Granulomatous disease: is it a nuisance or an asset during PET/computed tomography evaluation of lung cancers?

OBJECTIVES: To evaluate combined PET-computed tomography (CT) criteria for differentiating between granulomatous disease (GD) and malignancy (CA) in oncologic PET-CT studies. METHODS: Sixty-two patients who were referred for fluoro-2-deoxyglucose (FDG) PET-CT evaluation of pulmonary lesion(s) without a history of concurrent infection were studied. PET-CT was performed 1.5 h after intravenous administration of 555 MBq 18F-FDG in the fasting state with oral contrast. Combined PET-CT criteria including (i) calcifications (Ca2+) within lymph nodes, (ii) Ca2+ in lung nodules, (iii) liver and/or spleen Ca2+, (iv) locations of lung lesion(s), (v) hilar FDG uptake, (vi) comparison of lung versus maximum mediastinal FDG uptake, (vii) lymph node uptake not in the most probable lymphatic drainage pathway from a particular lung lesion, and (viii) extra pulmonary abnormal FDG uptake were each assigned a numerical score (0-3) with progressively higher score and sum of scores toward the increasing likelihood of GD. These patients either had pathological confirmation by biopsy/resection or were followed radiographically for a period of 2 years (CA=13; GD=49). Discriminant analysis was performed on all the above criteria with this gold standard. Simple t-test and box plot analysis were also performed on the summation of the scores (from 0 in CA to 13 in GD). RESULTS: When all eight criteria were entered into discriminant analysis, the combined PET-CT criteria classified correctly 71% of patients with a sensitivity of 65% and specificity of 92% for GD. The most significant discriminating criterion was FDG uptake in the lung lesion(s) less than maximum mediastinal uptake (P=0.01). The sum scores in GD and CA were significantly different (4.9+/-2.4 vs. 3.2+/-1.5, respectively, P=0.014). Box plots showed a clear separation at a cut-off value of around 3.5. CONCLUSION: Results show that the set of combined PET-CT criteria are highly specific for GD, which is not necessarily a nuisance during oncologic evaluation. Knowledge of these criteria may attribute some of the abnormal PET findings to GD, which is a useful asset for quick recognition and clinical interpretation.

Hypertrophic Osteoarthropathy on Bone Scintigraphy.

We present the case report of a patient with a history of lung cancer in whom the typical pattern of hypertrophic osteoarthropathy was seen on bone scintigraphy. We discuss the etiologies, pathophysiology, and management of this entity.

Spleen Uptake on a Bone Scan.

We present a patient with spleen uptake on bone scanning that was due to sickle cell disease. We also discuss other etiologies for this finding.

Complex Regional Pain Syndrome Diagnosed with Triple-Phase Bone Scanning.

In this report, we present a case of complex regional pain syndrome in a 55-y-old woman in whom the diagnosis was made on the basis of the bone scan findings. We also discuss the typical and atypical scintigraphic presentations of this entity, including pathophysiology and management.

Appearance of Meningioma on 99mTc-HMPAO SPECT: Correlation with MRI.

On brain perfusion SPECT, a primary brain lesion presents as a localized defect that corresponds to the mass lesion. (99m)Tc-HMPAO images generally show a focal defect in the region of abnormality, whether containing necrotic tissue, recurrent tumor, or both. Further characterization with MR imaging is needed to confirm the diagnosis, as demonstrated in this case report.

Prospective evaluation of aggressive medical therapy for atherosclerotic renal artery stenosis, with renal artery stenting reserved for previously injured heart, brain, or kidney.

Sixty-six patients with atherosclerotic renal artery stenosis (RAS) and serum creatinine < or =2.0 mg/dl were treated with antihypertensive therapy, a statin, and aspirin. Renal stenting was reserved for patients with injuries to the heart, brain, or kidneys. The primary end point was stenotic kidney glomerular filtration rate (GFR) at 21 months; secondary end points included major adverse clinical events, serum creatinine, total GFR, and blood pressure (BP). After baseline evaluation, 26 of 66 patients underwent renal stenting because of injuries to the heart, brain, or kidneys. After 21 months, 6 medical patients required renal stenting, and 5 patients experienced late clinical events (2 medical patients, 3 stent patients). There was no difference in final BP between groups. Whereas medical patients experienced 6% and 8% decreases in total and stenotic kidney GFR, stent patients experienced 7% and 11% increases in total kidney (p = 0.006) and stenotic kidney (p = 0.02) GFR. There was no difference in final serum creatinine. In conclusion, patients with atherosclerotic RAS and baseline creatinine < or =2.0 mg/dl can be safely managed with aggressive medical therapy, with a small decrease in GFR. For patients who develop injuries to the heart, brain, or kidneys, renal artery stenting may further reduce hypertension and improve renal function.

