Ultrasonographic features of intrathyroidal parathyroid adenoma causing primary hyperparathyroidism

Preoperative localization study is difficult in patients with primary hyperparathyroidism (PHPT) caused by intrathyroidal parathyroid adenoma. The objective of this study was to evaluate the usefulness of ultrasonography (US) in the diagnosis of intrathyroidal parathyroid adenoma. Between January 2004 and December 2009, seven of 373 patients who underwent parathyroidectomy because of PHPT in our hospital were found to have intrathyroidal parathyroid adenoma. The ultrasonographic features of intrathyroidal parathyroid adenoma were examined retrospectively. The most characteristic feature of intrathyroidal parathyroid adenoma was a hyperechoic line on the ventral surface of the parathyroid gland. A hyperechoic line was clearly detected even in small adenomas in which feeding vessels could not be detected on color Doppler sonography. In comparison with feeding vessels, a hyperechoic line was frequently detected in normally located parathyroid adenoma. (99m)Tc-sestamibi (MIBI) scintigraphy and computed tomography (CT) could show parathyroid adenoma in the intrathyroidal position in only three of five and in only one of three patients examined, respectively. Since a hyperechoic line is characteristic of parathyroid adenoma, an intrathyroidal parathyroid adenoma could be suspected by only non-invasive US.     

Noninvasive localization procedures in ectopic hyperfunctioning parathyroid tumors

In primary hyperparathyroidism (pHPT), parathyroidectomy is the treatment of choice, but anatomic variations of ectopic glands may cause surgical failure. Reliable preoperative noninvasive localization procedures would have a positive impact on the operative time and increase recovery rate. We retrospectively evaluated 186 patients with pHPT who were studied before successful parathyroidectomy by double tracer scintigraphy (99mTc-pertechnetate+201TI chloride or 99mTc-pertechnetate +99mTc-sestamibi, 160 patients), ultrasonography (148 patients) and computerized tomography (CT) scan (92 patients). During bilateral neck exploration, 159 (85.5%) single adenomas, 6 (3.2%) parathyroid carcinomas, and 3 (1.6%) double adenomas were found. Moreover, 18 (9.7%) patients had diffuse chief cells parathyroid hyperplasia. Removed parathyroid glands were in ectopic sites in 41 (22.0%) cases, mainly localized in the upper mediastinum or behind the esophagus. The overall sensitivity was 83.5 and 85.2% for 99mTc-pertechnetate+201TI chloride and 99mTc-pertechnetate+99mTc-sestamibi scintigraphy respectively, 80.4% for CT scan and 81.1% for ultrasonography. In patients with ectopic glands, sensitivity was 81.2, 79.5, 73.3 and 81.6% respectively. In 36 out of 41 patients with ectopic glands in whom the removed parathyroids were correctly localized, mean operative time was 95 min, and in 5 patients without preoperative localization it was 260 min. In conclusion, in pHPT, preoperative localization of an enlarged parathyroid is helpful, especially in ectopic adenomas and in anatomic variations in location, and it has been proved to reduce operative time and morbidity rate.     

Technetium-99m-sestamibi subtraction scintigraphy vs. ultrasonography combined with a rapid parathyroid hormone assay in parathyroid aspirates in preoperative localization of parathyroid adenomas and in directing surgical approach

