Gadolinium as a contrast agent for infusion sialograms in patients with iodine allergy

Objectives

To assess the adequacy of gadolinium in sialography as an alternative contrast agent for patients with iodine allergies. To directly compare images taken with gadolinium versus iodine-based contrast agents using the Iowa Sialography Classification System.

Methods

Retrospective chart review was performed on patients undergoing sialography between February 2008 and July 2022. Patients with sialograms obtained with gadolinium were identified and matched to similar sialograms obtained with iodine-based contrast agent. Patients were matched based on duct location, duct side, and initial radiology findings. Blinded reevaluation of sialograms was performed first independently and then by consensus by two head and neck radiologists to evaluate overall image adequacy and grade using the Iowa Sialography Classification System.

Results

Four patients with six sialograms (one bilateral parotid and one parotid + submandibular) obtained with gadolinium were identified and reevaluated. Five patients with six sialograms (one bilateral parotid) obtained with iodine-based were matched to the gadolinium sialograms. The overall adequacy of images for gadolinium sialograms was graded at an average of 4.25 (4 = good and 5 = excellent); whereas, the overall adequacy of iodine-based sialograms was graded at an average of 5. Inter-observer variability was observed in three sialograms obtained with gadolinium (50%), while no interobserver variability was observed in sialograms obtained with iodine-based contrast agent.

Conclusion

Gadolinium is an adequate alternative to use in sialography for patients with iodine allergies undergoing contemporary digital infusion sialography. Adverse reactions to iodine contrast agents are rare in sialography; however, the precautionary use of gadolinium is acceptable for the diagnostic and therapeutic benefits in sialography.Level of Evidence: IV.

Conventional and MR-sialography of accessory submandibular glands: A case report

Our review of the literature shows anatomical variation of the submandibular gland is a rare entity, unlike the variation that can be seen in parotid glands. Specifically, bilateral submandibular abnormality has only been reported on one occasion with limited imaging in our review. We report a 78-year-old female with a history of sialadenitis and sialolithiasis who presents with swelling and pain in the right submandibular gland. Sialography of the right submandibular gland disclosed a second primary duct branching off the main duct to a second submandibular gland. Cannulation of the left submandibular duct was unsuccessful due to scarring of the duct orifice; however, subsequent MR sialography identified marked submandibular duct dilation and the incidental finding of a second anteriorly located left submandibular gland. The anatomic detail provided by conventional digital sialography is contrasted to the useful but less-defined imaging provided by MR sialography. To our knowledge, this is the first reported case of bilateral accessory submandibular glands that has been evaluated using both conventional and MR sialography.

Performance of Aneurysm Wall Enhancement Compared with Clinical Predictive Scales: PHASES, ELAPSS, and UIATS

OBJECTIVE

To correlate the presence of objectively measured wall enhancement on high-resolution vessel wall imaging (HR-VWI) with the clinical predictive scales PHASES, ELAPSS, and UIATS.

METHODS

Patients with unruptured intracranial aneurysm (UIAs) prospectively underwent HR-VWI on a 3-T magnetic resonance imaging scanner at diagnosis. Aneurysmal wall enhancement was objectively quantified on T1 postcontrast magnetic resonance imaging using signal intensity values adjusted for the pituitary stalk to calculate a contrast ratio (CR_stalk). UIAs with CR_stalk ≥0.60 were considered "enhancing." Patients' demographics, comorbidities, and aneurysm morphology were reviewed to calculate PHASES, ELAPSS, and UIATS scores. Pearson coefficients were applied for statistical correlation. Univariable and multivariable logistic regressions were performed to assess for confounders.

RESULTS

One-hundred and twenty-three patients harboring 178 UIAs underwent HR-VWI. A total of 101 patients with 135 UIAs were analyzed. Enhancing UIAs were larger (8.4 ± 5.5 mm vs. 5.5 ± 2.3 mm; P < 0.001), had higher aspect ratio (2.3 ± 1.5 vs. 1.8 ± 0.7; P = 0.008), higher size ratio (3.0 ± 1.8 vs. 2.4 ± 1.1; P = 0.016), scored higher on PHASES (5.6 ± 3.9 vs. 4.4 ± 2.6; P = 0.04) and ELAPSS (19.4 ± 8.9 vs. 15.4 ± 7.3; P = 0.006) compared with nonenhancing UIAs. Treatment allocation as defined by UIATS was measured independently to enhancement status. No significant differences were found for UIATS between enhancing and nonenhancing UIAs (P = 0.63). Multivariable regression showed that size was the only independent factor significantly associated with UIA enhancement (odds ratio, 1.76; P = 0.005).

CONCLUSIONS

Enhancing UIAs score higher in PHASES and ELAPSS scales. This association is largely explained by aneurysm size, aspect, and size ratios. Morphologic UIA features should be accounted for in clinical predictive scales of aneurysm instability.

Quantifying Intra-Arterial Verapamil Response as a Diagnostic Tool for Reversible Cerebral Vasoconstriction Syndrome

BACKGROUND AND PURPOSE

There is mounting evidence supporting the benefit of intra-arterial administration of vasodilators in diagnosing reversible cerebral vasoconstriction syndrome. We prospectively quantified the degree of luminal diameter dilation after intra-arterial administration of verapamil and its accuracy in diagnosing reversible cerebral vasoconstriction syndrome.

MATERIALS AND METHODS

Patients suspected of having intracranial arteriopathy on noninvasive imaging and referred for digital subtraction angiography were enrolled in a prospective registry. Intra-arterial verapamil was administered in vascular territories with segmental irregularities. The caliber difference (Caliber_post - Caliber_pre) and the proportion of caliber change ([(Caliber_post - Caliber_pre)/Caliber_pre] × 100%) were used to determine the response to verapamil. The diagnosis of reversible cerebral vasoconstriction syndrome was made on the basis of clinical and imaging features at a follow-up appointment, independent of the reversibility of verapamil. Receiver operating characteristic curve analysis was performed to determine the best threshold.

RESULTS

Twenty-six patients were included, and 9 (34.6%) were diagnosed with reversible cerebral vasoconstriction syndrome. A total of 213 vascular segments were assessed on diagnostic angiography. Every patient with a final diagnosis of reversible cerebral vasoconstriction syndrome responded to intra-arterial verapamil. The maximal proportion of change (P < .001), mean proportion of change (P = .002), maximal caliber difference (P = .004), and mean caliber difference (P = .001) were statistically different between patients with reversible cerebral vasoconstriction syndrome and other vasculopathies. A maximal proportion of change  ≥32% showed a sensitivity of 100% and a specificity of 88.2% to detect reversible cerebral vasoconstriction syndrome (area under the curve = 0.951). The Reversible Cerebral Vasoconstriction Syndrome-2 score of  ≥5 points achieved a lower area under the curve (0.908), with a sensitivity of 77.8% and a specificity of 94.1%.

CONCLUSIONS

Objective measurement of the change in the arterial calibers after intra-arterial verapamil is accurate in distinguishing reversible cerebral vasoconstriction syndrome from other vasculopathies. A proportion of change  ≥32% has the best diagnostic performance.