Single-photon Emission Computed Tomography And Computed Tomography Research Articles

Left ventricular speckle-tracking-derived mechanical dispersion in patients with transthyretin amyloidosis and their first-degree relatives

Abstract Background Mechanical dispersion has shown to predict ventricular (LV) arrhythmias and sudden cardiac death in populations with established cardiac diseases, such as cardiomyopathies and heart failure. Transthyretin amyloid (ATTR) cardiomyopathy arises from deposition of misfolded, insoluble transthyretin (TTR) in extracellular matrix. The disease impacts profoundly cardiac tissue architecture and its mechanical properties. Purpose The aim of this prospective study was assessment of LV speckle-tracking-derived mechanical dispersion in patients with ATTR cardiomyopathy and their first-degree relatives. Methods We present data based on evaluation of 85 patients, including 34 (group 1) index patients with ATTR and 51 (group 2) first-degree relatives who were studied between June 2020 and January 2023. Study protocol included clinical data, free light chain blood immunoglobulins and urine immunofixation, transthoracic echocardiography (TTE) with global longitudinal strain (GLS) analysis, hybrid technique single-photon emission computed tomography and computed tomography (SPECT/CT) with [99mTc] Tc 3,3-disphono-1,2-propanodicarboxylic acid (DPD), genetic testing by an amplicon-based next-generation TTR sequencing approach, and in selected cases cardiac or soft tissue biopsy. Mechanical dispersion was calculated manually from GLS measurements and defined as the standard deviation (SD) of contraction duration from R on the electrocardiogram (ECG) to peak negative longitudinal strain of all LV segments. Results In group 1 patients were older (66.6±11 vs. 50.7±14) and presented with higher New York Heart Association (NYHA) class (2.4± 1 vs. 1.1± 0.6) (p<0.05). Overall, there were detected following types of TTR variants - Phe53Leu, Ala101Val, Glu112Lys, Glu109Lys, Glu122Lys, Glu82Lys. Compared to group 2, group 1 presented with higher N-terminal (NT)-pro hormone BNP (NT-proBNP) value (5859±7320 vs. 281±990 pg/ml), greater intraventricular septum thickness (19±4 vs. 12±3 mm) and LV mass index values (199±69 vs.111±42 g/m2), impaired LV ejection fraction (44±13 vs. 59±10 %) and GLS (-12.7±6 vs. -18.7±4 %) (p<0.05). Moreover, patients with ATTR cardiomyopathy had significantly higher value of LV speckle-tracking-derived mechanical dispersion compared to their first-degree relatives (96.2±22.3 vs. 77.9±23.3 ms, p=0.0007). Conclusions Patients with ATTR cardiomyopathy present with significantly higher LV mass index value, impaired GLS and higher value of LV speckle-tracking-derived mechanical dispersion compared to their first-degree relatives (p<0.05). Assessment of LV speckle-tracking-derived mechanical dispersion may in future translate into further enhancement of disease evaluation and improving prognosis in the group of patients.

Right ventricle involvement in cardiac transthyretin amyloidosis in SPECT/CT with [99mTc]Tc-DPD

