Mudalsha Ravina

Tumor thrombus: ancillary findings on FDG PET/CT in an oncologic population.

Purpose Thrombosis in cancer may manifest itself as venous thromboembolic disease or tumor thrombosis (TT). We present our experience with incidentally detected TT on FDG PET/CT in 21 oncologic patients. Patients and Methods We retrospectively reviewed all FDG PET/CT examinations during a 5-year period at the Army Hospital Research and Referral in New Delhi, India, and included all oncology cases with FDG-avid thrombosis in the report. The diagnosis of TT was based on FDG-avid solid masses inside the vessels in patients with known malignancy. The SUVmax was calculated. Results Twenty-one patients were included; the most common malignancies were renal cell carcinoma (n = 6), hepatocellular carcinoma (n = 3), and lung cancer (n = 3). Indication for the scan was initial staging (n = 15) and suspected recurrence (n = 6). Several vessels were affected, the most common was the inferior vena cava (n = 14), but most other major branches of the venous vasculature was represented, and some patients had thrombi in several vessels. FDG uptake was linear in 7 patients, linear with a dilated vessel in 6 patients, and focal in 7 patients. The mean SUVmax of the primary tumors was 10.3 (range, 2.6–31.2; median, 6.9), and the mean SUVmax of the thrombi was 7.85 (range, 1.7–23.2; median, 6.1). All but 2 patients had additional FDG-avid foci besides the thrombus. Conclusions This study supports results from other smaller studies regarding the usefulness of FDG PET/CT in TT and corroborates the hypothesis that the SUVmax and the patterns of FDG uptake can be helpful for differentiating BT from TT in oncological patients.

Imaging in extrapulmonary tuberculosis

Tuberculosis (TB) remains a major global public health problem, with 1.5 million deaths annually worldwide. One in five cases of TB present as extrapulmonary TB (EPTB), posing major diagnostic and management challenges. Mycobacterium tuberculosis adapts to a quiescent physiological state and is notable for its complex interaction with the host, producing poorly understood disease states ranging from latent infection to active clinical disease. New tools in the diagnostic armamentarium are urgently required for the rapid diagnosis of TB and monitoring of TB treatments, and to gain new insights into pathogenesis. The typical and atypical imaging features of EPTB are reviewed herein, and the roles of several imaging modalities for the diagnosis and management of EPTB are discussed.

Oncogenic osteomalacia: role of Ga-68 DOTANOC PET/CT scan in identifying the culprit lesion and its management

OBJECTIVE The aim of this study was to evaluate the role of 68Ga-DOTANOC positron emission tomography (PET)/CT scan in localization of culprit lesion for biopsy and required intervention [surgical excision/radiofrequency ablation (RFA)] in patients with long-standing oncogenic osteomalacia (OOM)/tumour-induced osteomalacia. METHODS 17 patients (8 males and 9 females) underwent 68Ga-DOTANOC PET/CT scan. The patients referred with clinical and biochemical evidence of hypophosphatemia and raised fibroblast growth factor-23. Qualitative and semi-quantitative parameters were used to identify culprit lesions. RESULTS 68Ga-DOTANOC PET/CT scan revealed 52 lesions in 17 patients, and 37/52 of these lesions were tracer avid. 26/37 lesions were non-specific focal tracer-avid skeletal lesions (fractures or degenerative changes). 11/37 tracer-avid skeletal lesions present in 9 patients (3 lesions in 1 patient and 1 each in rest of the 8 patients) were highly suspicious for culprit lesions in view of high maximum standardized uptake value (SUVmax) (range 1.5-15.4; mean 7.0 ± 4.6), lesion size (0.9-5.0 cm; mean 3.3 ± 1.5) and associated soft-tissue component. During subsequent imaging with CT/MRI, 7/9 patients showed concordant lesions which were excised or biopsied and histopathologically verified as phosphaturic mesenchymal tumours. Surgical excision was resorted to in most of the detected lesions, and RFA was performed in one patient. CONCLUSION There is some overlap in SUVmax between fracture-/bone-associated lesions and culprit lesions with a tendency of most non-culprit lesions to have lower SUVmax and no associated soft-tissue component. In such scenario, intensely tracer-avid, larger non-fracture lesions with soft-tissue component may lead to identification of culprit lesion among multiple lesions. Following detection of culprit lesion, surgical removal is the best treatment. RFA is alternative to surgery in cases where surgery is not possible owing to osteopenia/poor bone health. Advances in knowledge: The main challenge in patients of long-standing OOM is the presence of multiple skeletal lesions (both tumour- or tracer-avid fractures), and it is confusing to identify culprit lesion. This was noted in our study with 68Ga-DOTANOC and has not been mentioned in studies performed with 68Ga-DOTATATE/TOC PET/CT. In such scenario, 68Ga-DOTANOC PET/CT needs to be reviewed and read thoroughly to localize the culprit lesion out of the multiple tracer-avid lesions.

