Scan-positive Patients Research Articles

Evaluation of rapid antibody test and chest computed tomography results of COVID-19 patients: A retrospective study.

The purpose of this study was to evaluate the SARS‐CoV‐2 immunoglobulin M/immunoglobulin G (IgM/IgG) rapid antibody test results in symptomatic patients with COVID‐19 and their chest computed tomography (CT) data. A total of 320 patients admitted to our hospital for different durations due to COVID‐19 were included in the study. Serum samples were obtained within 0–7 days from COVID‐19 patients confirmed by reverse‐transcription polymerase chain reaction (RT‐PCR) and chest CT scan. According to the SARS‐CoV‐2 RT‐PCR results, the patients included in the study were divided into two groups: PCR positive group (n = 46) and PCR negative group (n = 274). The relationship between chest CT and rapid antibody test results were compared statistically. Of the 320 COVID‐19 serum samples, IgM, IgG, and IgM/IgG were detected in 8.4%, 0.3%, and 11.6% within 1 week, respectively. IgG/IgM antibodies were not detected in 79.7% of the patients. In the study, 249 (77.8%) of 320 patients had positive chest CT scans. Four (5.6%) of 71 patients with negative chest CT scans had IgM and two (2.8%) were both IgM/IgG positive. IgM was detected in 23 (9.2%), IgG in one (0.4%), and IgM/IgG in 35 (14%) of chest CT scan positive patients. The rate of CT findings in patients with antibody positivity was found to be significantly higher than those with antibody negativity. The results of the present study show the accurate and equivalent performance of serological antibody assays and chest CT in detecting SARS‐CoV‐2 within 0–7 days from the onset of COVID19 symptoms. When RT‐PCR is not available, we believe that the combination of immunochromatographic test and chest CT scan can increase diagnostic sensitivity for COVID‐19.

Evaluation of asymptomatic skeletal metastasis by 99mTc MDP bone scans in NSCLC patients attending INMAS, Rajshahi

<p><strong><em>Background: </em></strong>Lung cancer is the leading cause of cancer deaths worldwide. Lung cancer is often insidious, producing no symptoms until the disease is well advanced. In approximately 7-10% of cases, lung cancer is diagnosed in asymptomatic patients. Some patients are asymptomatic for skeletal metastasis and a recent prospective study showed that in staging of non-small cell lung cancer (NSCLC), failure to perform a bone scan could miss asymptomatic bone metastasis in 14–22% of patients. Radionuclide bone scintigraphy with <sup>99m</sup> Tc MDP (Technetium-99mmethylene diphosphonate) is very useful nuclear imaging tool to detect skeletal metastasis with a sensitivity of 98.2% and a specificity of 95.2%. The aim of this study was to detect the asymptomatic skeletal metastasis of non-small cell lung cancer patients by <sup>99m</sup>Tc MDP bone scan.</p><p><strong><em>Patients and methods:</em></strong> It is a retrospective study, carried out from January 2015 to December 2016 in Institute of Nuclear Medicine and Allied Sciences, Rajshahi. Bone scan was performed by an intravenous bolus injection of 20 m Ci <sup>99m</sup>Tc MDP. Bone phase images were taken at three hours after injection of the radiotracer.</p><p><strong><em>Results:</em></strong> A total of 52 patients were enrolled in the study. The mean age of the patients was 57.6 ± 14.5 years (mean ± SD) with range from 36 to 75 years and 42 (80.77%) were male and 10 (19.23%) were female. Out of 52 patients, only 06 (11.54%) patients were diagnosed as positive and 46 (88.46%) were negative for bone metastasis. Out of 06 patients with positive skeletal metastasis 04 (66.67%) patients had multiple sites (two or more) and 02 (33.33%) patients had solitary site of bone involvement. Common sites of metastasis were in thoracic (83.33%) and lumbar spine (83.33%), ribs (50%), pelvic bones (33.33%), long bones (16.66%), skull (16.66%) and other bony sites including clavicle, sternum, scapula, sacrum (16.66%). Regarding staging prior to bone scan, out of 06 bone scan positive patients 03 (50%) patients were in stage III, 02 (33.33%) patients were in stage IV and 01(16.67%) patient was in stage II. On the basis of histopathology, out of 06 skeletal metastatic patients 04 (66.67%) patients had adenocarcinoma, 01 (16.67%) patient had squamous cell carcinoma and 01 (16.67%) had large cell carcinoma. The exclusion of bone metastasis is important in the initial staging of non-small cell lung cancer.</p><p><strong><em>Conclusion:</em></strong> There is debate about whether bone scans should be performed routinely or restricted to patients who present with clinical or laboratory indicators suggesting skeletal metastasis. The present study indicates that if bone scans were done only in patients reporting skeletal symptoms an important number of patients (11.54%) would have been miss-staged due to asymptomatic bone metastasis. As bone scan is very cost effective in comparison to other imaging modalities (MRI / PET-CT), it can play a vital role in detecting asymptomatic skeletal metastasis in NSCLC patients.</p><p>Bangladesh J. Nuclear Med. 20(2): 110-114, July 2017</p>

