Imaging of frostbite injury by technetium-99m-sestamibi scintigraphy: a case report

The appearance of superficial tissue is often an unreliable indicator of deep-tissue viability in cases of frostbite. We present a 34-year-old black man who was brought to the emergency department at fourth post-injury day with frostbite injury involving both lower extremities after prolonged exposure to subzero temperatures. In our previous experimental study, 99mTc sestamibi scintigraphy has been employed for evaluating frostbite injuries in rabbit hindlegs. In the case presented, 99mTc sestamibi scintigraphy, as a new diagnostic tool, was performed for detection of skeletal muscle perfusion on the fourth post-injury day. The scintigraphic images show diffusely reduced uptake in soft tissues of both calves and feet. It was thought that this hypoperfusion was due to viable but ischemic tissue. Five days after medical therapy, 99mTc sestamibi scan showed prominently increased uptake in both calves and feet and skin necrosis was observed. Debridement of necrotic skin and subcutaneous tissue was performed, and split-thickness skin graft was applied for coverage of the skin defect. Healing was good 15 days after grafting. We think 99mTc sestamibi scan can be used for assessment of soft-tissue perfusion and evaluation of treatment in frostbite injury.     

Preoperative imaging of abnormal parathyroid glands in patients with hyperparathyroid disease using combination Tc-99m-pertechnetate and Tc-99m-sestamibi radionuclide scans.

OBJECTIVE: To evaluate the efficacy of combined Tc-99m-pertechnetate and Tc-99m-sestamibi radionuclide scanning for imaging abnormal parathyroid glands in hyperparathyroid disease in a prospective study. SUMMARY BACKGROUND DATA: Established methods to localize abnormal parathyroid glands lack accuracy for routine use. Tc-99m-sestamibi used in conjunction with iodine-123 has excellent potential for preoperative imaging in patients with hyperparathyroid disease. An alternative method for parathyroid imaging was studied using Tc-99m-pertechnetate and Tc-99m-sestamibi. METHODS: Thirty patients with hyperparathyroid disease had Tc-99m-pertechnetate and Tc-99m-sestamibi subtraction radionuclide scanning to visualize abnormal parathyroid glands before surgery. The patients had surgery and pathologic confirmation of all parathyroid glands. RESULTS: In 23 patients with primary hyperparathyroidism, 12 of 13 solitary adenomas were visualized. Six of nine patients with diffuse hyperplasia had bilateral uptake consistent with diffuse hyperplasia. Three of nine patients had negative scans. One patient previously operated on for diffuse hyperplasia had only one gland scanned. Seven patients with renal failure-associated hyperparathyroid disease were scanned: five had bilateral uptake of Tc-99m-sestamibi consistent with hyperplasia, and two who had been previously operated on had localization of remaining abnormal parathyroid glands. CONCLUSIONS: Tc-99m-pertechnetate combined with Tc-99m-sestamibi subtraction radionuclide scanning is less cumbersome to implement than iodine-123 combined with Tc-99m-sestamibi scanning. It has a high sensitivity for imaging solitary parathyroid adenomas or persistent solitary hyperplastic glands. However it does not have the resolution necessary to delineate all parathyroid glands in diffuse hyperplasia.     

Improving the yield of preoperative parathyroid localization: technetium Tc 99m-sestamibi imaging after thyroid suppression

