Annals of Nuclear Medicine (v.22, #4)

Correlation of chromogranin A levels and somatostatin receptor scintigraphy findings in the evaluation of metastases in carcinoid tumors by Sirianong Namwongprom; Franklin C. Wong; Ukihide Tateishi; Edmund E. Kim; Sombut Boonyaprapa (237-243).
Chromogranin A (CgA) has been gaining acceptance as a helpful tumor marker in patients with neuroendocrine tumors, with respect to both diagnosis and prognosis. The objective of this study was to correlate serum CgA levels and somatostatin receptor scintigraphy (SRS) findings in the evaluation of metastases in carcinoid tumors.A total of 125 patients(61 men and 64 women, aged from 23 to 84 years) with histologically diagnosed carcinoid tumor underwent serum CgA assay and SRS for detecting metastasis or disease recurrence. The quantitative determination of CgA was performed in serum using an enzyme immunoassay with a cut-off value fixed at 39 U/l. Scintigraphies were performed with 200–220 MBq of In-111-DTPA-Phel-octreotide including whole-body images as well as single-photon emission computed tomography and computed tomography scans of the chest and abdomen.The primary tumors originated from the gastrointestinal tract in 115 of 125 patients (92.0%), the lung in 7 of 125 patients (5.6%), the kidney in 2 of 125 patients (1.6%), and the breast in 1 of 125 patients (0.8%). The primary tumors originated from the foregut, midgut, and hindgut in 13.6%, 71.2%, and 12.8%, respectively. Correlation of SRS with other imaging modalities and clinical follow-up findings revealed a sensitivity, a specificity, and an accuracy of 82.9%, 97.7%, and 88.0%, respectively, and for CgA 62.2%, 83.7%, and 69.6%, respectively. There was 1 false-positive and 14 falsenegative SRS results and 7 false-positive and 31 falsenegative CgA analyses. SRS demonstrated higher sensitivity, specificity, and accuracy than CgA for the evaluation of metastatic carcinoid tumors. The concordance between SRS and CgA results was 67.2%. Discrepancies, such as positive SRS with normal CgA levels, were noted in 26 (20.8%) cases, whereas negative SRS with high CgA levels was seen in 15 (12.0%) cases. Combining the results of CgA and SRS increased the sensitivity (92.7%) but decreased the specificity (81.4%) of tumor detection.In our study, SRS proved to be more sensitive, more specific, and more accurate than CgA for metastatic evaluation of carcinoid tumors. Positive SRS correlated with elevation of serum CgA levels. Serum CgA might have some diagnostic utility in patients with negative SRS studies. Nevertheless, both SRS and CgA should be considered useful tools in the evaluation of metastases in carcinoid patients.
Keywords: Somatostatin receptor scintigraphy; Chromogranin A; Carcinoid tumors

Dual-time-point FDG-PET for evaluation of lymph node metastasis in patients with non-small-cell lung cancer by Yoshihiro Nishiyama; Yuka Yamamoto; Naruhide Kimura; Shinya Ishikawa; Yasuhiro Sasakawa; Motoomi Ohkawa (245-250).
The objective of this study was to retrospectively evaluate whether delayed additional F-18-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging can improve the certainty of this modality in evaluating lymph node metastasis in patients with non-small-cell lung cancer (NSCLC).Eighty-three patients with NSCLC were examined. FDG-PET imaging (whole body) was performed at 1-h (early) post-FDG injection and repeated 2 h (delayed) after injection only in the thoracic area. The PET images were evaluated qualitatively for regions of focally increased metabolism. If a lymph node was visible on the PET image, the semi-quantitative analysis using the standardized uptake value (SUV) was determined for both early and delayed images (SUVearly and SUVdelayed, respectively). Retention index (RI) was then calculated on the basis of the following equation: (SUVdelayed − SUVearly) × 100/SUVearly. The RI value of more than 0% was taken to be the PET criterion for malignancy.For early and delayed PET, sensitivities for lymph node staging were 54% and 62%, respectively, specificities were 89% for both, and accuracies were 78% and 81%, respectively. The results of combined delayed PET and RI showed a sensitivity of 62%, specificity of 96%, and accuracy of 86%.Dual-time-point FDG-PET (combined delayed PET and RI) showed better (although not statistically significant) specificity, positive predictive value, and accuracy than early or delayed PET alone for lymph node staging in NSCLC.
Keywords: FDG-PET; Lung cancer; Lymph node metastasis; Delayed imaging; Retention index

