Evaluation of Imaging Findings in Patients with Pretransplant and Posttransplant Tertiary Hyperparathyroidism.

OBJECTIVES: Tertiary hyperparathyroidism, characterized by autonomous overproduction of parathyroid hormone, can be seen in patients with long-standing secondary hyperparathyroidism (pretransplant) or after renal transplant (posttransplant). Parathyroid scintigraphy and ultrasonography are the most commonly used imaging procedures for the preoperative localization of abnormal parathyroid glands. We aimed to evaluate imaging findings in pretransplant and posttransplant tertiary hyperparathyroidism. MATERIALS AND METHODS: This study included 32 patients with pretransplant tertiary hyperparathyroidism and 20 patients with posttransplant tertiary hyperparathyroidism. On parathyroid scintigraphy with technetium-99m sestamibi, early-phase and latephase images were acquired. Images were evaluated for the presence and the number of active foci and the degree of uptake on the late-phase image. The existence of an autonomous gland was based on latephase retention and was scored from 0 to 2 (retention score). On ultrasonography, the criteria threshold for autonomy was the maximum length of the largest gland ≥10 mm (ultrasonography score). RESULTS: On parathyroid scintigraphy, the most commonly observed pattern in the pretransplant group was positivity in ≥3 glands, and in the posttransplant group the most commonly observed pattern was positivity in 1 to 2 glands. In pretransplant and posttransplant groups, the criteria threshold for the presence of an autonomous parathyroid gland on parathyroid scintigraphy (grade 2 retention) was met in 26 (81%) and 9 (45%) patients and on ultrasonography in 25 (78%) and 10 (50%) patients, respectively. In the whole group of patients (n = 52), correlation existed between ultrasonography score and retention score. Glandular weight was correlated with both retention score and ultrasonography score. CONCLUSIONS: Higher numbers of detectable glands and the presence of parathyroid autonomy were more common in the pretransplant group. This might be explained by parathyroid gland involution after transplant. The results may also suggest that factors other than autonomy are responsible for posttransplant tertiary hyperparathyroidism.

Establishment of local diagnostic reference levels for computed tomography with cloud-based automated dose-tracking software in Turkey.

PURPOSE: The purpose of this study is to establish local diagnostic reference levels (LDRLs) for computed tomography (CT) procedures using cloud-based automated dose-tracking software. METHODS: The study includes the dose data obtained from a total of 104,272 examinations performed on adult patients (>18 years) using 8 CT scanners over 12 months. The protocols included in our study were as follows: head CT without contrast, cervical spine CT without contrast, neck CT with contrast, chest CT without contrast, abdomen-pelvis CT without contrast, lumbar spine CT without contrast, high-resolution computed tomography (HRCT) of the chest, and coronary CT angiography (CTA). Dose data were collected using cloud-based automatic dose-tracking software. The 75th percentiles of the distributions of the median volume CT dose index (CTDIvol) and dose length product (DLP) values were used to determine the LDRLs for each protocol. The LDRLs were compared with national DRLs (NDRLs) and DRLs set in other countries. Inter-CT scanner variability, which is a measure of how well clinical practices are standardized, was determined for each protocol. Median values for each protocol were compared with the LDRLs for dose optimization in each CT scanner. RESULTS: The LDRLs (for DLP and CTDIvol, respectively) were 839 mGy.cm and 41.2 mGy for head CT without contrast, 530.6 mGy.cm and 19.8 mGy for cervical spine CT without contrast, 431.9 mGy.cm and 15.5 mGy for neck CT with contrast, 364.8 mGy.cm and 9.3 mGy for chest CT without contrast, 588.9 mGy. cm and 11.2 mGy for abdomen-pelvis CT without contrast, 713 mGy.cm and 24.3 mGy for lumbar spine CT without contrast, 326 mGy.cm and 9.5 mGy for HRCT, and 642.3 mGy.cm and 33.4 mGy for coronary CTA. The LDRLs were comparable to or lower than NDRLs and DRLs set in other countries for most protocols. The comparisons revealed the need for immediate initiation of an optimization process for CT protocols with higher dose distributions. Furthermore, protocols with high inter-CT scanner variability revealed the need for standardization. CONCLUSION: There is a need to update the NDRLs for CT protocols in Turkey. Until new NDRLs are established, local institutions in Turkey can initiate the optimization process by comparing their dose distributions to the LDRLs established in our study. Automated dose-tracking software can play an important role in establishing DRLs by facilitating the collection and analysis of large datasets.

