S J Erickson

Detection of osteomyelitis in the neuropathic foot: nuclear medicine, MRI and conventional radiography.

The diagnostic efficacy of (1) combined three-phase bone scintigraphy and In-111 labeled WBC scintigraphy (Bone/WBC), (2) MRI, and (3) conventional radiography in detecting osteomyelitis of the neuropathic foot was compared. Conventional radiography was comparable to MRI for detection of osteomyelitis. MRI best depicted the presence of osteomyelitis in the forefoot. Particularly in the setting of Charcot joints, Bone/WBC was more specific than conventional radiography or MRI.

MRI of injury to the lateral collateral ligamentous complex of the ankle.

We retrospectively evaluated the lateral collateral ligamentous complex of 43 patients who had complained of ankle pain following ankle sprain. The MR signs of ligamentous abnormality included discontinuity or absence, increased signal within the ligament, and ligamentous irregularity or waviness with normal thickness and signal intensity. Using these criteria, 30 anterior talofibular, 20 calcaneofibular, and no posterior talofibular ligament injuries were diagnosed. Compared with surgery (nine patients), MRI demonstrated six of seven anterior talofibular ligament injuries and six of six calcaneofibular ligament injuries. Magnetic resonance showed ligamentous abnormalities in 12 of 23 cases with normal stress radiography. Magnetic resonance imaging provides useful information for the evaluation of patients presenting with chronic pain after ankle sprain.

Periportal halo: a CT sign of liver disease.

Periportal halos are defined as circumferential zones of decreased attenuation identified around the peripheral or subsegmental portal venous branches on contrast-enhanced computed tomography (CT). These halos probably represent fluid or dilated lymphatics in the loose areolar zone around the portal triad structures. While this CT finding is nonspecific, it is abnormal and should prompt close scrutiny of the liver in search of an underlying etiology. Periportal halos which may be due to blood are commonly seen in patients with liver trauma. Periportal edema may cause this sign in patients with congestive heart failure and secondary liver congesion, hepatitis, or enlarged lymph nodes and tumors in the porta hepatis which obstruct lymphatic drainage. This CT sign has also been observed in liver transplants (probably secondary to disruption and engorgement of lymphatic channels) and in recipients of bone marrow transplants who might develop liver edema from microvenous occlusive disease. While the precise pathophysiologic basis of periportal tracking has not been proven, it represents a potentially important CT sign of occult liver disease.

In vivo proton (H1) magnetic resonance spectroscopy for cervical carcinoma

Proton magnetic resonance spectroscopy (MRS) may be a useful tool in both the initial diagnosis of cervical carcinoma and the subsequent surveillance after radiation therapy, particularly when other standard diagnostic methods are inconclusive. Single voxel magnetic resonance (MR) spectral data were acquired from 8 normal volunteers, 16 patients with cervical cancer before radiation therapy, and 18 patients with cervical cancer after radiation therapy using an external pelvic coil at a 1.5-T on a Signa system. The presence or absence of various resonances within each spectrum was evaluated for similarities within each patient group and for spectral differences between groups. Resonances corresponding to lipid and creatine dominated the spectrum for the eight normal volunteers without detection of a choline resonance. Spectra from 16 pretreatment patients with biopsy-proven cervical cancer revealed strong resonances at a chemical shift of 3.25 ppm corresponding to choline. Data acquired from the 18 posttreatment setting studies was variable, but often correlated well with the clinical findings. Biopsy confirmation was obtained in seven patients. H1 MRS of the cervix using a noninvasive pelvic coil consistently demonstrates reproducible spectral differences between normal and neoplastic cervical tissue in vivo. However, signal is still poor for minimal disease recurrence. Further study is needed at intervals before, during, and after definitive irradiation with biopsy confirmation to validate the accuracy of MRS in distinguishing persistence or recurrence of disease from necrosis and fibrosis.

Color Doppler sonography in the evaluation of the adult acute scrotum.

Color Doppler sonography (CDS) was used to evaluate 35 adult males with acute scrotal discomfort. Correlative nuclear scintigraphy was performed in 15 patients. Surgical correlation was available in 10 patients with clinical follow‐up in the remaining 25. The complete absence of intratesticular color flow was used as our criterion for testicular ischemia. This was found to be 100% sensitive and 100% specific in 8 patients with surgically confirmed testicular ischemia. Spontaneous detorsion was noted in one patient with hyperemia demonstrated by color imaging. Increased color flow was found in 20 patients with the clinical impression of scrotal inflammation. Nuclear scintigraphy and color Doppler imaging had 100% agreement in 15 patients. Color Doppler sonography is a useful and highly accurate diagnostic method in the evaluation of patients with the acute scrotal syndrome. Color flow imaging is comparable to nuclear scintigraphy in the diagnosis of testicular ischemia.

