Precise Localization of Urine Leak After Renal Transplantation on Radionuclide Renography: Added Value of the Unclamped Drainage Tube and SPECT-CT.

Identifying and localizing the site of post-renal transplantation urine leaks is important for patient management and treatment planning. Renal scintigraphy is a proven modality for confirming urine leaks after complicated post-renal transplantation. Routinely, renogram studies are performed with a clamped extraperitoneal drain. This results in the spread of radioactivity in the abdominal region, which makes localization of the leak site difficult in the planar images. Here we are trying to give an insight into minimalizing the accumulated urine volume by an unclamped extraperitoneal drain in order to precisely localize the site of the leak.

Synchronous Squamous Cell Carcinoma of Rectum and Anal Canal Detected by FDG PET/CT-A Rare Entity.

ABSTRACT: Squamous cell carcinoma is the most common malignancy of the anal canal, and FDG PET/CT is recommended in its nodal staging, radiotherapy planning, and response assessment. We share an interesting case of dual primary malignancy of the anal canal and rectum, which was detected by 18 F-FDG PET/CT and confirmed on histopathology as synchronous squamous cell carcinoma.

FDG PET/CT in Dressler Syndrome.

ABSTRACT: Nuclear imaging has paramount role in the evaluation of 4I (infective, inflammatory, innervation, infiltrative) cardiac diseases. We present a case of persistent pyrexia post-percutaneous transluminal coronary angioplasty with a history of inferior wall myocardial infarction 2 months back. Repeat coronary angiogram revealed that Right Coronary Artery (RCA) thrombus and IV antibiotics were started in suspicion of coronary stent infection. 18 F-FDG PET/CT revealed no hypermetabolism along RCA stent, with uptake along pericardium and inferior wall. 99m Tc-MIBI myocardial perfusion study showed perfusion defect in RCA territory corresponding to hibernating viable myocardium. Eventually patient was diagnosed with Dressler syndrome. Thus, molecular imaging helped in narrowing differentials in post cardiac intervention pyrexia and precise diagnosis.

Gangliocytic Paraganglioma of the Duodenum: A Masquerader.

Background: Gangliocytic paraganglioma (GP) is a rare tumor that most commonly arises from the duodenum and is characterized pathologically by 3 cell types: epithelioid, spindle, and ganglion cells. GP is often difficult to differentiate from a neuroendocrine tumor on the basis of preoperative imaging, and the diagnosis is based on final histopathologic and immunohistochemical analysis. Case Report: We report the case of a 28-year-old male who presented with pain in the abdomen, bilious vomiting, and weight loss. Imaging showed a mass involving the first and second part of the duodenum that was likely a neuroendocrine or gastrointestinal stromal tumor. He underwent robotic-assisted pancreatoduodenectomy, and the final pathology report identified GP with lymph node metastasis. The patient was doing well at 1-year follow-up. Conclusion: GP is often a histologic surprise as most cases are diagnosed in postoperative histopathology. While GP has a more benign course than a neuroendocrine tumor, radical surgical resection is warranted in cases of diagnostic dilemma, suspicion of malignancy, or lymph node metastasis. Robotic-assisted pancreatoduodenectomy is a feasible option.

18F-fluoro-2-deoxy-2-d-glucose PET-CT (FDG PET-CT) in staging of high-risk renal and urothelial bladder cancers (COPPER-T) trial protocol.