Clinical Features of SARS-CoV-2 Infection in Patients Undergoing Solid-Organ Transplant: Baskent University Experience.

OBJECTIVES: The clinical features and treatment approaches, outcomes, and mortality predictors of COVID-19 in solid-organ transplant recipients have not been well defined. This study investigated the clinical features of COVID-19 infection in solid-organ transplant recipients at our center in Turkey. MATERIALS AND METHODS: Our study included 23 solidorgan transplant recipients and 336 nontransplant individuals (143 previously healthy and 193 patients with at least 1 comorbidity) who were hospitalized due to COVID-19 disease in our hospital between March 2020 and January 2021. Demographic, clinical, and laboratory data of patients were compared. We used SPSS version 20.0 for statistical analysis. All groups were compared using chi-square and Mann-Whitney U tests. P <.05 was considered statistically significant. RESULTS: Mean age of solid-organ transplant recipients was 49.8 ± 13.7 years (78.3% men, 21.7% women). Among the 23 recipients, 17 (73.9%) were kidney and 6 (26.1%) were liver transplant recipients. Among nontransplant individuals, 88.7% (n = 298) had mild/moderate disease and 11.3% (n = 38) had severe disease. Among transplant recipients, 78.3% (n = 18) had mild/moderate disease and 21.7% (n = 5) had severe disease (P = .224). Transplant recipients had greater requirements for nasal oxygen (P = .005) and noninvasive mechanical ventilation (P = .003) and had longer length of intensive care unit stay (P = .030) than nontransplant individuals. No difference was found between the 2 groups in terms of mortality (P = .439). However, a subgroup analysis showed increased mortality in transplant recipients versus previously healthy patients with COVID-19 (P <.05). Secondary infections were major causes of mortality in transplant recipients. CONCLUSIONS: COVID-19 infection resulted in higher mortality in solid-organ transplant recipients versus that shown in healthy patients. More attention on secondary infections is needed in transplant recipients to reduce mortality.

Liver Stiffness Measurements Using Acoustic Radiation Force Impulse in Recipients of Living-Donor and Deceased-Donor Orthotopic Liver Transplant.

OBJECTIVES: The aim of this study was to evaluate the diagnostic efficiency of the acoustic radiation force impulse (Siemens Medical Solutions, Erlangen, Germany) elastography in assessment of fibrosis in orthotopic liver transplant patients. MATERIALS AND METHODS: We enrolled 28 orthotopic liver transplant patients (deceased and living donors), whose biopsy decision had been prospectively given clinically. Ten acoustic radiation force impulse elastographic measurements were applied before the biopsy or within 3 days after the biopsy by 2 radiologists. After the core tissue needle biopsy, specimens of all patients were analyzed according to the modified Ishak scoring system. Measurements of acoustic radiation force impulse elastography and pathology specimen results were compared. RESULTS: From 28 biopsies, fibrosis scores of 4 biopsies were evaluated as F0 (14.3%), 16 as F1 (57.1%), 4 as F2 (14.3%), and 4 as F3 (14.3%). Mean results of acoustic radiation force impulse measurements were calculated as 1.4 ± 0.07 in F0, 1.74 ± 0.57 in F1, 2.19 ± 0.7 in F2, and 2.18 ± 0.35 in F3. There were no significant correlations of mean acoustic radiation force impulse values between the F0 versus F1 (P = .956) and F0 versus F2 stages (P = .234). A statistically significant correlation of mean acoustic radiation force impulse values was found between the F0 and F3 fibrosis stages (P = .046). CONCLUSIONS: Acoustic radiation force impulse imaging is a promising screening test for detecting significant liver fibrosis (≥ F3 in modified Ishak) in living-donor or deceased-donor orthotopic liver transplant recipients.