Hepatic Metastases: CT Versus MR Imaging at 1.5T

A prospective multi-institutional study was performed to compare the sensitivity of computed tomography (CT) and high-field magnetic resonance (MR) imaging (1.5T) in the detection of hepatic metastases, T1-weighted and T2-weighted spin-echo (SE) MR images were compared with noncontrast, dynamic, and delayed CT. Sixty-nine oncology patients were studied. Non-contrast CT showed an overall sensitivity of 57%, dynamic CT 71%, delayed CT 72%, T1-weighted SE MR 47%, and T2-weighted SE MR 78%. Although there was no statistically significant (p}<0.05) difference among dynamic CT, delayed CT, and T2-weighted SE MR, these three methods were significantly more sensitive (p< 0.005) than non-contrast CT or T1-weighted SE MR. T2-weighted SE MR was significantly more sensitive (p< 0.006) than CT or T1-weighted SE MR in the detection of small (<1 cm) lesions. CT was more sensitive in the detection of extrahepatic disease. These data confirm the superiority of T2-weighted SE over T1-weighted SE pulse sequences at 1.5T.

Traumatic fracture of the pancreas: CT characteristics

Pancreatic fracture is a rare injury caused by blunt abdominal trauma. Few proven cases have been diagnosed by abdominal CT. The typical clinical triad of upper abdominal pain, leukocytosis, and hyperamylasemia is nonspecific. Abdominal CT gives the best opportunity for an immediate diagnosis. Nevertheless, few cases of traumatic pancreatic fracture have been diagnosed by abdominal CT within 24 h following injury and proven at laparotomy. In this report we describe five cases of traumatic pancreatic fracture identified on CT; four cases were verified at laparotomy. Traumatic pancreatic fracture generally occurs as a transverse transection across the neck of the pancreas. Commonly, an accompanying injury to other visceral organs is present. The diagnosis of pancreatic fracture requires a high index of suspicion with close scrutiny of the CT images.

Proximal interruption of a main pulmonary artery with transpleural collateral vessels : CT and MR appearances

The plain chest radiographic, CT, and MR findings in a 31-year-old woman with proximal interruption of the right main pulmonary artery and transpleural collaterals are presented. The diagnosis can be established by both dynamic CT and MR. Intercostal collaterals and their transpleural connections are best demonstrated with dynamic CT.

Cirsoid aneurysm treatment by percutaneous injection of sodium tetradecyl sulfate

BACKGROUND Cirsoid aneurysms are uncommon arteriovenous fistulas of the scalp. Surgery for these lesions can be difficult; transarterial embolization is rarely curative, while embolization of the venous pouch with permanent agents usually necessitates subsequent surgical removal of the embolic material. The ideal embolic agent would be one that is safe and effective, commercially available, and would not require subsequent removal. METHODS We treated an arteriovenous fistula of the scalp with direct puncture and injection of sodium tetradecyl sulfate, a commercially available sclerosing agent. RESULTS Control angiography immediately following percutaneous injection of sotradecol into the fistula showed decreased flow but not complete closure of the lesion. However, within several days of the embolization, the patients scalp pain and mass resolved. Four months after embolization, MRA demonstrated no evidence of residual or recurrent fistula. Color doppler flow imaging demonstrated only slightly decreased vascular resistance in the distal superficial temporal artery, possibly indirect evidence of persistent micro-fistulae. Twenty-three months after the procedure, the patient continued to be asymptomatic and had no palpable lesion. CONCLUSIONS Percutaneous injection of sotradecol can be considered as one of the treatment options for arteriovenous fistula of the scalp. Further experience is needed to compare the safety and effectiveness of sotradecol with other agents currently used in the treatment of scalp arteriovenous fistulae.

Magnetic resonance imaging scanning in the diagnosis of zone II flexor tendon rupture

This study was undertaken to determine the usefulness of magnetic resonance imaging (MRI) in the diagnosis of flexor tendon rupture in patients who had prior surgery. Magnetic resonance imaging scans were performed on 11 digits (16 tendons) with the clinical diagnosis of flexor tendon rupture. Clinical suspicion correlated with MRI and surgical findings. Clinical examination yielded a 60% accuracy in diagnosis. MRI differentiated rupture from adhesions with a 100% accuracy rate. The MRI scan is a valuable tool in diagnosing tendon ruptures and may help reduce the incidence of unnecessary tendon explorations.