Background and Study Design: Role of 18F-fluoro-2-deoxy-2-d-glucose positron emission tomography-computed tomography (FDG PET-CT) in evaluation of renal cell cancers (RCC) and urinary bladder cancers is not standardized, and the COPPER-T trial, which is a single centre prospective randomized study, was designed to compare it with conventional imaging for staging of clinically localized high risk RCC and urinary bladder carcinoma (Stage T2 and above). Patients and Methods: There will be two subgroups of patients: RCC and urinary bladder carcinoma. In each of these, the patients will be randomized to either Arm A or Arm B. In each of the arms, each patient will be subjected to diagnostic imaging by FDG PET-CT. The CT scan will be a contrast-enhanced scan like that in conventional staging. A radiologist and nuclear medicine specialist will report the scan independently. The radiologist will not have access to the PET scan sequences and will only review the contrast-enhanced computed tomography (CECT) images. In Arm A, the report of the conventional imaging modality, that is, CECT and bone scan if done, will be reviewed first by the clinician, and based on this report, a management plan will be made. Then, the PET-CT report will be reviewed, and change in the management plan will be noted. New findings or equivocal findings if any in the PET-CT report would be noted. In Arm B, the report of the PET-CT report will be reviewed first by the clinicians, and a management plan will be made. Then, the CECT and/or bone scan reports will be reviewed, and any change in the management plan will be noted. Outcome and Significance: Final analysis of the data after completion of the trial will help in clarifying the role of FDG PET-CT in high risk RCC and transitional cell carcinoma (TCC) of the bladder, its diagnostic accuracy compared with conventional imaging and the impact of using it on patient management.

Sub-Diaphragmatic Haemangioma Suspected on F-18 Fdg Pet/Ct Confirmed by Rbc Scintigraphy.

A 53-year-old woman presented with left submandibular gland carcinoma. Contrast-enhanced computerized tomography done for staging revealed suspicious metastatic omental deposit adjacent to left hemi-diaphragm apart from primary and cervical nodal metastasis. Staging F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography showed high FDG uptake in the primary and metastatic left cervical lymph nodes. However, no FDG uptake was seen in left sub-diaphragmatic mass. Known vascular malformations sites in the left posterior triangle of the neck and liver hemangiomas also showed no uptake. This pattern of uptake raised a suspicion of multiple vascular malformations. Tc-99 m red blood cell scintigraphy was done which confirmed the nature of subdiaphragmatic lesion as haemangioma.

Unusual Case of Neuroblastoma with Only Growth Plate Metastasis in Bilateral Lower Limbs on Metaiodobenzylguanidine Scintigraphy.

Neuroblastoma is the most common extracranial solid tumor in childhood developing from primitive neural crest cells. I-131-metaiodobenzylguanidine (MIBG) a norepinephrine analog is highly sensitive and specific to identify primary and distant metastatic sites. We report the case of a 2-year-old female child with progressively increasing abdominal distention. Computed tomography (CT) revealed a large mass lesion involving the right suprarenal region with no hepatic or lymph node metastasis. No obvious skeletal abnormality was detected on the whole-body skeletal survey and Tc-99 m-methylene diphosphonate bone scan to suggest metastasis. I-131-MIBG scintigraphy with single-photon emission computerized tomography-CT showed MIBG-avid primary tumor in a suprarenal location with bilateral lower limbs growth plate as the only site of metastasis.

Role of 99mTc sulphur colloid lymphoscintigraphy in a rare case of chylothorax and lymphocele formation post esophageal duplication cyst excision.

We report a rare case of chylothorax with lymphocele formation post esophageal duplication cyst (EDC) excision in a 2 year old male child. Patient developed chylothorax after excision of EDC. Pleural fluid cytology showed increased triglycerides and cholesterol levels. Filtered Tc-99m Sulphur colloid lymphoscintigraphy showed abnormal radiotracer uptake in the lower thoracic region on right side corresponding to lymphocele on SPECT-CT images with possible site of leak medially. In addition, Tc-99m pertechnetate scan was done to rule out possibility of residual duplication cyst revealed no abnormality. Patient underwent open and en-masse ligation of the duct. Patient recovered completely post-surgery. This case highlights the importance of lymphoscintigraphy with SPECT-CT in the evaluation of patients with post-operative complications of chylothorax with detection of site of chyle leak.

Optimization of Ordered Subset Expectation Maximization Parameters for Image Reconstruction in Tc-99m Methoxyisobutylisonitrile Myocardial Perfusion SPECT and Comparison with Corresponding Filtered Back Projection-Reconstructed Images.

