How can we use positron emission tomography/computed tomography more accurately for characterization of asbestos-related pleural thickening?

Introduction: There is no consensus about the standardized uptake value maximum (SUVmax) cut-off value to characterize pleural thickening worldwide. Sometimes, this causes unnecessary invasive diagnostic procedures. Our first aim is to determine a cut-off value for SUVmax. Secondly, we try to answer the following question: If we use this cut-off value together with morphological parameters, can we differentiate benign thickening from malignant pleural mesothelioma (MPM) more accurately? Material and methods: Thirty-seven patients who underwent 2-deoxy-2-fluoro-D-glucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) before pleural biopsy were included the study. All of patients had histopathologically proven primary pleural disease. Their [18F]FDG-PET/CT imaging reports were re-assessed. If a patient's SUVmax or size of the thickening was not mentioned in the report, we calculated it with their [18F]FDG-PET/CT. Results: Age, pleural effusion, size, and SUVmax were found to have a relationship with MPM. We found the size > 14 mm, and SUVmax > 4.0 as cut-off values for MPM. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for size > 14 mm were found to be 86.4%, 85.2%, 82.6%, 88.5%, respectively. For SUVmax > 4.0, sensitivity, specificity, PPV, NPV were 90.9%, 87.0%, 85.1%, 92.2%, respectively. Conclusions: If a patient has SUVmax > 4.0 and/or size > 14 mm, the risk of MPM is high. These patients should undergo biopsy. If a patient's SUVmax < 4.0, size < 14 mm and does not have pleural effusion, he/she has low risk for MPM. These patients can undergo the follow-up. If a patient's SUVmax < 4, size < 14, and has pleural effusion the MPM risk is approximately 4%. These patients can undergo biopsy/cytology/follow-up. Novel studies are needed for these patients.

Magnesium Picolinate Improves Bone Formation by Regulation of RANK/RANKL/OPG and BMP-2/Runx2 Signaling Pathways in High-Fat Fed Rats.

Magnesium (Mg) deficiency may affect bone metabolism by increasing osteoclasts, decreasing osteoblasts, promoting inflammation/oxidative stress, and result in subsequent bone loss. The objective of the present study was to identify the molecular mechanism underlying the bone protective effect of different forms of Mg (inorganic magnesium oxide (MgO) versus organic magnesium picolinate (MgPic) compound) in rats fed with a high-fat diet (HFD). Forty-two Wistar albino male rats were divided into six group (n = 7): (i) control, (ii) MgO, (iii) MgPic, (iv) HFD, (v) HFD + MgO, and (vi) HFD + MgPic. Bone mineral density (BMD) increased in the Mg supplemented groups, especially MgPic, as compared with the HFD group (p < 0.001). As compared with the HFD + MgO group, the HFD + MgPic group had higher bone P (p < 0.05) and Mg levels (p < 0.001). In addition, as compared to MgO, MgPic improved bone formation by increasing the levels of osteogenetic proteins (COL1A1 (p < 0.001), BMP2 (p < 0.001), Runx2 (p < 0.001), OPG (p < 0.05), and OCN (p < 0.001), IGF-1 (p < 0.001)), while prevented bone resorption by reducing the levels of RANK and RANKL (p < 0.001). In conclusion, the present data showed that the MgPic could increase osteogenic protein levels in bone more effectively than MgO, prevent bone loss, and contribute to bone formation in HFD rats.

Is it possible to achieve more accurate mediastinal nodal radiotherapy planning for NSCLC with PET/CT?

