Biomedical subjects
Publications and source records attributed to George Koulouris.
The key diagnosis and treating of vesicovaginal fistulae is accurate imaging. We illustrate the latest use of enhanced computed tomography for such cases.
Though recent research into the diagnosis and management of hamstring disorders has resulted in early and accurate recognition of injury, hamstring strain remains the most common form of muscle injury in the active population. With prompt recognition of hamstring strain, an appropriate rest and rehabilitation routine may be devised by the sports clinician in the hope of avoiding future and possibly more debilitating injury. As such, imaging has played a pivotal role in assisting athletes, both elite and recreational, in returning to activity expeditiously.
Groin pain is a frequently encountered symptom in the athlete. The differential diagnosis for an athlete presenting with groin pain is broad and diagnostic imaging plays a crucial role in reaching the correct diagnosis, allowing appropriate therapy to be instituted. In this article we present the radiological differential diagnosis of athletes presenting with groin pain. The common mechanisms of injury, presenting symptoms, and imaging findings for each of these entities are addressed.
The posterolateral corner (PLC) of the knee is a complex area, previously poorly understood by radiologists. Numerous structures make up the PLC, whose evaluation is difficult because of the variable presence of the individual components, their intimate and commonly overlapping insertions, and their oblique course on traditional imaging planes. The clinical relevance of PLC injuries, especially the infrequently repaired "minor" components, adds to the confusion. Our purpose is to review the anatomy, imaging, clinical evaluation, and treatment options for PLC injuries.
Spontaneous retropharyngeal hemorrhage from a cervical parathyroid adenoma is a rare complication of primary hyperparathyroidism. Because of its rarity, it has seldom been documented in the radiologic or ENT literature. Patients may present with a variety of manifestations, ranging from dysphagia to dysphonia to life-threatening dyspnea or hemorrhage. Awareness of a possible thyroid or parathyroid etiology may expedite treatment and prevent unnecessary interventions. We present a case of spontaneous retropharyngeal hemorrhage in which the "sentinel clot" sign enabled us to identify the lesion of origin.
Though cranial hemangiomas are second only to vertebral hemangiomas in frequency, such lesions are rarely congenital and multiple. It is probable that the true incidence of congenital calvarial hemangiomas is higher than that reported in the literature, as they are unlikely to undergo imaging, most being asymptomatic and without a significant soft tissue component. We present a case of multiple congenital calvarial and skull base cavernous-type hemangiomas, diagnosed in a 4-day-old female, involving the right zygoma, maxilla, frontal and petrous temporal bones and contralateral squamous temporal bone. Surgical biopsy confirmed the radiological diagnosis as well as the concomitant multiple subcutaneous capillary-type hemangiomas which were identified clinically. No specific clinical syndrome or chromosomal abnormality was identified and the underlying cerebral parenchyma was normal with no intra-axial involvement. With conservative treatment, two lesions completely resolved and a further two lesions subsequently decreased in both size and degree of enhancement. To the best of our knowledge, this is the first case of multiple congenital hemangiomas involving the calvarium and skull base. Despite this, the radiological features, combined with the clinical findings of multiple capillary hemangiomas, were characteristic enough to permit an accurate preoperative diagnosis. Osseous hemangiomas should feature prominently in any differential diagnosis of multiple hypervascular lesions, as they are common, more so when limited to an anatomical region, irrespective of site or age.
With its superior anatomical resolution and high sensitivity in depicting pathological processes of the joint, bone marrow and surrounding soft tissue structures, MR imaging is the ideal modality for demonstrating the manifestations and sequelae of the infective and inflammatory conditions common to the hip. Though the imaging features of these conditions may overlap, combining the clinical history and results and other imaging modalities yields a higher degree of specificity, ultimately enhancing the confidence of the radiological interpretation.
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MR imaging-evident intraosseous channels associated with the presence of a dural arteriovenous fistula have been described in the literature. We describe these channels in relation to a case of dural arteriovenous fistula seen on CT. The presence of this subtle sign should be sought, and the area reviewed in all CT evaluations of patients with pulsatile tinnitus.
OBJECTIVE: We compared sonography and MRI for assessing hamstring injuries in professional football players (Australian football) 3 days, 2 weeks, and 6 weeks after an injury and identified imaging characteristics at baseline that may be useful in predicting the time needed for return to competition. MATERIALS AND METHODS: Sixty men who are professional football players presented with suspected acute hamstring strain underwent sonography and MRI within 3 days of injury; those who were injured returned 2 and 6 weeks later for follow-up MRI and sonography. Two radiologists interpreted either the MR images or the sonograms and were blinded to the results of the other technique. The following six parameters were measured at each assessment: the muscle injured, the site of injury within the muscle, the longitudinal injury length (expressed in millimeters), the cross-sectional injured area (expressed as a percentage), and the presence of interand intramuscular hematoma. RESULTS: At baseline, MRI identified abnormalities in 42 (70.0%) of 60 patients, whereas sonography found abnormalities in 45 (75%) of 60. At 2 weeks, 29 (59.2%) of 49 scans showed abnormalities on MRI and 25 (51.0%) of 49 showed abnormalities on sonograms. Of those players who were injured at baseline, 15 (35.7%) of 42 and 10 (22.2%) of 45 still showed abnormal results on scans at 6 weeks on MRI and sonography, respectively. However, all but one player had returned to competition. The biceps femoris was the most commonly injured muscle and the musculotendinous junction was the most common site of injury. Injuries appeared significantly larger on MRI than on sonography at all time points. Our analysis showed that at baseline, the longitudinal length of hamstring tear on MRI had the highest statistical correlation with recovery (r = 0.58, p < 0.0001) and was the best radiologic predictor for return to competition. CONCLUSION: Sonography is as useful as MRI in depicting acute hamstring injuries and because of lower costs may be the preferred imaging technique. However, MRI is more sensitive for follow-up imaging of healing injuries. The longitudinal length of the strain as measured on MRI is a strong predictor for the amount of time needed until an athlete can return to competition.
