Comparative assessment of rest and post-stress left ventricular volumes and left ventricular ejection fraction on gated myocardial perfusion imaging (MPI) and echocardiography in patients with transient ischaemic dilation on adenosine MPI: myocardial stunning or subendocardial hypoperfusion?

BACKGROUND: Transient ischaemic dilation (TID) on myocardial perfusion imaging (MPI) is an important finding, conveying a high risk of subsequent cardiac events. However, the mechanism leading to TID on MPI is not well elucidated. This study aimed to determine if TID is due to true LV cavity dilation and ventricular stunning, or is due to relative subendocardial hypoperfusion. METHODS: 31 patients undergoing single-day Tc-99m adenosine sestamibi MPI were recruited. All had routine ECG-gated single-day rest-stress adenosine MPI, with transthoracic echocardiograms (echo) acquired concurrently at rest, and both immediately, and 2 hours, post-stress. Echocardiography was performed using a Vivid-7 (GE). LV volumes and LVEF were quantified blinded to MPI results, using biplane Simpson method on echo, and quantitatively (including TID) with QGS(®), on MPI. RESULTS: Patients were divided into quartiles for TID, with the top quartile considered TID positive [TID+ 9/31 (TID ratio 1.3 ± 0.09)], and TID negative [TID- 22/31 (TID ratio 1.01 ± 0.04)]. There was good correlation between resting echo and MPI physical measurements (LVEDV r(2) = 0.79, LVESV r(2) = 0.9, and LVEF r(2) = 0.75). On MPI, a significant drop in LVEF was observed between rest and early stress in the TID+ group (56.6% vs 46.5%, P < .002), as well as an increase in both LVESV (62 vs 79 mls, P < .0001) and LVEDV (113 vs 131 mls, P < .0001). However, no statistically significant change in LVEF, LVESV or LVEDV was identified on concurrent echo imaging (LVEF 57% vs 56%, P < .66; LVESV 48 vs 54 mls, P < .26; LVEDV 87 vs 97 mls, P < .299). No significant change in LVEF or ventricular volumes was noted in the TID- group by either echo or MPI. CONCLUSION: Transient dilation of the left ventricle on adenosine MPI is not related to chamber enlargement and myocardial stunning, but is more likely a function of subendocardial hypoperfusion and impaired coronary flow reserve.

Increased activity on In-111 octreotide imaging due to radiation fibrosis.

Indium-111 octreotide scintigraphy is a useful investigation in the diagnosis and staging neuroendocrine or nonendocrine malignancies such as carcinoid, granulomas, small cell lung cancer, medullary thyroid carcinoma, and others. Tumors with large numbers of somatostatin receptors can be accurately imaged and this can be useful in guiding treatment. Although uncommon, false-positives studies have been reported and often the cause is unexplained but assumed to be a high number of somatostatin receptors in other pathology. We present a case with increased uptake resulting in a scan due to pulmonary fibrosis.

Incidental Prostate-Specific Membrane Antigen Uptake in a Peripheral Nerve Sheath Tumor.

A 66-year-old man with recently diagnosed prostate cancer (Gleason score 9) was referred for Ga-prostate-specific membrane antigen (PSMA) PET/CT with prostate-specific antigen level of 7.5 µg/L. PET/CT demonstrated increased PSMA uptake (SUVmax 4.7) in a soft tissue density in the left adductor compartment. MRI and cytopathology of the biopsied soft tissue density was compatible with a peripheral nerve sheath tumor. This case illustrates that PSMA uptake can occur in a peripheral nerve sheath tumor and should be taken into consideration as a benign cause of PSMA uptake.

Adjuvant Iodine (131) Lipiodol after Resection of Hepatocellular Carcinoma.

Background. Survival after liver resection for HCC is compromised by a high rate of intrahepatic recurrence. Adjuvant treatment with a single, postoperative dose of intra-arterial I(131) lipiodol has shown promise, as a means of prolonging disease-free survival (DFS). Methodology. DFS and overall survival (OS) after a single dose of postoperative I(131) lipiodol were compared to liver resection alone, for treatment of hepatocellular carcinoma (HCC). Data were collected retrospectively for patients who had a curative resection for HCC between December 1993 and September 2011. Seventy-two patients were given I(131) lipiodol after surgery and 70 patients had surgery alone. Results. The DFS at 1, 3, and 5 years was 72%, 43%, and 26% in the surgery group and 70%, 39%, and 29% in the adjuvant I(131) lipiodol group (p = 0.75). The 1-, 3-, and 5-year OS was 83%, 64%, and 52% in the surgery group and 96%, 72%, and 61% in the adjuvant I(131) lipiodol group (p = 0.16). Conclusion. This retrospective study has found no significant benefit to survival, after adjuvant treatment with I(131) lipiodol.