Objective: To assess whether more accurate mediastinal lymph nodes radiotherapy can be performed with fluorode oxyglu cosepositron emission tomogaphy/computed tomography. METHODS: The retrospective study was conducted at Inonu University Medical Faculty, Malatya, Turkey, and Afyon Kocatepe University Medical Faculty, Afyon, Turkey, and comprised record of patients histopathologically diagnosed with non-small cell lung carcinoma and who underwent fluorodeoxyglucose positron emission tomography / computed tomography between January 2013 and December 2016. Surgery and pathology reports of the patients were reviewed. Histopathologically proven malignant and benign lymph nodes were re-identified with fluorodeoxyglucose positron emission tomography / computed tomography imaging. Anatomical and metabolic parameters of lymph nodes were re-assessed by specialists and compared with histopathology reports. Maximum standardised uptake values were used to assess sensitivity, specificity, positive predictive value, and negative predictive values. SPSS 22 was used for data analysis. RESULTS: The study included 144 mediastinal lymph nodes related to 42 patients who had a mean age of 62.4±9.8 years (range: 41-79 years). In terms of subtypes of the primary squamous cell carcinoma was found in 24(57.2%) patients, adenocarcinoma in 12(27.5%), and other subtypes in 6(15.3%) patients. Of the 144 lymph nodes, 48(33.3%) were metastatic. Sensitivity, specificity, positive predictive value, and negative predictive value were 92.8%, 64.3%, 56.9%, and 94.7%, respectively when maximum standardised uptake value >2.5 was used as the malignancy criterion. When lymph node maximum standardised uptake value / liver standardised uptake value-mean>1.69 was used as the criterion, the sensitivity, specificity, positive predictive value, and negative predictive value were 95.83%, 91.67%, 85.2%, and 97.8%, respectively. When the same values with lymph node >8mm was used as the criterion, the four resultant values were 89.6%, 93.8%, 87.8%, and 94.7%, respectively. When lymph node was replaced with mean attenuation >35 as the criterion, the consequent values were 79.2%, 93.8%, 86.4%, and 90.0%, respectively. CONCLUSIONS: Lymph node maximum standardised uptake value / liver standardised uptake valuemean> 1.69 was associated with higher negative predictive value and more useful positive predictive value compared to maximum standardised uptake value >2.5. When this parameter was used along with short axis or mean attenuation value, there were no significant increase in positive predictive value, but there was a decrease in negative predictive value.

Efficacy of Galium-68 DOTATATE PET/CT in the Detection of Metastasis Rate of Well-Differentiated Gastroenteropancreatic Neuroendocrine Tumors.

OBJECTIVES: The aim of this study was to determine metastasis rate in patients with well-differentiated grade1 (G1) and grade 2 (G2) gastroenteropancreatic neuroendocrine tumors (GEP NETs) using the gallium-68 DOTATATE positron emission tomography/computed tomography (68Ga-DOTATATE PET/CT). This study was also targeted toward investigating the relationship of maximum standardized uptake value (SUVmax) with mitotic count, histological grade, and Ki-67 index. METHODS: This retrospective study included 38 patients (i.e., 17 males and 21 females) with G1 or G2 GEP NETs who underwent 68Ga-DOTATATE PET/CT in Diyarbakir Gazi Yasargil training and research hospital between November 2014 and March 2018. The patients had at least one positive lesion that was approved by two nuclear medicine specialists with a minimum of 10 years of experience. RESULTS: The median age of the patients was 50 years (age range: 27-80 years), and their mean age was 52±15 years. Out of 38 patients, 1 (2.6%), 2 (5.2%), 2 (5.2%), 3 (7.8%), 10 (28.5%), and 19 (50%) patients had primary hepatic, primary mesenteric, colon, duodenal, gastric, and pancreatic NETs, respectively. In addition, the liver metastasis, local lymph node invasions, distant lymph node metastasis, bone metastasis, peritoneal involvement, and lung metastasis were observed in 42%, 21%, 15.7%, 13%, 7.8%, and 5% of the cases, respectively. The SUVmax median values of G1 and G2 tumors were 9.45 (range: 4.2-43.6) and 34.9 (range: 4.1-103), respectively (P=0.003). The Ki-67 index showed a negative correlation with the SUVmax value of the liver metastases and the highest SUVmax value (P=0.001 and P=0.002, respectively). There was also a negative correlation between mitosis count and the highest SUVmax value (P=0.011). CONCLUSION: Based on the findings, although [68Ga]DOTATATE PET/CT is successfully used to diagnose primary GEP NETs and their metastases, the SUVmax value obtained from DOTATATE PET/CT showed a negative correlation with Ki-67 and mitotic count.

