Quantitative Single-Photon Emission Computed Tomography/Computed Tomography for Evaluation of Salivary Gland Dysfunction in Sjögren's Syndrome Patients / 대한핵의학회잡지

PURPOSE: The purpose of the study was to investigate the usefulness of quantitative salivary single-photon emission computed tomography/computed tomography (SPECT/CT) using Tc-99m pertechnetate in Sjögren's syndrome (SS).METHODS: We retrospectively reviewed quantitative salivary SPECT/CT data from 95 xerostomic patients who were classified as either SS (n = 47, male:female = 0:47, age = 54.60 ± 13.16 y [mean ± SD]) or non-SS (n = 48, male:female = 5:43, age = 54.94 ± 14.04 y) by combination of anti-SSA/Ro antibody, labial salivary gland biopsy, unstimulated whole saliva flow rate, and Schirmer's test. Thyroid cancer patients (n = 43, male:female = 19:24, age = 46.37 ± 12.13 y) before radioactive iodine therapy served as negative controls. Quantitative SPECT/CT was performed pre-stimulatory 20 min and post-stimulatory 40 min after injection of Tc-99m pertechnetate (15 mCi). The %injected dose at 20 min and the %excretion between 20 and 40 min were calculated for parotid and submandibular glands, generating four quantitative parameters: %parotid uptake (%PU), %submandibular uptake (%SU), %parotid excretion (%PE), and %submandibular excretion (%SE). The most useful parameter for SS diagnosis was investigated.RESULTS: The uptake parameters (%PU and %SU) were significantly different among the SS, non-SS, and negative controls (p = 0.005 for %PU and p < 0.001 for %SU, respectively), but the excretion parameters (%PE and %SE) were not (p > 0.05 for both). The%PU and%SU were significantly lower in SS than in the negative controls and non-SS (p < 0.05 for all pair-wise comparisons). Additionally, the %SU was significantly lower in non-SS than in the negative controls (p < 0.05). Receiver-operating characteristic analysis revealed that the %SU had the greatest area-under-the curve of 0.720 (95% confidence interval = 0.618–0.807). Using the optimal cut-off value of %SU ≤ 0.07%, SS was identified with a sensitivity of 70.21% and a specificity of 70.83%.CONCLUSION: Reduced submandibular uptake of Tc-99m pertechnetate at 20 min (%SU) was proved useful for the diagnosis of SS. Quantitative salivary gland SPECT/CT holds promise as an objective imaging modality for assessment of salivary dysfunction and may facilitate accurate classification of SS.

Quantitative Single-Photon Emission Computed Tomography/Computed Tomography for Evaluation of Salivary Gland Dysfunction in Sjögren's Syndrome Patients / 대한핵의학회잡지

PURPOSE@#The purpose of the study was to investigate the usefulness of quantitative salivary single-photon emission computed tomography/computed tomography (SPECT/CT) using Tc-99m pertechnetate in Sjögren's syndrome (SS).@*METHODS@#We retrospectively reviewed quantitative salivary SPECT/CT data from 95 xerostomic patients who were classified as either SS (n = 47, male:female = 0:47, age = 54.60 ± 13.16 y [mean ± SD]) or non-SS (n = 48, male:female = 5:43, age = 54.94 ± 14.04 y) by combination of anti-SSA/Ro antibody, labial salivary gland biopsy, unstimulated whole saliva flow rate, and Schirmer's test. Thyroid cancer patients (n = 43, male:female = 19:24, age = 46.37 ± 12.13 y) before radioactive iodine therapy served as negative controls. Quantitative SPECT/CT was performed pre-stimulatory 20 min and post-stimulatory 40 min after injection of Tc-99m pertechnetate (15 mCi). The %injected dose at 20 min and the %excretion between 20 and 40 min were calculated for parotid and submandibular glands, generating four quantitative parameters: %parotid uptake (%PU), %submandibular uptake (%SU), %parotid excretion (%PE), and %submandibular excretion (%SE). The most useful parameter for SS diagnosis was investigated.@*RESULTS@#The uptake parameters (%PU and %SU) were significantly different among the SS, non-SS, and negative controls (p = 0.005 for %PU and p 0.05 for both). The%PU and%SU were significantly lower in SS than in the negative controls and non-SS (p < 0.05 for all pair-wise comparisons). Additionally, the %SU was significantly lower in non-SS than in the negative controls (p < 0.05). Receiver-operating characteristic analysis revealed that the %SU had the greatest area-under-the curve of 0.720 (95% confidence interval = 0.618–0.807). Using the optimal cut-off value of %SU ≤ 0.07%, SS was identified with a sensitivity of 70.21% and a specificity of 70.83%.@*CONCLUSION@#Reduced submandibular uptake of Tc-99m pertechnetate at 20 min (%SU) was proved useful for the diagnosis of SS. Quantitative salivary gland SPECT/CT holds promise as an objective imaging modality for assessment of salivary dysfunction and may facilitate accurate classification of SS.