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): Pfizer Research Grant (ID#57165999). Background Transthyretin amyloid (ATTR) cardiomyopathy continues to be considered a rare disease; however, it is now more frequently diagnosed, partly due to advances in imaging techniques. Application of hybrid technique single-photon emission computed tomography and computed tomography (SPECT/CT) provides greater anatomic resolution, enabling the assessment of regional cardiac involvement. Purpose The aim of this prospective study was assessment of right ventricle involvement in patients with ATTR in SPECT/CT with [99mTc]Tc 3,3-disphono-1,2-propanodicarboxylic acid (DPD). Methods We present data based on evaluation of 100 patients, including 28 (group 1) index patients with ATTR and 72 (group 2) first-degree relatives who were studied between June 2020 and January 2023. Study protocol included clinical data, free light chain blood immunoglobulins and urine immunofixation, transthoracic echocardiography (TTE) with global longitudinal strain (GLS) analysis, SPECT/CT with [99mTc]Tc-DPD, genetic testing by an amplicon-based next-generation TTR sequencing approach, and in selected cases cardiac or soft tissue biopsy. Results In group 1 there were 39% patients diagnosed with hereditary ATTR (ATTRm) and 61% with ATTR wild type (ATTRwt). There were detected following types of TTR variants - Phe53Leu, Ala101Val, Glu112Lys, Glu109Lys, Glu122Lys, Glu82Lys. Overall, 26% first-degree relatives were diagnosed with pathogenic TTR variant and 7% had positive SPECT/CT with [99mTc]Tc-DPD. In group 2 there was a significant predominance of Phe53Leu variant among carriers. Importantly, among patients with positive SPECT/CT with [99mTc]Tc-DPD 78% presented also right ventricle uptake. Overall, right ventricle involvement was present in 80% of patients with ATTRm and 76% of patients with ATTRwt who presented left ventricle uptake (p>0.05). Conclusions Right ventricle involvement in cardiac transthyretin amyloidosis can be assessed in SPECT/CT with [99mTc]Tc-DPD. In presented group 78% of patients who had cardiac tracer uptake presented as well right ventricle involvement. There were no statistically significant differences in rates between the ATTRwt and ATTRm groups (p>0.05). Assessment of right ventricle involvement in cardiac transthyretin amyloidosis in SPECT/CT may in future translate into further enhancement of disease evaluation and improving prognosis in the group of patients.

Value of Thallium-201 SPECT and SPECT/CT Brain Imaging in Differentiating Malignant from Nonmalignant Lesions: A Comparative Case-Series Study with Pathologic and/or Clinical Correlation (P3-13.005)

<h3>Objective:</h3> To describe results of patients who underwent Thallium-201 Single-photon Emission Computed Tomography and Computed Tomography (SPECT/CT) Brain Imaging and relate it to clinical and/or histopathologic findings. This is the first study in the Philippines that documented the correlation between Thallium-201 SPECT/CT findings with histologic and/or clinical diagnosis. <h3>Background:</h3> Thallium-201 SPECT/CT brain scanning is an imaging modality which can be done to differentiate between malignant and non-malignant lesions. Despite its availability, the procedure has been under-utilized and the lack of knowledge about its potential use can be the significant barrier in maximizing its clinical utility. <h3>Design/Methods:</h3> This is a retrospective case series study of 10 patients with cerebral lesions who underwent Thallium-201 SPECT/CT brain imaging in a hospital in the Philippines from 2010 to 2021. <h3>Results:</h3> From 2010 to 2021, a total of 10 patients underwent Thallium-201 SPECT/CT brain scan. Six had negative results while 4 had positive results. All of the patients who had positive results were found to have malignancy, whether recurrent or newly diagnosed. All of the patients with negative scan were found to have either an infectious and inflammatory disease and responded to treatment albeit in different degrees. Two of the 10 patients underwent biopsy whose results were consistent with the Thallium-201 SPECT/CT brain scan results. <h3>Conclusions:</h3> The findings in this study support the role of thallium scintigraphy in the diagnosis of patients with brain lesions most significantly when there is a need to differentiate between a malignant and benign condition. Thallium scintigraphy is a more affordable option compared to Magnetic Resonance Imaging whether conventional or combined with spectroscopy or perfusion studies. In the Philippine setting where cost can be an important factor in the choice of diagnostic procedure, this study further supports the use of Thallium-201 SPECT/CT scan in the diagnosis of patients with brain lesions. <b>Disclosure:</b> Dr. Pang has nothing to disclose. Dr. Luistro has nothing to disclose. Christianne Mojica has nothing to disclose. Dr. Domingo has nothing to disclose. Dr. Batara has nothing to disclose.

Persistent and Recurrent Primary Hyperparathyroidism: Etiological Factors and Pre-Operative Evaluation.