The Role of Pre-ablative Stimulated Thyroglobulin and Thyroglobulin/Thyroid-Stimulating Hormone Ratio for Predicting Metastasis in Thyroid Cancer

Objectives: In this study, we aimed to investigate the predictive value of pre-ablative stimulated thyroglobulin (Tg) and Tg/thyroid-stimulating hormone (TSH) to identify lymph node metastasis (LNM) or distant metastases (DM) prior to radioactive iodine (RAI) treatment. Methods: Patients without metastasis were included in group 1 (n=100), those with LNM were included in group 2 (n=83), and those with DM constituted group 3 (n=23). Tg and TSH values were measured approximately 4 hours prior to RAI ablation therapy. Results: There was a significant difference between group 3 and other groups (group 1 and group 2) in terms of Tg (p<0.001) and Tg/ TSH (p<0.001). For Tg level and Tg/TSH ratio, the areas under ROC were 0.990 [95% confidence interval (CI): 0.979-1] and 0.991 (95% CI: 0.981-1), respectively. The cut-off points for Tg and Tg/TSH were 102 ng/mL and 1.06, respectively. Conclusion: Our results suggest that Tg and Tg/TSH values can be used to predict DM. On the other hand, our study indicates that patients should be carefully evaluated for LNM even when Tg levels are l ow.

Dynamic renal scintigraphic estimation of deceased donor kidneys in a rat model.

At present a large number of the renal transplantations are being performed from the deceased donors. The success of these transplantations depends on the viability of the deceased donor kidneys. The aim of this study was to investigate the reliability of scintigraphic estimation of function of deceased donor kidneys by comparing the histopathologic and scintigraphic findings. Ten rats were included in the study (2-3 months old, 250-300 g, all male). Control scintigraphy was performed to all the rats by injection of 37 MBq Tc-99m DTPA from the tail vein in a dynamic manner. Brain death of the rats was achieved by inflation of a Fogartys catheter in the cranial cavity. Immediately, after brain death confirmation, dynamic renal scintigraphy was performed with the same parameters of control scintigraphy. In the comparison of scintigraphies obtained in the before and just after brain death period, there was impairment of tubular functions, concentration and excretion functions in the postbrain death period. In the immediate postbrain death period, there was a significant elevation in the glomerular filtration rate and time to maximum concentration values. In the histopathological evaluation of the kidney samples in the postbrain death period, there were definitive findings of tubular impairment. Dynamic renal scintigraphy also demonstrated definite impairment of tubular system and tubular functions in the deceased donor kidneys. This could explain the reason of the increased frequency of acute tubular necrosis seen among deceased donor kidneys.

Haematogenous muscular metastasis of non-small cell lung cancer in F-18 fluorodeoxyglucose positron emission tomography/computed tomography.

AIM OF THE STUDY: F-18 FDG PET/CT is the most effective method for demonstrating extrapulmonary metastases of lung cancer. The aim of this study is to investigate the level of muscular metastasis of non-small-cell lung carcinoma (NSCLC) in F-18 FDG PET/CT and to demonstrate the characteristics of this special group of patients. MATERIAL AND METHODS: A total of 1150 patients with the diagnosis of NSCLC, who were referred for F-18 FDG PET/CT, were included into the study. Among these patients, the findings of 13 who were shown to have muscle metastases were studied. RESULTS: In the retrospective analysis of the patients, 13 patients (12 male, 1 female; mean: 59 ±7 years old) were found to have haematogenous (excluding local invasion) muscular metastases of NSCLC using F-18 FDG PET/CT. Two of the 13 patients had only muscular metastases (one patient isolated, one patient two foci). The other 11 patients had additional distant metastases in six metastatic sites (bone in 7 patients, distant lymph node in 6, adrenal gland in 5, contralateral lung in 3, liver in 1, and brain metastasis in 1 patient). Five patients died during the mean 11 ±8 months follow up. CONCLUSIONS: Muscular metastasis is not a rare condition, especially in F-18 FDG PET/CT examinations, and is frequently associated with additional distant metastases.