Prognostic impact of pre-transplantation computed tomography and 67gallium scanning in chemosensitive diffuse large B cell lymphoma patients undergoing hematopoietic stem-cell transplantation by Ignacio G. Escobar; Pilar T. Alonso; Dolores C. Barrigon; Jose A. Perez-Simon; Maria V. Mateos Manteca; Jesus F. San Miguel Izquierdo (251-260).
In the present study, we evaluated computed tomography (CT) and 67gallium scanning (67Ga scan) pre-transplant as prognostic factors for overall survival (OS) and event-free survival (EFS) in patients with diffuse large B cell lymphoma, undergoing high-dose chemotherapy and stem-cell transplantation.Forty-two patients were included. Of these, 9 (21%) had both positive CT and 67Ga scans, 17 (41%) negative results with both techniques, and 16 (38%) positive CT/negative 67Ga scan. Whole-body planar imaging and single-photon emission computed tomography (SPECT) were performed 72 h after an intravenous administration of 67Ga citrate measuring between 7 mCi and 10 mCi (259–370 MBq).Patients with positive CT/positive 67Ga scan had a significantly worse EFS and OS at 5 years than those with negative 67Ga scan regardless of whether it was associated with a positive or a negative CT scan (29% and 16% vs. 81% and 93% vs. 88% and 100%, respectively, P < 0.001). After a median follow-up of 43 months (range 4–130 months), no differences were observed between patients with negative CT/negative 67Ga scan and those with positive CT/negative 67Ga scan, with an EFS and OS at 5 years of 88% versus 81% and 100% versus 93%, respectively. In multivariate analysis, the presence of a pre-transplant positive CT/67Ga scans adversely influenced both EFS and OS [HR 8, 95% confidence interval (CI) (1.4–38), P = 0.03 and HR 2; 95% CI (1.3–8), P = 0.02, respectively]. 67Ga scan helps to identify, in the pre-transplant evaluation, two groups with a different outcome: one group of patients with positive CT and negative 67Ga scans pre-transplant, who showed a favorable outcome with a low rate of relapse, and the other group of patients with both positive CT and 67Ga scans pre-transplant, who showed a poor prognosis and did not benefit from autologous stem-cell transplantation. They should have been offered other therapeutic strategies.
Keywords: Chemosensitive diffuse large B cell lymphoma; Hematopoietic stem-cell transplantation; Prognostic factors; CT and 67Ga scan

Mucosa-associated lymphoid tissue lymphoma studied with FDG-PET: a comparison with CT and endoscopic findings by Keisuke Enomoto; Kenichiro Hamada; Hidenori Inohara; Ichiro Higuchi; Yasuhiko Tomita; Takeshi Kubo; Jun Hatazawa (261-267).
We investigated the accumulation of 2-deoxy-2-[18F] fluoro-d-glucose positron emission tomography (FDG-PET) in patients with mucosa-associated lymphoid tissue (MALT) lymphoma patients as compared with computerized tomography (CT) and endoscopic imaging.FDG-PET was performed on 13 untreated patients with MALT lymphoma. CT scanning of the affected areas was performed in all the patients to compare with the FDG-PET images. In five patients with gastric MALT lymphoma, comparison was also made with the endoscopic findings.Of the 13 untreated MALT lymphoma patients, all 8 non-gastric MALT lymphoma patients exhibited abnormal accumulation of FDG. However, in the five gastric MALT lymphoma patients, no abnormal FDG accumulation was observed. Although lesions could be confirmed on CT images from the patients other than those with gastric MALT lymphoma, the mucosal lesions of gastric MALT lymphoma could be observed only by endoscopy.FDG-PET can be used to detect MALT lymphoma when it forms mass lesions, whereas it is difficult to detect non-massive MALT lymphoma of gastrointestinal origin.
Keywords: MALT; Lymphoma; FDG; PET; Findings