Primary hyperparathyroidism (pHPT) is the most common cause of hypercalcemia and currently the only definitive treatment is surgery. Although the success rate of parathyroidectomy is over 95% in experienced centers, surgical failure is the most common complication today. Persistent HPT (perHPT) is defined as persistence of hypercalcemia after parathyroidectomy or recurrence of hypercalcemia within the first 6 months, and recurrence of hypercalcemia after a normocalcemic period of more than 6 months is defined as recurrent HPT (recHPT). In the literature, perHPT is reported to be 2-22%, and the rate of recHPT is 1-15%. perHPT is often associated with misdiagnosed pathology or inadequate resection of hyperfunctioning parathyroid tissue, recHPT is associated with newly developing pathology from potentially pathologically natural tissue left in situ at the initial surgery. In the pre-operative evaluation, the initial diagnosis of pHPT and the diagnosis of perHPT or rec HPT should be confirmed in patients who are evaluated with a pre-diagnosis (suspect) of perHPT and recHPT. Surgery is recommended if it meets any of the recommendations in surgical guidelines, as in patients with pHPT, and there are no surgical contraindications. The first preoperative localization studies, surgical notes, operation drawings, if any, intraoperative PTH results, pathological results, and post-operative biochemical results of these patients should be examined. Localization studies with preoperative imaging methods should be performed in all patients with perHPT and recHPT with a confirmed diagnosis and surgical indication. The first-stage imaging methods are ultrasonography and Tc99m sestamibi single photon tomography Tc99mMIBI SPECT or hybrid imaging method, which is combined with both single-photon emission computed tomography and computed tomography (SPECT/CT). The combination of USG and sestamibi scintigraphy increases the localization of the pathological gland. In the secondary stage, Four-Dimensional computer tomography (4D-CT) or dynamic 4-dimensional Magnetic Resonance Imaging (4D-MRI) can be applied. It is focused on as a secondary stage imaging method, especially when the lesion cannot be detected by conventional methods. Positron Emission Tomography (PET) and PET/CT examinations with 11C-choline or 18F-fluorocholine are promising imaging modalities. Invasive examinations can rarely be performed in patients in whom suspicious, incompatible or pathological lesion cannot be detected in noninvasive imaging methods. Bilateral jugular vein sampling, selective venous sampling, parathyroid arteriography, imaging-guided fine-needle aspiration biopsy, and parathormone washout are invasive methods.

Clinical Usefulness of SPECT/CT for Assessing Postoperative Outcomes After Medial Opening-Wedge High Tibial Osteotomy.

Background:Qualitative studies have explored changes in Tc-99m hydroxymethylene diphosphonate (HDP) uptake on single-photon emission computed tomography and computed tomography (SPECT/CT) as a result of offloading after medial opening-wedge high tibial osteotomy (MOWHTO) in patients with medial compartment knee osteoarthritis. However, whether changes in the Tc-99m HDP uptake on SPECT/CT reflect the degree of clinical improvement in postoperative outcomes, especially when using minimal clinically important differences (MCIDs), has not been investigated.Purpose:To investigate the association between changes in Tc-99m HDP uptake on SPECT/CT and MCID-based improvement on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score in patients who underwent MOWHTO.Study Design:Cross-sectional study; Level of evidence, 3.Methods:The study included 35 knees in 31 patients who underwent MOWHTO. SPECT/CT was performed preoperatively and 3 years postoperatively with clinical and radiological assessments. On SPECT/CT, the knee joint was divided into 10 regions, and the radiotracer uptake amount of each region was divided by the uptake amount of the reference zone. Patients were divided into 2 groups based on whether they achieved the MCID of 16.1 points on the WOMAC at 3 years postoperatively, and changes in uptake amount on SPECT/CT were compared between the groups.Results:At 3 years postoperatively, 22 patients achieved the MCID on the WOMAC (62.9%; above-MCID group) and 13 patients did not (37.1%; below-MCID group). In the above-MCID group, significant improvement was observed in the WOMAC after MOWHTO (from 55.8 to 19.6; P < .05); however, significant improvement was not observed in the below-MCID group (from 38.8 to 32.3; P = .100). Based on mean change of uptake on SPECT/CT in each region, the above-MCID group showed significantly greater reduction of uptake on SPECT/CT than the below-MCID group in the femoral anteromedial compartment (P = .004), tibial anteromedial compartment (P = .009), and tibial anterolateral compartment (P = .031).Conclusion:Reduction in radiotracer uptake on SPECT/CT of the knee joint reflected clinical improvement in patient-reported outcomes following MOWHTO.

