Left inguinal hernia mimicking metastasis on bone scan.

Inguinal hernia is a well-known entity that usually affects males. The most common herniated organs are parts of the bowel, omentum, or fat. Urinary bladder herniation into the inguinal region is very rare and is often diagnosed during inguinal hernia surgery. This case highlights the importance of additional views and anatomic imaging to accurately interpret the unusual scan findings.

Follicular variant of papillary thyroid carcinoma presenting as a toxic nodule by I-123 scintigraphy.

The risk of malignancy in a "hot" thyroid nodule detected by radioiodine scintigraphy is rare. We report a case of a 63-year-old man with a hyperfunctioning nodule demonstrated by radioiodine scintigraphy and cytology suspicious for follicular variant of papillary thyroid carcinoma (FVPTC). There were no locoregional or distant metastases at initial diagnosis. Histopathologic examination following thyroidectomy confirmed the presence of an encapsulated FVPTC. A year into follow-up, his I-131 whole body scan performed following the withdrawal from exogenous thyroid hormone was negative, whereas his serum thyroglobulin (Tg) levels were intermediate. A subsequent PET/CT scan revealed a small, but stable, metabolically active pretracheal lymph node, which on biopsy was confirmed to be stage III FVPTC. In conclusion, the presence of hyperfunctioning thyroid nodule(s) does not preclude malignancy and, therefore, proper cytohistologic evaluation in such patients may help to exclude a coexistent thyroid carcinoma. Patients treated for localized PTC may benefit from serial PET/CT follow-up in the early detection and management of recurrence or distant metastases.

The role of nuclear imaging in multiple endocrine neoplasia 1 (MEN 1).

Multiple endocrine neoplasia 1 (MEN 1) is a rare genetic disorder classically characterized by a predisposition to tumors of the parathyroid glands, anterior pituitary gland, and pancreatic islet cells (1). In addition to exhibiting these characteristic tumors, MEN 1 patients also have an increased propensity for other tumors such as carcinoids, adrenal adenomas, angiofibromas, and lipomas (1, 2, 3). Although MEN 1 is rare, with a prevalence of approximately 2 per 100,000 people, recognition of this syndrome is extremely important for both patient treatment and evaluation of family members (1, 4). The tumors of MEN 1 are usually benign; however, malignancy of some carcinoid, islet cell, and gastrointestinal tract tumors can cause mortality (5, 6, 7, 8). Diagnosis of MEN 1 is usually made by a combination of history and physical examination, biochemical serum testing, and various imaging modalities (9, 10). We present a classic case of MEN 1 with unique presentation and diagnosis using predominantly nuclear imaging in order to emphasize the role of nuclear imaging in diagnosing and treating MEN 1.

Spontaneous transition of an autonomously functioning thyroid adenoma to Graves' disease.

We report a case of a 57-year-old postmenopausal woman with an autonomously functioning thyroid adenoma spontaneously developing Graves' disease (GD) as documented by I-123 scintigraphy. To date, anecdotal case reports citing the progression of an autonomous nodule to GD have documented either a major thyroidal insult, spontaneous or therapeutic, or the activation of thyroid tissue by circulating thyroid stimulating IgG, with variable progression characteristics. In contradiction to the proposed inciting factors, our patient underwent a minimally invasive fine needle aspiration biopsy followed by suppressive pharmacotherapy. Her antithyroid antibody assay detected low titers of thyroperoxidase antibody (<10 U/mL). We conclude that this is a rare case of autonomously functioning adenoma where neither significant thyroid tissue damage nor the presence of thyroid stimulating IgG can be implicated as an inciting trigger in its progression to GD.

HIV-associated lymphocytic interstitial pneumonitis causes diffuse sestamibi lung uptake in myocardial perfusion imaging.

Technetium-99m ((99m)Tc) sestamibi myocardial perfusion scintigraphy (MPI) is widely used for the diagnosis and assessment of prognosis in patients with suspected coronary artery disease. During these investigations, inspection of raw projected data for the purpose of quality control may occasionally yield incidental noncardiac findings that suggest the presence of another primary noncardiac disease. We present a 66-year-old HIV patient with a tissue diagnosis of lymphoid interstitial pneumonitis (LIP), who demonstrated a diffuse increase of (99m)Tc sestamibi in bilateral lung fields both in rest and stress MPI.

Ordered subset expectation maximization and wide beam reconstruction "half-time" gated myocardial perfusion SPECT functional imaging: a comparison to "full-time" filtered backprojection.

OBJECTIVES: Compared to filtered back projection (FBP), OSEM with resolution recovery (OSEM-RR) and wide beam reconstruction (WBR)(UltraSPECT Ltd.), which resolve resolution and suppress noise simultaneously during reconstruction, have been shown to maintain/improve myocardial perfusion SPECT quality, even with low count density half-time acquisitions. We postulated that their characteristics would be advantageous for gated SPECT, where each frame is only 1/8th the count density of the summed perfusion images. METHODS: An 9 mCi rest/32 mCi (333/1184 MBq) stress Tc(99m) sestamibi protocol was used. 15-min FBP, and additional 7-min OSEM-RR and WBR post-stress 8-frame/cardiac cycle SPECT scans were acquired with 90 degrees -angled dual-headed detectors equipped with high resolution collimators in 156 patients. In 82 patients (48F, 34M) (123-252 lbs) with perfusion defects gated image quality was graded visually: 1 (poor)-5 (excellent) Regional LV wall motion (WM) was scored: 0 (normal)-4 (dyskinesis) in a total of 50 vascular territories with defects. Using Myometrix software (GE Healthcare), post-stress EDV, ESV, and EF were calculated for each method. Additionally, for purposes of comparison, the FBP gated tomograms were processed with other commercially available packages, Emory Toolbox and Cedars QGS. RESULTS: Despite half-time acquisitions, compared to FBP, image quality increased marginally with OSEM-RR (P = .09) but very significantly with WBR (P = 1.9 x 10(-21)). The WM score was greater only for WBR (P = 4.8 x 10(-8)). Although quantitative parameters correlated well with those determined by FBP (all EF r's > 0.85; all volume r's > 0.93), EFs were significantly lower (P = .0001 for OSEM-RR, 3.4 x 10(-14) for WBR), primarily due to a decrease in EDV with OSEM-RR (P = 7.3 x 10(-13)) and an increase in ESV with WBR (P = 9.2 x 10(-5)). However, inter-method differences in these parameters were of similar magnitude to differences encountered among the commercially available software methods. CONCLUSIONS: Half-time OSEM-RR and particularly WBR improve gated SPECT diagnostic quality compared to full-time FBP due to increased resolution and reduced noise. However, these attributes, which affect endocardial edge detection, result in a systematic offset in EDV, ESV, and EF.