OBJECTIVE: To determine the sensitivity and positive predictive value (PPV) of subtraction scintigraphy (SS) vs. ultrasonography (US) of the neck combined with rapid intact parathyroid hormone (iPTH) assay in US-guided fine-needle parathyroid aspirates in preoperative localization of parathyroid adenomas and in directing surgical approach. DESIGN: The results of SS for localization of parathyroid adenoma were determined in 121 patients with primary hyperparathyroidism (pHPT) and compared with findings at surgery and with the results of US alone (in patients without nodular goitre) and US in combination with the iPTH assay in US-guided fine-needle aspirates (FNAs) of suspicious parathyroid lesions (in patients with concomitant nodular goitre). PATIENTS: All 121 patients had biochemically documented pHPT; all were referred for first-time surgery. MEASUREMENTS: SS was performed with 99mTc-sestamibi and 99mTc-pertechnetate. High-resolution US of the neck was performed by a single endocrine surgeon and combined with US-guided FNAs of suspicious parathyroid lesions in all patients with nodular goitre (n = 43). RESULTS: The sensitivity and PPV of SS were significantly higher in patients without vs. with goitre (89.3% and 95.7%vs. 74.3% and 76.5%, respectively; P < 0.001). The sensitivity and PPV of US were significantly higher in patients without vs. with goitre (96% and 97.3%vs. 67.7% and 71.9%, respectively; P < 0.001). The iPTH assay of US-guided FNAs of suspicious parathyroid lesions in patients with nodular goitre significantly improved both the sensitivity and PPV of US imaging (90.7% and 100%, respectively), allowing for an accurate choice of surgical approach in 118 (97.5%) of 121 patients. SS was more accurate than US alone in detection of ectopic parathyroid adenomas. However, US alone was characterized by a higher sensitivity in detection of small parathyroid adenomas (< 500 mg) at typical sites (P < 0.01). CONCLUSIONS: Both the sensitivity and PPV of SS and US alone are comparable, with significantly less accurate results obtained in patients with goitre. In cases of equivocal results of US and/or in patients with concomitant goitre, an iPTH assay in US-guided FNAs of suspicious parathyroid lesions may be used to establish the nature of the mass, distinguish between parathyroid and nonparathyroid tissue (goitre, lymph nodes) and improve the accuracy of US parathyroid imaging, allowing for successful directing of surgical approach in a majority of patients.     

Advantages of combined technetium-99m-sestamibi scintigraphy and high-resolution ultrasonography in parathyroid localization: comparative study in 91 patients with primary hyperparathyroidism

OBJECTIVE: To evaluate the usefulness of the combination of Tc-sestamibi/Tc-pertechnetate subtraction scintigraphy (SS) and high-resolution neck ultrasonography (US) in patients with primary hyperparathyroidism (pHPT) undergoing parathyroidectomy. DESIGN AND METHODS: Ninety-one patients with proved pHPT were studied, excluding patients with persistent or recurrent disease. There were 65 (71.4%) women and 26 (28.6%) men, with a median age of 59 years (range 18-78 years). All patients underwent both SS and US prior to surgery, and the results were compared with operative and histological findings. The intraoperative quick-parathyroid hormone assay was available for 52 (57.1%) patients. When multiglandular disease was found, both SS and US were considered truly positive only when at least two enlarged parathyroid (PT) glands had been localized. RESULTS: Eighty-three (91.2%) solitary PT adenomas and three (3.3%) carcinomas were found. Moreover, two (2.2%) patients had a double adenoma and three (3.3%) patients had diffuse PT hyperplasia. The overall sensitivity of combined SS+US was 94.5% (86.8% and 80.4% for SS and US respectively). There was a significant (P<0.05, Student's t-test) difference in size between the PT glands correctly identified and undetected by SS, whereas the site of the removed PT tumors significantly (P<0.05, Fisher exact test) influenced only the US sensitivity. CONCLUSIONS: When the preoperative localization of the PT glands is chosen, the combination of SS and US represents a reliable noninvasive localization technique and should be considered for use in each patient with pHPT undergoing surgery.     

高频超声诊断80例隐匿性甲状腺癌的临床分析

目的探讨高频超声在隐匿性甲状腺癌中的应用价值。方法分析我院从2009年1月至2011年1月间经病理证实的80例患者甲状腺癌的超声表现。结果 80例隐匿性甲状腺癌高频超声检出甲状腺癌结节102个,诊断符合率83.3%。结论高频超声对隐匿性甲状腺癌的定位和定性非常重要。     

Comparison of histological findings and parathyroid scintigraphy in hemodialysis patients with secondary hyperparathyroid glands

To determine the usefulness of parathyroid scintigraphy in histological estimation for secondary hyperparathyroidism (2HPT) using Tc-99m sestamibi or Tc-99m tetrofosmin. Tc-99m sestamibi (MIBI) and Tc-99m tetrofosmin (Tetro) parathyroid imaging following double-phase study, magnetic resonance imaging (MRI), and ultrasound were performed on 14 patients with 2HPT. All patients underwent parathyroidectomy. The uptake of two tracers in parathyroid areas was compared with the histopathologic findings. Forty-nine parathyroid glands were surgically explored and histologically proven to be hyperplastic. Of these, 42 were diagnosed with nodular type (N-type) hyperplasia, and 7 with diffuse type (D-type) hyperplasia. MIBI and Tetro parathyroid imagings detected 34 and 35 parathyroid glands, respectively. The sensitivity of MIBI was determined to be 76.2% (32/42) for N-type, and 28.6% (2/7) for D-type. The sensitivity of Tetro was determined to be 78.6% (33/42) for N-type and 28.6% (2/7) for D-type. The sensitivity of both MIBI and Tetro was significantly higher for N-type than for D-type, 76.2% (32/42) vs. 28.6% (2/7) in MIBI, P = 0.022; 78.6% (33/42) vs. 28.6% (2/7) in Tetro, P = 0.015. The sensitivity of MRI was determined to be 76.2% (32/42) for N-type and 42.9% (3/7) for D-type, and the sensitivity of ultrasound was 71.4% (30/42) for N-type and 71.4% (5/7) for D-type. There was no significant difference in the sensitivity of MRI or ultrasound between N-type and D-type. The uptake ratios of MIBI and Tetro were also greater for N-type than for D-type. The detectability of both MIBI and Tetro was greater for N-type than for D-type. Tc-99m MIBI or Tc-99m Tetro parathyroid scintigraphy therefore may be used clinically to distinguish N-type from D-type parathyroid gland hyperplasia.     