Acoustic Radiation Force Impulse Elastography Findings of Achilles Tendons in Patients on Chronic Hemodialysis and in Renal Transplant Patients.

OBJECTIVES: The Achilles tendon, which is composed of tendinous parts of gastrocnemius and soleus muscles, is the strongest and the largest tendon in the human body. Chronic renal disease can lead to reduced physical activity and exercise capacity. Spontaneous rupture of the Achilles tendon can occur in patients with chronic renal failure, with recurrent microtraumas, hypoxia, and chronic acidosis as predisposing factors. Here, we assessed and compared the elastographic findings in the Achilles tendon using acoustic radiation force impulse elastography in patients on chronic hemodialysis, in renal transplant patients, and in healthy volunteers. MATERIALS AND METHODS: Our study included 25 patients on chronic hemodialysis, 25 renal transplant patients, and 25 healthy individuals (control group). The thickness and shear wave velocity of the Achilles tendons were measured bilaterally by ultrasonography and acoustic radiation force impulse elastography. RESULTS: The mean shear wave velocity was 3.67 m/s in the right and 3.64 m/s in the left Achilles tendon in the hemodialysis group. In the renal transplant group, the mean shear wave velocity was 4.29 and 4.25 m/s for the right and left Achilles tendon, respectively. In the control group, the mean shear wave velocity was 6.68 and 6.59 m/s, respectively for the right and left Achilles tendon. A statistically significant difference in shear wave velocities was shown among the groups (P < .05). CONCLUSIONS: Achilles tendons in patients with chronic renal failure and on hemodialysis were softer than in renal transplant patients and softer than in the control group. Chronic tendinopathy causes softening of the tendon. In the renal transplant group, stiffness of the Achilles tendon was increased versus the hemodialysis group but still softer than the control group, which could be explained as a positive clinical effect of renal transplant. Acoustic radiation force impulse elastography is an objective, easy, and noninvasive method to assess Achilles tendinopathy.

Use of Computed Tomography Volumetry to Assess Liver Weight in Patients With Cirrhosis During Evaluation Before Living-Donor Liver Transplant.

OBJECTIVES: Computed tomography liver volumetry has been widely used to detect total and segmental liver volume in living-donor liver transplantation. However, use of this technique to evaluate the cirrhotic liver remains unclear. In this study, we evaluated the accuracy of freehand computed tomography volumetry to assess total liver volume by comparing weights of total hepatectomy specimens in patients with cirrhosis. For our analyses, we considered the density of a cirrhotic liver to be 1.1 kg/L. MATERIALS AND METHODS: Liver volume was measured using a freehand computed tomography technique in 52 patients with cirrhosis from different causes and who had no solid lesions before transplant. Measurements were made with a 16-slice multidetector computed tomography scanner (Siemens Somatom Sensation 16, Erlangen, Germany). For volumetric measurements, 10-mm-thick slices with 10-mm reconstruction intervals were preferred. Total hepatectomy weights of explant livers and computed tomography volumetry data were compared. RESULTS: We excluded 3 cirrhotic patients with Budd-Chiari syndrome due to wide variations in scatterplot results. In the 49 patients included in the final analyses, average estimated liver volume by computed tomography was 721 ± 398 mL and actual cirrhotic liver weight was 727.8 ± 415 g. No significant differences were shown between these measurements. A simple regression analysis used to analyze correlations between estimated liver volume by computed tomography and real cirrhotic liver weight showed correlation of 0.957 (P < .001). When computed tomography liver volumetry as the independent variable and cirrhotic liver weight as dependent variable were considered, regression analyses showed R2 = 0.915. CONCLUSIONS: Freehand computed tomography liver volumetry can be confidently used to evaluate liver volume in cirrhotic liver patients similar to use of this technique to estimate actual weights in normal livers. This technique can also be valuable during pretransplant and liver resection evaluations to ensure a more successful outcome.