699P - High incidence of metastases detected on 18F-FDG PET-CT in patients with gall bladder cancer incidentally discovered after laparoscopic cholecystectomy

Gall bladder cancer (GBC) is a relatively rare disease with clinical and imaging features similar to benign gall bladder diseases (BGBD) like gall stone disease or cholecystitis. A few of the BGBD patients who undergo laparoscopic cholecystectomy (LC) are later found to have GBC. In these patients, it is important to evaluate the extent of disease for further management. This study was conducted to evaluate the incidence of metastases in patients referred for 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) following incidental discovery of GBC after LC for BGBD. We retrospectively evaluated the data of patients referred to our department between January 2011 and December 2015 for FDG PET-CT with GBC diagnosed on histopathology (HP) after LC for BGBD. Abnormal FDG uptake on PET images corresponding to morphological abnormalities on contrast enhanced CT images was considered positive for disease. HP examination and clinical or imaging follow-up were used as the reference standard for confirmation of diagnosis. FDG PET-CT imaging was performed 1-8 (median 3.5) months after LC in 44 patients (8M, 36F) aged 30-75 (median 50.2) years. PET-CT was positive in 32/44 (72.7%) and negative in 12/44 patients (27.3%). Loco-regional disease was detected in 30/44 patients (68.2%) involving the gall bladder fossa, liver or regional lymph nodes. Metastatic seeding to the omentum, mesentery or laparoscopic port sites was found in 15 (34.1%) and distant metastasis in 5 patients (11.3%). Based on the reference standard, 28 patients had true positive scans. Findings in 4 scan-positive patients could not be confirmed; these were presumed false positive and remain on follow-up. All 12 scan-negative patients were true negative. PET-CT showed sensitivity, specificity, PPV, NPV and accuracy of 100%, 75.0%, 87.5%, 100%, and 90.9% respectively in detecting residual / recurrent disease. There is high propensity for seeding metastasis when GBC is discovered after LC for BGBD. FDG PET-CT has high diagnostic performance in detecting residual / recurrent disease as well as metastases in these patients.

Prognostic Implications of Imaging-Based Bone Marrow Assessment in Lymphoma: 18F-FDG PET, MR Imaging, or 18F-FDG PET/MR Imaging?

2017 Objectives To evaluate FDG-PET/CT as a potential molecular imaging modality for venous thromboembolism (VTE) in a prospective, observational proof-of-concept pilot study. Methods Patients with proven deep venous thrombosis or pulmonary embolism (DVT+/PE+) or disproven DVT or PE (DVT-/PE-) were eligible. Exclusion criteria (non-inclusion) were: Age Results Eleven patients were included: Two women and nine men with a mean age of 65 years (range 50-78 years); seven DVT+, four DVT-, four PE+, and no PE- (four patients were both DVT+ and PE+). The duration of symptoms prior to inclusion was 2-7 days for the DVT+ patients, and 2 weeks-5 months for the PE+ patients. All seven DVT+ patients showed abnormal FDG uptake in the corresponding leg, while none of the DVT- patients or the PE+ patients showed abnormal FDG uptake in the venous vasculature. Conclusions Our results substantiate the potential role of FDG-PET/CT in VTE, especially for DVT with all DVT+ being positive and all DVT- being negative. The results from lung scan positive patients are likely due to non-specificity of the latter modality in determining the age of the clots. Therefore, the results from FDG-PET/CT images could actually represent the true nature of older and inactive PE. Although further studies are warranted for definite clarification, FDG-PET/CT may give rise to a paradigm shift in both diagnostic and therapeutic strategies for the management of VTE by screening the entire body for VTE and underlying occult malignancies, and by differentiating acute from chronic VTE.