Technetium-99m tetrofosmin parathyroid imaging in patients with primary hyperparathyroidism

OBJECTIVE: To confirm the clinical significance of 99mTc-tetrofosmin imaging for the localization of hyperfunctioning parathyroid glands in patients with primary hyperparathyroidism. METHODS: All patients were imaged with 99mTc-tetrofosmin at 10 minutes and 2 hours after radiotracer injection, and with ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI). The parathyroid/thyroid uptake ratio of 99mTc-tetrofosmin (P/T uptake ratio) was calculated. PATIENTS: Twenty patients with primary hyperparathyroidism were referred to our clinic, underwent surgical neck exploration or mediastinotomy and were diagnosed as having parathyroid adenoma. These patients were investigated for the preoperative localization by 99mTc-tetrofosmin scintigraphy. RESULTS: 99mTc-tetrofosmin imaging demonstrated focal uptake in 19 out of 20 patients with parathyroid adenoma. Two of the lesions were ectopic. US identified 17 parathyroid glands. CT and MRI initially detected 17 parathyroid glands. However, two additional parathyroid glands were localized on repeated CT and MRI in tandem with the results of the 99mTc-tetrofosmin imaging. Thus, the sensitivity and specificity of tetrofosmin imaging were 95% (19/20) and 95% (19/20); US, 85% (17/20) and 94% (16/17); initial CT, 85% (17/20) and 94% (16/17); and initial MRI, 88% (17/20) and 94% (16/17), respectively. The P/T uptake ratio at 2 hours after tetrofosmin injection was correlated with the serum concentration of intact PTH (rs=0.47, p<0.05) and the resected tumor weight (rs=0.53, p<0.05). CONCLUSION: 99mTc-tetrofosmin scintigraphy is useful for localization of parathyroid adenoma. Tetrofosmin uptake depends on the tumor weight and serum intact PTH levels.     

Minimally invasive radio-guided surgery for primary hyperparathyroidism: From preoperative to intraoperative localization imaging

The introduction and successful implementation of minimally invasive radio-guided parathyroidectomy (MIRP) has revolutionized the surgical approach to remove parathyroid adenomas. A prerequisite for such success is an accurate localization of the offending adenoma. To achieve this goal, a multimodality approach is commonly employed using a combination of anatomical and functional imaging. Of the anatomical cross-sectional techniques, ultrasonography is the most widely available but is operator-dependent and has reduced sensitivity, specially in the presence of thyroid nodules. Similarly, computed tomography and magnetic resonance imaging have low sensitivities but provide value in detecting retrotracheal, retro-oesophageal and mediastinal adenomas. Functional imaging with ^99mTc-Sestamibi is currently the most vital imaging procedure in this respect with variable protocols including dual-phase and dual isotope imaging. The sensitivity and specificity can improve by acquiring in single photon emission tomography (SPECT) mode and using co-registration with low dose CT to provide anatomical data (SPECT/CT). The current recommended approach is the combination of functional imaging with ^99mTc-Sestamibi and high-resolution ultrasound (US), supplemented with intraoperative gamma probe in certain cases and quick persurgical measurement of parathyroid hormone. This review aims to explore the utility of various imaging modalities, alone and in combination, in detecting parathyroid adenoma and facilitating the current approach of MIRP.     