An iterative reconstruction using median root prior and anatomical prior from the segmented μ-map for count-limited transmission data in PET imaging by Kazuya Sakaguchi; Hiroyuki Shinohara; Takeyuki Hashimoto; Takashi Yokoi; Kimiichi Uno (269-279).
Recently, whole-body positron emission tomography (PET) examination has greatly developed. To reduce the overall examination time, the transmission scan has been increasingly shortened. Many noise-reduction processes have been developed for count-limited transmission data. Segmented attenuation correction (SAC) is one method by which the pixel values of transmission image are transformed into several groups. The median root prior-ordered subset convex (MRP-OSC) algorithm is another method that is applicable to control the noise level on the basis that the change of the pixel value is locally monotonous. This article presents an alternative approach on the basis of the Bayesian iterative reconstruction technique incorporating a median prior and an anatomical prior from the segmented μ-map for count-limited transmission data.The proposed method is based on the Bayesian iterative reconstruction technique. The median prior and the anatomical prior are represented as two Gibbs distributions. The product of these distributions was used as a penalty function.In the thorax simulation study, the mean square error from the true transmission image of the presented method (5.74 × 10−5) was lower than MRP-OSC (6.72 × 10−5) and SAC (7.08 × 10−5). The results indicate that the noise of the image reconstructed from the proposed technique was decreased more than that of MRP-OSC without segmentation error such as that of an SAC image. In the thorax phantom study, the emission image that was corrected using the proposed technique displayed little noise and bias (27.42 ± 0.96 kBq/ml, calculated from a region of interest drawn on the liver of the phantom); it was very similar to the true value (28.0 kBq/ml).The proposed method is effective for reducing propagation of noise from transmission data to emission data without loss of the quantitative accuracy of the PET image.
Keywords: Positron emission tomography; Transmission scan; Ordered subset convex; Segmented attenuation correction; Median root prior-expectation maximization

Comparison of FDG-PET findings of brain metastasis from non-small-cell lung cancer and small-cell lung cancer by Ho-Young Lee; June-Key Chung; Jae Min Jeong; Dong Soo Lee; Dong Gyu Kim; Hee Won Jung; Myung Chul Lee (281-286).
We compared the F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) findings of brain metastasis between patients with non-small-cell lung cancer (NSCLC) and small cell lung cancer (SCLC).A whole-body FDG and a brain PET were performed in 48 patients (31 men, 17 women; 57 ± 9 years, 42 NSCLC, 6 SCLC), who had brain metastasis on magnetic resonance (MR). All primary lung lesions were detected by FDG-PET and confirmed pathologically. We analyzed the PET findings, lesion sizes, and the pathological result of primary lung cancer.Of the 48 patients, 31 (64.6%) showed hypermetabolic lesions on FDG-PET of the brain image, and 14 (29.2%) showed hypometabolic lesions. Three patients (6.3%) had both hypermetabolic and hypometabolic lesions. On the lesion-based analysis, 74 lesions (67.3%) showed hypermetabolism on FDG-PET, and 36 lesions (32.7%) showed hypometabolism. All primary lung lesions were hypermetabolic on FDG-PET. When the FDG findings of metastatic brain lesions were analyzed with the pathological types of primary lung cancer, NSCLC was more frequently associated with hypermetabolic metastatic brain lesions than SCLC (80% and 26.7%, respectively, P < 0.01). On comparing the sizes of metastatic lesions between SCLC (1.3 ± 1.2 cm) and NSCLC (1.8 ± 1.2 cm), lesions of <1 cm were more frequent in SCLC than in NSCLC (P = 0.012). But no significant relationship was found between the size and PET finding of metastatic lesion (P = 0.412).Even when the primary lesion of lung cancer showed hypermetabolism in FDG-PET, FDG accumulation in metastatic brain lesions was variable. One-third of brain metastases from lung cancer showed hypometabolism. NSCLC was more frequently associated with hypermetabolic metastatic brain lesions than SCLC. The PET findings of brain lesions were affected not only by the size of lesion but also by its biological characteristics.
Keywords: Brain metastasis; FDG-PET; Small cell lung cancer; Non-small-cell lung cancer