PURPOSE OF THE STUDY: To establish the most appropriate ordered subset expectation maximization (OSEM) parameters for image reconstruction in Tc-99m methoxyisobutylisonitrile (MIBI) myocardial perfusion SPECT (MPS) and comparison with corresponding filtered back projection (FBP)-reconstructed images. METHODS: A total of 99 stress-rest MPS studies (47 normal and 52 abnormal) were retrospectively analyzed using 16 different combinations of iterations and subsets. Images were reconstructed both with and without postreconstruction Butterworth filter (cutoff frequency and order for stress: 0.4 and 10 and for rest: 0.52 and 5, respectively) for each combination. A total of 3168 images were evaluated qualitatively by two nuclear medicine physicians on a scoring scale of 1-4. Best visual quality image iteration-subset combination was determined for each patient both with and without Butterworth filter and was further compared with FBP-reconstructed image. The interobserver agreement was obtained using kappa statistics. RESULTS: The best quality images were obtained using a combination of four iterations and six subsets for both with and without Butterworth filter. The value of kappa for interobserver agreement for OSEM images with Butterworth filter was 0.570 and for OSEM images without Butterworth filter was 0.857. On comparison, FBP images were better than OSEM-reconstructed images without Butterworth filter (P < 0.0001 calculated using Fisher's exact test) with substantial agreement (kappa = 0.628). However, OSEM-reconstructed images with Butterworth filter were better than FBP images and showed moderate agreement (kappa = 0.486). CONCLUSION: The most appropriate OSEM reconstruction parameter in Tc-99m MIBI MPS is 4-iteration and 6-subset combination. FBP-reconstructed images were better than the images reconstructed with OSEM without postreconstruction Butterworth filter. However, OSEM-reconstructed image with Butterworth filter was better than FBP images.

Comparison between Two-sample Method with 99mTc-diethylenetriaminepentaacetic acid, Gates' Method and Estimated Glomerular Filtration Rate Values by Formula Based Methods in Healthy Kidney Donor Population.

PURPOSE OF THE STUDY: Glomerular filtration rate (GFR) is the most important parameter for the assessment of renal function. GFR by plasma sampling technique is considered accurate in the selection of donors for renal transplantation. Estimated GFR (eGFR) calculations using Gates' method and Modification of Diet in Renal Disease (MDRD) and Cockcroft-Gault (CG) equations are simple methods but have not been validated in the Indian population. Hence, we aimed to assess the correlation between these three techniques. MATERIALS AND METHODS: The plasma sampling technique was done using two samples at 60 and 180 min after injection of 1 mCi (37MBq) 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) in 66 healthy donors. Age, sex, height, weight, and plasma creatinine were recorded. Normalized GFR (nGFR) by two-sample method and eGFR (for Gates', MDRD, and CG) values were calculated using formulae. RESULTS: There were 14 male and 52 female donors. Mean age was 46.56 ± 12.88 years (24-69 years). Mean height was 153.74 ± 8.35 cm, whereas mean weight was 56.97 ± 11.88 kg. Mean nGFR value was 80.4 for two-sample method while mean eGFR value for Gates', CG, and MDRD were 83.3, 89.36, and 97.47 ml/min/1.73 m2 (eligibility value at our institution = 70), respectively. While the correlation between nGFR and eGFR CG and MDRD was weak moderate (correlation coefficient = 0.5), nGFR and eGFR Gates' had a moderate correlation (0.686). Mean total bias for eGFR Gates', CG, and MDRD were 2.87, 8.93, and 17.0, respectively. P30 of eGFR Gates', CG and MDRD were 60.6%, 57.6%, and 62.1%, respectively. CONCLUSIONS: Due to the large variability in eGFR Gates', CG and MDRD, nGFR estimation using the plasma sampling technique with 99mTc-DTPA appears necessary while screening healthy donors for renal transplantation.

Prevalence of ECG changes during adenosine stress and its association with perfusion defect on myocardial perfusion scintigraphy.