Comparison of Two Different Segmentation Methods on Planar Lung Perfusion Scan with Reference to Quantitative Value on SPECT/CT / 대한핵의학회잡지

PURPOSE: Until now, there was no single standardized regional segmentation method of planar lung perfusion scan.We compared planar scan based two segmentation methods, which are frequently used in the Society of Nuclear Medicine, with reference to the lung perfusion single photon emission computed tomography (SPECT)/computed tomography (CT) derived values in lung cancer patients.METHODS: Fifty-five lung cancer patients (male:female, 37:18; age, 67.8 ± 10.7 years) were evaluated. The patients underwent planar scan and SPECT/CT after injection of technetium-99 m macroaggregated albumin (Tc-99 m-MAA). The % uptake and predicted postoperative percentage forced expiratory volume in 1 s (ppoFEV1%) derived from both posterior oblique (PO) and anterior posterior (AP) methods were compared with SPECT/CT derived parameters. Concordance analysis, paired comparison, reproducibility analysis and spearman correlation analysis were conducted.RESULTS: The % uptake derived from PO method showed higher concordance with SPECT/CT derived % uptake in every lobe compared to AP method. Both methods showed significantly different lobar distribution of%uptake compared to SPECT/CT. For the target region, ppoFEV1% measured from PO method showed higher concordance with SPECT/CT, but lower reproducibility compared to AP method. Preliminary data revealed that every method significantly correlated with actual postoperative FEV1%, with SPECT/CT showing the best correlation.CONCLUSIONS: The PO method derived values showed better concordance with SPECT/CT compared to the AP method. Both PO and AP methods showed significantly different lobar distribution compared to SPECT/CT. In clinical practice such difference according to different methods and lobes should be considered for more accurate postoperative lung function prediction.

Quantitative Single-Photon Emission Computed Tomography/Computed Tomography for Glomerular Filtration Rate Measurement / 대한핵의학회잡지

PURPOSE: We propose a quantitative Tc-99m diethylenetriaminepentaacetic acid (DTPA) single-photon emission computed tomography/computed tomography (SPECT/CT) for glomerular filtration rate (GFR) measurement.METHODS: Quantitative SPECT/CT data obtained at 2–3 min post-Tc-99m DTPA injection (370 MBq) were used to determine % injected doses (%IDs) for individual kidneys. The reproducibility of %ID measurement was tested and compared with planar scintigraphy. Cr-51 ethylenediaminetetraacetic acid (EDTA) GFR was used as reference standard. Nine young volunteers, representing normal GFR, and ten older volunteers, reflecting impaired GFR, were enrolled. The established GFR equation derived from these volunteerswas applied to 19 renal tumor patients post-partial nephrectomy.RESULTS: At 2–3 min, %ID was most reproducible with the highest intraclass correlation (ICC) (0.9379) and lowest % coefficient of variation (CV) (6.5259%), which were more reliable than the ICC (0.9368) and %CV (6.7689%) of planar scintigraphy. Cr-51 EDTA GFR (93.16 ± 24.81 ml/min) correlated significantly with %ID (7.66 ± 2.15%, r = 0.7906, p = 0.0001), yielding an equation: Cr-51 EDTA GFR (ml/min) = (%ID × 9.1462) + 23.0653. This equation revealed significant decreases in total and nephrectomized kidney GFR (p = 0.0012 and p < 0.0001, respectively) from preoperative to 3-month postoperative measurements.CONCLUSIONS: Quantitative Tc-99m DTPA SPECT/CT produces reliable and clinically applicable %ID estimates that translate to the GFR of individual kidneys.

Usefulness of Multislice Computerized Tomographic Angiography in Evaluation of Intracranial Aneurysms: Surgical Correlation

OBJECTIVE: The usefulness of multislice computerized tomographic angiography(MCTA) in operating intracranial aneurysms is studied by comparing the features of MCTA with intraoperative findings. METHODS: From December 2001 to February 2003, 74 clippings of aneurysmal neck were carried out based mainly on the aneurysmal features of preoperative MCTA. MCTA studies consisted of four rows(multislice technology), with slice thickness of 1.25mm at 0.6mm reconstruction intervals and pitch of 0.75. Timing was determined using the Smart Prep automatic triggering system. The locations of aneurysms were classified into 3 subgroups: internal carotid artery, middle cerebral artery, and anterior communicating artery and distal anterior cerebral artery. The aneurysmal features on MCTA were compared with their operative findings, using our comparison items, and graded subsequently. RESULTS: A total of 77 intracranial aneurysms were identified among 64 patients on preoperative MCTA, and one of them was false positive. Two angiographically unrecognized microaneurysms were identified on operation. In the detection of intracranial aneurysm, MCTA had 98.4% sensitivity and 96.9% specificity on a perpatient basis. On a per-aneurysm basis, MCTA sensitivity and specificity were 98.6% and 97.3%, respectively. The shapes of aneurysms on MCTA were not related with the grade(chi-square test: X2=1.566, p=0.457), but each grades of simple, bilobulation, and multilobulation were grade 1. Sum of grading scores were related with site of aneurysm(Chi-square test: X2=48.635, p=0.001), In particular, sum of grading scores of MCA aneurysms were 5. Although fine vascular architectures such as hypoplastic A1 and posterior communicating artery, perforating artery of A-COM, and anterior choroidal artery were invisible on MCTA, the MCTA images of ICA and A-COM aneurysms were also found to be valuable in intracranial aneurysm surgery. CONCLUSION: MCTA is useful in planning the surgery of intracranial aneurysm compared to single detector CTA. Postoperative DSA of stabilized patient is mandatory for confirming operative results and any missing unruptured aneurysm after MCTA based cerebral aneurysm surgery.

Growing Fracture of the Skull: A Case Report

The authors report a case of growing fracture of the skull, also called as leptomeningeal cyst, in a young boy who presented with symptoms of skull defect, headache, and pulsating mass on right posterior parietal area. Successful duroplasty and cranioplasty with autogenous bone were performed resulting in disappearance of all symptoms. The most significant factor contributing to the growing fracture is an underlying dura tear. A brief review of the relevant literature is also presented.

Growing Fracture of the Skull: A Case Report

The authors report a case of growing fracture of the skull, also called as leptomeningeal cyst, in a young boy who presented with symptoms of skull defect, headache, and pulsating mass on right posterior parietal area. Successful duroplasty and cranioplasty with autogenous bone were performed resulting in disappearance of all symptoms. The most significant factor contributing to the growing fracture is an underlying dura tear. A brief review of the relevant literature is also presented.