Emission tomography for assessment of diffuse alcoholic liver disease.

A method of quantitative liver tomoscintigraphy (SPECT) was compared for accuracy with planar scintigraphy (PS) in a group of patients with diffuse alcoholic liver disease. SPECT sensitivity was also compared with that of transmission computed tomography (CT), US, aminopyrine breath test (ABT) and liver chemistries (LC). One hundred and fourteen alcoholic patients with proven liver disease and 17 patients free of liver disease were included. Seven quantitative scintigraphic features and a score, including all criteria were considered. With a specificity of 95%, the sensitivity was 79% in steatosis and 97% in cirrhosis. SPECT showed a better sensitivity than PS (SPECT 89%, PS 66%), especially in patients with steatosis. In the same subsets of patients, SPECT sensitivity also compared favorably with that of transmission CT (SPECT 92%, CT 65%), ultrasonography (SPECT 88%, US 53%) and ABT (SPECT 90%, ABT 63%).     

Value of hepatobiliary scintigraphy and ultrasonography in the differential diagnosis of jaundice

In order to compare the reliability of hepatobiliary scintigraphy using DISIDA (DHS) and ultrasonography (US) in the diagnosis of obstructive jaundice, 36 consecutive patients clinically suspected for obstruction were examined with both methods. Sixteen patients who were definitively shown to have obstruction, were all correctly detected with DHS; US was positive in 15 cases, revealing the cause of the obstruction in four cases. The site of obstruction was predicted in eight cases by DHS and in 11 cases by US. Associated gallbladder diseases were evaluated better by US than by DHS, but a perforation was only demonstrated clearly by DHS. In the 20 patients with nonobstructive disease the false positive results were found in one case using DHS and in two cases using US. In this series of patients DHS and US showed high sensitivity and specificity, which were further increased when the two techniques were combined.     

Fluorine-18 2-deoxy-2-fluoro-D-glucose PET in the preoperative staging of breast cancer: comparison with the standard staging procedures

The present study compared the diagnostic accuracy of fluorine-18 2-deoxy-2-fluoro-D-glucose positron emission tomography (FDG-PET) with conventional staging techniques. The differentiation between malignant and benign lesions and the detection of multifocal disease, axillary and internal lymph node involvement, and distant metastases were evaluated. One hundred and seventeen female patients were prospectively examined using FDG-PET and conventional staging methods such as chest X-ray, ultrasonography of the breast and liver, mammography and bone scintigraphy. All patients were examined on a modern full-ring PET scanner. Histopathological analysis of resected specimens was employed as the reference method. The readers of FDG-PET were blinded to the results of the other imaging methods and to the site of the breast tumour. The sensitivity and specificity of FDG-PET in detecting malignant breast lesions were 93% and 75% respectively. FDG-PET was twofold more sensitive (sensitivity 63%, specificity 95%) in detecting multifocal lesions than the combination of mammography and ultrasonography (sensitivity 32%, specificity 93%). Sensitivity and specificity of FDG-PET in detecting axillary lymph node metastases were 79% and 92% (41% and 96% for clinical evaluation). FDG-PET correctly indicated distant metastases in seven patients. False-positive or false-negative findings were not encountered with FDG-PET. Chest X-ray was false-negative in three of five patients with lung metastases. Bone scintigraphy was false-positive in four patients. Three patients were upstaged since FDG-PET detected distant metastases missed with the standard staging procedure. It is concluded that, compared with the imaging methods currently employed for initial staging, FDG-PET is as accurate in interpreting the primary tumour and more accurate in screening for lymph node metastases and distant metastases. Due to a false-negative rate of 20% in detecting axillary lymph node metastases, FDG-PET cannot replace histological evaluation of axillary status.     