Insufficiency of bone scintigraphy in vertebral lesions of langerhans cell histiocytosis compared to f-18 fluorodeoxyglucose positron emission tomography/computed tomography and diagnostic computed tomography.

Langerhans cell histiocytosis (LCH) is a benign disorder related to the histiocytes which can infiltrate bone tissue. The most effective method for demonstrating severity of this disease is PET/CT and bone scintigraphy might show bone lesions. We present a seventeen year old male patient with disseminated LCH presented with exophtalmos and having multiple vertebral lesions which were identified by F-18 FDG PET/CT scan and diagnostic CT but not in the bone scintigraphy.

Classical vs. unit area method in the evaluation of differential renal function in unilateral hydronephrosis.

BACKGROUND: There are some problematic results in determination of differential renal function (DRF) by means of Tc-99m DMSA renal scintigraphy in hydronephrotic kidneys. In this study the classical method (CM) and unit area methods (UAM) in the estimation of DRF in unilateral hydronephrosis before and after intervention were compared. METHODS: Twenty patients (12 M, 8 F; mean: 42.6±18.5 years old) who were candidates for surgery or intervention because of unilateral hydronephrosis were the subjects of this study. All the patients were evaluated by Tc-99m DMSA scintigraphy before and 3-6 months after the intervention. In order to estimate DRF both CM and UAM (obtained by division of the counts including the kidney ROI to pixel of the same ROI) were performed. Bland-Altman analyses were performed in order to compare the DRF values obtained from both methods. RESULTS: The agreement between CM and UAM was poor in the preoperative estimation, however, the agreement was good after the operation or intervention. CONCLUSIONS: In this study it seems that DRF estimation with CM in unilateral hydronephrosis might be problematic in the determination of surgery thus UAM might be introduced as the method of choice in the determination of DRF in unilateral hyronephrosis.

Brain death scintigraphy and pathology results in a rat model.

OBJECTIVES: Brain scintigraphy with Tc-99m-labeled diethylenetriaminopenta-acetic acid is a sensitive diagnostic method showing loss of cerebral blood flow that occurs after brain death. Cerebral blood flow can be quantitatively estimated by this method. The aim of this study was to compare histopathologic changes occurring with the decrease of cerebral blood flow (as shown by Tc-99m-labeled diethylenetriaminopenta-acetic acid brain death scintigraphy) after brain death in an experimental model. MATERIALS AND METHODS: The study included examination of cerebral blood flow by Tc-99m-labeled diethylenetriaminopenta-acetic acid brain scintigraphy in the 20 rats, 1 day before brain death, after producing brain death in 11 surviving rats. Tc-99m-labeled diethylenetriaminopenta-acetic acid brain scintigraphy was performed under intubation and monitored. The Mann-Whitney U test was performed to compare groups (scintigraphic quantification results before and after brain death). RESULTS: In the time activity curves generated from the analysis of the scintigraphies, decreases in counts in the brain death group were obtained in the arterial phase (P < .01). Decreases of the cerebral blood flow between the first and the sixth minutes were statistically significant (P < .05). Common principal histopathologic changes of the brain death (ie, autolysis and color loss in the nerve cells, diffuse edema, petechial hemorrhage in the brain tissues) were observed in all subjects. CONCLUSIONS: Quantitative findings of the brain scintigraphy by Tc-99m-labeled diethylenetriaminopenta-acetic acid was related with the histopathologic findings seen during the early brain death, with significant decreases of the cerebral blood flow. Quantification of Tc-99m-labeled diethylenetriaminopenta-acetic acid brain death scintigraphy as an easier and less-expensive scintigraphic method of cerebral blood flow might indicate a definite diagnosis of brain death and thus, potential donors can be determined earlier, leaving to increased transplant rates.