BACKGROUND: Preoperative localization is essential for successful directed, minimally invasive or reoperative parathyroidectomy. Standard technetium Tc 99m-sestamibi imaging is the most sensitive modality for localization. We reviewed our experience with (99m)Tc-sestamibi imaging and specifically investigated the effect of thyroid suppression on repeat imaging of patients who had initially nonlocalizing scans. METHODS: . The records of patients who underwent (99m)Tc-sestamibi imaging during evaluation for primary hyperparathyroidism were reviewed. A subset of patients with initially nonlocalizing scans underwent thyroid suppression with either thyroxin or liothyronine and then had their scans repeated. RESULTS: Ninety-nine patients with primary hyperparathyroidism underwent (99m)Tc-sestamibi imaging followed by parathyroidectomy (initial operation, 78; reoperation, 21). Successful parathyroid localization was obtained on standard imaging in 67 patients. Fourteen of 32 patients who had nonlocalizing (99m)Tc-sestamibi imaging studies underwent an additional scan after thyroid suppression. In 10 of 14 patients (71%), repeat (99m)Tc-sestamibi imaging after thyroid suppression successfully localized abnormal parathyroid tissue. CONCLUSIONS: Thyroid suppression may improve the yield of (99m)Tc-sestamibi imaging in patients with hyperparathyroidism who have an initially nonlocalizing study. This diagnostic strategy may be helpful in patients motivated to undergo a directed, minimally invasive operation, as well as in the evaluation of patients for reoperative parathyroidectomy.     

The false negative technetium-99m-sestamibi scan in patients with primary hyperparathyroidism: correlation with clinical factors and operative findings

False negative (FN) results limit the efficacy of technetium-99m-sestamibi scanning for parathyroid localization. We determined the incidence of FN results and attempted to correlate it with clinical and operative findings. One hundred forty-six patients underwent parathyroidectomy; 89 had primary hyperparathyroidism (76 single adenoma and 13 multiglandular disease) and underwent sestamibi scanning. The false negative rate was 22 per cent with an overall sensitivity of 77 per cent and a positive predictive value of 99 per cent. Patients with single adenomas were more likely to have a true positive scan than those with multiglandular disease [83% vs 38%; odds ratio (OR) = 7.754, 95% confidence interval (CI) = 2.184-27.524; P < or = 0.0001]. Inferior adenomas (90% vs 59%; OR = 6.261, 95% CI = 2.037-19.243; P < or = 0.0001) and larger adenomas (1422.3 +/- 1576.2 vs 474.6 +/- 193.2 g; P < or = 0.0001) were more likely to be detected by sestamibi imaging. Patients with normal preoperative calcium levels were more likely to have an FN sestamibi scan. Sestamibi parathyroid imaging is limited by a 22 per cent FN rate and is less accurate for detecting abnormal parathyroid tissue in patients with small adenomas, multiglandular disease, superior adenomas, or preoperative normocalcemia.     

In vitro suppression of parathyroid hormone secretion by 22-oxa-calcitriol in human parathyroid hyperplasia due to uraermia

SUMMARY: 22-oxa-calcitriol (OCT), a vitamin D analogue, suppresses parathyroid hormone (PTH) secretion and has less calcaemic activity than 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] in vivo. In this study, we evaluated the effect of OCT on PTH secretion in vitro using human hyperplastic parathyroid tissue obtained during surgery for advanced renal hyperparathyroidism and normal bovine parathyroid glands to compare the effects of 1,25(OH)₂D₃. 22-oxa-calcitriol suppressed PTH secretion by nodular hyperplastic parathyroid tissue and normal bovine tissue in a dose dependent manner, the same as 1,25(OH)₂D₃. We showed the additive effect of extracellular calcium level on suppression of PTH secretion by OCT and 1,25(OH)₂D₃. These results suggest that OCT suppresses PTH secretion, the same as 1,25(OH)₂D₃ not only in normal parathyroid cells but also on hyperplastic parathyroid cells.     