99Tcm-labelled HSA-nanocolloid versus 111In oxine-labelled granulocytes in detecting skeletal septic process

Fifty-seven investigations of the skeletal system were performed on 54 patients, using a 99Tcm-labelled nanometer-sized HSA colloid in a crossover comparison with 111In oxine-labelled granulocytes for the detection of sites of infection. The findings were in agreement in 55 out of 57 investigations (96.5%). Based on 44 studies in which a final clinical diagnosis was obtained, both methods were found to display the same specificity (93%), whilst the sensitivity of 99Tcm nanocolloid scintigraphy (87%) was slightly higher than that obtained with 111In leucocyte scintigraphy (81%). In our opinion, 99Tcm nanocolloid is easier to use and the total duration of the investigation is considerably shorter. The use of 99Tcm is scintigraphically more advantageous and, with the dosage required, the absorbed radiation dose to the red bone marrow is three times lower than with 111In granulocytes. For the detection and therapy monitoring of osteomyelitis, as well as for the investigation of arthroplasties suspected of infective loosening, we consider scintigraphy with 99Tcm nanocolloid to be equivalent to leucocyte scintigraphy. Identical findings were obtained with both tracers in suspected spondylodiscitis.     

Evaluation of ultrasonic and scintigraphic studies of the liver.

Ultrasonic and scintigraphic examination of the liver took place in 148 patients. 29 had normal livers, 36 had cirrhosis, 11 had obstructive jaundice, 12 had fatty livers, 60 had focal liver defects. In case of diffuse liver disease the accuracy of both methods is about the same except for fatty liver which is poorly diagnosed by scintigraphy. Focal liver disease is determined with a relative high percentage false-negative for scintigraphy and a relative high percentage false-positive for echography. It is recognized that previous knowledge of the scintigraphic result may raise the accuracy of ultrasound examination of the liver. As echography could distinguish cystic from solid lesions both methods of liver imaging are considered complementary.     

A comparison of computed tomography, ultrasound and scintigraphy in the diagnosis of alcoholic liver disease

In 35 alcoholics with histologically proven liver disease, computed tomography (CT), grey scale ultrasonography and liver scintigraphy were evaluated for their abilities to detect an abnormal liver and to identify the patients with cirrhosis. Abnormal studies were present on CT in 83% of patients, in 64% on ultrasound and in 94% on scintigraphy. In 10 control patients specificity was 90% by CT, 100% by ultrasound and 70% by scintigraphy. CT and ultrasound were poor in identifying the alcoholics with cirrhosis. Scintigraphy suggested cirrhosis in all but one of the patients with this diagnosis. Similar images were obtained in half of the patients with fatty change without cirrhosis but, with the exception of one patient, this appeared to be due to co-existent hepatitis. The results suggest that scintigraphy is the best of the imaging tests for screening alcoholics for cirrhosis.     

Fluorine-18 2-deoxy-2-fluoro-D-glucose PET in the preoperative staging of breast cancer: comparison with the standard staging procedures

The present study compared the diagnostic accuracy of fluorine-18 2-deoxy-2-fluoro-D-glucose positron emission tomography (FDG-PET) with conventional staging techniques. The differentiation between malignant and benign lesions and the detection of multifocal disease, axillary and internal lymph node involvement, and distant metastases were evaluated. One hundred and seventeen female patients were prospectively examined using FDG-PET and conventional staging methods such as chest X-ray, ultrasonography of the breast and liver, mammography and bone scintigraphy. All patients were examined on a modern full-ring PET scanner. Histopathological analysis of resected specimens was employed as the reference method. The readers of FDG-PET were blinded to the results of the other imaging methods and to the site of the breast tumour. The sensitivity and specificity of FDG-PET in detecting malignant breast lesions were 93% and 75% respectively. FDG-PET was twofold more sensitive (sensitivity 63%, specificity 95%) in detecting multifocal lesions than the combination of mammography and ultrasonography (sensitivity 32%, specificity 93%). Sensitivity and specificity of FDG-PET in detecting axillary lymph node metastases were 79% and 92% (41% and 96% for clinical evaluation). FDG-PET correctly indicated distant metastases in seven patients. False-positive or false-negative findings were not encountered with FDG-PET. Chest X-ray was false-negative in three of five patients with lung metastases. Bone scintigraphy was false-positive in four patients. Three patients were upstaged since FDG-PET detected distant metastases missed with the standard staging procedure. It is concluded that, compared with the imaging methods currently employed for initial staging, FDG-PET is as accurate in interpreting the primary tumour and more accurate in screening for lymph node metastases and distant metastases. Due to a false-negative rate of 20% in detecting axillary lymph node metastases, FDG-PET cannot replace histological evaluation of axillary status.     