Current surgical therapy for bronchiectasis: surgical results and predictive factors in 86 patients.

BACKGROUND: This study retrospectively evaluated the surgical indications and outcomes of 86 patients with bronchiectasis. METHODS: Between 2000 and 2013, the clinical and surgical specifications as well as follow-up results of patients with bronchiectasis were reviewed. Cystic and cylindric morphologic features were determined by chest computed tomography and hemodynamics (perfused and nonperfused), by lung ventilation/perfusion scans. The main indication for surgical resection was localized areas of cystic, nonperfused bronchiectasis. RESULTS: Patients were a mean age of 37.8 ± 14.5 years. Symptom duration was 43.4 ± 36.9 months. Bronchiectasis was saccular in 66 patients (76.7%) and varicose in 20 (23.3%). Localized defects were limited in one region of the lung in 53 (61.6%), and 54 (62.8%) showed a mixed or an obstructive ventilatory pattern. Failure of medical therapy was the most common indication for pulmonary resection. The 86 patients underwent 98 operations. Ten underwent staged thoracotomies (contralateral lobectomy, 7; contralateral segmentectomy, 3). Complete resection of all bronchiectatic areas was done in 78 patients (90.7%). Complications developed in 14 patients (14.6%). The mortality rate was 1.1% (n = 1). After surgical treatment, 71 of 86 patients (82.5%) were free of symptoms (excellent), and the remaining 15 (17.5%) had a reduction in preoperative symptoms. The 53 patients with localized perfusion defects underwent complete resection and had symptom-free (excellent) postoperative results. Complete resection independently predicted symptom-free outcome (p < 0.05); a forced expiratory volume in 1 second of less than 60% of the predicted value, an incomplete resection, and a preoperative antibiotic therapy independently predicted postoperative complications (p < 0.05). CONCLUSIONS: Bronchiectasis can be improved with operation. In properly selected patients, pulmonary resection can be done with acceptable morbidity and mortality rates and can lead to lasting symptomatic improvements.

Abdominal lymph node metastasis in patients with non-small-cell lung cancer as shown by PET/CT.

PURPOSE: The aim of this study is to investigate the frequency and the spread of abdominal lymph node metastasis in patients with non-small-cell lung cancer (NSCLC) by (18)F-FDG PET/CT. PATIENTS AND METHODS: Retrospective evaluation of the (18)F-FDG PET/CT examinations of 1191 patients diagnosed with NSCLC was performed. The metastatic abdominal lymph nodes of the patients were classified as inside the routine imaging field (covering the field of chest CT including adrenal glands) and outside the field. RESULTS: Seventy-four patients (6 F, 68 M; mean: 61 ± 11 years old) among 1191 patients (6%) were identified to have abdominal lymph node metastases. These abdominal lymph node metastasis changed management in 10 out of 74 patients (14%), and there were lymph node metastases outside the routine conventional imaging field in 43 (58%) patients. CONCLUSION: (18)F-FDG PET/CT provided identification of the distant metastatic lymph nodes out of conventional imaging field in more than half of NSCLC patients with abdominal metastasis which changed patient management in 14% of the patients due to abdominal lymph node metastasis outside the routine imaging field. This study shows the necessity of imaging NSCLC patients with an imaging protocol with larger imaging field like PET/CT.

The role of positron emission tomography/CT in hypoxic ischaemic encephalopathy in children.

The role of positron emission tomography/CT (PET/CT) in diagnosis and follow-up of newborns with hypoxic ischaemic encephalopathy has been documented before; however, this is the first presentation of elder children with both diagnostic and follow-up PET/CT results as far as we know.

Bone marrow uptake in parathyroid scintigraphy is a consequence of extremely high parathyroid hormone levels.