OBJECTIVE: Myocardial perfusion scintigraphy (MPS) is a valuable, noninvasive imaging modality in the evaluation of patients with coronary artery disease. Adenosine stress may occasionally be associated with ECG changes. This study evaluated the strength of association between adenosine stress-related ECG changes and perfusion defects on Tc-MPS. PATIENTS AND METHODS: 117 (mean age: 61.25±9.27 years; sex: men 87, women 30) patients with known/suspected coronary artery disease underwent adenosine stress MPS. ECG was monitored continuously during adenosine stress for ST-depression. On the basis of the summed difference score, reversible perfusion defects were categorized as follows: normal: less than 4, mild: 4-8, moderate: 9-13, and severe: more than 13. RESULTS: ST-depression was observed in 27/117 (23.1%) and reversible perfusion defects were observed in 18/27 (66.66%) patients. 2/27, 6/27, and 10/27 patients had mild, moderate, and severe ischemia, respectively. 9/27 patients had normal perfusion. ECG changes and perfusion defects showed a moderate strength of association (correlation coefficient r=0.35, P=0.006). The sensitivity, specificity, positive predictive value, and negative predictive value of ECG findings for prediction of ischemia were 35.29, 86.36, 67.67, and 63.33%, respectively. CONCLUSION: ECG changes during adenosine stress are not uncommon. It shows a moderate strength of association with reversible perfusion defects. ECG changes during adenosine merit critical evaluation of MPS findings.

Comparison of 18F-Fluorocholine Positron Emission Tomography/Computed Tomography and Four-dimensional Computed Tomography in the Preoperative Localization of Parathyroid Adenomas-initial Results.

OBJECTIVE: We aimed to compare the diagnostic accuracy of 18F-Fluorocholine (FCH)-positron emission tomography/computed tomography (PET/CT) and four-dimensional (4D)- CT in detection and localization of eutopic and ectopic parathyroid adenoma (PA) in patients with hyperparathyroidism. MATERIALS AND METHODS: Five patients with primary hyperparathyroidism underwent FCH-PET/CT after 60 min of 185 MBq of intravenous 18F-FCH administration. Images were acquired from head to mediastinum at 3 min per bed position. No intravenous contrast was used. All patients underwent 4D-CT within 2 weeks of the FCH-PET/CT, with a precontrast, post contrast arterial, and venous phase with 75 ml intravenous Iohexol 350 followed by 25 ml saline chase. Histopathology was considered as the gold standard. RESULTS: Both modalities showed 100% concordance in the detection of parathyroid lesions. Both FCH-PET/CT and 4D-CT detected 7 lesions in 5 patients, with 4 patients having a single lesion, and 1 patient having three lesions. Of the 7 reported lesions, 4 were eutopic and 3 were ectopic. No additional lesions were detected by either modality in comparison to the other. All 7 specimens were resected and histopathology showed PA/hyperplasia. CONCLUSION: FCH-PET/CT and 4D-CT are equally efficacious in detection and localization of eutopic and ectopic PA. This may open up the possibility of using FCH-PET/CT in patients with negative conventional imaging who cannot undergo contrast studies.

Unusual Presentation of Rare Cardiac Tumor: The Role of F-18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Primary cardiac tumors are rare with angiosarcoma being the most common among malignant cardiac tumor. We present a case of 30-year-old female patient in whom F-18-fluorodeoxyglucose positron emission tomography/computed tomography demonstrated a necrotic mass in right atrium with multiple fluorodeoxyglucose avid lesions in both upper and lower alveolus, liver, multiple bones, and bilateral lungs. Patient underwent biopsy from gum swelling which revealed metastatic angiosarcoma.

Identification of optimal mask size parameter for noise filtering in 99mTc-methylene diphosphonate bone scintigraphy images.

