Table 1.
Evidence quality for single photon emission CT (SPECT)-CT in musculoskeletal radiology based on Oxford Centre of Evidence-Based Medicine guidelines [67]
| Indication | Study | Design | Level of evidence |
| Malignant disease in the axial skeleton | Utsunomiya et al [26] | 45 patients with 42 metastatic foci and 40 benign foci. Two independent readers scoring diagnostic confidence for each lesion for bone scintigraphy alone and bone scintigraphy and CT images viewed together and, finally, bone scintigraphy, CT images and fused images | Level II |
| All underwent planar scintigraphy and SPECT and CT directed by SPECT findings. SPECT and CT images then were digitally combined. The three types of images were evaluated separately for lesion visibility, diagnostic performance and diagnostic certainty. | Strobel et al [27] | Prospective study of 37 patients with 42 focal skeletal lesions | Level II |
| Horger et al [28] | 47 patients with 104 equivocal lesions on bone scintigraphy. Findings of bone scintigraphy (planar and SPECT), SPECT+CT or radiography and SPECT-CT were compared with regard to location and benignity | Level II | |
| Romer et al [29] | 272 patients with malignancy underwent bone scintigraphy. 112 (41%) required further investigation by SPECT because of diagnostic uncertainty with standalone whole-body planar scintigraphy. For 57 of these patients, inline CT over the body region of interest accompanied SPECT; the remaining 55 subjects underwent only SPECT for logistic reasons. The 57 SPECT/CT studies were retrospectively reported by readers blinded to the clinical pretest probability and the planar scan findings. 52 lesions were rated as indeterminate on the SPECT images. Afterwards, the corresponding SPECT/CT images were assessed and the previous indeterminate findings were reclassified either as definitely benign, indeterminate or definitely malignant | Level II | |
| Barwick et al [30] | 48 oncological patients were retrospectively reviewed, comparing diagnostic confidence between SPECT-CT and SPECT alone | Levels III/IV | |
| Helyar et al [31] | Retrospective review of 40 consecutive prostate cancer patients who underwent whole-body planar bone scintigraphy, SPECT and SPECT-CT. The images were reported by two independent reviewers and interreviewer agreement was evaluated. Each abnormal focus of increased uptake was scored using a four-tier scale of diagnostic confidence. In total, 50 lesions on planar bone scintigraphy in the 40 patients were evaluated | Level III | |
| Benign musculoskeletal disease | Even-Sapir et al [32] | 76 consecutive non-cancer patients with non-specific bone scan findings, which needed further morphologic data for interpretation. Bone scan indications were pain (n=61), trauma (n=7), suspected infection or inflammation (n=6) and fever of unknown origin (n=2). The reviewing physicians commented on whether SPECT-CT reached a final diagnosis and whether additional imaging was warranted | Level III |
| Linke et al [33] | 71 non-cancer patients with extremity pain underwent 3-phase bone scan and SPECT-CT. Planar and SPECT images and planar scintigraphic and SPECT-CT images were interpreted separately from each other. The results were classified as: normal, trauma, tumour, osteomyelitis and degenerative disease. The additional diagnostic value of skeletal SPECT/CT for extremity pain was assessed | Level III | |
| Hip and groin | Mulholland et al [40] | Demonstration of femoroacetabular impingement syndrome in a single case using SPECT-CT | Levels IV/V |
| Foot and ankle | Gnanasegaran et al [43] | SPECT-CT series of 31 patients with unexplained foot pain and post-surgical patients compared with SPECT alone assessed for additional diagnostic information and potential change in management | Level IV |
| Leumann et al [44] | MRI and SPECT-CT of 25 patients were analysed by 3 orthopaedic surgeons blinded to the study. Defined criteria was used for cartilage, subchondral bone plate and subchondral bone, including bone marrow signal change on MRI and activity on SPECT-CT. For MRI alone, SPECT-CT alone and the combined correlation, the treatment decision had to be defined | Level IV | |
| Wiewioski et al [45] | Correlation between pain from osteochondral lesions and pathological uptake seen on SPECT-CT in 15 patients and response to diagnostic local anaesthetic infiltration into the ankle joint | Level IV | |