Differential diagnosis of gall-bladder masses using colour Doppler ultrasonography

To evaluate the diagnostic accuracy of colour Doppler ultrasonography in the differential diagnosis of gall-bladder lesions, we studied colour Doppler flow imaging of gall-bladder masses in 75 patients with gall-bladder masses, including 26 patients with cancer, 18 with benign polyps, 10 with adenomyomatosis and 21 with pseudo-tumorous sludge and 28 healthy subjects as controls. The presence of a colour signal, pattern of the colour signal, blood flow velocity and resistive index (RI) within lesions were assessed using colour Doppler ultrasonography. In cancerous lesions, the colour signal pattern was diffuse or arborizing (sensitivity 90.5% (19/21); specificity 62.5% (10/16)) and the velocity and RI were (mean ± s.d.) 39.0 ± 12.4 cm/s and 0.62 ± 0.12, respectively, which was significantly different (P< 0.01) compared with controls (11.4 ± 2.5 and 0.75 ± 0.03, respectively). The colour signal pattern obtained from polyps was linear at their base in 62.5% (10/16) of cases, but the velocity (13.6 ± 5.5) and RI (0.74 ± 0.08) did not differ from those of the controls. Lesions other than cancer and polyp had no colour signal. There were overlaps in the values of velocity and RI between malignant and benign lesions. When 20 cm/s for velocity and 0.65 for RI were used as the respective cut-off values, the sensitivity and specificity of this method in the diagnosis of malignant lesions was 95.2% (20/21) and 87.5% (14/16) for velocity and 66.7% (14/21) and 87.5% (14/16) for RI, respectively. In a prospective study consisting of 10 patients with cancer and 21 patients with polyps, the sensitivity and specificity were 90 and 66.7% for the colour signal, 100 and 100% for velocity and 80 and 90.4% for RI, respectively. In conclusion, colour Doppler ultrasonography can be useful in the diagnosis of gallbladder masses in combination with conventional ultrasonographic findings of gall-bladder masses, especially in the differentiation of cancers from benign lesions.     

Focal MIBI uptake is a better indicator of active myeloma than diffuse uptake

PURPOSE: Technetium-99m 2-methoxyisobutylisonitrile (MIBI) imaging has been proposed as a front-line investigation to detect bone disease both before and after the treatment of myeloma. In this study, we have compared the pattern of MIBI uptake (focal and diffuse) between patients with proven myeloma and a cohort of patients without myeloma, in order to identify the uptake pattern that best correlates with disease activity. METHODS: Nineteen scans were taken in 16 consecutive patients (nine males and seven females: aged 39-71 yr) with active myeloma. A further 20 scans (10 subjects having MIBI myocardial perfusion scintigraphy and 10 subjects having MIBI parathyroid adenoma localisation studies), comprised the control (non-myeloma) cohort. Scans were evaluated in a double-blinded fashion by two observers for any diffuse skeletal MIBI uptake (homogeneous uptake in spine, sternum and/or long bones), and/or abnormal focal uptake (patchy, focal or tubular uptake in the skeleton or soft tissues). RESULTS: The pattern of MIBI uptake was significantly different in the myeloma-positive subjects and the control cohort. Focal uptake was highly discriminatory, being seen in 15 of 19 (79%) scans of the myeloma-positive group as opposed to one of 20 (5%) scans of the control group (P < 0.0001). In contrast, diffuse uptake was seen in 17 of 19 (89%) scans in patients with myeloma, and in 11 of 20 (55%) of the control cohort (P = 0.02). Using multiple logistic regression analysis, any focal uptake was significantly predictive for active myeloma (P = 0.0007) but diffuse uptake was not (P = 0.15). Diffuse uptake alone, without focal uptake, was found in four of 19 scans with myeloma and in 10 of 20 without active myeloma, but was not significantly associated with absence of active myeloma (P = 0.06). Using the criteria of Pace et al. for positivity (diffuse activity >50% myocardial activity), we demonstrated improved specificity from 45% to 100%, but significantly impaired sensitivity for presence of myeloma (79% vs. 37%, P = 0.02). CONCLUSION: Our study thus illustrates that the presence of any focal uptake of MIBI is useful in indicating active myeloma whereas diffuse uptake is not.     

