Computed Tomography Observer Agreement in Staging Malignant Lymphoma.

OBJECTIVE: To determine pretreatment computed tomography observer agreement in patients with newly diagnosed lymphoma. METHODS: Forty-nine computed tomography scans were reviewed by 3 experienced radiologists, with each scan assessed twice by 1 observer. Predefined nodal and extranodal regions were assessed, and Ann Arbor stages were assigned. K-statistics were defined as poor (κ < 0.2), fair (κ > 0.2 to κ ≤ 0.4), moderate (κ > 0.4 to κ ≤ 0.6), substantial (κ > 0.6 to κ ≤ 0.8), and almost perfect (κ > 0.8 to κ ≤ 1). RESULTS: Nodal interobserver agreement varied from 0.09 for infraclavicular involvement to 0.95 for para-iliac involvement; intraobserver agreement was substantial to almost perfect, except for infraclavicular nodes. Extranodal interobserver agreement varied from 0.56 to 0.88; intraobserver agreement was substantial to almost perfect. Ann Arbor stage interobserver agreement varied from 0.57 to 0.69; intraobserver agreement was substantial. CONCLUSION: Computed tomography observer agreement in staging malignant lymphoma appears to be suboptimal.

CT and 18F-FDG PET for noninvasive detection of splenic involvement in patients with malignant lymphoma.

OBJECTIVE: The purpose of this study was to determine the sensitivity and specificity of (18)F-FDG PET, CT, and combined PET/CT in the detection of splenic involvement at initial staging of lymphoma. MATERIALS AND METHODS: A retrospective longitudinal analysis was performed on the records of 111 patients with proven lymphoma who had undergone PET and CT before and after treatment. CT scans were evaluated independently by two radiologists, and PET scans by two nuclear medicine physicians. Abnormal CT findings were defined as low-attenuation nodules or a splenic index greater than 725 cm(3) (> 2 SDs above the mean in 100 controls). An abnormal PET finding was defined as splenic uptake greater than hepatic uptake. True splenic involvement was defined retrospectively on the basis of the treatment response assessed with criteria revised in the International Harmonization Project on lymphoma. Observer agreement and sensitivity and specificity values were calculated. RESULTS: Observer agreement for CT splenic index and PET findings was good. For initial splenic staging, the sensitivity and specificity of CT, PET, and PET/CT were 91% and 96%, 75% and 99%, and 100% and 95%. CONCLUSION: For initial staging of splenic involvement in malignant lymphoma, the sensitivity and specificity of PET/CT can reach 100% and 95%. The sensitivity of the combined approach is higher than that of either technique alone.

Diagnostic evaluation of separately acquired PET and CT images by nuclear medicine physicians and radiologists in cancer patients.

The aim of our study was to analyze how many oncology patients might benefit from a) integrated positron emission tomography - multidetector computed tomography (PET/MDCT) and additionally b) clinically relevant information provided by either the CT scan or PET scan. A total of 285 consecutive patients 164 male and 121 female, age range 17-84 years, 153 lung cancer, 112 lymphoma, 20 miscellaneous, referred for PET and separate CT scan, were included. The CT scan was performed after the intravenous injection of a soluble contrast media. Patients were retrospectively classified into six Groups: Group I: No pathological uptake on the PET scan, Group II: Suspected lesions were correctly identified by the PET scan alone, Group III: Side-by-side evaluation of PET and CT appeared sufficient to assess the localization of lesions, Group IV: Side-by-side reading was not sufficient and integrated PET/CT was considered beneficial. Additionally all patients with a CT scan with additional clinical relevant information (not visualized by the PET scan) were classified in Group V. Group VI was set for lesions detected by PET alone (not visualized by the CT scan). The CT scan was used as the gold standard to confirm or disprove PET lesion localization. Our results showed: A number of 77 patients, (Group I: 77/285, 27%) had no pathologic fluorine-18-fluorodeoxyglucose (18F-FDG)-uptake. Lesions were correctly localized by either conventional PET alone (Group II: 76/285, 27%) or side-by-side evaluation of PET and CT scans (Group III: 44/285, 15%). Integrated PET/CT or software fusion, was considered beneficial in 31% (88/285) of the patients with pathological 18F-FDG-uptake (Group IV). Additionally to the above, in 15% of all patients clinically relevant information, referring to disseminated small pulmonary lesions, abdominal aortic aneurysms >5 cm, thrombi or pulmonary emboli, was also provided by the CT scan (Group V). Also, in 7% of all patients, unsuspected pathological lesions, mainly bone metastases, were correctly detected by PET alone (Group VI). In conclusion, in 54% of all oncologic patients, PET alone was diagnostic. In 46% of all patients side-by-side reading (15%) or integrated PET/CT images (31%) were considered beneficial for more accurate anatomical localization of the lesions. Additionally, the CT scan added clinically relevant information in 15% of all patients and the PET scan showed unsuspected metastases in 7% of all studied patients. Therefore, integrated reading of PET and MDCT images by nuclear physicians and radiologists may gain quality in the staging of oncology patients.