Role of 18F-FDG PET in demonstrating disease burden in patients with tuberculous meningitis

OBJECTIVE To study the role of 18fluoro-deoxy glucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan in documenting the disease burden in patients with tuberculous meningitis (TBM), and compare these findings with conventional imaging and magnetic resonance imaging (MRI). SUBJECTS AND METHODS Ten patients with definite TBM were prospectively recruited. The severity of TBM was graded into stage I to III. The patients were subjected to whole body 18F-FDG PET/CT imaging and MRI brain. 18F-FDG PET/CT results were compared with the findings of brain MRI and other convectional imaging modalities (ultrasonography of abdomen and chest radiograph). RESULTS There were ten patients with TBM whose median age was 27 (14-55) years, and the median duration of illness was 4 (0.5-8.0) months. Two patients were in stage I, six in stage II, and two in stage III meningitis. 18F-FDG PET/CT confirmed the cranial MRI findings in six patients, revealed additional brain lesion in one and did not detect the existing MRI lesions in three patients. 18F-FDG PET/CT however detected additional lesions in vertebrae, spinal cord and lymph nodes which were not seen on the conventional imaging. CONCLUSION 18F-FDG PET/CT has a complementary role to MRI for detection of cranial lesions and is more sensitive in detecting the extra cranial tuberculosis burden in the patients with TBM.

Role of cholescintigraphy with single-photon emission computerized tomography-computed tomography in detecting bronchobiliary fistula: Unusual complication of a common disease

Bronchobiliary fistula (BFF) is an abnormal communication between the biliary tree and airway. A patient usually presents with cough and bilioptysis, and at times, it poses diagnostic and therapeutic challenge. This case demonstrates the usefulness of cholescintigraphy with single-photon emission computerized tomography in diagnosing BFF in case of hydatid cyst of the liver.

Thoraco-Abdominal duplication cyst- role tc-99m pertechnetate spect-ct scintigraphy in localising ectopic gastric mucosa

Thoraco-abdominal duplication cyst, a congenital malformation of the posterior primitive foregut rarely presents with anaemia. Ectopic gastric mucosa is seen in around 20%-30% of the enteric duplication cysts. We report the scintigraphic findings of one such case which helped in final diagnosis and management of the patient.

Hypothyroidism in mccune–albright syndrome and role of bone scan in management of fibrous dysplasia: An unusual case scenario with review of literature

The McCune–Albright syndrome (MAS) is a triad of café-au-lait skin pigmentation, precocious puberty (PP), and polyostotic fibrous dysplasia of bone (FD). In general, FD seems to be the most common component of MAS but very rarely precocious puberty can be found in association with café-au-lait skin pigmentation in the absence of FD (about 1% of the cases). Therefore, a more clinically relevant definition of MAS is fibrous dysplasia of bone (FD) and at least one of the typical hyperfunctioning endocrinopathy and/or café-au-lait spots, with almost any combination possible. Bone scan can be the modality of choice to look for bone disease burden of fibrous dysplasia in most patients of MAS and may change the management accordingly. Most of the cases of MAS reported worldwide are associated with hyperthyroidism, up to best of our knowledge on the basis of literature search in pubmed and Google; no case was reported with hypothyroidism. Herein, we report a 12-year-old girl diagnosed with MAS and associated hypothyroidism.We have also reviewed the MAS related literature.

Gallbladder visualization on Tc-99m-labeled red cell scintigraphy: A rare finding with an emphasis on role of single-photon emission computed tomography/computed tomography

Tc-99m labeled red blood cell (RBC) scintigraphy is one of the most sensitive tests to diagnose occult gastrointestinal (GI) bleed. Visualization of gallbladder is a rare finding in this study. Most of the previously reported cases with similar false-positive finding were associated chronic renal failure, anemia, and received multiple blood transfusions. Thus, while interpreting GI bleed scan, a thorough clinical history is of utmost importance to avoid any false-positive findings. Here, we report a case of gallbladder visualization in 99mTc-RBC scintigraphy confirmed by single-photon emission computed tomography/computed tomography in a patient with chronic renal failure and anemia with failed renal transplant within 3 months.

An interesting case of unknown primary presenting as heel pain

A 64‐year‐old male presented with heel pain that had been present for past 3 months. An excision of the calcaneal lesion with bone cementing was performed which on histopathology revealed metastatic squamous cell carcinoma. Subsequent F‐18fluorodeoxyglucose positron emission tomography/computerized tomography revealed increased tracer uptake in the left hemithorax, mediastinum on the right side, right scapula, right clavicle, pelvis and left distal extremity [Figure 1A] maximum intensity projection images]. Fused PET‐CT with sagittal reformats [Figure 1B] of the left distal extremity reveals FDG avid skeletal lesions involving the remaining unexcised calcaneum, talus, navicular, cuneiform and proximal An Interesting Case of Unknown Primary Presenting as Heel Pain