Ultrasonographic detection of hepatocellular carcinoma: correlation of preoperative ultrasonography and resected liver pathology

AIM: The aim of this study was to determine the sensitivity of ultrasonography for detecting hepatocellular carcinoma in patients who underwent surgical liver resection. MATERIALS AND METHODS: The preoperative ultrasonography reports of 103 patients who underwent hepatic resection surgery were retrospectively reviewed. The patients had chronic liver disease with good liver function and a relatively normal liver echo-texture. The presence of a mass or masses in the resected part of the liver segments on preoperative ultrasonography was regarded as possible hepatocellular carcinoma, and these results were compared with the surgically resected hepatic lobes or segments. Accuracy for detection was assessed on a lesion-by-lesion basis, on a segment-by-segment basis, and on a patient basis. RESULTS: One hundred and fifty-seven hepatocellular carcinomas were found in 244 hepatic segments of 103 patients. One hundred and one of 157 hepatocellular carcinomas were detected using ultrasonography in 97 patients resulting in a sensitivity of 64%. In six patients, a solitary hepatocellular carcinoma was missed in each patient, a patient sensitivity being 94%. Using ultrasonography, 87 of 100 (87%) hepatocellular carcinomas larger than 2 cm in diameter, and 14 of 57 (25%) hepatocellular carcinomas 2 cm or smaller in diameter were revealed. On the basis of segment-by-segment analysis, the sensitivity was 78% (99 of 127 segments), specificity was 97% (114 of 117 segments), accuracy was 87% (213 of 244 segments), positive predictive value was 97% (99 of 102 segments), and negative predictive value was 80% (114 of 142 segments). CONCLUSION: In patients with chronic liver disease and good hepatic function, ultrasonography has a sensitivity of 94% in the identification of affected patients, but for individual lesions, the sensitivity is only 64%.     

The investigation of painless haematuria--a comparison of intravenous urography and DMSA scintigraphy

In order to test in a prospective study the suggestion that there should be a shift from the intravenous urogram to DMSA scintigraphy for the diagnosis of suspected renal masses, both investigations were performed in 63 patients with painless haematuria. While the sensitivity of both investigations was similar in renal lesions, specificity was slightly less for scintigraphy. These findings, together with the intrinsic limitations of the DMSA scintigram in detecting lesions elsewhere in the urinary tract, lead us to conclude that the intravenous urogram should remain the initial investigation for painless haematuria unless there are specific contraindications.     

Comparison of dipyridamole-echocardiography with dipyridamole-thallium scintigraphy for the diagnosis of myocardial ischemia

After an intravenous infusion of dipyridamole (0.56 mg/kg), we performed both echocardiography and thallium scintigraphy in 63 patients who were referred for known or suspected coronary artery disease. Of those patients, 25 returned for coronary arteriography within 1 month after the tests, thus forming the study group for this report. Sensitivity for detection of coronary artery disease, when analyzed region-by-region, was 80% for thallium scintigraphy and 57% for echocardiography, whereas specificity was 85% and 98%, respectively. When evaluating individual patients for the presence or absence of ischemia, we found a sensitivity of 95% for scintigraphy and 58% for echocardiography; corresponding specificities were 50% and 100%. By using arteriography as the gold standard for comparison, it appears that thallium scintigraphy has a significantly higher sensitivity but lower specificity for the detection of coronary artery disease than does echocardiography. Echocardiography may, however, be a useful adjunct to thallium scintigraphy in the evaluation of patients with coronary artery disease.     

Staging and monitoring of malignant lymphoma of the bone: comparison of 67Ga scintigraphy and MRI.

The aim of this study was two-fold: to compare 67Ga scintigraphy with MRI (a) for the staging of malignant lymphoma of the bone and (b) with regard to accuracy in detecting residual disease after first-line chemotherapy for restaging. METHODS: Twenty-one patients with 36 malignant osseous lesions were examined, including 7 patients with primary or multifocal osseous lymphoma and 14 patients with malignant lymphoma and simultaneous or secondary involvement of the bone. After first-line therapy, MRI and 67Ga scintigraphy were performed on 13 patients. The remission status based on all clinical and radiological findings during the follow-up was used as the gold standard. RESULTS: The osseous lesions were located on the axial skeleton in 64% of patients and on the appendicular skeleton in 36%. 67Ga scintigraphy detected 77% of the osseous lesions examined by MRI. For restaging after first-line therapy, MRI had a sensitivity of 90% and a specificity of 80% when dynamic MRI information was included. There were several false-positive results as a result of the pathologic increase in signal intensity ratios of reactive hematopoietic regions after chemotherapy. For 67Ga scintigraphy, a sensitivity of 70% and a specificity of 93% were calculated. CONCLUSION: These data show that monitoring malignant lymphoma of the bone still presents diagnostic problems. Given the high sensitivity of MRI and the high specificity of 67Ga scintigraphy but the limited specificity of MRI and sensitivity of 67Ga scintigraphy, both methods are valuable but should be used as complementary diagnostic tools.     