Power Doppler ultrasonography for the assessment of vascular invasion by pancreatic cancer

Aim: To investigate the diagnostic accuracy of power Doppler ultrasonography (US) in assessing the vascular invasion by pancreatic cancer. Methods: A prospective study of 40 consecutive patients with pancreatic cancer (head 35, body 5) was performed. All patients underwent surgery. The relationships between tumor and each vessel were classified into four types according to the closest circumferential contact of the tumor with the vessel. A type 0 indicated no contact; type 1 indicated less than one third contact; type 2 indicated one third to 99% contact, and type 3 indicated encasement. Vascular invasion was diagnosed in types 2 and 3. The diagnostic accuracy was evaluated in the portal vein and in the splanchnic arteries (celiac artery, common hepatic artery, and superior mesenteric artery). The power Doppler US findings were confirmed by the operative findings. The results of power Doppler US were compared with those of CT scan and angiography. Results: Portal vein invasion was confirmed in resected specimens in 23 cases and by operative findings in 5 cases. For the diagnosis of portal vein invasion, sensitivity, specificity, and overall accuracy of power Doppler US were, respectively, 79.3, 90.9, and 82.5%. The respective values were 79.3, 100, and 85% for CT and 72.4, 81.8, and 75% for angiography. For the diagnosis of arterial invasion, sensitivity, specificity, and overall accuracy of power Doppler US were 80, 92, and 90%, respectively. The corresponding values were 47, 88, and 73% for CT and 47, 100, and 80% for angiography. Conclusion: Power Doppler US proved to be useful for the diagnosis of vascular invasion by pancreatic cancer.     

Musculoskeletal ultrasound for ankylosing spondylitis: A systematic review and meta-analysis

Objective:To clarify if musculoskeletal ultrasound (US) would give additional information for the clinical examination to diagnose and evaluate the activity of ankylosing spondylitis (AS).Methods:A literature search was performed in PubMed, Embase, Web of Science, the Cochrane Library, Sinomed, Chinese National Knowledge Infrastructure (CINK), and Wanfang databases from their inceptions to May 15, 2020. Studies that examined the musculoskeletal US, which detected sacroiliac joints in people with AS were included. The pooled analyses were performed using Meta Disc version 1.4 software.Results:A total of 9 studies encompassing 984 participants were included. Statistical analysis suggested an area under the curve (AUC) of 0.9259 (sensitivity 0.86, specificity 0.54) indicating that US had excellent diagnostic test accuracy for AS, an AUC of 0.6441 (sensitivity 0.87, specificity 0.51) indicating that the US did not have a good diagnostic test accuracy for AS activity. A subgroup analysis revealed that the AUC of power Doppler US (PDUS) and color Doppler US (CDUS) was 0.5000 and 0.9274, respectively, indicating that CDUS was superior to PDUS.Conclusion:US, especially CDUS, is a valid and reproducible technique for the diagnosis of AS. While the accuracy of AS activity evaluation of the US is not ideal. It may be considered for routine use as part of the standard diagnostic tools in AS.     

Familial isolated parathyroid adenoma in a consanguineous family.

The 23-year-old Caucasian male propositus presented with symptomatic hypercalcemia, hypophosphatemia and normocalciuria for 2 months. His 29-year-old brother had undergone an operation for recurrent parathyroid adenoma at age 26 and 28. No other member of the family was affected. His father and mother were second-degree relatives. Laboratory studies showed primary hyperparathyroidism (pHPT), while the remaining endocrine studies and genetic testing for multiple endocrine neoplasia 1 and 2A were normal. Technetium-cardiolite scintigraphy and ultrasound scans revealed a parathyroid mass at the left lower neck. Apart from bilateral hearing loss due to gentamicin treatment as a pre-term child, the patient was in of good health. Signs or symptoms of other endocrinopathies were absent. The patient was referred for parathyroidectomy with subsequent autotransplantation of the remaining glands into his sternocleidomastoid muscle. Histological examination revealed an adenoma with oncocytic differentiation, similar to that seen in his brother. The disease may follow a recessive mode of inheritance or may be due to a dominant germ-cell mutation in one of the parents. The presented case may ultimately help in elucidating the molecular genetic basis of this rare form of pHPT.     

Role of gamma probes in performing minimally invasive parathyroidectomy in patients with primary hyperparathyroidism: optimization of preoperative and intraoperative procedures

