Clinical Application Of Ultrasound In The Detection And Diagnosis Of Parathyroid Nodules

As one of the most important endocrine glands in human body, the parathyroid glands have the feature of small size, large numbers and localization variation. It can secrete parathyroid hormone, which have the ability of increasing the level of serum calcium, as well as decreasing the level of phosphorus, to participate in the regulation of calcium and phosphorus balance. When the organic change happened in the parathyroid gland, too much of the PTH are produced, which may later triggers the symptoms of hyperparathyroidism that involve injuries of many systems and organs, such as kidney stones, bone pain and ectopic calcification, etc. The pathological change would reflect in the minor or whole nodular changes of the glands. When classified by pathologic mechanism and nature, parathyroid nodules can be divided into four types:parathyroid cysts(PCs), parathyroid adenoma(PTA), parathyroid hyperplasia (PTH) and parathyroid carcinoma (PTC). PCs may be primary cysts or be caused by cystic degeneration of parathyroid adenoma. Normally, it was found accidentally and without special clinical symptoms except someone with high level of serum PTH; PTA is likely to be caused by gene mutations or abnormal signal transduction pathways. Because the clinical manifestation of this disease has no specificity and it is easy to be missed and misdiagnosed, the symptoms of advanced stage are often serious or even life-threatening when followed with hyperparathyroidism crisis; Parathyroid hyperplasia often happens in uremic patients taken a long-term hemodialysis. Serum PTH in these patients has increased significantly, and related symptoms are obvious, which can seriously influence the quality of life; Parathyroid carcinoma are rare and aggressive. It presents as a slow growing with obvious hyperparathyroidism crisis. Therefore, we should actively explore and research the diagnosis and treatment of parathyroid nodules, which have important clinical significance. Most clinical researches have demonstrated that operation is the first choice for patients with parathyroid nodules, which can reduce PTH secretion from the beginning. Therefore, preoperative definite diagnosis and accurate localization of the nodules are key to successful surgical removal. As a noninvasive method, modern imaging technologies have provided great location diagnostic value for most disease. High resolution ultrasonography has gradually become the preferred diagnostic imaging method in diagnostic superficial organ disease in neck, especially parathyroid nodules, because of the different imaging modes and the high resolution in spatial, in time and in velocity. Two-dimensional ultrasonography can make preliminary inspections with the nodules, such as the size, number, location, source, internal structure, relationship with nearby structures; CDFI show the nutrient vessel and its blood kinetics status and CEUS show the microcirculation of the nodule, which is helpful in differentiating benign and malignant nodules and studying the process of evolvement from its blood flow perfusion; Real-time elastography can quantify the textures, which would be helpful for distinguishing the benign and malignant tumor;3D-US show the space conformations, and can calculate the volume after volumetric scanning. In addition, FNA/CNB under ultrasound guided is considered to be safety, accuracy, and effective, which can be used to guide the treatment. Present researches on diagnosing parathyroid nodules by ultrasound are still not deep and thoroughly, the value of multi-ultrasound has to be studied further.Based on the specific ultrasonographic features of PCs, PA, and PTH, this subject tries to evaluate clinical value in the ultrasonic diagnosis of parathyroid nodules.Part One Application of Ultrasound in the Diagnosis and Differential Diagnosis of Parathyroid CystsObjective Explore the ultrasonographic features of parathyroid cysts to improve the diagnostic ability.Subjects11patients who visited the department of ultrasound in medicine at Changzheng hospital were diagnosed with cysts in parathyroid area by high resolution ultrasonography during the2011.1-2014.3period.Methods To make detailed records of the characters of ultrasound for every nodule, such as2D-US, CDFI,3D-US,etc. All patients take ultrasound-guided fine-needle aspiration to observe physics characters of the cyst fluid, and test the serum PTH, serum calcium, serum phosphorus, and cyst fluid PTH.5of the cysts have been given sclerosis therapy and6of them radiofrequency ablation.Results Of all the11patients,2patients sought medical advice due to neck complaints, while others had no symptoms. The serological of all patients were within the normal range. All cysts located in the lower parathyroid area(bottom left:4;bottom right:7), the ultrasonic characteristics of them were periphery in focus, strong sound transmission, diversified in form, and having reverse movement with thyroid in the same side when swallowing and pressing the probe. CDFI revealed no obvious blood flow signal in the nodules. CEUS showed no obvious strengthening, with the capsule wall appeared isoechoic. The volume calculated by3D-US were3.02～12.89ml,average (6.20±4.51) ml. The cyst fluid PTH were98pg/ml-205pg/ml,average (123.25±32.39) pg/ml, which were higher than the upper limit of normal serum PTH. All cysts with minimally invasive treatment gradually become smaller or even disappear.Conclusions PCs can be easily diagnosed because of the ultrasonic characteristics like other cysts, such as hepatic cysts, except for thyroid cyst. But sometimes