The value of contrast enhanced ultrasonography in detection of liver metastases from colorectal cancer: a prospective double-blinded study

OBJECTIVE: To compare sensitivity and specificity of contrast enhanced ultrasonography (CEUS) with conventional ultrasonography (US) in detection of liver metastases in patients with colorectal adenocarcinoma (CRC) in a patient-by-patient analysis. MATERIALS AND METHODS: A prospective study of 461 consecutive patients referred to the Department of Colorectal Surgery, Aarhus University Hospital with primary or local recurrence of CRC. In order to detect possible liver metastases all patients underwent liver US, followed by CEUS by another investigator. Multislice CT scanning (MDCT), and intraoperative ultrasonography (IOUS) were then performed. Fine-needle biopsy was performed on all suspicious lesions. Each examination was interpreted blindly and the combination of biphasic MDCT, IOUS, follow up and biopsy was the gold standard. RESULTS: Standard of reference found liver metastases in 54 patients (14.8%). Contrast enhanced ultrasonography improved the sensitivity significantly in detection of liver metastases from 0.69 by US to 0.80 (p=0.031). In 24 patients, CEUS found a higher number of metastases than US (p<0.001). The specificity (0.98) and the positive predictive value (0.86) was the same. CONCLUSION: Contrast enhanced ultrasonography improves sensitivity in detection of liver metastases in patients with CRC and in nearly half of the cases CEUS found a higher number of metastases than US.     

Role of Tc-99m sestamibi scintigraphy in the diagnosis and surgical decision-making process in primary hyperparathyroid disease

PURPOSE: Ultrasound (US) and scintigraphy are used most frequently of all the available imaging techniques for the preoperative evaluation of patients with possible primary hyperparathyroid disease. The aim of this study was to assess the value of dual-phase Tc-99m MIBI scintigraphy compared with US in the detection of adenomatous or hyperplastic glands and in the surgical decision-making process for patients with a biochemical diagnosis of primary hyperparathyroid disease. METHODS: Ninety-seven patients with increased levels of parathyroid hormone and calcium, and at least 6 months' follow-up after US and scintigraphy, were examined retrospectively to assess the influence of the diagnostic work-up on the therapeutic decision of the referring clinicians and to evaluate the sensitivity of these diagnostic tools in the surgically treated patients. Forty-eight patients underwent surgery. RESULTS: Parathyroid adenomas were found in 43 patients and hyperplasia in 1, whereas 4 patients had no evidence at surgery. The sensitivity and specificity rates were 84.4% and 95.9% for scintigraphy, and 66.6% and 98.6% for US, respectively. Of the 49 nonsurgically treated patients, 35 had negative results with both MIBI and US; only 3 had positive findings with both imaging methods. Patients treated conservatively had significantly lower parathyroid hormone and serum calcium levels than did the patients who had surgery. CONCLUSIONS: The data suggest that the high sensitivity of dual-phase MIBI scintigraphy can improve the detection of hyperfunctioning parathyroid glands. Furthermore, despite the controversy surrounding the use of imaging methods in the preoperative assessment of primary hyperparathyroid disease, these data suggest that the decision of the clinician to order surgery for a patient with a moderate increase of serum PTH level may be influenced by the results of the imaging methods.     

Technetium-99m MDP scintigraphy. An insensitive tool for the detection of bone marrow metastases

Seventy-nine cases with known carcinoma of the lung or breast who underwent both bone marrow aspiration and Tc-99m MDP bone scintigraphy were reviewed. The bone images were assessed for the presence of the pattern of bone marrow expansion which is visualized by diffuse increased metaphyseal activity, particularly evident at the knees, ankles, and elbows. This pattern was found to be an insensitive marker for the presence of marrow metastases (sensitivity 15%). The specificity of the finding was 86%. When diffuse increased metaphyseal activity is present on a Tc-99m MDP bone scan in a patient with malignant disease, the possibility of bone marrow metastases should be pursued by marrow aspiration and biopsy.     