OBJECTIVE: In the last decade, surgery of primary hyperparathyroidism (HPT) due to a solitary adenoma has moved on from the traditional wide bilateral neck exploration (BNE) to more limited approaches such as unilateral neck exploration and minimally invasive parathyroidectomy. DESIGN: To define the role of intraoperative gamma probe and injection of a low (99m)Tc-MIBI dose in performing minimally invasive radio-guided surgery (MIRS) in HPT patients with a solitary parathyroid adenoma. METHODS: From September 1999 to July 2002, 214 patients with primary HPT entered the study. All patients were preoperatively investigated by a (99m)Tc-pertechnetate/MIBI subtraction scan and high-resolution neck ultrasound. The intraoperative technique we developed differs from other previously described techniques being based on the injection of a low (37 MBq) MIBI dose in the operating theatre a few minutes before the beginning of intervention. RESULTS: On the basis of scan/ultrasound findings 147 patients were selected for a MIRS and 144 of them (98%) were successfully treated by this approach: a solitary parathyroid adenoma was removed through a small 2-2.5 cm skin incision with a mean operative time of 35 min, and a mean hospital stay of 1.2 days. In the other 67 patients with scan/ultrasound evidence of concomitant nodular goiter (n=45) or multi-gland disease (n=13) or with a negative scan (n=9), the gamma probe was utilized during a traditional BNE. A low 37 MBq MIBI dose proved to be sufficient to perform a MIRS; moreover it delivered to the patient and surgeon a low, negligible, radiation exposure dose. CONCLUSIONS: The combination of a (99m)Tc-pertechnetate/MIBI subtraction scan and neck ultrasound appears to be an accurate imaging protocol in selecting primary HPT patients as candidates for a MIRS. A MIBI dose as low as 37 MBq injected in the operating theatre just before the start of surgery appears to be adequate to perform radio-guided surgery.     

A Pilot Comparison of 18F-fluorocholine PET/CT,Ultrasonography and 123I/99mTc-sestaMIBI Dual-Phase Dual-Isotope Scintigraphy in the Preoperative Localization of Hyperfunctioning Parathyroid Glands in Primary or Secondary Hyperparathyroidism: Influence of Thyroid Anomalies

We compared ¹⁸F-fluorocholine hybrid positron emission tomography/X-ray computed tomography (FCH-PET/CT) with ultrasonography (US) and scintigraphy in patients with hyperparathyroidism and discordant, or equivocal results of US and ¹²³I/^99mTc-sesta-methoxyisobutylisonitrile (sestaMIBI) dual-phase parathyroid scintigraphy. FCH-PET/CT was performed in 17 patients with primary (n = 11) lithium induced (n = 1) or secondary hyperparathyroidism (1 dialyzed, 4 renal-transplanted).The reference standard was based on results of surgical exploration and histopathological examination. The results of imaging modalities were evaluated, on site and by masked reading, on per-patient and per-lesion bases.In a first approach, equivocal images/foci were considered as negative. On a per-patient level, the sensitivity was for US 38%, for scintigraphy 69% by open and 94% by masked reading, and for FCH-PET/CT 88% by open and 94% by masked reading. On a per-lesion level, sensitivity was for US 42%, for scintigraphy 58% by open and 83% by masked reading, and for FCH-PET/CT 88% by open and 96% by masked reading. One ectopic adenoma was missed by the 3 imaging modalities. Considering equivocal images/foci as positive increased the accuracy of the open reading of scintigraphy or of FCH-PET/CT, but not of US. FCH-PET/CT was significantly superior to US in all approaches, whereas it was more sensitive than scintigraphy only for open reading considering equivocal images/foci as negative (P = 0.04). FCH uptake was more intense in adenomas than in hyperplastic parathyroid glands. Thyroid lesions were suspected in 9 patients. They may induce false-positive results as in one case of oncocytic thyroid adenoma, or false-negative results as in one case of intrathyroidal parathyroid adenoma. Thyroid cancer (4 cases) can be visualized with FCH as with ^99mTc-sestaMIBI, but the intensity of uptake was moderate, similar to that of parathyroid hyperplasia.This pilot study confirmed that FCH-PET/CT is an adequate imaging tool in patients with primary or secondary hyperparathyroidism, since both adenomas and hyperplastic parathyroid glands can be detected. The sensitivity of FCH-PET/CT was better than that of US and was not inferior to that of dual-phase dual-isotope ¹²³I/^99mTc-scintigraphy. Further studies should evaluate whether FCH could replace ^99mTc-sestaMIBI as the functional agent for parathyroid imaging, but US would still be useful to identify thyroid lesions.     

