seventy-one percent of our patients with direct CCSFs had successful balloon embolization. In the literature, successful closure of direct CCSFs has ranged from 58 to 100%. As experience with embolization techniques broadens, morbidity and mortality is reduced. The clinical features, diagnostic procedures, therapeutic options, and complications of treatment of CCSFs are discussed.

Rupture of inferior thyroid artery aneurysm.

We report a case in which rupture of an aneurysm of the inferior thyroid artery caused respiratory arrest. The aneurysm was embolized successfully by an angiographic technique. Published reports of rupture of thyroid artery aneurysms are reviewed.

Evaluation of spinal infections by plain radiographs, computed tomography, intrathecal metrizamide, and CT-guided biopsy.

16 cases of spinal infection were reviewed to evaluate the usefulness of plain radiographs, noncontrast computed tomography (CT), computed tomographic metrizamide myelography (CTMM), plain film metrizamide myelography, and CT-guided biopsy techniques. Noncontrast CT was more useful than plain films in the evaluation of disc space and bony involvement and soft tissue extension of infection into the paraspinal spaces. CTMM was needed for evaluation of epidural or subdural involvement of infection in the cervical and thoracic spine, while plain film metrizamide myelography was useful as a survey for CTMM. CT-guided biopsy was definitive in establishing the etiology of the offending organism.

Long-term delta-9-tetrahydrocannabinol treatment. Computed tomography of the brains of rhesus monkeys.

High-resolution computed tomographic (CT) scanning of the brain was performed on three groups of rhesus monkeys for the detection of ventricular or cisternal enlargement. These three groups comprised four age-matched controls that had no prior drug usage--four monkeys receiving short-term (two to ten months) orally administered delta-9-tetrahydrocannabinol (delta 9-THC [now known nonproprietarily as dronabinol] and four monkeys receiving long-term (five years) orally administered delta 9-THC. Our results show a statistically significant enlargement of the frontal horns and the bicaudate distance in the long-term group as compared with the control and less significant enlargement of these areas in the long-term group compared with the short-term group. These findings suggest atrophy of the head of the caudate nucleus and the frontal portion of the brain of rhesus monkeys receiving long-term treatment with delta 9-THC.

Outpatient low-dose computed tomography metrizamide myelography and evaluation of lumbar disk disease.

Outpatient low-dose computed tomography metrizamide myelography (CTMM) for the evaluation of lumbar disk disease is described in 55 patients. Ten individuals (group 1) were studied using 3.5 ml of 150 mg I/ml (525 mg I total) of metrizamide. Forty-five additional patients (group 2) were examined with 5 ml of 110 mg I/ml (550 mg I total) concentration of metrizamide. Group 2 experienced less post-procedure headache (6.6%) and nausea (2.2%) than did group 1 (30% and 10%, respectively). Group 2 demonstrated a lowered rate of headache (p less than .01) and showed a trend to less nausea (p less than .09) than a recently published study describing full-dose lumbar myelography. In addition, CTMM in group 2 produced more uniform mixing of metrizamide than in group 1. Overall, low-dose CTMM increased accuracy and reduced morbidity, patient cost, and inconvenience as compared with routine full-dose lumbar myelography.