OBJECTIVE: We retrospectively evaluated patients with end-stage renal disease (ESRD) who were referred to our department for parathyroid scintigraphy. The aim of this study was to investigate the causes of bone marrow uptake observed on parathyroid scintigraphy. METHODS: We included 18 ESRD patients (10 F, 8 M; mean, 52 ± 13 years old; range, 45-59) in the study. The disease duration of the patients was mean 7.7 ± 4.7 years. The patients' mean plasma calcium and parathormone (PTH) levels were 9.7 ± 1.4 mg/dL and 1,553.3 ± 691.7 pg/mL, respectively. Dual-phase technetium-99m 2-methoxyisobutyl-isonitrile (Tc-99m MIBI) parathyroid imaging and, if necessary, additional Tc-99m pertechnetate scintigraphy were performed. Quantification of the planar early phase parathyroid images was performed for various regions (sternum, humerus, ribs) with the same size rectangular region of interest (ROI, 176 × 176 pixels). Average counts were compared with paired samples Student's t tests, and P<.05 was considered statistically significant. RESULTS: Tc-99m MIBI parathyroid imaging revealed parathyroid hyperplasia, adenoma, and ectopic adenoma in 7, 3, and 2 patients, respectively. The other 7 patients had normal scintigraphy results with regard to parathyroid pathologies. Bone marrow uptake in the sternum, ribs, and humerus was observed in 6 patients. The difference between the average quantitative value obtained from the ROIs drawn on the sternum and humerus was also statistically significant compared to patients without bone marrow uptake (P<.05). All 6 patients' exhibited extremely high PTH levels (>2,000 pg/mL; mean, 2,413.7 ± 150 pg/mL) compared to the other 12 patients (mean, 1,342.8 ± 249 pg/mL). CONCLUSION: Our results show that bone marrow uptake on parathyroid scintigraphy is a consequence of extremely high PTH levels in ESRD patients; no further analysis is required.

The role of the three phase bone scintigraphy in the management of the patients with costochondral pain.

AIM: The bone scintigraphy is indicated in patients with costochondral pain in order to identify the organic etiology. We aimed to investigate the local and projecting pain, or incidental findings in the three phase bone scintigraphy of the patients referred for costochondral pain. METHODS: We included 50 patients (36F, 24M; mean: 41±18 years-old) referred to our department for three phase bone scintigraphy for costochondral pain between January 2009-July 2012. RESULTS: Among the 50 patients 22 had normal scintigraphy. An increased activity accumulation in the sternoclavicular joint was observed in 12 patients (right in 4, left in 4 and bilateral in 4) only in late phase and in 9 patients (right in 2, left in 1 and bilateral in 6) with increased vascularity. Among projecting pain causes, activity was present on sternum in 4 patients, on humerus in 2 patients and on the first costae in 2 patients. For the characterization of inflammatory pathology, the three phase bone scintigraphy showed sensitivity, specificity, accuracy, positive and negative predictive values of 43%, 94%, 78%, 77% and 78% respectively. CONCLUSION: Bone scintigraphy is an effective diagnostic method for the identification of local or projecting pain, and additionally unexpected incidental pathologies ssociated with costochondral pain. However regarding the characterization of inflammatory process false negatives should be considered. CONFLICT OF INTEREST: None declared.

Twenty four hour imaging delay improves viability detection by Tl-201 myocardial perfusion scintigraphy.