Successful endoscopic surgical treatment of pleuroperitoneal communication in two infant cases

BackgroundPleuroperitoneal communication (PPC) is an uncommon, but potentially life-threatening complication of peritoneal dialysis (PD). If a fistula does not close with conservative treatment, surgical repair is required. However, approximately half of these patients are forced to shift from PD to hemodialysis. Although it is important to confirm the site of the fistula to achieve a successful surgical treatment, this identification is more difficult in pediatric patients than in adults.Case presentationWe report two infantile cases of severe PPC associated with PD. In both cases, the age at onset was less than 2 years, and right-sided pleural effusion with dyspnea was observed. PPC was diagnosed by the change in color of the pleural fluid after the injection of a dye into the peritoneal cavity. Peritoneal scintigraphy and single-photon emission computed tomography and computed tomography (SPECT/CT) were performed, and these were effective in locating the fistula site. Endoscopic surgery (video-assisted thoracic surgery (VATS) and laparoscopic surgery) was performed. Indocyanine green (ICG), which was injected into the abdominal cavity, showed the exact site of the fistula. The fistula was successfully closed by attaching an absorbable sheet to it from the thoracic side and an autograft (the falciform ligament) to it from the abdominal side in one patient. In the other patient, the fistula site was resected and sutured, and reinforced with an absorbable sheet. In both cases, PD was resumed without any complication.ConclusionWe successfully treated two infants of PPC by endoscopic surgery. To identify the fistula site, the ICG navigation method was useful. Even in small infants, PPC can be treated successfully by endoscopic surgical repair if the site of the fistula is identified.

187. Compared to gold standard bone SPECT/CT showed superior accuracy in detecting pseudarthrosis

BACKGROUND CONTEXT Pseudarthrosis remains the primary cause of persistent pain postoperatively after spinal fusion surgery, leading to failed back surgery syndrome. The utility of the integrated single-photon emission computed tomography and computed tomography (SPECT/CT) in a bone scan as a problem-solving tool in evaluating patients with suspected pseudarthrosis, hardware failure and adjacent level disease has been previously reported. A number of studies have been done showing its benefits and limitations when compared to other imaging techniques. Direct comparison against the gold standard of surgical pseudarthrosis confirmation is limited. PURPOSE The purpose of this study is to evaluate the diagnostic accuracy of SPECT/CT, computed tomography (CT) and magnetic resonance imaging (MRI) scans in preoperatively identifying pseudarthrosis with verification by intraoperative findings. STUDY DESIGN/SETTING Retrospective study. PATIENT SAMPLE Patients undergoing revision spinal surgery. OUTCOME MEASURES Imaging comparison to gold standard. METHODS After obtaining IRB approval, a retrospective study of patients who underwent revision spinal fusion was completed. The surgeries were performed by a single orthopedic spine surgeon over a 12-month period. Patients included in the study had SPECT/CT imaging done prior to surgery, and had either MRI or CT scan or both. All available preoperative imaging results (SPECT/CT, CT and MRI) and operative reports were collected, verified and compared. Estimates of sensitivity, specificity, likelihood ratios (LRs), positive predictive value (PPV) and negative predictive value (NPV) were all calculated to evaluate the diagnostic accuracy. RESULTS A total of 60 surgical patients (62% female, mean age 58 years), including 19 cervical fusion (32%), five thoracolumbar fusion (8%) and 36 lumbar fusion (60%), were included in this series. Prior to spinal surgery, average time to imaging of 60 patients who underwent SPECT/CT, 31 patients who underwent CT, and 33 patients who underwent MRI was around 5 months, respectively. Results of diagnostic accuracy show that when compared to lower sensitivity studies like CT (11%) and MRI (6%), SPECT/CT sensitivity was high at 91% (95% CI 75-98%) leading a significant negative likelihood ratio at -LR 0.1 (95% CI 0.04-0.36) and a PPV of 83% (95% CI 70-91%); specificity was moderate at 79% (95% CI 59-92%) with a moderate positive likelihood ratio of +LR 4 (95% CI 2-9) and a NPV of 88% (95% CI 71-96%). CONCLUSIONS SPECT/CT scan was found to demonstrate excellent criterion validity to rule-out a diagnosis of pseudarthrosis when a negative result was observed; however, further validation is warranted. DISCUSSION Pseudarthrosis can be challenging to diagnose as it can also occur with other postoperative complications such as adjacent level disease and/or hardware failure, SPECT/CT scan should be integrated into routine clinical practice as a diagnostic tool in patients with persistent postoperative pain. A negative SPECT-CT virtually rules out pseudarthrosis. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Utility of hybrid SPECT/CT in primary melanoma lymphoscintigraphy: A retrospective case series.