Treatment Updates in Advanced Thymoma and Thymic Carcinoma

Thymomas and thymic carcinomas are rare diseases of the anterior mediastinum. Although some thymomas are quite indolent and able to be resected in a curative fashion, the treatment of metastatic disease remains a challenge, especially for the more aggressive thymic carcinoma histology. Based on the results of single-arm trials, combination chemotherapy is the standard of care in the first-line, and anthracycline-based treatments should be used if patients are reasonably fit. Several single-agent cytotoxic chemotherapy agents have some effectiveness in subsequent lines of therapy, especially pemetrexed and, in octreotide scan-positive patients, octreotide. Prospective trials of new agents are difficult to conduct given the rarity of thymoma, but various targeted therapies do show promise. Greater international research collaboration, as well as modern techniques in molecular and genomic characterization, should help to advance the treatment of thymic malignancies in the near future.

AXR is the most useful initial screening tool in determining position of ‘retained’ patency capsule

IntroductionCapsule endoscopy carries a risk of capsule retention. In patients with risk factors for this, patency capsule (PC) is recommended. Patients are screened at 30 h with radiofrequency scanner, if...

Abnormal Fluorodeoxyglucose PET in Pulmonary Langerhans Cell Histiocytosis

Pulmonary Langerhans cell histiocytosis (PLCH) is an inflammatory lung disease strongly associated with cigarette smoking and an increased risk of malignant neoplasms. Although the chest CT scan characteristics of PLCH are well recognized, the PET scan characteristics of adults with PLCH are unknown. We identified 11 patients with PLCH who underwent PET scanning over a 6-year period from July 2001 to June 2007. The presenting clinicoradiologic features including PET scan and chest CT scan findings were analyzed. Five of 11 patients had positive PET scan findings. Of the five PET scan-positive patients, 4 (80%) were women, 4 (80%) were current smokers, and the median age was 45 years (age range, 31 to 52 years). PET scan-positive findings were more likely to be present if the scan was performed early in the clinical course. Three PET scan-positive patients (60%) had multiorgan involvement. PET scan-positive patients had predominantly nodular inflammatory lung disease (> 100 nodules) with most nodules measuring < 8 mm, whereas all PET scan-negative patients had predominantly cystic lung disease with fewer nodules (< 25 nodules). Notable abnormal PET scan findings included foci of increased uptake in nodular lung lesions, thick-walled cysts, bone, and liver lesions. The mean maximum standardized uptake value of the PET scan-positive lesions ranged from 2.0 to 18.2. PLCH may be associated with abnormal thoracic and extrathoracic PET scan results. Patients with nodular disease seen on chest CT scans appear more likely to have abnormal PET scan findings. Our results suggest that PET scan imaging cannot reliably distinguish between the benign inflammatory nodular lesions of PLCH and malignant lesions.

The value of SPECT scans in identifying back pain likely to benefit from facet joint injection.

Lumbar facet disease is sometimes implicated in low back pain. Identification is difficult and this may account for a variable response. Single photon emission computerized tomography (SPECT) is a scanning technique which enables localization of facet joint pathology. We determined whether recognition of facet disease by this method improved the response to corticosteroid injection treatment. Fifty-eight patients with low back pain and displaying accepted clinical criteria for facet joint disease were evaluated by SPECT. Twenty-two had facetal uptake of isotope. These and the tender facet joints of 36 scan-negative patients were injected with 40 mg methylprednisolone and 1 ml 1% lignocaine under X-ray control. Pain was assessed by a blind observer using the McGill questionnaire (MGQ), Present Pain Intensity score (PPI) and a Visual Analogue Scale (VAS). VAS, PPI and MGQ were reduced in the scan-positive patients at 1 month (P = 0.05, P = 0.0005, P = 0.005) and MGQ at 3 months (P = 0.01), whilst scan-negative patients were unchanged. The percentage of scan-positive patients who reported improvement was 95% at 1 month and 79% at 3 months, significantly greater than the control group (P = 0.0005, P = 0.01). Within 6 months, pain improvement in the SPECT-positive group was no longer statistically significant. Tenderness did not correlate with increased uptake on SPECT scan. Osteoarthritis of the facets was more common in the SPECT-positive patients (P < 0.001), but did not correspond with sites of increased uptake on SPECT scan. These results suggest that SPECT can enhance the identification of back pain sufferers likely to obtain short-term benefit from facet joint injection.

In vivo imaging of pituitary tumours using a radiolabelled dopamine D2 receptor radioligand.