OBJECTIVE: Since twenty-four-hour imaging by Tl-201 myocardial perfusion scintigraphy has been introduced as an effective additional procedure, the aim of this study was to compare this method's result with only rest redistribution procedure in the diagnosis of myocardial viability. METHODS: Thirty patients (Seven female, 23 male; mean: 59.8 ± 10.7, 55.8-63.8 years old) with diagnosis of coronary artery disease were involved in this study. All patients had anamnesis of previous myocardial infarction and/or total occlusion of any main artery in the coronary angiography. Myocardial perfusion scintigraphy with Tl-201 with rest four hour (early) redistribution and 24 hour delayed redistribution protocol were performed to all of the patients. The images were evaluated according to 17 segment basis by an experienced nuclear medicine physician and improvement of a segment by visual interpretation was considered as viable myocardial tissue. RESULTS: Viability was found at 52 segments in the early redistribution images and additional 18 segments in the 24 hour delayed redistribution images on segment basis in the evaluation of 510 segments of 30 patients. On per patient basis, among the 26 patients who had viable tissue, 14 (54%) had additional improvement in 24 hour delayed images. Three (12%) patients had viable tissue in only 24 hour delayed images. CONCLUSION: Delayed imaging in Tl-201 MPS is a necessary application for the evaluation of viable tissue according to considerable number of patients with additional improvement in 24 hour images in our study, which is restricted to the patients with myocardial infarct.

Gall bladder visualization in lymphoscintigraphy.

BACKGROUND: The aim of this study was to evaluate gall bladder visualization in lymphoscintigraphy of extremities. METHODS AND RESULTS: Thirteen patients who had prediagnoses of lymphedema and were referred for lower extremity lymphoscintigraphy to our department were retrospectively evaluated. Lower extremity lymphoscintigraphy with Tc-99m sulfur colloid was performed on the patients, and planar images of the lower extremity and abdominal region were taken in early phase and late phase (at the 24th hour) routinely. Lymphoscintigraphy results of eight patients were normal regarding lymphatic flow or lymph nodes; however, additional pathologic tracer accumulations in gall bladder were observed, which disappeared at 24th hour images in three patients. Five patients had various pathologies regarding lymph flow or lymph nodes. However, there were no patients with gall bladder activity except those three patients who had casual anamnesis of fasting prior to the exam. CONCLUSION: The fasting state of the patients might be the cause of gall bladder visualization during the lymphoscintigraphy of the extremities with sulfur colloid.

A novel false-positive cause in testis scintigraphy in the diagnosis of testis torsion.

Testis scintigraphy is the most reliable modality in the diagnosis of testis torsion since it directly reflects the vascularity of the testis. The 'rim sign' is considered as the pathognomonic sign of the missed torsion. However, there are some possible false-positive cases. In this case report, we would like to present an unexpected false-positive cause of the 'rim sign' in testis scintigraphy in an 18-year-old male patient.

PET/CT images of a patient with haemophagocytic lymphohistiocytosis.

Haemophagocytic lymphohistiocytosis (HLH) is a rare immune disorder that predominantly affects macrophages and T lymphocytes and leads to multiple organ disease and death. The characteristic pathological finding in the bone marrow and the other affected tissues is haemophagocytosis of macrophages (macrophages digesting erythrocyte). Primary (hereditary) and secondary (acquired) forms of the disease are present. A patient with documented HLH disease revealed by positron emission tomography/CT is reported in this paper.

Isolated left pulmonary artery agenesis: a case report.

UNLABELLED: Unilateral pulmonary artery agenesis without any cardiovascular malformation is a rare anomaly. We present the imaging findings of a patient who was diagnosed as isolated left pulmonary artery agenesis. A 27-year-old female patient was admitted to our hospital due to dyspnea during exercise for five years. Chest X-ray revealed minimally small left pulmonary hilum and left lung. She was admitted to our clinic with the suspicion of pulmonary artery pathology. Absent perfusion of the left lung with normal ventilation was visualized on scintigraphy. MDCT angiography of pulmonary arteries showed absent left main pulmonary artery with systemic collaterals around left hemithorax. Pulmonary artery agenesis can be asymptomatic and isolated until adulthood. Both scintigraphy and CT angiography images of pulmonary artery agenesis of a patient are rare in the literature. Pulmonary ventilation-perfusion scintigraphy can be used not only for pulmonary embolism but also pathologies involving pulmonary artery and its branches. CONFLICT OF INTEREST: None declared.