NUCLEAR MEDICINE REVIEW最新文献

Background: The purpose of the study was to present the cardiological procedures performed and scintigraphic devices used in Poland in 2019-2021 - based on the results of a nationwide survey.

Material and methods: Forty-three (100%) institutions performing scintigraphic cardiology tests responded to the survey: 29 classic nuclear medicine centers (NM), 4 PET centers, and 10 institutions performing NM and PET examinations.

Results: In 2021, 51 SPECT devices (including 5 dedicated cardiocentric semiconductor cameras, 12 SPECT gamma cameras, and 39 hybrid SPECT/CT devices) and 15 PET devices (14 PET/CT and 1 PET/MR) were used for cardiological examinations. The total number of cardiological SPECT and PET examinations has reached 33,107; PET shares 0.8%. The most frequently performed NM cardiological examination in 2019-2021 was myocardial perfusion scintigraphy (98-99% of all tests). NM cardiac amyloidosis studies accounted for less than 1% of all studies, and diagnostics of inflammation in the chest using labeled leukocytes - for less than 0.5%. The most frequently performed cardiological heart examination using the PET technique was the diagnostics of inflammation in the chest (166 of 269 examinations, i.e. 61.7%, in 2021), followed by the assessment of cardiac viability (46 examinations, i.e. 17.1%).

Conclusions: In Poland, in 2021, cardiac scintigraphy was performed in 39 classic nuclear medicine centers and 14 PET centers, using modern equipment, in approximately 1/1000 inhabitants per year. Polish nuclear cardiology is based on classical nuclear medicine. Almost 99% of the tests are stress and rest myocardial perfusion studies. PET has limited practical use (< 1% of cardiac studies).

Secondary anemia in hemoglobinopathies like thalassemia can cause expansion of the bone marrow cavities because of compensatory marrow hyperplasia. This case demonstrates spontaneous osteonecrosis of the distal left femur in a patient with β-thalassemia that may be secondary to ischemic infarction secondary to occlusion of the microvasculature within the expanded cancellous bone. This subject was referred to Hazrat Rasool Akram Hospital because of fever, cough, and bone pain. In the CT scan she had scattered peripheral CGO in both lungs due to COVID-19 with two paravertebral masses due to extramedullary hematopoiesis. The patient had also generalized bone pain so the physician asked for a whole-body bone scan and incidentally, we found a cold lesion with a rim of increased uptake in the distal left femur that with bone biopsy it was consistent with osteonecrosis. This case illustrates the importance of performing a whole-body bone scan in β-thalassemia for the management of patients and diagnosis of occult osteonecrosis.

Background: The exact role of positron emission tomography with fluorine-18-deoxyglucose ([18F]FDG PET/CT) in an early diagnosis of relapsed ovarian cancer is not clearly defined. The aim of the study was to assess the value of [18F]FDG PET/CT in the detection and differentiation of recurrent ovarian cancer.

Material and methods: Eighty-four patients with suspected recurrent ovarian cancer underwent [18F]FDG PET/CT examination. Results of PET/CT were analyzed taking into account clinical data of the patients, histological diagnosis, and 6-month follow-up.

Results: The [18F]FDG PET/CT examinations showed abnormal findings in 67 patients (79.76%). There were 63 true positive results (75.00%), 14 true negative (16.67%), 4 false positive (4.76%), and 3 false negative (3.57%) results. Sensitivity, specificity, positive and negative predictive values of [18F]FDG PET/CT were 95%, 78%, 94%, and 82%, respectively. In patients with elevated serum Ca 125 concentration (n = 43), sensitivity and specificity of [18F]FDG PET/CT was 95.00% and 66.67%, respectively. Recurrence was confirmed in 22 (88.00%) of 25 patients referred for [18F]FDG PET/CT due to suspected relapse in imaging tests.