Sentinel lymph node (SLN) biopsy is widely accepted as an important part of staging cutaneous malignant melanoma. Hybrid single photon emission computed tomography and computed tomography (SPECT/CT) may identify additional SLN and provide important information to the surgeon performing SLN biopsy. We report our experience at a major referral centre for melanoma surgery. Retrospective case series of pre-operative sentinel node lymphoscintigraphy for primary melanoma over a consecutive 12-month period. All patients had planar imaging and hybrid SPECT/CT. At least 1 SLN was successfully identified in 82 of 86 eligible patients (95.3%). These 82 patients had 144 SLNs (mean 1.8). There were no patients where the SLN was seen only with SPECT/CT. Additional information was provided by SPECT/CT in 32 patients (39.0%). Histology reports were available for 52 patients, 9 (17.3%) had at least 1 SLN positive for metastatic disease. We achieved a high rate of SLN identification. SPECT/CT was most frequently helpful when the primary melanoma was located in the head, neck and trunk. Routine use of SPECT/CT during lymphoscintigraphy provides important anatomical information and may reduce the false-negative rate.

Development of a Protocol for SPECT/CT in the Assessment of Wrist Disorders

Background Single-photon emission computed tomography and computed tomography (SPECT/CT) is a hybrid diagnostic imaging modality that allows clinicians to integrate their diagnostic evaluations and deliver a definitive diagnosis in musculoskeletal disorders. Specifically, in identification of osseous pathology, the conventional bone scan delivers greater specificity compared with magnetic resonance imaging (MRI). However, use of SPECT/CT enhances the sensitivity and specificity. Use of this modality denotes the possibility to specify the lesion more accurately and precisely while grading the activity according to osseous structural changes. Purpose This study aimed to evaluate the clinical utility of SPECT/CT in the diagnoses and management of osseous wrist disorders. The objectives were to examine the value of SPECT/CT in the diagnosis of osseous-related wrist pain and whether the findings altered management. Patients and Methods A retrospective cohort study of 20 patients with such wrist pain was conducted. SPECT/CT was used in the diagnostic process for these patients. Results Following SPECT/CT imaging, the common final diagnoses were osteoarthritis (10; 50%) and avascular necrosis (5; 25%). Less common diagnoses included ulnar carpal impact syndrome, infection, malunion, complex regional pain syndrome, and carpal boss. Some presented with multiple pathologies. SPECT/CT changed the final diagnosis in 11 cases, resulting in nonoperative treatment (7; 63%) or surgery (4; 37%). Conclusion Findings from this study and the literature demonstrate the clinical utility of SPECT/CT in the assessment of osseous-related wrist disorders. We present an algorithm for the assessment of wrist pain with osseous pathology. This commences with clinical assessment and plane radiographs (first-line investigation). Some cases will require a second-line investigation (ultrasound, CT, and/or MRI). If the diagnosis remains unclear, SPECT/CT is recommended as a third-line investigation.

Increased 99mTc MDP activity in the costovertebral and costotransverse joints on SPECT-CT: is it predictive of associated back pain or response to percutaneous treatment?

Pain related to costovertebral and costotransverse joints is likely an underrecognized and potentially important cause of thoracic back pain. On combined single-photon emission computed tomography and computed tomography (SPECT-CT), increased technetium-99m methylene diphosphonate (99mTc MDP) activity at these articulations is not uncommon. We evaluated whether this activity corresponds with thoracic back pain and whether it predicts response to percutaneous injection. All 99mTc MDP SPECT-CT spine examinations completed at our institution from March 2008 to March 2014 were retrospectively reviewed to identify those with increased 99mTc MDP activity in the costovertebral or costotransverse joints. The presence of corresponding thoracic back pain, percutaneous injection performed at the relevant joint(s), and response to injection were recorded. A total of 724 99mTc MDP SPECT-CT examinations were identified. Increased 99mTc MDP activity at costovertebral or costotransverse joints was reported in the examinations of 55 patients (8%). Of these, 25 (45%) had corresponding thoracic back pain, and nine of 25 patients (36%) underwent percutaneous injection of the joint(s) with increased activity. At clinical follow-up two days to 12 weeks after injection, one patient (11%) had complete pain relief, two (22%) had partial pain relief, and six (67%) had no pain relief. The findings suggest that increased activity in costovertebral and costotransverse joints on 99mTc MDP SPECT-CT is only variably associated with the presence and location of thoracic back pain; it does not predict pain response to percutaneous injection.