Hepatobiliary scintigraphy with 99Tcm-HIDA and 99Tcm-sulphur colloid

The results of a study comparing the ability of ⁹⁹Tc^m-sulphur colloid and ⁹⁹Tc^m-HIDA to demonstrate circumscribed defects and obstruction of the biliary flow to the intestines are reported. As regards focal liver diseases, colloid scintigraphy (SC) had a nosographic sensitivity and specificity of 0.87 and 0.85, respectively. The corresponding figures for the HIDA scintigraphy were 0.40 and 0.92. The sensitivities are significantly different. Concerning the diagnosis of extrahepatic obstruction, sulphur colloid scintigraphy had a nosographic sensitivity and specificity of 0.31 and 0.94. The corresponding figures for HIDA scintigraphy were 0.69 and 0.84. These sensitivities are significantly different too. The most frequent cause of false results was a pattern of hepatocellular disease in sulphur colloid scans in patients with a longstanding biliary obstruction. The second most frequent error was due to circumscribed defects in SC as well as in HIDA scans in patients with obstructive diseases and a high value of serum bilirubin. A third source of error was the pattern of an obstruction in HIDA scans in patients with focal diseases. The significance of the star pattern the sulphur colloid scan in patients with obstruction is stressed, as the significance of this pattern not has been evaluated previously. It is concluded that the two different scintigraphic methods are complementary tools in the examination of patients with liver diseases     

FDG-PET-CT and whole-body MRI for triage in patients planned for radioembolisation therapy

Purpose

The purpose was to evaluate the potential of FDG–PET–CT and whole-body MRI (WB-MRI) as diagnostic triage methods for patients planned for radioembolisation of metastatic liver disease.

Materials and methods

135 patients with multifocal liver metastases were evaluated for potential palliative therapy with radioembolisation using 90-Yttrium microspheres. All patients were examined consecutively with FDG–PET–CT and WB-MRI for exclusion of relevant extra-hepatic tumor manifestations. All patients underwent 99mTc-albumine angiography followed by scintigraphy to exclude significant hepato-pulmonary shunting.

Results

Out of the 135 patients included into the pre-therapeutic diagnostic algorithm, 56% were eligible and received radioembolisation, while 44% could not be treated. In 91% the exclusion criteria was diagnosis of significant extra-hepatic metastatic disease. In 85% exclusion diagnosis was made concordantly by both FDG–PET–CT and WB-MRI, in 9% diagnosis was provided by PET–CT, in 6% by WB-MRI alone. Patient-based sensitivity for detection of extra-hepatic disease was 94% for PET–CT and 91% for WB-MRI. False-positive diagnosis of extrahepatic disease leading to exclusion for radioembolisation therapy was made in 2% of patients, in one patient by PET–CT and in one patient by WB-MRI alone. Overall, specificity for inclusion of radioembolisation therapy by combining both modalities was 99%. In 9% of patients angiographic diagnosis made radioembolisation impossible, in 7% solely the angiographic findings were decisive.

Conclusion

Both FDG–PET–CT and WB-MRI are efficient diagnostic triage methods for patients planned for radioembolisation of liver metastases. Overall, FDG–PET–CT shows a trend to higher diagnostic accuracy compared to WB-MRI and may be used as imaging method of choice as a standalone examination. In combination, both modalities exhibited high sensitivity for the diagnosis of extra-hepatic tumor manifestations and result in high specificity.     

Cemented total hip prosthesis: radiographic and scintigraphic evaluation

Conventional radiographs, technetium-99m bone scans, and gallium-67 scans were reviewed in 44 patients who had undergone cemented total hip joint replacement and were imaged because of suspicion of prosthesis loosening or infection. A complete radiolucent line of 2 mm or wider along the bone-cement interface or metal-cement lucency on conventional radiographs was used as the criterion for prosthetic loosening with or without infection and proved to be 54% sensitive and 96% specific. Scintigraphic criteria for prosthetic loosening were increased focal uptake of the radiopharmaceutical for the femoral component and increased focal or diffuse uptake for the acetabular component. For bone scintigraphy, sensitivity was 73% and specificity was 96%. Combining the results of conventional radiographs and bone scans increased sensitivity to 84% and decreased specificity to 92% for the diagnosis of loosening, infection, or both. The study also showed that Ga-67 scintigraphy has a low sensitivity for the detection of infection.     