we have to make a definitive diagnosis by measuring the content of PTH in the cysts, which can combined with sclerosis therapy or radiofrequency ablation. This minimally invasive treatment is safe and effective, worth clinical promotion. Part Two Application of Ultrasound in the Detection and Diagnosis of Primary Parathyroid adenomaObjective To summarize the ultrasonographic appearance of parathyroid adenoma. To analyze the relationship between the size of adenoma and serum biochemical index. We aim to improve the diagnosis and early detection of primary parathyroid adenoma with ultrasound.Subjects15patients who visited the department of ultrasound in medicine at Changzheng hospital were diagnosed with parathyroid nodules by high resolution ultrasonography during the2011.1-2014.3period.Methods Use normal control group(10healthy volunteers with19normal glands) and self-control method(bilateral control) to determine the ultrasonic features of the nodules; All of them had implemented radionuclide scan, endocrine biochemical test, and related pathological examination respectively.Results There were24nodules detected by ultrasound in15patients.In order to define the characteristic of the nodules,11of the patients (73.3%) with16nodules had taken core needle biopsy under ultrasound-guidance,3of them(20%) with7nodules had taken fine needle aspiration and measured the parathyroid hormone content by fine needle washing,1of them(6.7%) with one nodule had taken surgical removal.22of them were confirmed as parathyroid adenoma by pathological examination, while2misdiagnosed nodules were thyroid adenoma and lymph node separately. We found the sensitivity of ultrasound and radionuclide is95.5%(21/22)、68.2%(15/22) respectively. The positive predictive value is91.3%(21/23)、93.8%(15/16) respectively. In the10healthy volunteers, we found19normal glands with ultrasound, while all of them appeared negative with radionuclide san. In correlation analyses, the volume of every single nodule or the total volume of one patient is not relevant with his serum calcium, serum phosphate or serum PTH; It is statistics significance at difference of volume and serum calcium and serum phosphate between solitary nodular and multiple nodules (P=0.013).Conclusions This study indicated that there was no correlation between the size of adenoma and serum biochemical index. Double-phase radionuclide scan can increase the diagnostic coincidence rate of high resolution ultrasonography in diagnosing parathyroid adenoma. Part Three Study on Relationship between Ultrasonographic Imaging Characteristics and Serum Biochemical Index of Renal Parathyroid HyperplasiaObjective Summarize the ultrasonographic imaging characteristics of renal parathyroid hyperplasia to explore the relationship between the characteristics and serum biochemical index. And then make a preliminary judgment on the functional status of the hyperplasia glands.Subjects23uremic patients taken a long-term hemodialysis who visited the department of ultrasound in medicine at Changzheng hospital during the2011.1-2014.3period.Research To research the numbers, volume, imaging characteristics of ultrasound, endocrine biochemical test, and related pathological examination in renal parathyroid hyperplasia.Methods23uremic patients taken a long-term hemodialysis have had high resolution ultrasound test, recording the numbers and the imaging characteristics of the hyperplasia nodules. All of the patients had endocrine biochemical test (serum calcium, serum phosphate, serum PTH) and related pathological examination (taken as a golden standard)respectively. And then explore the relationship between the imaging characteristics and serum biochemical index.Results23uremic patients with63hyperplasia node were all suggested to be parathyroid hyperplasia by pathology findings. The accuracy rate of ultrasound is100%. In the23patients,4of them had one node,7of them have two node,4of them had three node,7of them have four node, and1of them have five node. In the63nodules, the volume calculated by3D-US were0.0156ml～3.91ml, average(0.998±0.959)ml. The volume of every single nodule or the total volume of one patient is not relevant with his serum biochemical index. The ultrasound-detected number of hyperplasia node was correlated significantly with serum PTH(P<0.0001, r=0.681), had moderate correlations with serum phosphate, and was not relevant with serum calcium; the location of the hyperplasia nodule is not relevant with serum biochemical index; There is a moderate negative correlation between serum calcium and PTH (P<0.05, r=-0.517), and a significantly positive correlation between serum phosphate and PTH (P<0.0001,r=0.818). Most nodules (58/63) appeared isoechoic on CEUS, and abundant color signals on CDFI. According to the pathological classification, our study classified the ultrasonographic images of parathyroid hyperplasia nodules into two types generally: diffuse hyperplasis (Type Ⅰ) and nodular hyperplasis (Type Ⅱ). Divied Type Ⅱ into nodular hyperplasis without calcification (Type Ⅱa) and nodular hyperplasis with calcification(Type Ⅱb). Among the63nodules,43of them were type Ⅰ,11of them were type Ⅱa,9of them were type Ⅱb. In the comparisons, there were no significant differences in serum PTH between the different types.(2-independent samples nonparametric tests)Conclusions The ultrasound-detected number of hyperplasia node is correlated with serum PTH and phosphate. The levels of serum biochemical index can be different between different types. Further study plans to use PTH evaluation results by fine needle washing after aspiration to evaluate the secretory function of every node.