Liver uptake on bone scanning: a diagnostic algorithm.

In this report, we present a case of liver uptake seen on a bone scan that was due to diffuse metastatic disease from breast carcinoma. We discuss possible etiologies for the uptake and offer an algorithm to narrow the differential diagnosis.

Lumbosacral Transitional Vertebra Diagnosed on 99mTc-Methylene Diphosphonate SPECT/CT.

Lumbosacral transitional vertebra (LSTV) is a congenital anomaly of the lumbosacral junction. The association between back pain and LSTV is controversial; however, in our patient the symptoms localized to a hemisacralized left transverse process of L5. LSTV should be included in the differential diagnosis in young patients with lower back pain, and scintigraphic imaging should be considered for diagnostic purposes.

17-year-old runner with shin pain.

Stress injury is a common cause of exercise-induced anterior shin pain. It is important to distinguish between the various causes of stress injury in a timely manner in order to optimize favorable treatment outcomes. Here, we will discuss a case of medial tibial stress syndrome, or shin splints, as one of the causes of shin pain, as well as how to approach shin pain for a successful diagnosis.

Scintigraphy of patient with hematochezia.

Gastrointestinal bleeding can result in significant morbidity. Scintigraphy plays an important role in detecting, localizing, and grading the bleed. Effective scintigraphic evaluation of gastrointestinal bleeding can be complicated by its intermittent nature and the patient's hemodynamic instability. Dynamic evaluation, delayed imaging, and an understanding of the labeling process are necessary tools to help improve detection rate and localization.

Complementary role of 18F-FDG PET and 123I-ioflupane SPECT in the diagnosis of Lewy body disease.

We present a case demonstrating how correlative imaging with (123)I-ioflupane SPECT and (18)F-FDG PET can be used to help make the diagnosis of Lewy body disease more specific.

The role of scintigraphy in confirmation of suspected brain death.

We present a case illustrating how cerebral perfusion scintigraphy can be used to assist in crucial medical decision making in the intensive care setting for patients who are maintained on life support but are clinically suspected to have brain death. Cerebral perfusion scintigraphy can confirm brain death but cannot be used to diagnose it. (99m)Tc-HMPAO and (99m)Tc-ethylcysteinate dimer are the preferred imaging agents since they cross the blood-brain barrier.

Application of heat-damaged Tc-99m RBCs in a patient with suspected hepatic metastasis.

We present a patient with a remote history of splenectomy and recent hemicolectomy for colon adenocarcinoma. On routine surveillance chest/abdomen/pelvis CT, a lesion suspicious for hepatic metastasis was identified. Followup MRI was inconclusive. For more specific tissue characterization, imaging with Tc-99m heat-damaged RBCs was obtained to guide further patient management. Tc-99m-labeled, heat-damaged RBC scintigraphy is an underused modality that is highly specific for detecting ectopic or accessory splenic tissue. There have been many reported cases of patients undergoing unnecessary biopsies or laparotomies to remove suspicious masses that were subsequently found to be ectopic splenic tissue.

Pulse wave as an alternate signal for data synchronization during gated myocardial perfusion SPECT imaging.

PURPOSE: Proper identification of the cardiac cycle is essential for gated SPECT myocardial perfusion imaging. We have developed an alternate method of ECG for gating, that is, using the peripheral pulse wave (PW) as the triggering signal for gated SPECT acquisition. The aim of this study is to compare the use of this method of gating with the standard ECG trigger. METHODS: We tested the PW triggering by comparing it with the ECG trigger. We evaluated 33 patients (25 males, 8 females), average age of 61 years (39-80) referred for stress myocardial perfusion imaging. Data from all patients were acquired twice and were processed by CEqual and QGS software. We compared the left ventricular ejection fraction (LVEF), end-diastolic and end-systolic volumes (EDV, ESV). Paired t test and Pearson correlation coefficient were used for comparison. RESULTS: The mean LVEF, EDV, and ESV calculated with the ECG trigger were 0.52, 120, and 64, respectively, those with the pulse-wave trigger were 0.48, 126, and 71, respectively. Mean paired difference for LVEF was -0.034 (P<0.001), for EDV 5.9 (P=0.012), and for ESV 7.9 (P<0.001). Pearson correlation coefficient for LVEF was 0.955, for EDV 0.987, and for ESV 0.991 (P<0.001 for all correlations). CONCLUSION: Triggering of gated-data acquisition by the PW is feasible. Quantitative parameters of cardiac function correlate highly with those obtained from the ECG trigger and the absolute differences are not clinically significant across a wide range of values.