Interobserver and intermethod variability in data interpretation of breast strain elastography in suspicious breast lesions

Background/aim: Strain elastography has the disadvantage of being operator-dependent. Interobserver variability is observed during image acquisition and interpretation. This study aimed to analyze the interobserver and intermethod variability of strain elastography in image interpretation and evaluate the diagnostic performance combining elasticity score and strain ratio with ultrasonography. Materials and methods: A retrospective study was conducted on 70 breast lesions evaluated with B-mode ultrasonography and strain elastography. B-mode ultrasonography findings, elasticity scores, and strain ratio values were evaluated using static images by two radiologists. BI-RADS assessment of the lesions and the decision of both observers as to whether the biopsy was required using B-mode ultrasonography, and the combined ultrasonography+elasticity score, and the combined ultrasonography+elasticity score+strain ratio were compared with the histopathological results. Also, the interobserver agreement was analyzed for all the combinations. Results: There was very good agreement (weighted κ = 0.865) between the observers for the elasticity scores. Very good agreement was observed between the observers for BI-RADS assessments using the combined ultrasonography+elasticity score and the combined ultrasonography+elasticity score+strain ratio (weighted κ = 0.848, and 0.902, respectively). Area under the curve of B-mode ultrasonography, the combined B-mode ultrasonography+elasticity score, and the combined B-mode ultrasonography+elasticity score+strain ratio, were calculated as 0.859, 0.866, and 0.916 for observer 1, and 0.851, 0.829, and 0.916 for observer 2, respectively. There were no statistically significant differences between the observers' diagnostic performances in any of the combinations (P = 0.703, 0.067, and 0.972, respectively). Conclusion: In the evaluation and further assessment of breast lesions, semiquantitative strain ratio calculation may help improve diagnostic accuracy by reducing interpretational variety, when used together with B-mode ultrasonography and elasticity scoring, especially for inexperienced individuals.

Incidence and Immunologic Analysis of Coronavirus Disease (COVID-19) in Hemodialysis Patients:A Single-Center Experience.

OBJECTIVES: COVID-19 is a great threat to the modern world and significant threat to immunocompromised patients, including patients with chronic renal failure. We evaluated COVID-19 incidence among our hemodialysis patients and investigated the most probable immune mechanisms against COVID-19. MATERIALS AND METHODS: Baskent University has 21 dialysis centers across Turkey, with 2420 patients on hemodialysis and 30 on peritoneal dialysis. Among these, we retrospectively evaluated 602 patients (257 female/345 male) with chronic renal failure receiving hemodialysis as renal replacement therapy; 7 patients (1.1%) were infected with SARS-CoV-2. We retrospectively collected patient demographic characteristics, clinical data, and immunological factors affecting the clinical course of the disease. We divided patients into groups and included 2 control groups (individuals with normal renal functions): group I included COVID-19-positive patients with normal renal function, group II included COVID-19-positive hemodialysis patients, group III included COVID-19-negative hemodialysis patients, and group IV included COVID-19-negative patients with normal renal function. Lymphocyte subsets in peripheral blood and typing of human leukocyte antigens were analyzed in all groups, with killer cell immunoglobulin like receptor genes analyzed only in COVID-19-positive patients and healthy controls. RESULTS: No deaths occurred among the 7 COVID-19-positive hemodialysis patients. Group I patients were significantly older than patients in groups II and III (P = .039, P = .030, respectively) but not significantly different from group IV (P = .060). Absolute counts of natural killer cells in healthy controls were higherthan in other groups (but not significantly). ActivatedT cells were significantly increased in both COVID-19-positive groups versus COVID-19-negative groups. Groups showed significant differences in C and DQ loci with respect to distribution of alleles in both HLA classes. CONCLUSIONS: Although immunocompromised patients are at greater risk for COVID-19, we found lower COVID-19 incidence in our hemodialysis patients, which should be further investigated in in vitro and molecular studies.

Is Unenhanced Computed Tomography Reliable in the Assessment of Macrovesicular Steatosis in Living Liver Donors?