Tc-methylene diphosphonate (Tc-MDP) bone scintigraphy images have limited number of counts per pixel. A noise filtering method based on local statistics of the image produces better results than a linear filter. However, the mask size has a significant effect on image quality. In this study, we have identified the optimal mask size that yields a good smooth bone scan image. Forty four bone scan images were processed using mask sizes 3, 5, 7, 9, 11, 13, and 15 pixels. The input and processed images were reviewed in two steps. In the first step, the images were inspected and the mask sizes that produced images with significant loss of clinical details in comparison with the input image were excluded. In the second step, the image quality of the 40 sets of images (each set had input image, and its corresponding three processed images with 3, 5, and 7-pixel masks) was assessed by two nuclear medicine physicians. They selected one good smooth image from each set of images. The image quality was also assessed quantitatively with a line profile. Fisher's exact test was used to find statistically significant differences in image quality processed with 5 and 7-pixel mask at a 5% cut-off. A statistically significant difference was found between the image quality processed with 5 and 7-pixel mask at P=0.00528. The identified optimal mask size to produce a good smooth image was found to be 7 pixels. The best mask size for the John-Sen Lee filter was found to be 7×7 pixels, which yielded Tc-methylene diphosphonate bone scan images with the highest acceptable smoothness.

Role of (18)F-FDG PET-CT in Monitoring the Cyclophosphamide Induced Pulmonary Toxicity in Patients with Breast Cancer - 2 Case Reports.

Drug induced pulmonary toxicity is not uncommon with the use of various chemotherapeutic agents. Cyclophosphamide is a widely used chemotherapeutic drug in the treatment of breast cancer. Although rare, lung toxicity has been reported with cyclophosphamide use. Detection of bleomycin induced pulmonary toxicity and pattern of (18)F-fluorodeoxyglucose ((18)F-FDG) uptake in lungs on fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG PET-CT) has been elicited in literature in relation to lymphoma. However, limited data is available regarding the role of (18)F-FDG PET-CT in monitoring drug induced pulmonary toxicity in breast cancer. We here present two cases of cyclophosphamide induced drug toxicity. Interim (18)F-FDG PET-CT demonstrated diffusely increased tracer uptake in bilateral lung fields in both these patients. Subsequently there was resolution of lung uptake on (18)F-FDG PET-CT scan post completion of chemotherapy. These patients did not develop significant respiratory symptoms during chemotherapy treatment and in follow up.

PSMA Expression in Papillary Thyroid Carcinoma: Opening a New Horizon in Management of Thyroid Cancer?

Prostate-specific membrane antigen (PSMA) is a type 2 transmembrane protein highly expressed in prostate cancer cells. We present the case of a 50-year-old man with metastatic papillary carcinoma of the thyroid, with rising thyroglobulin level and negative whole-body radioiodine scan after total thyroidectomy. Considering the limited treatment options available, it was decided to perform Ga-PSMA-HBED-CC PET/CT scan. It revealed intense radiotracer uptake in mediastinal and left supraclavicular lymph nodes, brain metastases, bilateral lung nodules, and skeletal sites. Patient also underwent F-FDG PET/CT. It demonstrated similar findings; however, the number of lesions detected in brain was less compared with Ga-PSMA PET/CT.

Tc-99m TRODAT uptake in an osteoid tumor of clivus.

Tc-99m TRODAT is cocaine analog and binds to the dopamine transporter in vivo. Tc-99m TRODAT single-photon emission computed tomography/computed tomography. (SPECT/CT) is useful for demonstrating presynaptic dopaminergic dysfunction in patients with Parkinsonism. However, few reports have shown extrastriatal uptake of Tc-99m TRODAT. We present the case of a 67-year-old male who underwent Tc-99m TRODAT SPECT/CT for evaluation of Parkinsonism. In addition to tracer binding in the striatum, tracer uptake was noted in an osteoid tumor of the clivus. Integrated SPECT/CT enabled precise localization and characterization of the extrastriatal site of tracer binding and emphasizes the importance of such coincidental findings.

Efficacy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography as a predictor of response in locally advanced non-small-cell carcinoma of the lung.