Evaluation of myocardial perfusion and function by gated SPECT in patients with Behçet’s disease by Eser Kaya; Hayrettin Saglam; İsmail Ciftci; Mustafa Kulac; Semsettin Karaca; Mehmet Melek (287-295).
Behçet’s disease (BD) is a systemic multi-system vasculitis that can have a wide range of effects on the cardiovascular system.To determine the existence of myocardial perfusion defects caused by coronary microvascular dysfunction in BD and to evaluate coronary arterial distribution and left ventricular systolic function by gated single-photon emission computed tomography (SPECT).The study population consisted of 23 (15 men and 8 women) patients with BD and 20 healthy controls (12 men and 8 women). Technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) gated SPECT studies were performed at stress and rest in a 2-day protocol. Stress and rest left ventricular ejection fraction (LVEF) were calculated. Using non-gated SPECT images myocardial perfusion scores [summed stress score (SSS), summed rest score (SRS), summed difference score (SDS), and fix defect score (FDS)] and perfusion defect extent as percentage (stress, rest ischemic, and fix %LV) were determined. Using gated SPECT images, wall motion score indices (stress wall motion score indices and rest wall motion score indices) were calculated. Coronary angiography (CAG) was applied to patients with abnormal myocardial perfusion scintigraphy (MPS).The mean ages of the BD and control groups were 39.3 ± 10.6 years and 36.2 ± 8.3 years, respectively. No statistically significant differences were observed between the two groups regarding clinical features and cardiologic findings. Abnormal MPS was found in 13 (56.5%) of the BD patients; 3 patients had non-transmural infarcts and 10 patients reversible perfusion defects. Reversible perfusion defects were also found in two controls (10.0%). When the two groups were compared regarding the gated SPECT findings, differences were determined in the following parameters; SSS, SRS, SDS, FDS, stress and rest LVEF, stress and rest %LV, and stress and rest WMSI. In the BD group, when gated SPECT results were compared between those with and without abnormal MPS, differences were determined in SSS, SRS, SDS, FDS, stress and rest %LV, and stress and rest WMSI. Epicardial coronary arteries were normal in CAG.Myocardial perfusion and function are disturbed owing to influenced coronary microvascularity in BD, and CAG is frequently observed to be normal. Gated SPECT is a non-invasive reliable method that simultaneously evaluates the existence, extent and severity of myocardial ischemia or infarction and the wall movements in cardio-Behçet.
Keywords: Behçet’s disease; Myocardial perfusion and function; Gated SPECT

Evaluation of diagnostic abilities of Ga-SPECT for head and neck lesions by Jin Kotani; Joji Kawabe; Shigeaki Higashiyama; Etsushi Kawamura; Ai Oe; Takehiro Hayashi; Hiroko Kurooka; Chikako Tsumoto; Makoto Kusuki; Hideo Yamane; Susumu Shiomi (297-300).
Single-photon emission computed tomography (SPECT) using gallium (Ga) has been frequently used for diagnosing head and neck tumors in patients. Although the usefulness of Ga-SPECT is well known, the degree of the increase in diagnostic ability with Ga-SPECT for head and neck tumors has not been reported. We compared the ability of the planar images of Ga scintigraphy, SPECT images of Ga scintigraphy, and CT images to diagnose head and neck primary tumors and neck metastases.The subjects of this study were 167 patients with malignant head/neck lesions. For Ga scintigraphy, Ga-67-citrate (74 MBq) was injected via a cubital vein. Planar and SPECT images were taken 72 h after the Ga-67-citrate injection. The rate of detection of the primary lesions was compared first between SPECT and planar images then between SPECT and CT images. The rate of detection for each stage of disease according to the TNM classification was also analyzed.The rate of detection of primary lesions was 50% with planar imaging and 69% with SPECT. And similarly, regarding the rate of detection of lymph node metastases, there was a significant difference between planar imaging and SPECT. The rate of detection of primary lesions was 70% for both CT and SPECT. At T stage, the rates of detection of primary lesions with each imaging technique were 11% with planar imaging and 39% with SPECT, and 22% with CT for stage T1.This study revealed the marked superiority of SPECT images over planar images in terms of the ability to detect primary tumors and tumor metastasis to cervical lymph nodes. Furthermore, the primary T1 tumor detection rate of SPECT images was higher than that of CT images. On the basis of these results, the concomitant use of SPECT is highly recommended when Ga scintigraphy is performed to check for malignant head/neck tumors.
Keywords: Ga scintigraphy; SPECT; CT; Head and neck tumors; TNM classification