OBJECTIVES: In this retrospective study, we aimed to determine the diagnostic value of unenhanced computed tomography in the assessment of macrovesicular steatosis in potential living liver transplant donors by using biopsy as a reference standard. MATERIALS AND METHODS: This retrospective study was approved by our institutional review board, and all included patients provided written informed consent. Our study group included 181 donor candidates (mean age of 35.9 ± 9.3 y) who underwent unenhanced computed tomography and subsequent needle biopsy (mean period after scan of 12.74 d) in the right hepatic lobe (at least 2 samples per patient). Histologic degree of macrovesicular steatosis was determined. A radiologist with 10 years of experience assessed steatosis ofthe right hepatic lobe by using 2 methods: (1) a 4-point visual grading system that used attenuation comparison between the liver and hepatic vessels and (2) the liver attenuation index, which was calculated with region of interest measurements of hepatic attenuation. We used statistical analyses to compare accuracy in the diagnosis of macrovesicular steatosis. RESULTS: Our study population was divided into 3 groups according to histologic steatosis grade. Group 1 consisted of 157 candidates with 0% to 5% steatosis, group 2 consisted of 11 candidates with 6% to 15% steatosis, and group 3 consisted of 13 candidates with 16% to 100% steatosis. Mean liver attenuation (in Hounsfield units ± standard deviation) was 58.93 ± 5.07 for group 1, 47.8 ± 4.17 for group 2, and 39.11 ± 6.5 for group 3. Significant differences in liver attenuation were observed between groups using one-way analyses of variance (F = 107307; P < .01). For visual grading, correlation coefficient for computed tomography was 0.959. CONCLUSIONS: Unenhanced computed tomography to assess liver attenuation represents an objective and noninvasive means for detection of hepatic steatosis. This method can prevent unnecessary biopsies.

Assessment of Parotid and Submandibular Glands With Shear Wave Elastography Following Radioactive Iodine Therapy for Papillary Thyroid Carcinoma.

OBJECTIVES: Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy. Radioactive iodine (RAI) therapy is used for remnant ablation following thyroidectomy. Side effects such as dysphagia, xerostomia, and sialoadenitis may occur. We aimed to determine the differences in the parotid and submandibulary glands between healthy patients and patients with PTC who had undergone RAI therapy and have dry mouth symptoms using both shear wave elastography and ultrasonography. METHODS: We enrolled 30 patients with PTC who had undergone RAI therapy following surgery and 30 healthy controls. Ultrasonography and shear wave elastography of submandibular and parotid glands were performed. The volume of the submandibular glands and the thickness of parotid glands were determined. Ten independent measurements were obtained from each gland, with the region of interest placed at different points on the glands. The mean shear wave velocities (SWVs) were calculated and compared between the patients and controls. RESULTS: In the PTC group, there was a significant reduction in the volume of the submandibular glands (P < .05) and in the thickness of the parotid glands (P < .05) compared with the control group. The mean SWVs of the parotid glands and submandibular glands were significantly higher in the PTC group compared with the control group (P < .0001). The SWVs of the parotid glands were higher than the SWVs of the submandibular glands (P < .0001). CONCLUSIONS: Shear wave elastography could be a noninvasive and easy assessment method of parotid and submandibular glands in patients who had undergone RAI therapy and experience dry mouth.

Can unenhanced brain magnetic resonance imaging be used in routine follow up of meningiomas to avoid gadolinium deposition in brain?

PURPOSE: We hypothesized that unenhanced brain MRI can be used in follow up of patients with intracranial meningioma to avoid gadolinium deposition in the brain and allow measurement of meningioma dimensions from pre-contrast T2-weighted images. METHODS: Dimensions of meningiomas were measured on pre-contrast T2, post-contrast T1 weighted images. RESULTS: The sizes of meningiomas in post-contrast axial T1-weighted images were similar with that in pre-contrast axial T2-weighted images. Signal intensity increase was detected in dentate nucleus and globus pallidus (P < 0.05). CONCLUSION: Gadolinium deposition could be avoided in patients with meningioma by using unenhanced brain MRI for follow up scans.