MRI及99Tcm-MIBI显像对甲状旁腺机能亢进症的诊断价值

目的：评价MRI及^99Tcm-甲氧基异丁基异腈（MIBI）显像在原发性甲状旁腺机能亢进症（PHT）中检出病理性腺体的临床价值。方法：25例经手术证实的PHT患者实行了术前定位MRI检查，若甲状旁腺部位发现可凝软组织肿物，其信号高于周围正常甲状腺，则认为是病理性甲状旁腺，其中23例同时进行了双时相99Tcm-MIBI显像，如早期相出现放射性浓聚区且延迟相持续存在则考虑为异常甲状旁腺，MRI和99Tcm-MIBI显像阅片结果与病理检查结果对照。结果：术中共发现39个异常甲状旁腺，包括19个腺瘤（18例），19个增生（6例）和1个上皮细胞癌（1例），MRI和99Tcm-MIBI显像对检出病理性腺体的准确性分别为84．1％和85．0％,但前者灵敏度（74．4％）高于后者（67．6％），而后者的特异性（97．8％）高于前者（91．8％），两种方法联合应用准确性提高到91．3％，灵敏度为91．2％，特异性为91．3％，结论：99Tcm-MIBI显像可作为继B超检查之后的首选术前定位检查法，但最理想的最联合应用MIR和99Tcm-MIBI显像。     

Comparison of magnetic resonance imaging and (67)gallium scintigraphy in the evaluation of posttherapeutic residual mediastinal mass in the patients with Hodgkin's lymphoma

INTRODUCTION: Detection of residual disease following the completion of primary treatment in Hodgkin's lymphoma (HL) patients diagnosed with mediastinal tumor mass has an exceptional importance in the assessment of therapeutic response. Magnetic resonance imaging (MRI) and (67)gallium ((67)Ga) scintigraphy can be used to identify active tumor tissue in the mediastinal residuum. AIMS: To evaluate: the accuracy of MRI and (67)Ga scintigraphy in the prediction of clinical HL relapse/progression; congruence of findings and the probability of mediastinal disease relapse/progression regarding to the detection of active/inactive tissue by both imaging methods. MATERIALS AND METHODS: Thirty HL patients with abnormal mediastinal tissue following the completion of primary treatment were examined by MRI and (67)Ga scintigraphy. Positive findings were: high signal intensity on unenhanced T2-weighted images on MRI and the abnormal accumulation of gallium on scintigraphy or SPECT. These findings were compared with the clinical follow-up. RESULTS: Sensitivity, specificity, accuracy, positive and negative predictive values were: 75.0%, 96.2%, 93.3%, 75.0%, 96.2% in MRI and 50.0%, 88.5%, 83.3%, 40.0%, 92.0% in (67)Ga scintigraphy. Discrepant results concerning the mediastinal tissue activity were found in 3 of 30 patients (10%). No statistically significant differences were found between both imaging methods in sensitivity, specificity and accuracy. Estimated 2-years progression free survival (PFS) for patients without and with active residual mediastinal tissue by MRI was 96% and 25% (p=0.0001), respectively. The probability of 2-years PFS in the cases with negative and positive findings on (67)Ga scintigraphy was 92% and 60% (p=0.026), respectively. CONCLUSION: Although MRI showed better results than (67)Ga scintigraphy in the assessment of residual mediastinal tissue activity in HL patients after primary treatment, the difference between these methods was not statistically significant. Both methods could be included in the standard restaging protocol.     

A case with primary amyloidosis of the liver and spleen: radiologic findings

A case with primary amyloidosis of the liver and spleen is presented. In the liver, ultrasonography showed heterogeneous echogenicity. Portal phase CT showed heterogeneous enhancement, and delayed phase CT showed delayed enhancement with focal hypoattenuating areas. Bone scintigraphy showed diffuse accumulation. In the spleen, arterial phase CT showed the lack of parenchymal enhancement, and T2-weighted MR imaging showed decreased signal intensity. The combination of imaging findings of the liver and spleen was suggestive of amyloidosis.