Conclusions: A high frequency of recurrent ovarian cancer detected in the [18F]FDG PET/CT examinations due to increased Ca 125 concentration in patients without clinical symptoms and without changes in other imaging tests confirmed the usefulness of [18F]FDG PET/CT in such cases. In patients with suspected recurrent ovarian cancer implied in radiological findings, [18F]FDG PET/CT results in most cases differed from the original results of imaging examination. Our results showed high accuracy of [18F]FDG PET/CT in the evaluation of recurrent ovarian cancer and presented this diagnostic method as a useful tool in detecting and differentiating suspected lesions in this group of patients.

Brown tumours are rare bone lesions occurring in patients with severe hyperparathyroidism (HPT) because of increased osteoclastic activity due to high levels of parathyroid hormone (PTH). We report the case of 30-year-old woman with secondary hyperparathyroidism due to severe chronic kidney diseases who underwent [18F]F-choline PET/CT scan for localization of the hyperfunctioning parathyroid gland before surgical treatment. [18F]F-choline PET/CT scan showed increased choline uptake in the lower left parathyroid gland and in multiple bone lytic lesions. Multiple focal choline uptake in bone corresponded to brown tumours - fibrous osteitis cystica.

A 65 years old man with high-risk prostate adenocarcinoma underwent bone scintigraphy with 99mTc-methylene diphosphate ([99mTc]Tc-MDP). The scan revealed a focus of radiotracer uptake in the left pubic region, which was suspicious for metastatic involvement. Additional imaging with single photon emission computed tomography (SPECT/CT) confined the uptake to be extra-osseous and contributed to the calcified zone in the prostate bed. Prostatic bed calcification with [99mTc]Tc-MDP uptake mimics metastasis and can be easily missed on planar images.

Introduction: Nuclear medicine (NM) methods play an important role in the evaluation of renal function in a wide range of clinical indications. The aim of our study was to evaluate the correlation between measured GFR (mGFR) obtained by the three-plasma sample slope-intercept NM method (TPSM) - reference method vs. estimated GFR (eGFR) using Fleming's single plasma sample method (SPSM) at 120 min, 180 min, and 240 min and correlation of reference method with eGFR with camera-based Gates' protocol.

Material and methods: A total of 82 subjects (33 male/49 female) with a mean age of 54.87 ± 15.65 years were included and mGFR value was obtained by the three-plasma sample slope-intercept NM method and eGFR was obtained with Fleming's single sample method. eGFR was also quantified with the camera-based Gates' protocol after i.v. application of [99mTc]Tc-DTPA.

Results: Our study revealed a very strong positive significant correlation between all three SPSMs with the TPSM as the reference method. Between the Gates' method and the TPSM in the group of patients with mGFR ≥ 61-84 mL/min/1.73 m2 and mGFR ≥ 84 mL/min/1.73 m2, a moderate positive statistically significant correlation was obtained.

Conclusions: The SPSM method shows a very strong correlation with the reference and low bias in all three groups of patients and can be routinely used for GFR estimation.

Background: As a result of constantly improving surgical methods, an increasing number of patients have medical devices implanted in the cardiovascular system (including vascular grafts and endografts). Such patients are characterised by their high risk of infectious complications due to the possibility of biofilm formation on implanted material. This work aims to analyse the utility of 2-[18F]FDG PET/CT in diagnosing vascular graft and endograft infections.

Material and methods: The study was undertaken on a group of 58 patients, of whom 34 were in the study group, and 24 were in the control group. The 2-[18F]FDG PET/CT study was conducted in the Nuclear Medicine Department at the University Hospital of Lublin. The inclusion criteria for the study group were the presence of a vascular graft or endograft that encompasses the aorta, and strong clinical suspicion of its infection. The inclusion criteria for the control group were the presence of a vascular graft or endograft in the large arteries and the absence of signs of its infection on 2-[18F]FDG PET/CT, as well as the absence of clinically apparent signs and symptoms during six months of observation after 2-[18F]FDG PET/CT. All patients found in the database that met the criteria were included.

Results: Vascular endografts were more common in the control group than in the study group. However, in the case of infection of the vascular endograft, signs of infection in 2-[18F]FDG PET/CT were more severe. Images in the study group were divided into three groups that represent image patterns based on CT and PET characteristics. The first pattern (P1) was recognised in six patients. The second (P2) and third (P3) were visible in 11 and 17 patients, respectively.