Low regional cerebral blood flow in burning mouth syndrome patients with depression.

The main aims of this study were to (i) investigate the emotional disorder status of patients with burning mouth syndrome (BMS) and (ii) detect regional cerebral blood flow in BMS patients with the application of combined single-photon emission computed tomography and computed tomography (SPECT/CT). The degree of pain was measured using the visual analysis scale, and emotional disorder with the self-rating anxiety scale, self-rating depression scale, and Hamilton depression rating scale in 29 patients with BMS and 10 healthy controls. SPECT/CT was performed in 29 patients with BMS and 10 healthy controls, and statistical parametric mapping method was used for between-group analyses. The incidence rate of depression in patients with BMS was 31.0%. Compared to the control group, patients with BMS displayed significantly different depression and anxiety scales (P<0.05). Significantly lower regional cerebral blood flow in the left parietal and left temporal lobes was recorded for BMS patients with depression (P<0.05). Patients with BMS experience more depression and anxious emotion. Moreover, depression in patients with BMS may be associated with lower regional cerebral blood flow in the left temporal and left parietal lobes.

SPECT/CT to diagnose pleuroperitoneal communication-associated hydrothorax in peritoneal dialysis

A 19-year-old man with end-stage renal failure secondary to bilateral hypoplastic kidney received nightly automated peritoneal dialysis (PD). Three months after starting PD, he complained of dyspnea. Chest X-ray showed right-sided pleural effusion (Figure 1). Congestive cardiac failure, hypoalbuminemia, and fluid overload were ruled out, so pleuroperitoneal communication (PPC) was suspected. Peritoneal scintigraphy with Tc-99m macro-aggregated albumin was performed. Simultaneously, single-photon-emission computed tomography and computed tomography (SPECT/CT) was performed to identify the leakage site using a hybrid system (BrightView XCT; Philips Medical Systems, Cleveland, OH). Radioactive tracer presence in the right hemithorax indicated the existence of PPC, with the right posterior diaphragm suggested as the presumptive leakage site (Figure 2). Nightly automated PD was suspended, and daytime PD was done at low volumes without worsening symptoms until living related renal transplantation was performed.

Value of sentinel lymph node biopsy in papillary thyroid cancer: initial results of a prospective trial

The objectives of the study were to evaluate the performance of sentinel lymph node biopsy (SLNB) in detecting occult metastases in papillary thyroid carcinoma (PTC) and to correlate their presence to tumor and patient characteristics. Twenty-three clinically node-negative PTC patients (21 females, mean age 48.4years) were prospectively enrolled. Patients were submitted to sentinel lymph node (SLN) lymphoscintigraphy prior to total thyroidectomy. Ultrasound-guided peritumoral injections of (99m)Tc-phytate (7.4MBq) were performed. Cervical single-photon emission computed tomography and computed tomography (SPECT/CT) images were acquired 15min after radiotracer injection and 2h prior to surgery. Intra-operatively, SLNs were located with a gamma probe and removed along with non-SLNs located in the same neck compartment. Papillary thyroid carcinoma, SLNs and non-SLNs were submitted to histopathology analysis. Sentinel lymph nodes were located in levels: II in 34.7% of patients; III in 26%; IV in 30.4%; V in 4.3%; VI in 82.6% and VII in 4.3%. Metastases in the SLN were noted in seven patients (30.4%), in non-SLN in three patients (13.1%), and in the lateral compartments in 20% of patients. There were significant associations between lymph node (LN) metastases and the presence of angio-lymphatic invasion (p=0.04), extra-thyroid extension (p=0.03) and tumor size (p=0.003). No correlations were noted among LN metastases and patient age, gender, stimulated thyroglobulin levels, positive surgical margins, aggressive histology and multifocal lesions. Sentinel lymph node biopsy can detect occult metastases in PTC. The risk of a metastatic SLN was associated with extra-thyroid extension, larger tumors and angio-lymphatic invasion. This may help guide future neck dissection, patient surveillance and radioiodine therapy doses.