OBJECTIVE: To evaluate the imaging findings following acute hamstring injury. DESIGN AND PATIENTS: We retrospectively reviewed the imaging findings of hamstring muscle complex (HMC) strain in 170 patients referred to our institution over a 3-year period. A total of 179 injuries to the HMC were demonstrated in 170 patients (154 male, 16 female, mean age 28.2 years). The mean duration of symptoms was 4.7 days (range 1-10 days). MR imaging was performed in 97 cases and sonography in 102 cases (both modalities were performed in 20 examinations). Attention was directed to the frequency of muscle involvement, the location of the injury within the muscle-tendon unit, the extent of the injury and discriminating avulsion from muscle injury. RESULTS AND CONCLUSIONS: Twenty-one patients had proximal tendon injury, with sixteen avulsions and five partial tears. Sixteen of these patients had surgical confirmation of hamstring avulsion from the ischial tuberosity (14 conjoint, 2 biceps femoris alone) and all were reliably diagnosed with MR imaging (16/16), but less so with sonography (7/12). Four distal tendon avulsions were also observed (three semitendinosus, one biceps femoris). With respect to muscle injury, the biceps femoris was most commonly injured (124/154). Semimembranosus was an uncommon muscle injury (21/154) and semitendinosus rare (9/154). Imaging can discriminate a hamstring tendon avulsion from musculotendinous strain and helps identify which patients necessitate surgical management as opposed to conservative treatment.
OBJECTIVE: To describe the imaging features of the normal anatomy and injury of the posterior tibiotalar ligament (PTTL) of the ankle in a group of patients presenting with posteromedial impingement. MATERIALS AND METHODS: Twenty-five consecutive patients underwent imaging for posteromedial ankle pain following injury. All 25 patients were investigated with MR imaging, 17 with ultrasound and 5 with radionuclide bone scanning. Clinical data and surgical findings were correlated with the results of radiological investigation. RESULTS: The PTTL demonstrated scar formation and a hypertrophic response consistent with previous injury in all 25 patients. Displacement or encasement of the surrounding tendons and their sheaths was often encountered (12/25). Bony avulsion was demonstrated in 5/25 occasions with ultrasound and 2/25 with MR imaging. Twelve patients underwent surgery, confirming the radiological findings. CONCLUSION: Imaging can effectively evaluate the integrity of the PTTL in the context of ongoing posteromedial ankle pain.
Contrast material-enhanced magnetic resonance (MR) angiography of the hand noninvasively provides information comparable to that provided by conventional angiography. It is a quick and easy examination that takes less than 5 minutes to perform and produces high-quality images with use of a dedicated surface coil that provides a high signal-to-noise ratio, allowing small pixel size and high spatial resolution. Contrast-enhanced MR angiography requires intravenous injection of gadopentetate dimeglumine and acquisition of a volumetric slab of image data from the hand. This information is then projected with a maximum-intensity-projection algorithm. The technique is generally robust with reproducible findings. Image interpretation requires an understanding of (a) the normal vascular anatomy and anatomic variants of the hand and (b) common vascular diseases. MR angiography of the hand is commonly used to create an arterial "road map" prior to surgery, manage traumatic transection, and identify emboli. Vascular malformations are readily identified and connective tissue disorders including vasculitis are well demonstrated with this technique, which can also be used to assess bone viability following trauma to the carpus or to evaluate the viability of vascularized bone. Common artifacts may be secondary to contracture deformities or "wraparound" effect. However, most potential pitfalls can be avoided by being vigilant.
Increasing activity in the general population and the high demands placed on athletes have resulted in injuries to the hamstring muscle complex (HMC) being commonplace in sports. Imaging of HMC injuries can form a considerable part of a sports medicine practice, with a wide spectrum of such injuries being reflected in their varied imaging appearances. Magnetic resonance (MR) imaging and ultrasonography (US) are the imaging modalities of choice in this setting. Both MR imaging and US provide exquisitely detailed information about the HMC with respect to localization and characterization of injury. Optimization of MR imaging involves the use of a surface coil and high-resolution techniques, allowing the musculoskeletal radiologist not only to diagnose injury and assess severity but also to provide the clinician with useful clues with respect to prognosis. The portability and availability of US make it an attractive modality for the diagnosis of acute hamstring injuries, although its effectiveness is dependent on operator experience. A thorough knowledge of the HMC anatomy and of the spectrum of imaging findings in HMC injury is crucial for providing optimal patient care and will enable the musculoskeletal radiologist to make an accurate and useful contribution to the treatment of athletes at all levels of participation.