Conclusions: Comparative analysis of the study and control groups demonstrates the utility of 2-[18F]FDG PET/CT in the diagnosis of vascular graft/endograft infection.

We present a case of a 79-year-old asymptomatic patient with prostate adenocarcinoma, Gleason score 9 (4 + 5), with the initial prostate-specific antigen (PSA) level of 17 ng/mL, treated with radiotherapy and hormonotherapy, who was diagnosed with the rapid growth of PSA levels up to 78.8 ng/mL. Due to suspected bone metastases, first, bone scintigraphy was performed. However, it showed only one intense "hot" lesion in the Th7 projection. This image was not consistent with a high level of PSA, for which reason a computed tomography (CT) scan was performed. It revealed lytic metastasis in Th7 and one more suspicious change in L2, which still was inconsistent with the patient's clinical picture. The patient was referred for [68Ga]Ga-PSMA-11 PET/CT. It showed an uncountable number of foci of increased marker accumulation in bones, mostly without visible change in CT examination. This case showed that the clinical results and suspicions of the advancement of a patient's disease are still the most important data in care and therapy planning.

Background: This study aims to evaluate the performance of a deep learning enhancement method in PET images reconstructed with a shorter acquisition time, and different reconstruction algorithms. The impact of the enhancement on clinical decisions was also assessed.

Material and methods: Thirty-seven subjects underwent clinical whole-body [18F]FDG PET/CT exams with an acquisition time of 1.5 min per bed position. PET images were reconstructed with the OSEM algorithm using 66% counts (imitating 1 min/bed acquisition time) and 100% counts (1.5 min/bed). Images reconstructed from 66% counts were subsequently enhanced using the SubtlePET™ (SP) deep-learning-based software, (Subtle Medical, USA) - with two different software versions (SP1 and SP2). Additionally, images obtained with 66% counts were reconstructed with QClear™ (GE, USA) algorithm and enhanced with SP2. Volumes of interest (VOI) of the lesions and reference VOIs in the liver, brain, bladder, and mediastinum were drawn on OSEM images and copied on SP images. Quantitative SUVmax values per VOI of OSEM or QClear™ and AI-enhanced 'shortened' acquisitions were compared.

Results: Two hundred and fifty-two VOIs were identified (37 for each reference region, and 104 for the lesions) for OSEM, SP1, SP2, and QClear™ images AI-enhanced with SP2. SUVmax values on SP1 images were lower than standard OSEM, but on SP2 differences were smaller (average difference for SP1 11.6%, for SP2 -4.5%). For images reconstructed with QClear™, SUVmax values were higher (average +8.9%, median 6.1%, SD 18.9%). For small lesions with SUVmax values range 2.0 to 4.0 decrease of measured SUVmax was much less significant with SP2 (for liver average -6.5%, median -5.6% for lesions average -5.6%, median - 6.0, SD 5.2%) and showed the best correlation with original OSEM. While no artifacts and good general diagnostic confidence were found in AI-enhanced images, SP1, the images were not equal to the original OSEM - some lesions were hard to spot. SP2 produced images with almost the same quality as the original 1.5 min/bed OSEM reconstruction.

Conclusions: The studied deep learning enhancement method can be used to accelerate PET acquisitions without compromising quantitative SUVmax values. AI-based algorithms can enhance the image quality of accelerated PET acquisitions, enabling the dose reduction to the patients and improving the cost-effectiveness of PET/CT imaging.

The oncophilic nature of [99mTc]Tc-MIBI makes this radiopharmaceutical useful in cancer diagnostics, with particular emphasis on breast cancer. Increased uptake of [99mTc]Tc-MIBI in tests performed for non-oncological indications always raises the suspicion of its neoplasmatic character and requires further clinical diagnostics, which is especially justified in patients with a previous history of cancer. However, the presented case illustrates that focally increased uptake of [99mTc]Tc-MIBI is not always associated with the presence of cancer cells and may result from post-therapeutic changes.