Influence on therapeutic decision making of SPECT-CT for different regions of the foot and ankle.

Background. Single-photon emission computed tomography and computed tomography (SPECT-CT) has a high impact on diagnosis and treatment decision of different joints. The aim of this study was to evaluate whether there is a different gain of SPECT-CT for different foot regions. Material and Methods. We retrospectively identified 86 patients who received a SPECT-CT of the foot and ankle between April 2011 and December 2012. We divided all patients into the following subgroups: ankle (group 1), subtalar (group 2), Chopart (group 3), and Lisfranc (group 4). The local ethical committee approved the study. Results. The clinical treatment decision was changed based on SPECT-CT results in 64.5% of group 1, 65.2% of group 2, and 75% each of groups 3 and 4. Eighty patients (93%) had pain relief after treatment based on SPECT-CT. The overall SPECT-CT sensitivity was 0.94 and the specificity was 0.57. The positive and negative predictive values were 0.87 and 0.75, respectively. Conclusion. The impact of SPECT-CT on treatment decision is slightly higher in diseases of the Chopart and Lisfranc joints than in the upper ankle and subtalar joints. The additional information has a clinical relevance due to the high rate of pain relief by treatment based on SPECT-CT diagnosis.

Reliability of different radioisotopic techniques in diagnosing solitary hot spots in the spine of patients with malignant neoplasm

Early diagnosis of spinal metastases is of key importance in further therapeutic management. The aim of the study was to assess the reliability of single-photon emission computed tomography (SPECT) or SPECT and computed tomography (SPECT/CT) in the diagnosis of solitary hot nodules in the spine identified by scintigraphy. In this retrospective study, 70 patients with neoplastic disease and a solitary nodule detected in the spine were analyzed. Using a SPECT/CT γ-camera, the type and site of the foci in the vertebra were analyzed. Bone scintigraphy, SPECT, and CT were performed. Reliability of the results was assessed depending on the applied technique. In malignant lesions, increased isotope uptake was observed in the vertebral body with the posterior arch (89%), the body and both arches (67%), and the body alone (14%). In benign lesions, increased uptake was observed in the body area or in the joint area. Using SPECT, 25 of 27 cases (93%) of foci were properly classified as malignant. Using SPECT/CT, malignant lesions were observed in 26 of 27 cases (96%). Using SPECT, 19 of 43 cases were identified as benign (44%), and using SPECT/CT, 31 of 43 were identified as benign (72%). The agreement between SPECT and SPECT/CT was higher for malignant lesions (89%) than for benign lesions (67%). The use of CT in SPECT/CT examinations allowed to change the SPECT diagnosis of malignant lesions to that of benign lesions in 50% of the cases. The criteria used in the diagnosis of solitary nodules in the spine direct the diagnosis largely towards noncancerous lesions. Reliability of positive assessment was significantly lower than that of negative one - 51% in SPECT and 68% in SPECT/CT. A hybrid SPECT/CT camera is more reliable than SPECT alone in the assessment of spinal lesions.

An Unusual Case of Extraosseous Accumulation of Bone Scan Tracer in a Renal Calculus - Demonstration by SPECT-CT

Extraosseous localization of radioisotope, used in bone scan, in a variety of physiological and pathological conditions is a well-known phenomenon. The causes of extraosseous accumulation of bone-seeking radiotracers should be kept in mind when bone-imaging studies are reviewed to avoid incorrect interpretations. We report an extremely rare occurrence of extraosseous accumulation of bone scintigraphy tracer in a renal calculus, in a patient with adenocarcinoma of prostate, that was demonstrated by Single Photon Emission Computed Tomography and Computed Tomography (SPECT-CT) fusion imaging.