The role of imaging techniques in the study of renal osteodystrophy

Secondary hyperparathyroidism is the most common form of this condition found in renal osteodystrophy. Enlarged parathyroid glands are the rule in severe secondary hyperparathyroidism because of a marked parathyroid cell hyperplasia. For several years, ultrasonography, computed tomography, and scintigraphy with thallium201-technetium99 have been useful techniques to identify enlarged parathyroid glands. More recently, ultrasonography with color Doppler and parathyroid scintigraphy with 99mTc-sestamibi have proved to be useful as well. Computed tomography and magnetic resonance imaging can be used, but their sensitivity is similar to ultrasonography and they cost more. Ultrasonography with color Doppler signals has made it possible to evaluate tissue blood supply, an aid in differentiating thyroid nodules. The degree of blood supply may be an indirect index of cell proliferation when there is neither necrosis nor calcification, because an enriched blood supply suggests vigorous cell growth and nodule formation. Scintigraphy with 99mTc-sestamibi allows identification of ectopic glands, including those located in the mediastinum, and also provides functional information. Sestamibi uptake is closely related to both parathyroid hormone levels and to the histological type of parathyroid proliferation. In our experience, when hyperparathyroidism is not too severe, 2 weeks after 2 g of calcitriol is administered intravenously, these scintigraphic images can disappear (inhibition test). This suggests a possibility for a medical treatment. By contrast, when parathyroid hormone levels are higher, parathyroid sestamibi uptake remained unchanged. In such patients, parathyroidectomy or ethanol injection should be the best treatment. These glands would correspond to the most actively functioning glands; they would have a lesser expression of vitamin D receptors, rendering them refractory to medical treatment with calcitriol.     

核素显像对甲状旁腺功能亢进的诊断价值

目的评价3种核素显像方法在甲状旁腺功能亢进症(甲旁亢)诊断中的应用价值。方法35例拟诊甲旁亢患者进行了核素显像,包括201Tl/99mTcO4-减影法8例和99mTc-MIBI双时相法27例,后者有20例同时做了99mTc-MIBI/99mTcO4-减影法显像。阳性指标为减影或延迟图像上出现异常增高的放射性聚集灶,所有显像资料均参照临床最终诊断结果进行了评价,并与同期的B超或CT检查作了对比分析。结果确诊的35例甲旁亢患者,其中甲状旁腺腺瘤31例(异位1例)、甲状旁腺增生3例与甲状旁腺腺癌1例。201Tl/99mTcO4-减影法、99mTc-MIBI双时相法及99mTc-MIBI/99mTcO4-减影法显像诊断甲旁亢的灵敏度分别达62.5%、88.9%、90.0%,特异度均为100%,同期B超的灵敏度和特异度分别为74.3%和85.7%。另28例甲旁亢患者有CT资料,22例有阳性发现(78.6%)。99mTc-MIBI/99mTcO4-减影法显像较其它方法具有更高的诊断效能。结论核素显像能较准确地检测功能亢进的甲状旁腺,是患者术前定位的重要辅助诊断手段。     

Evaluation of various imaging methods in the differential diagnosis of intraductal papillary-mucinous tumor (IPMT) of the pancreas

BACKGROUND/AIMS: IPMT (intraductal papillary-mucinous tumor) of the pancreas has unique clinicopathological characteristics. The lesions which show characteristic clinical features of IPMT exhibit a wide spectrum of histological types ranging from atypical hyperplasia to invasive cancer. Therefore, surgical treatment cannot be recommended for all patients with IPMT. It is necessary to assess the malignant potential of IPMT in individual patients in order to select an appropriate approach. The aim of this study was to evaluate the effectiveness of endoscopic ultrasonography and intraductal ultrasonography as compared with ultrasonography and computed tomography for this purpose. METHODOLOGY: Ultrasonography, computed tomography, endoscopic ultrasonography and intraductal ultrasonography were performed in 49 cases of IPMT (atypical hyperplasia 7, adenoma 23, noninvasive 7 and invasive adenocarcinoma 12). On the basis of the histopathological analysis of another 28 cases of resected IPMT specimens, criteria for differential diagnosis by imaging modalities were defined as follows: Nonneoplastic lesion (atypical hyperplasia): no wall thickening or nodule; noninvasive IPMT (adenoma and intraductal carcinoma): a nodule or wall thickening is present; and invasive IPMT with pancreatic parenchymal invasion: a mass with a heterogenous pattern or interruption of the pancreatic duct wall by the mass. RESULTS: The diagnostic accuracy rate for differentiating nonneoplastic lesion noninvasive IPMT, and invasive IPMT was 33% by ultrasonography, 38% by computed tomography, 77% by endoscopic ultrasonography, and 67% by intraductal ultrasonography. Sensitivity, specificity and accuracy rates for differentiating neoplastic and nonneoplastic IPMT by ultrasonography was 33%, 100%, 42%, by computed tomography 36%, 100%, 44%, by endoscopic ultrasonography 90%, 71%, 88%, by intraductal ultrasonography 94%, 29%, 84%, respectively. Sensitivity, specificity and accuracy rates for differentiating invasive and noninvasive IPMT by ultrasonography was 25%, 100%, 80%, by computed tomography 33%, 100%, 83%, by endoscopic ultrasonography 55%, 97%, 88%, by intraductal ultrasonography 56%, 91%, 84%, respectively. Diagnostic accuracy for invasive IPMT except minimally invasive cases by endoscopic ultrasonography and intraductal ultrasonography was 80%, based on the results of the examination which demonstrated a higher grade lesion. CONCLUSIONS: With these criteria, ultrasonography and computed tomography showed high specificity, but low sensitivity for the differential diagnosis of neoplastic/nonneoplastic and invasive/noninvasive IPMT. However, endoscopic ultrasonography and intraductal ultrasonography had high sensitivity and diagnostic accuracy for the differential diagnosis of neoplastic/nonneoplastic lesions. Combination of endoscopic ultrasonography and intraductal ultrasonography showed a high accuracy rate in the diagnosis of invasive IPMT. Thus endoscopic ultrasonography and intraductal ultrasonography contributed significantly to the choice of the treatment for IPMT.     

