Bladder paragangliomas: a pictorial review.

Bladder paragangliomas (bPGL) are rare neuroendocrine tumors arising from the sympathetic paraganglia present in the bladder wall. Bladder PGLs are typically submucosal or intramural but when subserosal may not be readily visible at cystoscopy. The average size at presentation is 3.9 cm (range 1.0-9.1 cm). When small, bPGL are usually spherical, well-marginated and homogeneous. Larger bPGL are typically more complex with peri- and intra-tumoral neovascularity and central necrosis. On ultrasound, increased color Doppler signal is typical. The increased soft tissue resolution of MRI enables localization of bPGL within the bladder wall more accurately than CT. Restricted diffusion and avid contrast enhancement help differentiate small bPGLs from leiomyomas, which have similar appearances on ultrasound and CT. Nuclear medicine techniques identify bPGLs and their metastases with high specificity, 68Ga-DOTATATE PET/CT having largely replaced 123I-mIBG SPECT/CT as the first line functional investigation. Imaging is essential to aid surgical planning, as endoscopic resection is often not possible or incomplete due to tumor location. For patients with advanced disease, 68Ga-DOTATATE PET/CT and 123I-mIBG SPECT/CT assess suitability for peptide receptor radionuclide therapy. Up to 63% of bPGL patients have a germline mutation, most commonly in the SDHB subunit gene, increasing their risk of developing pheochromocytomas and further paragangliomas; lifelong annual biochemical and periodic imaging screening from skull base to pelvis is therefore recommended.

Homelessness in mental illness: Opportunities & prospects in the Indian context.

Homelessness is considered a serious public health concern. Bidirectional relationship has been established between homelessness and mental illness by research studies and its association with compromised well-being, poor quality of life and low productivity. Recent legislative enactments in India have necessitated on the part of the state to address issues related to the rights of persons with mental illness including shelter and housing. Therefore, it becomes imperative to discuss opportunities and prospects in India towards rehabilitating homeless mentally ill in context of existing programs, policies and legislations.

Radionuclide bone SPECT/CT in the evaluation of knee pain: comparing two-phase bone scintigraphy, SPECT and SPECT/CT.

OBJECTIVE:: To assess the role of single photon emission computed tomography (SPECT/CT) in the evaluation of knee pain as well as comparing bone scintigraphy (BS), SPECT and SPECT/CT, and assessing the incremental value of SPECT/CT. METHODS:: BS, SPECT and SPECT/CT of patients with knee pain (39 patients, 65 knees, 105 lesions) were directly compared for lesion detection, localisation and characterisation using lesion-based, knee-based and patient-based analyses in this retrospective study. RESULTS:: Lesion detection: BS (91.4%), SPECT (100%) and SPECT/CT (100%). SPECT and SPECT/CT detected significantly more lesions than BS (p < 0.05). Lesion localisation: BS (38.5-41.7%), SPECT (74.4-83.3%) and SPECT/CT (100%). SPECT localised significantly more lesions than BS; SPECT/CT localised significantly more lesions than BS and SPECT (p < 0.01). Lesion characterisation: BS (23.0-52.1%), SPECT (30.8-56.2%) and SPECT/CT (92.3-96.9%). SPECT/CT characterised significantly more lesions than BS and SPECT (p < 0.01). Characterisation of non-arthropathy lesions: BS (6.25%), SPECT (12.5%) and SPECT/CT (93.75%). SPECT/CT characterised significantly more non-arthropathy lesions than BS and SPECT (p < 0.01). BS and SPECT detected none, while SPECT/CT detected 100% of the causative/contributing/associated conditions that co-existed with osteoarthritis. Therefore SPECT/CT detected not only just osteoarthritis but also the causative/contributing/associated conditions. CONCLUSION:: SPECT/CT added significant incremental value to BS and SPECT irrespective of whether evaluation was lesion-based, knee-based or patient-based. SPECT/CT represents a viable alternative to MRI, and addition of SPECT/CT to BS and SPECT should be considered in the evaluation of knee pain. ADVANCES IN KNOWLEDGE:: Incremental value of bone SPECT/CT in knee pain.

Incidence and Significance of Incidental Focal Thyroid Uptake on (18)F-FDG PET Study in a Large Patient Cohort: Retrospective Single-Centre Experience in the United Kingdom.

