Visualizing patterns of intervertebral disc damage with dual-energy computed tomography: assessment of diagnostic accuracy in an ex vivo spine biophantom.

BACKGROUND: Previously, dual-energy computed tomography (DECT) has been established for imaging spinal fractures as an alternative modality to magnetic resonance imaging (MRI). PURPOSE: To analyze the diagnostic accuracy of DECT in visualizing intervertebral disc (IVD) damage. MATERIAL AND METHODS: The lumbar spine of a Great Dane dog was used as an ex vivo biophantom. DECT was performed as sequential volume technique on a single-source CT scanner. IVDs were imaged before and after an injection of sodium chloride solution and after anterior discectomy in single-source sequential volume DECT technique using 80 and 135 kVp. Chondroitin/Collagen maps (cMaps) were reconstructed at 1 mm and compared with standard CT. Standardized regions of interest (ROI) were placed in the anterior anulus fibrosus, nucleus pulposus, and other sites. Three blinded readers classified all images as intact disc, nucleus lesion, or anulus lesion. Additionally, clinical examples from patients with IVD lesions were retrospectively identified from the radiological database. RESULTS: Interrater reliability was almost perfect with a Fleiss kappa of 0.833 (95% confidence interval [CI] 0.83-0.835) for DECT, compared with 0.780 (95% CI 0.778-0.782) for standard CT. For overall detection accuracy of IVD, DECT achieved 91.0% sensitivity (95% CI 83.6-95.8) and 92.0% specificity (95% CI 80.8-97.8). Standard CT showed 91.0% sensitivity (95% CI 83.6-95.8) and 78.0% specificity (95% CI 64.0-88.5). CONCLUSION: DECT reliably identified IVD damage in an ex vivo biophantom. Clinical examples of patients with different lesions illustrate the accurate depiction of IVD microstructure. These data emphasize the diagnostic potential of DECT cMaps.

The role of body computed tomography in hospitalized patients with obscure infection: Retrospective consecutive cohort study.

OBJECTIVE: Patients with severe infection or sepsis require fast identification of the focus and prompt eradication. This study aims at investigating the role of body computed tomography (CT) and identifying outcome predictors in a general ward setting of patients with obscure infection. METHODS: We retrospectively identified 196 consecutive body CTs acquired in 179 patients with obscure infection, i.e. severe infection or sepsis from general wards with unclear focus, over 12-months in the year 2018. Reports were extracted using a full-text search in the radiological information system (RIS) of a large university medical center. CT reports were classified according to diagnostic confidence of the reader (i.e. certain, likely, possible, no focus), and correlated with clinical and laboratory parameters. The discharge diagnosis was set as the diagnostic reference standard. Contingency tables were prepared for statistical analysis with Chi-squared test amongst other analyses and the calculation of AUC statistics. RESULTS: In 133 out of 196 (67.9 %) body CTs from general wards with severe infection or sepsis, body CT identified an infectious focus. 90 % of the infections were located in the chest, abdomen, and genitourinary tract, in descending order. In 76.5 % (150 of 196) of examinations, CT correctly predicted the final infectious source. The positive predictive value (PPV) of a CT-detected focus was 84.2 % (95 % CI 79.0%-88.3%). A high diagnostic confidence of the reader resulted in a PPV of 96.4 % (95 % CI 87.4%-99.1%) while a low confidence resulted in a PPV of 63.3 % (95 % CI 48.2%-76.3%). CONCLUSION: In patients with obscure infection treated in general wards, body CT detects the infectious source with a high positive predictive value. Focus detection accuracy highly depends on the diagnostic confidence of the CT reader.

Evaluation of long-term functional donor-site morbidity after deep circumflex iliac crest artery bone flap harvest.

PURPOSE: Free flap surgery can be associated with donor-site morbidity. The purpose of this study was to analyze long-term functional outcomes at the donor site after deep circumflex iliac artery (DCIA) bone flap harvesting. METHODS: Fourteen patients (8 men and 6 women, mean age 53.9 years; range 22-87 years) with mandible resection (8 carcinomas, 4 ameloblastomas, 1 osteonecrosis, and 1 myxofibroma) and DCIA flap reconstruction were included in an observational study. Ranges of motion in the hip and lumbar spine, Harris hip score (HHS), jumping mechanography, chair rising, and balance testing were performed on a ground force reaction plate (Leonardo Mechanograph, Novotec Medical GmbH, Germany). The primary outcome was the Esslinger fitness index (EFI, maximum peak power in W/kg normalized to age and gender). RESULTS: Functional assessment was performed preoperatively and 29.0 months postoperatively (range 12-51 months). Mean DCIA flap length was 6.3 cm (range 3.3-10.1 cm). Jaw reconstruction was successful in all cases. HHS (99.2 vs. 97.7 points, P = .004) and all ranges of motion in the lumbar spine and hip joint except for dorsal extension were significantly reduced postoperatively (range -4° to -11.0°). There was no significant difference between pre- and postoperative EFI (77.9% vs. 74.28%, P = .591) and body sway (1.25 cm2 vs. 2.01 cm2 , P = .806). Sensory deficits (n = 5), load dependent pain (n = 3), and limitations of daily activities (n = 3) were subjective complaints. CONCLUSION: Functional donor site morbidity after DCIA harvesting can be expected to be low in the long-term.