Localization of parathyroid tumours in the minimally invasive era: which technique should be chosen? Population-based analysis of 253 patients undergoing parathyroidectomy and factors affecting parathyroid gland detection

A series of 253 consecutive patients with proved primary hyperparathyroidism due to parathyroid tumours was reviewed. There were 68 (26.9%) men and 185 (73.1%) women, with a median age of 57 years (range 13-82 years). All patients, prior to successful parathyroidectomy, underwent one or more preoperative localization procedures such as: neck ultrasonography (US) in 191 (75.5%), (201)Tl/(99m)Tc-pertechnetate subtraction scintigraphy (TPS) in 144 (56.9%), CT scan in 92 (36.4%), (99m)Tc-sestamibi/(99m)Tc-pertechnetate subtraction scintigraphy (MPS) in 90 (35.6%), selective venous sampling (SVS) with parathyroid hormone (PTH) assay in 30 (11.9%), and magnetic resonance imaging (MRI) in 6 (2.4%) patients. The results were compared with operative and histological findings that showed 235 (92.9%) solitary parathyroid adenomas, 13 (5.1%) carcinomas and 5 (2.0%) double adenomas. Sensitivity and positive predictive value were 82.9% and 93.8% for US, 83.6% and 91.8% for TPS, 81.3% and 98.7% for CT scan, 85.1% and 96.1% for MPS, 65.4% and 80.9% for SVS, and 80.0% and 80.0% for MRI respectively. No different results (P=NS) were found using US, TPS, MPS or CT scan, whereas SVS and MRI sensitivity was lower (P<0.05). The combination of MPS and US was 94.0% sensitive (P<0.05) but when TPS, CT scan or MRI were also used overall sensitivity did not improve significantly (P=NS). In conclusion, MPS should be used as the starting preoperative localization procedure, while US and MPS together represent the most reliable noninvasive localization tool. If MPS and US are negative or not in agreement, further studies are not cost-effective and the patient should undergo bilateral neck exploration.     

Computed tomography versus color duplex ultrasound for surveillance of abdominal aortic stent-grafts.

PURPOSE: To compare the ability of computed tomography (CT) and color duplex ultrasound (CDUS) to detect endoleak and accurately measure aortic aneurysm diameters after endovascular repair. METHODS: Between February 2000 and October 2004, 178 consecutive patients (156 men; mean age 74 years, range 49-89) were treated with aortic stent-grafts (86 Ancure, 55 AneuRx, and 37 Excluder). The follow-up protocol included serial CT and CDUS at 1 month and every 6 months thereafter. Sensitivity, specificity, positive predictive value, negative predictive value, and Kappa statistics (kappa) were calculated using CT as the gold standard; Bland-Altman analysis was used to determine the 95% limits of agreement. Paired and unpaired t tests and correlation coefficients were used to compare the methods. RESULTS: Follow-up ranged from 1 to 53 months (mean 16), during which 367 paired CT and CDUS studies were acquired. The mean diameter of the AAA sac after repair was 5.15 cm by CT versus 4.99 cm by CDUS (p=0.07); 93% of paired studies were somewhat similar (相似文献