Evaluation of thyroid nodules with technetium-99m MIBI and technetium-99m pertechnetate

BACKGROUND: Most thyroid centers use fine-needle aspiration (FNA) and technetium-99m pertechnetate for the preoperative assessment of thyroid nodules. This approach is sufficient in most cases other than follicular neoplasm, and follicular carcinoma is more common than papillary carcinoma in developing countries such as in our center. Technetium 99m-methoxyisobutylisonitrile (MIBI) proposed for myocardial perfusion was also found to be taken up by a variety of tumors including thyroid cancer. METHODS: We evaluated MIBI uptake of nodular thyroid disease and compared it with pertechnetate scan, FNA, and histologic findings for the differentiation of malignant thyroid nodules from benign lesions. Seventy-one patients were included in the study. Three-phase pertechnetate scintigraphy was completed after a single injection of 150 MBq. Perfusion/uptake mismatch (uniform perfusion with cold uptake) was regarded as positive for malignancy, whereas perfusion/uptake match (cold perfusion with cold uptake) was regarded as negative. After 1 week, 400 MBq of MIBI was injected, images were obtained at 20 minutes and 2 hours, and evaluated semiquantitatively by use of a 4-point (0-3) scoring system. MIBI scans were considered positive if there was uptake superior to normal thyroid tissue on early and delayed images (score = 3). In the following days and weeks, all patients underwent FNA followed by surgery. RESULTS: Histopathologic diagnosis revealed a total of 23 thyroid carcinomas, 21 (91%) and 19 (83%) were positive on MIBI and pertechnetate, respectively. Of the 48 patients with benign nodules, 11 (23%) and 29 (60%) were positive on MIBI and pertechnetate, respectively. The specificity of MIBI, pertechnetate, and FNA is 77%, 40%, and 90%, respectively. CONCLUSIONS: In combination with FNA and three-phase pertechnetate scan, MIBI could be helpful in preoperative assessment of thyroid nodules. Intense MIBI activity increases the probability of thyroid cancer, whereas reduced activity drastically decreases the probability of malignancy.     

Accuracy of technetium-99m SPECT-CT hybrid images in predicting the precise intraoperative anatomical location of parathyroid adenomas

BACKGROUND: This study evaluated the accuracy of single photon emission computed tomography (SPECT)-CT imaging for the preoperative localization of parathyroid adenomas. METHODS: This study included both a quantitative and qualitative accuracy measure. The quantitative measure was the distance between the location of the adenoma on the SPECT-CT scan and the location of the adenoma intraoperatively. Qualitatively, surgeons were asked whether or not the adenoma was in the exact location predicted by the SPECT-CT scan. The time from initial incision to identification of the parathyroid was recorded. Patients referred to London Health Sciences Centre for a suspected parathyroid adenoma were eligible for this study. RESULTS: Twenty-three patients participated in this study. Eighteen (78.3%) had a single adenoma, 2 (8.7%) had double adenomas, and 3 (13.0%) had multiglandular hyperplasia. SPECT-CT correctly detected and localized 16 of 18 (88.9%) cases of single parathyroid adenomas. The mean distance between the location of the adenoma on the SPECT-CT scan and the location of the adenoma intraoperatively was 16.3 mm (95% < or = 19.0 mm). For single adenomas, the median time from skin incision to identification was 14 minutes (range, 8-40 minutes). The preoperative detection and localization of a single focus of sestamibi uptake yielded a parathyroid adenoma in the specified location in 80.0% of cases (95% CI, 97.4-66.5%). CONCLUSIONS: SPECT-CT predicted the intraoperative location of a single parathyroid adenoma within 19.0 mm with 95% confidence. The correct detection and localization of multiglandular disease remains difficult.     

Renal allograft accumulation of technetium-99m sulfur colloid as a predictor of graft rejection

Differentiation between rejection (the most common cause) and many other possibilities for detrimental effects on graft function represents a difficult issue to diagnose the cause of renal allograft dysfunction. This study was designed to determine whether technetium-99m sulfur colloid (TSC) accumulation predicted graft rejection. We prospectively studied 54 episodes of allograft dysfunction in 53 kidney transplant recipients who underwent TSC scintiscanning and graft biopsy. Visual analysis of TSC uptake compared uptake, in the allograft with that in the marrow of the fifth lumbar vertebra (L5). A 3+ result meant that allograft uptake was greater than L5 marrow uptake; 2+, the same; 1+, less and finally 0, no allograft uptake. Transplant accumulation of 2+ or more was considered consistent with rejection (P = .01). Allograft biopsies interpreted based on the Banff Working Classification showed rejection in 45 of 54 renal biopsies with 42 the biopsy-proven rejection episodes showing at least 2+ graft uptake. Furthermore, this nuclear medicine technique had a sensitivity of 93.3%, a specificity of 44.4%, a positive predictive value of 89.3%, a negative value of 57.1% and an efficiency of 83.3% for the diagnosis of renal allograft rejection.     