Evaluation of brain and whole-body pharmacokinetics of 11C-labeled diphenylhydantoin in rats by means of planar positron imaging system by Yukinori Hasegawa; Yasukazu Kanai; Shinji Hasegawa; Takashi Okamoto; Tamiko Matsui; Eku Shimosegawa; Yoshihisa Kurachi; Jun Hatazawa (301-307).
A planar positron imaging system (PPIS) enables whole-body dynamic imaging of radiopharmaceuticals labeled with positron-emitting nuclides. We evaluated the difference in the brain and whole-body pharmacokinetics of 11C-diphenylhydantoin (11C-DPH) between intravenous and duodenal administration in rats.Male Wistar rats (8 weeks old, mean body weight 250 g) were examined under anesthesia. A tracer amount of 11C-DPH (2 μg or less; about 5 MBq) was injected into the tail vein (n = 3) or duodenum (n = 3). Immediately following the administration, PPIS scans were obtained for 20 min. Regions of interest (ROIs) were set on the brain, heart, liver, intestinal field, and urinary bladder, identified on the integrated images. The relative uptake value (RUV, %) was calculated as the regional count divided by the whole-body count multiplied by 100. Sequential changes in the RUV for each ROI were analyzed for the brain and other organs.Following intravenous injection of 11C-DPH, the RUV in the brain was 1.59 ± 0.07%, 1.53 ± 0.09%, 1.40 ± 0.09%, and 1.38 ± 0.08% at 5 min, 10 min, 15 min, and 20 min after the injection, respectively. After duodenal administration, the corresponding values were 0.54 ± 0.16%, 1.01 ± 0.12%, 1.43 ± 0.24%, and 1.52 ± 0.06%, respectively. The 11C-DPH distribution was significantly lower at 5 min and 10 min following duodenal administration than after intravenous injection (P < 0.01). Radioactivity in the urinary bladder was identified by 20 min after both intravenous injection and duodenal administration.The present study demonstrated a difference in the brain distribution of 11C-DPH between intravenous and duodenal administration in rats. Use of the PPIS is feasible for the evaluation of the pharmacokinetics in both the target organ and the whole body in small animals.
Keywords: PPIS; 11C-DPH; Pharmacokinetics

Non-invasive detection of ischemic left ventricular dysfunction using rest gated SPECT: expectation of simultaneous evaluation of both myocardial perfusion and wall motion abnormality by Hirofumi Maeba; Kazuya Takehana; Seishi Nakamura; Susumu Yoshida; Takanao Ueyama; Kengo Hatada; Toshiji Iwasaka (309-316).
Although the accurate detection of ischemic etiology is important in the management of patients with severe left ventricular (LV) dysfunction, it is difficult to determine using a non-invasive strategy. The present study investigates whether perfusion and regional functional abnormalities identified by quantitative electrocardiographic gated single-photon emission computed tomography (QGS) at rest can detect ischemic LV dysfunction in patients with severe LV dysfunction.Rest QGS with 99mTc-tetrofosmin was performed on 54 consecutive patients with LV ejection fraction of ≤40%. Ischemic LV dysfunction (n = 32) was defined according to the established standard. Regional perfusion and wall motion were calculated using a 14-segment model (six mid-ventricular and eight apical segments) and compared with a normal control group.The numbers of reduced [mean −1 standard deviation (SD) of normal individuals] and severely reduced (mean −2 SD) wall motion segments were similar between patients with ischemic and non-ischemic LV dysfunction (13.5 ± 1.1 vs. 13.6 ± 0.9 and 10.6 ± 2.0 vs. 9.9 ± 3.0 segments, respectively). The number of hypoperfused (mean −1 SD) segments was significantly greater in patients with ischemic LV dysfunction than in those with non-ischemic LV dysfunction (9.3 ± 3.8 vs. 2.0 ± 2.8 segments, P < 0.0001). The analysis of the receiver operating characteristics showed that a cut-off value of 4 hypoperfused segments among 14 segments provided the best separation between ischemic and non-ischemic LV dysfunction (sensitivity = 88% and specificity = 91%). Furthermore, patients with non-ischemic LV dysfunction had no severely hypoperfused (mean −2 SD) segments in any of the segments, whereas patients with ischemic LV dysfunction had 4.4 ± 0.2 segments.The QGS strategy at rest can accurately differentiate patients with ischemic LV dysfunction from those with severe LV dysfunction by simultaneous regional evaluation of wall motion and myocardial perfusion.
Keywords: Left ventricular dysfunction; Ischemic LV dysfunction; Electrocardiographic gated SPECT

Prone thallium-201 (201Tl) myocardial perfusion single-photon emission computed tomography (SPECT) reduces false-positive rates when evaluating inferior wall abnormalities by minimizing diaphragmatic attenuation. The present study investigates the diagnostic validity of prone 201Tl stress myocardial perfusion SPECT for detecting coronary artery disease in the inferior wall of the left ventricle in Japanese patients.Of the 104 consecutive patients who underwent 201Tl stress myocardial perfusion SPECT to diagnose coronary artery disease, we evaluated 46 who underwent image acquisition in both the supine and prone positions, and coronary angiography within 3 months thereafter. Images were acquired in the routine supine position immediately following 201Tl (111 MBq) injection and 4 h following early acquisition. Images were acquired in the prone position only during the early phase following supine acquisition. We evaluated the SPECT images of the inferior half segments of the left ventricle using a five-point defect scoring system. According to the coronary angiographic findings, we investigated the diagnostic accuracy of stress-rest supine, stress supine, stress prone, and combined supine-prone images. Reduced uptake in the stress supine image of the combined images was considered as attenuation when uptake was normal in the prone image.The sensitivity of the stress-rest supine, stress supine, stress prone, and stress-combined supine-prone images was 77%, 86%, 55%, and 55%, and the specificity was 71%, 54%, 79%, and 83%, respectively. Diagnostic accuracy was the highest in stress-rest supine images.Prone images tended to improve the specificity of detecting coronary artery disease in the inferior wall, but not diagnostic accuracy compared with stress-rest supine images because of decreased sensitivity.
Keywords: Prone imaging; Myocardial perfusion SPECT; Coronary artery disease