OBJECTIVE: The study assessed the role of (18)F-fluorodeoxyglucose ((18)F-FDG) Positron emission tomography (PET)/computed tomography (CT) in evaluating the prognostic value of metabolic response for progression-free survival (PFS) and overall survival (OS) in patients with locally advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Thirty patients with locally advanced NSCLC were enrolled in this prospective study and randomly allocated to one of two treatment arms. Arm A (n=15) received two cycles of neoadjuvant chemotherapy [paclitaxel (200 mg/m(2)) and carboplatin (AUC5)] and external beam radiotherapy (60 Gy/30 fractions/6 weeks). Arm B (n=15) received the same neoadjuvant chemotherapy followed by external beam radiotherapy (48 Gy/20 fractions/4 weeks) with concomitant cisplatin 30 mg/m(2) weekly. Patients underwent (18)F-FDG PET/CT at baseline and after 6 weeks of completion of intended treatment. Pretreatment and post-treatment maximum standardized uptake values (SUVmax) were noted. Patients with a reduction of SUVmax more than 50% were considered to be metabolic responders and those with a reduction 50% or less as nonresponders. Median follow-up was 18.98 months. RESULTS: Twenty-one patients completed the intended treatment. The median pretreatment and post-treatment SUVmax values were 14 and 6.4 for arm A and 15.3 and 3.5 for arm B, respectively. Significant decrease in SUVmax was observed in both arms. Metabolic response in arm A and arm B was 50 and 64%, respectively. The median PFS and OS of the responders were 22.31 and 24.73 months and those for nonresponders were 7.83 and 8.26 months, respectively. No significant difference in OS and PFS was observed between responders and nonresponders in the two arms. CONCLUSION: PET/CT distinguishes responders from nonresponders early after completion of chemoradiation in patients with locally advanced NSCLC, but did not provide any prognostic significance.

Utility of (18)F-choline photon emission tomography/computed tomography in the diagnosis of parathyroid adenoma.

Recently, the role of (18)F-choline in the detection of parathyroid adenomas has been reported. At our institution, we are currently studying the role of this tracer in comparison to the standard methoxy-isobutyl-isonitrile.(MIBI) scan with single photon emission tomography/computed tomography. Our initial results show that (18)F-choline is at least as good as 99mTc-MIBI scan. We present here a representative case of a 45-year-old woman with multiple skeletal lytic lesions and a high parathyroid hormone.(PTH) who underwent both these imaging techniques with concordant results, further confirmed by histopathology and postoperative fall in serum PTH levels.

Radioiodine therapy under rhTSH for follicular thyroid carcinoma with sellar metastasis and non-rising TSH.

Metastasis to the pituitary gland/sella turcica is an uncommon complication of thyroid cancer. Treating this condition is a challenge in the setting of pituitary insufficiency due to this lesion, and recombinant human thyroid-stimulating hormone (rhTSH) stimulation becomes critically essential. We present a rare case of an 82-year-old female patient with follicular carcinoma of the thyroid with metastasis to the sella turcica in addition to multiple skeletal and lung metastases. MRI of the brain showed a hypointense suprasellar lesion on T 1 weighted images. The thyroid-stimulating hormone level remained persistently low even 4 weeks after thyroidectomy. A whole-body pertechnetate scan could not localize any abnormal tracer uptake and radioactive iodine uptake was also persistently low. The patient did not have symptoms related to pituitary involvement but TSH and early morning adrenocorticotrophic hormone levels were low. After thorough discussion with the neurosurgeon and radiotherapist, it was decided to start the patient on high-dose radioiodine treatment. Persistently low TSH level was a concern for starting radioiodine therapy. In view of this clinical context, rhTSH stimulation was used to achieve adequate TSH levels prior to radioiodine therapy. Subsequently, the patient was treated with 3.7 GBq (100 mci) of high-dose radioiodine. A post-therapy scan demonstrated radioiodine concentration in the thyroid bed remnant, multiple skeletal lesions and the sellar region. Thus, the use of rhTSH was critical in the management of this patient. It helped in radioiodine treatment by stimulating radioiodine uptake in the remnant and at the metastatic sites.