The efficacy of technetium-99m-MIBI scan and intraoperative methylene blue staining for the localization of abnormal parathyroid glands

(Received for publication on Jan. 21, 1998; accepted on July 7, 1998)     

Combined diagnosis in breast carcinoma: preoperative role of mammoscintigraphy with Tc99m-sestamibi. Our Experience

The Authors, taking recent literature on tumoral pathology breast studies in to consideration, studied a group of patients with a node or a suspect adenous zone by clinical and instrumental examination with mammoscintigraphy. 22 patients were selected by clinical examination, mammography and ultrasonography. A mammoscintigraphy (Tc 99m Sestamibi) was performed before the surgical operation. The histologic examination revealed 14 cases of breast cancer; 12 of these (86%) resulted positive after scintigraphy, while 2 were false negative. In this study, the scintigraphic exam and its diagnostic accuracy were analyzed, both in relation to anatomical structure of the mammary gland (thick breast, fibrocystic mastopathy, postsurgical scars, etc.) and also in relation to characteristics of the suspected node, the nature of which was not possible to determine from other exams carried out. In conclusion, after comparison between our experience and those reported in literature, we conclude that because of its high specificity and sensibility the mammoscintigraphy exam assumes an important comparative index in obtaining elements for an additional evaluation when other instrumental examinations are dubious.     

In vitro engineering of human autogenous cartilage.

A challenge in tissue engineering is the in vitro generation of human cartilage. To meet standards for in vitro-engineered cartilage, such as prevention of immune response and structural as well as functional integration to surrounding tissue, we established a three-dimensional cell culture system without adding exogenous growth factors or scaffolds. Human chondrocytes were cultured as spheroids. Tissue morphology and protein expression was analyzed using histological and immunohistochemical investigations on spheroid cryosections. A cartilage-like tissue similar to naturally occurring cartilage was generated when spheroids were cultured in medium supplemented only with human serum. This in vitro tissue was characterized by the synthesis of the hyaline-specific proteins collagen type II and S-100, as well as the synthesis of hyaline-specific mucopolysaccharides that increased with prolonged culture time. After 3 months, cell number in the interior of in vitro tissues was diminished and was only twice as much as in native cartilage. Additionally, spheroids quickly adhered to and migrated on glass slides and on human condyle cartilage. The addition of antibiotics to autologous spheroid cultures inhibited the synthesis of matrix proteins. Remarkably, replacing human serum by fetal calf serum resulted in the destruction of the inner part of the spheroids and only a viable rim of cells remained on the surface. These results show that the spheroid culture allows for the first time the autogenous in vitro engineering of human cartilage-like tissue where medium supplements were restricted to human serum.     

Non-invasive investigation of the upper gastrointestinal tract using technetium-99m.

The use of technetium-99m in the noninvasive investigation of the upper gastrointestinal tract is discussed with particular reference to the evolution of a method of assessing gastric function or gastric acid secretion non-invasively and to the applications of this method in the investigation of surgical patients with disease of the upper gastrointestinal tract. The assessment of maximal acid output and the insulin response is described and the use of the test in the diagnosis of pernicious anaemia, hypo- and hyperchlorhydric states, gastric cancer, hiatus hernia and Barrett's oesophagus, coeliac disease, Meckel's diverticulum, and abdominal aortic aneursym outlined. The use of chemicals labelled with this tracer in hepatobiliary scanning is briefly described.     