Erdheim-Chester disease: a rare syndrome with a characteristic bone scintigraphy pattern by Trifon J. Spyridonidis; Costas Giannakenas; Panagiota Barla; Dimitrios J. Apostolopoulos (323-326).
Erdheim-Chester disease is a rare noninherited, non-Langerhans’ cell histiocytosis, with multiorgan involvement. The skeleton is frequently involved in as many as 70–80% of all cases. In nearly half of the cases, there is an involvement of other organs such as the cardiovascular system, lung, kidneys, brain, and orbits. Extra-skeletal involvement is correlated with increased morbidity and mortality. In recent years, the disease is being described with increasing frequency although fewer than 200 cases have been identified worldwide. Besides its rarity, the disease has a characteristic almost pathognomonic bone scan appearance, which in some cases facilitates diagnosis of the syndrome. Bone scans also contribute to the qualitative assessment of skeletal involvement.
Keywords: Erdheim-Chester disease; Bone scintigraphy; Skeletal involvement

A case of cavernous hemangioma in which malignancy was preoperatively excluded by FDG-PET by Shigeaki Higashiyama; Joji Kawabe; Takehiro Hayashi; Hiroko Kurooka; Ai Oe; Jin Kotani; Etsushi Kawamura; Susumu Shiomi (327-330).
A contrast-enhanced mass was revealed by computed tomography and magnetic resonance imaging in the left pelvic cavity of a 71-year-old man. Although the mass appeared to be a cavernous hemangioma, malignancy could not be ruled out. Abdominal angiography was performed but failed to rule out malignancy because it revealed vascular dislocation and encasement. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was then performed, and suggested a benign tumor, with a standardized uptake value (SUV) of 1.7. Following this finding, because the tumor was large and rupture could not be ruled out, we decided to perform surgery. The resected tumor was a benign cavernous hemangioma, consistent with the result obtained by FDG-PET.
Keywords: FDG-PET; Cavernous hemangioma; Intrapelvic

The use of a handheld gamma probe for identifying two accessory spleens in difficult locations in the same patient by Eric Bergeron; Sebastien Ratte; Simon Jeannotte; Mary Jo Recoskie (331-333).
Severe thrombocytopenia in idiopathic thrombocytopenic purpura may recur owing to retained accessory spleens. Accessory spleen may hide in unusual and difficult locations. We present an interesting case in which we used a handheld gamma probe intraoperatively to localize two accessory spleens. The two accessory spleens were successfully retrieved and removed. A handheld gamma probe is used as a valuable tool in localizing residual splenic tissue following splenectomy.
Keywords: Idiopathic thrombocytopenic purpura; Splenectomy; Accessory spleen; Hepatosplenic scintigraphy; Gamma probe

FDG positron emission tomography imaging of drug-induced pneumonitis by Miwa Morikawa; Yoshiki Demura; Shiro Mizuno; Shingo Ameshima; Takeshi Ishizaki; Hidehiko Okazawa (335-338).
Several studies have reported the findings of fluorine-18-labeled fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in benign lung disease with diffuse pulmonary injury; however, the characteristics and effectiveness of FDG-PET imaging for interstitial pneumonitis have not been substantiated. We report two cases of drug-induced pneumonitis in two patients treated for breast cancer who were diagnosed by FDG-PET examination. Both the cases showed diffuse interstitial infiltration in the bilateral lungs on computed tomography, but the degree of FDG accumulation was different. It is probable that the degree of FDG accumulation reflected the activity of the drug-induced pneumonitis. The present cases show very interesting FDG-PET imaging findings of diffuse lung disease.
Keywords: FDG-PET; Drug-induced pneumonitis; Interstitial pneumonitis