| Knupp et al [46] | 27 patients with varus or valgus hindfoot were assessed using radiography, plain CT, bone scan and SPECT-CT. The degree of deformity, stage of osteoarthritis and level of bone scan and SPECT-CT activity were measured | Levels IV/V | |
| Mohan et al [47] | Assessed the additional value of SPECT-CT in 16 patients referred from a specialist orthopaedic clinic and role in changing management of bony foot and ankle pathology | Levels IV/V | |
| Breunung et al [50] | Single case describing additional benefit of SPECT-CT in the investigation of heel pain | Levels IV/V | |
| Knee pain | Fernando et al [55] | Case review of selected single cases of SPECT-CT findings in painful knees | Levels IV/V |
| Upper limb | Huellner et al [57] | Retrospective study of 21 patients investigating non-specific pain of the hand or wrist. All patients underwent planar early-phase imaging and late-phase SPECT-CT in addition to MRI. Lesions were divided into causative and not causative pathologies on the basis of clinical follow-up. Oedema-like bone marrow MR signal changes were compared with focally increased SPECT-CT tracer uptake | Level IV |
| Hirschmann et al [58] | Case review of four selected cases demonstrating clinical value of SPECT-CT for shoulder pathology | Levels IV/V | |
| Musculoskeletal infection | Bar-Shalom et al [59] | 82 patients evaluated for known or suspected infection. 47 patients underwent 67 Ga SPECT/CT and 35 patients underwent 111In-labelled WBC SPECT/CT. Any additional information revealed by SPECT/CT as compared with planar and SPECT scintigraphy was recorded | Level IV |
| Horger et al [60] | 27 patients with suspected bone infection underwent immunoscintigraphy with 99mTc-labelled AGA. Planar images were acquired immediately, 4 h and 24 h post injection, and SPECT/CT was performed using a dual-head gamma camera fitted with a low-energy X-ray system. Accumulation of AGA in lesions was quantified, comparing uptake at 4 h and 24 h after injection. The validation was based on culture data derived from surgical or biopsy samples (20 lesions in 18 patients) or clinical follow-up without further therapy for more than 6 months (9 lesions) | Level II | |
| Filippi and Schillaci [61] | 99mTc-hexamethylpropyleneamine oxime (HMPAO) scintigraphy was performed on 28 patients. 15 with suspected bone infection and 13 with suspected orthopaedic implant infection. Planar scans were obtained 30 min, 4 h and 24 h after injection. SPECT-CT was acquired 6 h after injection. Results were matched with the results from surgery or cultures and clinical follow-up | Level II | |
| Horger et al [62] | 31 suspected bone infection patients with pathological findings on 3-phase bone scan underwent additional SPECT-CT. 99mTc-DPD was used for all patients. Bone scintigraphy findings (planar scans as well as SPECT) were categorised as positive, negative or equivocal for the presence of osteomyelitis. In a second step, they were compared with SPECT-CT and SPECT+CT/X-ray/MRI. Validation was achieved through surgery, biopsy or by clinical follow-up | Level II | |
| Heiba et al [63] | 213 patients with suspected diabetic foot infection. Blood flow/pool images were obtained followed by leukocyte reinjection and next day dual isotope 3 phase 99mTc HDP bone scan, 111In leukocyte scan (WBCs) planar and SPECT-CT. Bone marrow scanning/WBCs SPECT-CT was obtained on the following day when images were suspicious for mid-/hindfoot osteomyelitis. Diagnosis was classified as ostemyelitis, soft-tissue infection, both ostemyelitis/soft-tissue infection and other/no bony pathology by microbiology/pathology or clinical follow-up. Differentiation between various diagnostic categories and overall osteomyelitis diagnostic accuracy was assessed | Levels II/III | |
| Filippi et al [64] | 17 diabetic foot patients with 19 suspected infection locations were analysed. After 99mTc-HMPAO leukocyte labelling and administration, planar scans were obtained at 30 min, 4 h and 24 h. SPECT-CT was acquired at 6 h. The final diagnosis was established by clinical follow-up and by bone biopsy at 14 sites | Level II | |
| Gnanasegaran et al [65] | Single case report of usefulness of SPECT-CT in the diagnosis of spinal tuberculosis | Level IV | |
| Hassan et al [66] | Single case report of additional value of SPECT-CT in diagnosing heterotopic ossification around an amputation stump in a case of suspected osteomyelitis | Level IV |
AGA, antigranulocyte antibodies; HDP, hydroxydiphosphonate; WBC, white blood cell.