Human parathyroid hormone does not influence human erythropoiesis in vitro

Background. Although renal anaemia is associated with secondary hyperparathyroidism, the relationship of both conditions remains obscure. Previously it was reported that high levels of bovine parathyroid hormone (PTH) did not inhibit in vitro human erythropoiesis, but whether human PTH inhibits in vitro human erythropoiesis has not been determined. Method. To clarify the direct effects of human biologically active N-terminal (1-34) PTH and intact (1-84) PTH on human haematopoietic progenitor growth, we investigated colony assays of human erythropoiesis and granulomonopoiesis. Results. Neither N-terminal PTH (300 ng/ml) nor intact PTH (5000 pg/ml) inhibited haematopoietic progenitor growth. Conclusion. Our findings confirm that human PTH does not directly inhibit human erythropoiesis.     

In vitro assessment of parathyroid immunogenicity: the effect of cryopreservation

Post-parathyroidectomy hypoparathyroidism, although fortunately uncommon, is a disorder of major inconvenience and potential morbidity. Attempts at modifying parathyroid tissue to facilitate allotransplantation without host immunosuppression are warranted. Cryopreservation has been reported to improve survival of canine parathyroid allografts. We employed a modification of the mixed lymphocyte culture to study the effect in vitro of cryopreservation on human parathyroid tissue. Dispersed parathyroid cells from fresh and previously cryopreserved tissue from 10 patients were incubated with unrelated mononuclear cells for 6 days, and incorporation of tritiated thymidine was measured after a 1-day pulse. Studies with irradiated mononuclear cells and parathyroid cells confirmed the model as a one-way test in which mononuclear cells respond to parathyroid cells but not vice versa. An antigenicity index was computed to express mononuclear cell tritiated thymidine incorporation for similar numbers of viable parathyroid cells. Although absolute values of the antigenicity index varied from patient to patient, there were no consistent differences in the antigenicity index of patients' fresh compared with cryopreserved tissue. In an attempt to identify the cells responsible for immunogenicity, we incubated cytocentrifuged parathyroid cell suspensions with antiserum directed at leukocyte common antigen, a marker of lymphoid tissue. Cell suspensions of parathyroid tissue demonstrated leukocyte common antigen-positive cells (median, 2.7% positive; range, 0% to 16%). There were no consistent differences in the number of leukocyte common antigen-positive cells in fresh compared with cryopreserved tissue, and the number of leukocyte common antigen-positive cells did not correlate with the antigenicity index.     

Assessment of cavernous hemangioma of bladder by technetium-99-tagged albumin scan.

A case of cavernous hemangioma of the bladder is presented and its endoscopic appearance is illustrated. A scan utilizing technetium-99-labeled albumin has been found valuable in determining the extent of the lesion.     

In vitro accumulation of mineral components by invertebrate cartilage

In vitro mineralization of the gill cartilage ofLimulus (horse-shoe crab) has been reported previously (Eilberg et al. 1975). The present study demonstrates that cranial cartilage ofLoligo (squid) and odontophore cartilage ofBusycon (marine snail) also mineralize in vitro in hydroxypatite-metastable media, but not in carbonate-metastable media. In all three of these cartilages, light phase-contrast microscopy revealed that the mineral phase occurred in the form of spherical or ovoid granules ranging between 2 and 9 m in diameter. During mineralization, the granules appeared successively in the perichondrium, in the matrix, and finally, within chondrocytes. Mineralization occurred more rapidly inBusycon odontophore cartilage which has a significantly higher content of phosphatidyl serine than inLimulus gill orLoligo head cartilages. In all tissues the mineralization process is related to temperature, taking place most actively at 37°C and only weakly at 50°C.     

In vitro fertilisation of human o?cytes.

This paper describes attempts to cure infertility due to irremediable Fallopian tube lesions by the laparoscopic recovery of pre-ovulatory ovarian o?cytes, their fertilisation in vitro, and their subsequent reimplantation into the uterine cavity.