Bone suppressed images improve radiologists' detection performance for pulmonary nodules in chest radiographs.

OBJECTIVES: To assess the effect of bone suppression imaging on observer performance in detecting lung nodules in chest radiographs. MATERIALS AND METHODS: Posteroanterior (PA) and lateral digital chest radiographs of 111 (average age 65) patients with a CT proven solitary nodule (median diameter 15 mm), and 189 (average age 63) controls were read by 5 radiologists and 3 residents. Conspicuity of nodules on the radiographs was classified in obvious (n = 32), moderate (n = 32), subtle (n = 29) and very subtle (n = 18). Observers read the PA and lateral chest radiographs without and with an additional PA bone suppressed image (BSI) (ClearRead Bone Suppression 2.4, Riverain Technologies, Ohio) within one reading session. Multi reader multi case (MRMC) receiver operating characteristics (ROC) were used for statistical analysis. RESULTS: ROC analysis showed improved detection with use of BSI compared to chest radiographs alone (AUC = 0.883 versus 0.855; p = 0.004). Performance also increased at high specificities exceeding 80% (pAUC = 0.136 versus 0.124; p = 0.0007). Operating at a specificity of 90%, sensitivity increased with BSI from 66% to 71% (p = 0.0004). Increase of detection performance was highest for nodules with moderate and subtle conspicuity (p = 0.02; p = 0.03). CONCLUSION: Bone suppressed images improve radiologists' detection performance for pulmonary nodules, especially for those of moderate and subtle conspicuity.

Bone mineral density in male adolescents with autism spectrum disorders and disruptive behavior disorder with or without antipsychotic treatment.

OBJECTIVE: To investigate the long-term effects of antipsychotic (AP) treatment and AP-induced hyperprolactinemia on bone mineral density (BMD) and body composition in male adolescents with autism spectrum disorders (ASDs) and/or disruptive behavior disorder (DBD). DESIGN: Physically healthy 10- to 20-year-old boys with ASD and/or DBD, chronically treated (n=56; mean 52 months, range 16-126 months) or not treated (n=47) with an AP, were recruited to this observational study. Prolactin levels and biochemical bone parameters were measured and BMD of the lumbar spine and total body, and body composition were assessed by dual-energy X-ray absorptiometry, and volumetric BMD of the lumbar spine calculated. Group differences were tested with Student's t-test, χ(2) test, Fisher exact test, and logistic regression analysis. RESULTS: Forty-nine percent of the boys treated with an AP had hyperprolactinemia. The mean volumetric lumbar spine BMD z-score was lower (P=0.043), the total percentage of body fat z-score was higher (P=0.042), and biochemical bone marker carboxyterminal cross-linking telopeptide of bone collagen was lower in the AP-treated boys with hyperprolactinemia than in the AP-treated boys without hyperprolactinemia. Seven to 11% of the hyperprolactinemic boys had low BMD. The mean lumbar spine and total body BMD z-scores and body composition were similar in the boys who were or were not treated with an AP. The total study population had a lower mean lean tissue mass (mean z-score -0.37, P=0.004) and a higher percentage of total body fat (mean z-score 1.16, P<0.001) than healthy controls (normative data); biochemical bone parameters were within normal limits. CONCLUSION: AP-induced hyperprolactinemia in boys with ASD or DBD may have a negative effect on lumbar spine BMD. Longitudinal studies are needed to confirm this finding and further disentangle the effects of the disorder, lifestyle, treatment, and hyperprolactinemia.