MR Imaging Appearances of Soft Tissue Flaps Following Reconstructive Surgery of the Lower Extremity

MR imaging appearances of different types of reconstructive muscle flaps following reconstructive surgery of the lower extremity with associated post-surgical changes due to altered anatomy, radiation, and potential complications, can be challenging. A multidisciplinary therapeutic approach to tumors allows for limb salvage therapy in a majority of the patients. Decision-making for specific types of soft tissue reconstruction is based on the body region affected, as well as the size and complexity of the defect. Hematomas and infections are early complications that can jeopardize flap viability. The local recurrence of a tumor within six months after a complete resection with confirmed tumor-free margins and adjuvant radiation therapy is rare. Identification of a new lesion similar to the initial tumor favors a finding of tumor recurrence.

[99m]tc-ubiquicidin [29-41], a promising radiopharmaceutical to differentiate orthopedic implant infections from sterile inflammation

Ubiquicidin [UBI] [29-41] is a synthetic cationic antimicrobial peptide that preferentially binds to bacterial cell membrane at the site of infection. We aimed to assess diagnostic value of [99m]Tc-UBI [29-41] as a radiopharmaceutical in differentiation of bacterial infection from sterile inflammation in suspected orthopedic implants. Nine patients suspected for orthopedic implant infection, all males with the mean age of 41.6 +/- 20.9 years, were studied. A dose of 10 MBq/Kg [range: 555-740 MBq] [99m]Tc-UBI [29-41] was injected intravenously. A dynamic study followed by static whole body imaging at 30, 60 and 120 min post-radiotracer injection was acquired. Periprosthetic tissue culture was considered the closest test to a gold standard for diagnosing infections and scintigraphic scans were categorized as true- or false-positive and true- or false-negative, considering the bacterial culture as the gold standard. No adverse reaction was observed during or after the radiotracer injection days. There were five true positive, four true negative and no false positive and false negative scans. Sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV] were all calculated as 100%. We found a high diagnostic accuracy for [99m]Tc-UBI [29-41] scintigraphy in differentiation of bacterial infection from sterile inflammation in suspected orthopedic implants. Therefore, [99m]Tc-UBI [29-41] scintigraphy might be potentially recommended as a safe and promising imaging modality in these settings. However, further studies on a larger number of patients and different pathologies are still needed

Ultrasonographic evaluation of inflammatory swellings of buccal space.

Objectives : The main objective of the study was a) to differentiate cellulitis and abscess in buccal space region, b) to study the ultrasonographic anatomy of cheek region and c) to investigate the use of ultrasound in the diagnosis of inflammatory swellings of cheek region. Patients and Methods : The study consisted of 25 patients with unilateral buccal space inflammatory swellings of odontogenic origin. The contra lateral side was used as control. Toshiba ultrasonographic device with a linear array transducer (5-8 MHz) was used. The areas of interest were scanned under both transverse and longitudinal sections and were interpreted by a single observer. The clinical diagnosis of cellulitis or abscess was confirmed by the absence or presence of pus respectively both sonographically and by aspiration. Also various anatomical structures present in buccal space were studied. Results : Clinically 23(92%) were diagnosed as buccal space abscess and 2 (8%) were cellulitis. Ultrasonographically and therapeutically 24 (96%) were buccal space abscess and 1 (4%) was cellulits. The sensitivity of clinical criteria over ultrasonographic diagnosis was 96% with a specificity of 100%. Also the cheek thickness in males and females varied from 8.2 to 17.1mm with a mean of 11.6mm±2.1 (SD) and 8.2 mm to 14.2 mm with a mean of 11±1.8 (SD). The subcutaneous tissue appeared moderately echogenic, buccinator - highly echogenic, deep adipose tissue - less echogenic and parotid duct was appreciated as a thin hyperechogenic band crossing the buccinator muscle. Buccal space, masticator space and parotid space were appreciated. Conclusion : This study supports the ultrasonographic method of imaging of orofacial inflammatory swellings with high sensitivity and specificity. This imaging modality can also help in aspiration of pus in different spaces. We have described the ultrasonographic anatomy of the above mentioned spaces which can help a beginner in this field.

Technetium-99m-labelled sulesomab [Leukoscan] in the evaluation of soft tissue infections

To perform a retrospective review of all patients receiving technetium-99m [[99m]Tc]-labelled sulesomab over a 4-year period to determine if soft tissue infections can be accurately identified. We reviewed the results of 124 99mTc-sulesomab studies performed over a 4-year period. Of these, 34 were performed for undiagnosed fever in which soft tissue infection was suspected to be the main cause. The patients' clinical notes, microbiology reports and other imaging findings were reviewed to determine the clinical outcome following the scan. The scans were regarded as being true-positives if [i] uptake correlated with the site from which fluid or tissue was obtained and which grew bacteria, and/or [ii] the site of abnormality was reported as having an infection on other imaging or [iii] there was a clinical correlation with the referring clinician's evaluation of the patient. Planar imaging was performed using standard protocols, together with single-photon emission computed tomography [if required] at 1 and 4 h after injection of 20-30 mCi [740-1,110 MBq] 99mTc-sulesomab. Three patients were unevaluable. In the remaining 31 patients, 21 99mTc-sulesomab studies were regarded as true-positives and 6 patients had true-negative scans. One patient had a false-positive scan [abnormal uptake with negative microbiology] and 3 had false-negative scans [infection confirmed but a negative scan]. In suspected soft tissue infection, 99mTc-sulesomab imaging has a sensitivity of 88% with a specificity of 86% and overall accuracy of 87%. 99mTc-sulesomab provides an accurate method of imaging for suspected soft tissue infection, which is also fast and convenient, as cell labelling is not required

Hydatid cyst in soft tissues of the calf

A rare case of primary intramuscular hydatid cyst is reported here because of its unusual presentation. A young man presented clinically as having a soft tissue nodular mass in right calf. Histopathological examination revealed characteristic findings, which were consistent with hydatid cyst. A high level of awareness concerning the occurrence of these cysts is important, especially in regions where echinococcus is endemic. Radiological investigations can be helpful in non-invasive diagnosis of the condition. Surgical treatment follows the principles of malignant tumors, namely, wide surgical resection. A 40 years old man of rural origin had six months history of painless lump in right calf region, which gradually started increasing in size. There was no history of trauma, fever or weight loss. Local examination revealed a walnut sized, ovoid, non-tender mass in the posteromedial aspect of right calf in its middle third. The mass was found to be attached to the deep muscles. The clinical picture was suggestive of soft tissue tumor. General physical examination revealed no abnormality. Systemic examination was also normal. No evidence of visceromegaly was noted. Chest was clear. Plain radiograph of the right leg revealed an ovoid, partly calcified 4x3 cm mass in soft tissues on posteromedial aspect of mid-calf, with intact bones. Total leukocyte count [TLC] was 6,700 micro L with eosinophils upto 8%. Ultrasonography of the lesion, using 7.5 MHz transducer, was performed, which showed a well-defined 4x3 cm septated, cystic mass with multiple daughter cysts. Fluid level was also noted in one of the cysts. The findings were suggestive of hydatid cyst. Chest radiograph and abdominal ultrasonography were performed, which were normal. The patient underwent surgery. On exploration, a hydatid cyst attached to fascia covering tibialis posterior was found. This was excised and soft tissue washed with 0.5% silver nitrate solution. Histopathology confirmed echinococcus cyst. The patient was put on medical treatment and discharged in a satisfactory condition