Ventilation-perfusion SPECT/CT in Diagnosing Swyer-James (MacLeod) Syndrome

We present the characteristics of a ventilation-perfusion scan correlating to both planar and single photon emission computed tomography and computed tomography (SPECT/CT) images of the lungs in a patient with Swyer-James (MacLeod) syndrome. A Tc-99m MAA lung perfusion scan was recorded with multiple projections and SPECT/CT. In the ventilation scan, initially dynamic acquisition of aerosol Tc-99m DTPA was obtained with an interval of 0.4 seconds per frame, followed by multiple static projections and SPECT/CT. Anatomically co-registered SPECT/CT of perfusion images demonstrated diffusely decreased perfusion without CT chest lesions over the affected radiolucent left lung. The SPECT/CT of ventilation scan showed heterogeneous radiotracer distribution and multiple defects resembling airflow obstruction over the left lung. A dynamic ventilation scan revealed diminished inhaled radioisotope in the left lung compared with the normal right lung. In contrast to over aeration of the left lung observed in the same area on CT, the dynamic hypoventilation implies the presence of air trapping. The SPECT/CT of ventilation-perfusion study showed matched defects in the left lung excluding a residual area of normal density, and permitted a specific reconstructive display to exhibit the pathophysiology of Swyer-James (MacLeod) syndrome with anatomic and functional co-registration.

A segmentectomy of the right upper lobe has an advantage over a right upper lobectomy regarding the preservation of the functional volume of the right middle lobe: Analysis by perfusion single-photon emission computed tomography/computed tomography

To evaluate the advantages of a segmentectomy of the right upper lobe (RUL) over a right upper (RU) lobectomy regarding the preservation of the functional volume of the right middle lobe (RML), the postoperative forced expiratory volume in one second (FEV(1)) of the RML was compared between an RU lobectomy and an RUL segmentectomy, by using a coregistered perfusion single-photon emission computed tomography and computed tomography (SPECT/CT). The pulmonary function tests and perfusion SPECT/CT were conducted before and after surgery (RU lobectomy: 7; RUL segmentectomy: 13). The FEV(1) of the RML before and after surgery was calculated from the data of the pulmonary function test and SPECT/CT. In the RU lobectomy group, the percentage change of FEV(1) was 71% +/- 12%, which was significantly lower in comparison to 92% +/- 9% in the RUL segmentectomy group (P = 0.001). In the lobectomy group, the preoperative FEV(1) of the RML was 0.17 +/- 0.10 l, which decreased significantly to 0.06 +/- 0.06l after surgery (P = 0.009). In the segmentectomy group, FEV(1) of the RML before and after the surgery were 0.23 +/- 0.10 l and 0.20 +/- 0.111, of which the difference was not significant. An RUL segmentectomy has an advantage over an RU lobectomy regarding the preservation of pulmonary function, due to a greater preservation of not only the lung tissue, but also the FEV(1) of the RML.

Postoperative change in pulmonary function of the ipsilateral preserved lung after segmentectomy versus lobectomy☆

Anatomical repositioning and expansion of the ipsilateral preserved lung after lung resection may influence postoperative pulmonary function. To study the postoperative changes in pulmonary function of the preserved lung after lobectomy compared with that after segmentectomy, the preoperative and postoperative forced expiratory volume in 1s (FEV(1)) of the ipsilateral non-operated lobe was measured using perfusion single-photon-emission computed tomography and computed tomography (SPECT/CT). Eighty-nine patients (n=24; lobectomy, n=65; segmentectomy) who were examined with pulmonary function test and perfusion SPECT/CT both before and after surgery were enrolled in this study. The FEV(1) values of the ipsilateral non-operated lobes before and after surgery were measured using perfusion SPECT/CT. The FEV(1) of the ipsilateral non-operated lobe increased after segmentectomy of the right upper lobe (p=0.07) and after both lobectomy and segmentectomy of the left upper lobe (p=0.04 and 0.001, respectively), but decreased after lobectomy of the right upper lobe (p=0.06). In the right upper lobe, the percentage change in FEV(1) of the ipsilateral non-operated lobe after lobectomy was significantly lower than that after segmentectomy (p<0.001). The FEV(1) of the ipsilateral non-operated lobe had not significantly changed after surgery on the lower lobes. The FEV(1) of the ipsilateral non-operated lobes increased after surgery on left upper lobe, whereas it decreased after right upper lobectomy. The surgery on lower lobe did not affect the FEV(1) of the ipsilateral non-operated lobes. Our data may facilitate determining the indications for lung cancer surgery, especially in patients with tumours involving the upper lobes.