4DCT Scanning Technique for Primary Hyperparathyroidism: A Scoping Review.

Steven Raeymaeckers,Johan De Mey,Maurizio Tosi,Lorenzo Faggioni

doi:10.1155/2021/6614406

Abstract

Objective 4DCT for the detection of (an) enlarged parathyroid(s) is a commonly performed examination in the management of primary hyperparathyroidism. Protocols are often institution-specific; this review aims to summarize the different protocols and explore the reported sensitivity and specificity of different 4DCT protocols as well as the associated dose. Materials and Methods A literature study was independently conducted by two radiologists from April 2020 until May 2020 using the Medical Literature Analysis and Retrieval System Online (MEDLINE) database. Articles were screened and assessed for eligibility. From eligible studies, data were extracted to summarize different parameters of the scanning protocol and observed diagnostic attributes. Results A total of 51 articles were included and 56 scanning protocols were identified. Most protocols use three (n = 25) or four different phases (n = 23). Almost all authors include noncontrast enhanced imaging and an arterial phase. Arterial images are usually obtained 25–30 s after administration of contrast, and less agreement exists concerning the timing of the venous phase(s). A mean contrast bolus of 100 mL is administered at 3-4 mL/s. Bolus tracking is not often used (n = 3). A wide range of effective doses are reported, up to 28 mSv. A mean sensitivity of 81.5% and a mean specificity of 86% are reported. Conclusion Many different 4DCT scanning protocols for the detection of parathyroid adenomas exist in the literature. The number of phases does not appear to affect sensitivity or specificity. A triphasic approach, however, seems preferable, as three patterns of enhancement of parathyroid adenomas are described. Bolus tracking could help to reduce the variability of enhancement. Sensitivity and specificity also do not appear to be affected by other scan parameters like tube voltage or tube current. To keep the effective dose within limits, scanning at a lower fixed tube current seems preferable. Lowering tube voltage from 120 kV to 100 kV may yield similar image contrast but would also help lower the dose.

Highlights

Primary hyperparathyroidism is a common endocrine disease
We look at other scanning protocol factors like tube current and tube voltage, contrast bolus volume, and timing: factors that can affect the sensitivity of the exam and influence the effective dose, a key part to consider in multiphasic studies using ionizing radiation
We evaluated the number of obtained phases and their timing: we defined a subdivision in an arterial phase, a venous phase (40 seconds–70 seconds), a delayed venous phase (70 seconds–100 seconds), and a very delayed phase

Summary

Introduction

Primary hyperparathyroidism is a common endocrine disease. In the case of an asymptomatic patient over the age of 50 without end-organ complications, conservative treatment can be assumed [1, 2]. e only cure for the disease is surgery, with resection of the affected gland(s). In the case of an asymptomatic patient over the age of 50 without end-organ complications, conservative treatment can be assumed [1, 2]. E only cure for the disease is surgery, with resection of the affected gland(s). E most accessible diagnostic technique is ultrasound because it is widely available at low cost, and it presents no adverse effects [4]. Ultrasound is the preferred method of examination for the thyroid gland. Is way parathyroid lesions can be differentiated from thyroid nodules and other thyroid pathologies. Color Doppler can be used to differentiate parathyroid lesions from other cervical masses, such as lymph nodes and thyroid nodules [6]. False-negative results can occur, especially in the case of ectopic glands or in the presence of a large thyroid goiter [7]

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