Knowledge of the dopamine D2 receptor status of pituitary tumours may play a predictive role in differential diagnosis and therapeutic decisions. This study was performed to evaluate the value of pituitary dopamine D2 receptor scintigraphy with (S)-2-hydroxy-3-123I-iodo-6-methoxy-N-[(1-ethyl-2-pyrrolidinyl) methyl]benzamide (123I-IBZM) in the diagnostic evaluation of patients with pituitary tumours. Scintigraphy using 123I-IBZM was performed in 5 patients with PRL-secreting macroadenomas, 2 patients with PRL-secreting microadenomas, 17 patients with clinically non-functioning pituitary adenomas (NFPAs), 12 patients with GH-secreting adenomas and 1 patient with a TSH-secreting macroadenoma. Single-photon emission tomography (SPECT) showed significant uptake of 123I-IBZM in the pituitary region in 3/5 macroprolactinoma patients. These results closely correlated with the response of plasma PRL levels to the dopamine D2 receptor agonist quinagolide. In two scan-positive prolactinoma patients, repeated SPECTs during therapy with quinagolide showed a reduction in the pituitary uptake of 123I-IBZM. Pituitary SPECT was negative in the 2 microprolactinoma patients, who responded to quinagolide administration. In 4/17 patients with NFPA, significant uptake of the radioligand in the pituitary region was observed. In 2/3 scan-positive NFPA patients, who were treated with quinagolide, shrinkage of the pituitary tumours was observed. Treatment with quinagolide resulted in stabilization of tumour growth in the other scan-positive patients. Four out of 17 patients with NFPA and a negative SPECT were treated with quinagolide. Tumour growth was observed in 1 patient, and tumour size did not change in the other 3 patients. The pituitary region of none of the 12 acromegaly patients showed significant uptake of 123I-IBZM. Sensitivity of the GH-secreting adenomas to quinagolide was demonstrated in 8/12 patients in vivo by an acute test, and in 6/9 of the tumours in vitro. Pituitary SPECT was negative in the patient with the TSH-secreting macroadenoma and this tumour also showed no sensitivity to quinagolide in vivo or in vitro. We conclude that 123I-IBZM is a ligand for in vivo imaging of dopamine agonist- sensitive macroprolactinomas, but not for microprolactinomas or GH-secreting adenomas. The technique potentially provides a means of predicting the dopamine agonist-responses of non-functioning pituitary adenomas in vivo.

Urinary Tissue Factor Levels in Prostatic Carcinoma: A Potential. Marker of Metastatic Spread ?

Recent investigations have suggested that levels of urinary tissue factor (UTF) may be elevated in some forms of cancer. We have determined UTF levels in healthy controls, patients presenting for surgery with benign prostatic hypertrophy (BPH) and untreated prostate cancer. Patients undergoing check cystoscopy, who were free of recurrent bladder cancer, and a cohort of men with bone scan positive prostate cancer recently treated by androgen ablation were also studied. UTF levels were higher in patients with prostate cancer when compared with controls, those undergoing check cystoscopy and patients with BPH. In patients with prostate cancer, bone scan positive patients had higher levels than bone scan negative subjects. The androgen ablated group had UTF levels similar to those of the control groups and significantly lower than the bone scan positive group. A weak correlation was found between UTF and serum prostate specific antigen (PSA) levels when patients with BPH and untreated cancer were analysed, but no correlation was demonstrable between PSA and UTF when cancer patients alone were evaluated. It was concluded that UTF levels are elevated in untreated prostate cancer and reflect bone scan status. In patients with bone scan positive disease UTF also reflects disease activity and may therefore be a useful disease marker in prostate cancer.

Clinical presentation and investigation of patients proceeding to isotope lung scanning for suspected pulmonary embolism

The presenting features of 250 consecutive patients who underwent a ventilation/perfusion lung scan for suspected pulmonary embolus (PE) were analysed. Ninety-six patients had lung scans highly suggestive of PE, with one or more unmatched segmental perfusion defects (scan positive), 86 had low probability scans (scan negative) and 68 an indeterminate scan. Scan positive patients were more likely to have a PaO2 of less than 10.7 kPa, an elevated P(A-a)O2 and an abnormal chest X-ray compared with scan negative patients but these measurements were of poor specificity. Furthermore, scan-positive patients had a higher incidence of lung disease. Localized chest wall tenderness was more common in scan-positive patients, occurring in 9% of patients, but there were no other significant differences in individual symptoms, signs or electrocardiographic findings between scan-positive and scan-negative patients. The diagnosis of PE should not be made on clinical grounds alone and all patients suspected of having a PE should at least undergo isotope lung scanning.