OBJECTIVE: To assess the prevalence and pathological nature of incidental focal thyroid uptake on (18)F-FDG (2-[(18)F]-fluoro-2-deoxy-D-glucose) PET (positron emission tomography) and examine the role of the maximum standardised uptake value (SUVmax) to differentiate benign from malignant thyroid pathology. MATERIAL AND METHODS: (18)F-FDG PET reports were retrospectively reviewed. Incidental focal tracer uptake in the thyroid was noted in 147 patients (0.5%). Patients with known primary thyroid malignancy were excluded. The final diagnosis was made following ultrasonography of the neck, fine-needle aspiration cytology (FNAC) or histopathology of the surgically resected specimen where surgery was indicated. A Mann-Whitney U test was used to compare the SUVmax of benign and malignant thyroid pathology. Receiver operating characteristic (ROC) analysis was performed to identify an SUVmax cutoff in differentiating benign from malignant pathology. RESULTS: A final diagnosis was achieved in 47/147 (32%) of the patients. The diagnoses included benign lesions in 36 patients and malignancy in 9 patients. In 2 patients, FNAC demonstrated indeterminate follicular lesions; however, surgical excision was not performed. There was a highly significant difference in the mean SUVmax of malignant focal thyroid uptake (15.7 ± 5.9) compared to that of benign lesions (7.1 ± 6.8) with a p value of 0.000123. An SUVmax of 9.1 achieved a sensitivity of 81.6%, specificity of 100% and area under the curve of 0.915 in the ROC analysis differentiating benign from malignant disease. CONCLUSION: The malignancy potential of incidental focal thyroid uptake remains high and warrants prompt and appropriate follow-up by the clinician. The SUVmax may aid in further characterisation of the lesion and its management.

Value of SPECT/CT in the evaluation of knee pain.

Bone scintigraphy (BS) has a good sensitivity but limited specificity. Moreover, planar imaging limits localization of lesion especially of overlapping structures in close proximity. SPECT allows tomographic imaging, resulting in better localization and characterization of the lesion. Addition of CT to SPECT in hybrid SPECT/CT further improves the precision of localization and accuracy of characterization of the lesion. Combining functional and anatomical imaging is complementary with improved sensitivity, specificity, and diagnostic confidence. These advantages of SPECT/CT are illustrated by 3 cases where diagnostic confidence was higher with SPECT/CT compared to BS or CT alone, highlighting the incremental value of SPECT/CT in assessing knee pain.

Can (18)F-FDG PET/CT reliably assess response to primary treatment of head and neck cancer?

INTRODUCTION: Where chemoradiotherapy or radiotherapy alone with curative intent is used as the primary treatment of locally advanced head and neck cancers, salvage surgery may offer a second chance of cure in the face of recurrent or residual disease. Early detection of recurrent or residual disease is therefore the key to facilitating timely and efficacious salvage surgery. CT and MRI can be difficult to interpret in the posttreatment neck. Functional imaging, such as F-FDG PET/CT, has the potential to improve restaging accuracy. The aim of our study was to assess the efficacy of F-FDG PET/CT performed 3 months following primary treatment of head and neck cancer. METHODS: We retrospectively reviewed 35 patients with head and neck squamous cell cancer (mean age, 61 years; 28 male patients) who underwent F-FDG PET/CT imaging at 3 months following primary treatment, which included chemoradiotherapy (n = 31) or radiotherapy alone (n = 4). Patient follow-up was available for at least 12 months (range, 12-48 months; median, 36 months). Scans were categorized as true positive, true negative, false positive, and false negative based on clinicoradiological follow-up and histology. RESULTS: Twenty patients had negative scans with no recurrence during the follow-up period, and 3 had false-negative scans with recurrent disease at 5, 8, and 12 months. Eleven patients had true-positive scans, confirmed histologically in all, and there was 1 false-positive scan giving a sensitivity of 79%, specificity of 96%, positive predictive value of 92%, negative predictive value of 87%, and overall accuracy of 89%. CONCLUSIONS: F-FDG PET/CT is an accurate method for assessing response after primary locally advanced head and neck cancer treatment. Although false-positive scans are rare, a few patients will have a relapse after a negative scan, and so continued close follow-up is required.

Heterotrophic ossification in a patient suspected of having osteomyelitis: additional value of SPECT/CT.

A 46-year-old man, with a history of bilateral amputations, presented with a long-standing chronic nonhealing wound at the left below-knee amputation, which was sustained after a crush injury. The patient was referred for a bone scan to exclude osteomyelitis of the left stump. The bone scan showed increased uptake in the left below-knee amputation stump, raising the possibility of an infection. However, SPECT/CT of this area confirmed the uptake to correspond to the heterotrophic ossification of the left below-knee stump and no evidence of osteomyelitis.