Value of shear wave elastography by virtual touch tissue imaging quantification in patients with diffuse thyroid gland pathology

Background/aim: This study was performed to assess the diagnostic accuracy of shear wave elastography by virtual touch tissue imaging quantification in patients with diffuse thyroid gland pathology and to differentiate Graves' disease from Hashimoto's thyroiditis. Materials and methods: Thirty patients with Hashimoto's thyroiditis and 22 patients with Graves' disease were evaluated with conventional ultrasonography and shear wave elastography by virtual touch tissue imaging quantification. Thirty healthy participants formed the control group. Ten elastographic measurements of each thyroid lobe were performed in all three study groups. The mean shear wave velocity was calculated and compared between the patients and controls. Results: The mean shear wave velocity of the controls (1.92 ± 0.14 m/s) was significantly lower than that of the patients with Graves' disease (2.71 ± 0.22 m/s) and Hashimoto's thyroiditis (2.50 ± 0.20 m/s). Patients with Graves' disease had significantly higher shear wave velocities than those with Hashimoto's thyroiditis (P < 0.001). Conclusion: Shear wave elastography by virtual touch tissue imaging quantification can be used to discriminate a normal thyroid gland from diffuse thyroid gland pathology after conventional sonography and may assist in the diagnosis of Graves' disease and Hashimoto's thyroiditis.

Diagnostic value of acustic radiation force impulse imaging in the assessment of salivary gland involvement in primary Sjögren's sydrome.

AIMS: The aim of this study is to investigate the diagnostic value of Acoustic Radiation Force Impulse (ARFI) imaging in the assessment of salivary gland involvement in primary Sjögren's syndrome (pSS). MATERIAL AND METHODS: Twenty five patients with pSS and 25 healthy volunteers were included. First, echostructures and the thickness of the submandibular and parotid glands were evaluated by B-mode ultrasonography. Then, ARFI imaging with Virtual Touch Quantification® was performed. Ten independent shear wave velocity measurements were taken from each gland. Finally, the mean shear wavevelocity (SWV) values were calculated, and used for further analysis. RESULTS: The mean SWV values of parotid and submandibular glands were significantly higher in the pSS patients than in the healthy control group (p<0.001). The cut-off of SWV values were calculated to be 1.98 m/s for submandibular glands, and 1.93 m/s for parotid glands. In pSS patients, the mean SWV values of parotid glands were higher than those of the submandibular glands (p<0.001) and no statistically significant relationships between symptom duration or the degree of xerostomia and mean SWV values of parotid and submandibularglands were found (all p>0.005). CONCLUSIONS: Our findings indicate that ARFI imaging may provide a non-invasive, simple and fast means of assessment of glandular impairment as an alternative test when other salivary gland tests are inconclusive or cannot be performed. ARFI may be a valuable adjunct for the clinical diagnosis of pSS.

Does renal function affect gadolinium deposition in the brain?

OBJECTIVE: Was to compare T1 signal intensity ratios of dentate nucleus to cerebellar white matter (DN/cerebellum), dentate nucleus to pons (DN/pons) and globus pallidus to thalamus (GP/thalamus) in patients with normal renal function and in patients on chronic hemodialysis. To find out if renal function affects the deposition of gadolinium in brain after administration of linear gadolinium based contrast agents (GBCA). METHODS: Seventy eight contrast enhanced brain MRIs (Magnetic Resonance Imaging) with linear GBCA of 13 patients on chronic hemodialysis and 13 patients with normal renal function retrospectively evaluated. The DN/pons, DN/cerebellum and GP/thalamus signal intensity ratios were measured from each brain MRI on unenhanced axial T1 weighted images. RESULTS: In hemodialysis group statistically significant increase in the signal intensity ratios of DN/pons, DN/cerebellum and GP/thalamus were found between the first and the last brain MRIs (p = .001). The increase in the signal intensity ratios of DN/pons, DN/cerebellum and GP/thalamus between the first and the last brain MRIs in control group were not significant (p > 0.05). The signal intensity increase in DN and globus pallidus were significantly higher in hemodialysis group than control group (p < 0.05). CONCLUSIONS: Patients on hemodialysis had significantly higher DN and GP signal intensity increase compared to the patients with normal renal function. Renal function affects the rate of gadolinium deposition in the brain after administration of linear GBCA.

Solid Liver Lesions in an Infant With Neonatal Cholestasis: Is it Always Malignant?

In this report we describe a patient with neonatal cholestasis who was found to have a liver lesion with suspicious imaging features, although ultimately it was histologically proved to be a pseudotumor. We discuss the characteristic features and imaging findings of macroregenerative nodules of the liver.