Abnormal Thallium 201 Scintigraphy during Low-Dose Vasopressin Infusions

Thallium 201 (201Tl) myocardial scans were obtained in 16 patients just prior to the discontinuation of a vasopressin infusion (.1 to .2 units/min) administered for the treatment of upper gastrointestinal bleeding. Repeat scintigraphy was performed two to three hours after the vasopressin was stopped. Eleven of the 16 patients (69 percent) demonstrated areas of decreased myocardial 201Tl uptake that resolved after the infusion was stopped. Heart rate-blood pressure product was significantly lower at the time of the second scan. Autopsies were secured in three of 11 scan-positive patients: one had severe coronary artery obstruction, one nonsignificant disease, and another had normal coronary arteries. Vasopressin, even at low doses, can induce abnormalities in myocardial perfusion that are probably mediated by a direct effect on the coronary circulation. They are usually not detectable by routine monitoring techniques and conceivably form the basis for the cardiovascular morbidity associated with the use of this agent.

An Evaluation of 99mTc-Labeled Red Blood Cell Scintigraphy for the Detection and Localization of Gastrointestinal Bleeding Sites

99mTechnetium-labeled red blood cell scintigraphy was performed upon 39 patients with clinical evidence for acute lower gastrointestinal bleeding from an unknown source. Seventeen of 39 patients (44%) had a scan became positive 6 or more h after injection, consistent with intermittent bleeding, in 8 of 17 patients (47%). In the 11 patients in whom the bleeding site was definitely identified by arteriography, surgery, or colonoscopy, scintigraphy correctly localized the bleeding site in 10 of 11 patients (91%). Four of 11 patients (36%) had an active bleeding site identified by arteriography. Ten of 17 patients (58%) with a positive scan required either gelfoam embolization (4 patients) or surgery (6 patients) to control the bleeding, whereas only 1 of 22 patients (5%) required surgery when the scan was negative. Six deaths occurred in the scan-positive patients compared with no deaths in the scan-negative patients. None of the 8 patients who had arteriography and no active bleeding site by scintigraphy had arteriographically demonstrable active bleeding. Scintigraphy provides a reliable noninvasive test to screen patients in whom arteriography is being considered to localize active bleeding sites. If the arteriogram is negative, the scintigraphic findings alone may guide the surgical or arteriographic intervention. In addition, scintigraphy identifies two patient populations which have considerably different morbidity and mortality.

AN ANALYSIS OF BONE SCINTIGRAPHY IN EARLY (OPERABBEL) BREST CANCER

A retrospecitve review of the results of boen scintigrams (scans), perfromed on 85 consecutive patients with operable breast cancer at the Royal Melbourne Hospital, revealed a true positive scan rate of 10%. No significant association was found between positive scans and either tumour size or clinical status of axillary nodes; however, a statistically significant association was demonstrated between positive scans and the presence of pathologically involved axillary nodes. Scans were positive in nine out of 54 patients (17%) with involved nodes and in eight out of 21 (38%) with four or more involved nodes, but in none out of 24 patients with negative nodes. (P is less than 0.05). Of the 85 patients, 29 had scans showing increased uptake; 13 of these had benign disease demonstrated radiologically, and technical or reporting error accounted for another seven. This left nine true positives. Clinical metastases subsequently developed in eight of the nine scan-positive patients (89%), but in only 17 of the 76 scan-negative patients (22%), within the follow-up period (mean 16 months). (P is less than 0.0005.) Seven of the eight scan-positive patients who developed clinically obvious metastases had four or more involved axillary lymph nodes. It is concluded that the finding of an unequivocally positive bone scan in a patient with clinically “early” breast cancer strongly suggests the presence of metastases and must be considered in planning appropriate treatment. Furthermore, although the bone scan is unlikely to be positive if nodes are histologically negative, it can be an important staging investigation and prognostic index for patients who are found to be node-positive, especially if a large number of lymph nodes are involved.

The value of preliminary bone scanning in staging and assessing the prognosis of breast cancer.

Preliminary bone scans have been performed on all patients with early breast cancer. The incidence of positive scans has been recorded and several factors determining scan status have been enumerated. Particular attention has been focused on the natrual history of scan positive and scan negative patients. Eighteen per cent of stage I and 41 per cent of stage II cancers had positive bone scans. Scan results were correlated with age, menopausal status, tumour position, tumour size and histological node status. Postmenopausal patients were found to have a significantly increased risk of being scan positive (P less than 0-01). Follow-up studies have confirmed that the lesions demonstrated by scanning actually represent metastatic foci. At 18 months 85-7 per cent of scan positive patients had evidence of disseminated disease compared with only 11-4 per cent of scan negative patients (P less than 0-01). Clinically overt advanced disease evolves from positive scan lesions. It is clear that a significant percentage of patients felt to have early breast cancer already have widely disseminated disease at the initial presentation. The biological significance of bone scan lesions makes a sensitive screening test for dissemination an essential part of the preliminary assessment of patients with breast cancer. Bone scans provide an excellent prognostic index at a patient's initial assessment.