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Background Upper extremity MRI and proton MR spectroscopy are increasingly considered to be outcome measures in Duchenne muscular dystrophy (DMD) clinical trials. Purpose To demonstrate the feasibility of acquiring upper extremity MRI and proton ( 1 H) MR spectroscopy measures of T2 and fat fraction in a large, multicenter cohort (ImagingDMD) of ambulatory and nonambulatory individuals with DMD; compare upper and lower extremity muscles by using MRI and 1 H MR spectroscopy; and correlate upper extremity MRI and 1 H MR spectroscopy measures to function. Materials and Methods In this prospective cross-sectional study, MRI and 1 H MR spectroscopy and functional assessment data were acquired from participants with DMD and unaffected control participants at three centers (from January 28, 2016, to April 24, 2018). T2 maps of the shoulder, upper arm, forearm, thigh, and calf were generated from a spin-echo sequence (repetition time msec/echo time msec, 3000/20-320). Fat fraction maps were generated from chemical shift-encoded imaging (eight echo times). Fat fraction and 1 H 2 O T2 in the deltoid and biceps brachii were measured from single-voxel 1 H MR spectroscopy (9000/11-243). Groups were compared by using Mann-Whitney test, and relationships between MRI and 1 H MR spectroscopy and arm function were assessed by using Spearman correlation. Results This study evaluated 119 male participants with DMD (mean age, 12 years ± 3 [standard deviation]) and 38 unaffected male control participants (mean age, 12 years ± 3). Deltoid and biceps brachii muscles were different in participants with DMD versus control participants in all age groups by using quantitative T2 MRI ( P < .001) and 1 H MR spectroscopy fat fraction ( P < .05). The deltoid, biceps brachii, and triceps brachii were affected to the same extent ( P > .05) as the soleus and medial gastrocnemius. Negative correlations were observed between arm function and MRI (T2: range among muscles, ρ = -0.53 to -0.73 [ P < .01]; fat fraction, ρ = -0.49 to -0.70 [ P < .01]) and 1 H MR spectroscopy fat fraction (ρ = -0.64 to -0.71; P < .01). Conclusion This multicenter study demonstrated early and progressive involvement of upper extremity muscles in Duchenne muscular dystrophy (DMD) and showed the feasibility of MRI and 1 H MR spectroscopy to track disease progression over a wide range of ages in participants with DMD. © RSNA, 2020 Online supplemental material is available for this article.

Infants and children are vulnerable to congenital and developmental hip and lower extremity disorders. These disorders have diverse causes in pediatric patients, and owing to potential related complications that can lead to degenerative disease in adulthood, an accurate diagnosis is essential. A common disease is developmental dysplasia of the hip, which affects nearly 1% of newborns. This condition is best evaluated with US and conventional radiography. Slipped capital femoral epiphysis affects approximately 0.01% of young teenagers and is initially evaluated with radiography. Femoroacetabular impingement is a risk factor for early osteoarthritis and can be assessed with radiography, CT, or MRI. Limb length discrepancy is defined as a greater than 2-cm difference in length between paired bilateral lower extremities. There are several methods of measuring this difference, and the use of an accurate imaging modality is essential for treatment. Developmental bowing is a physiologic condition involving varus angulation of the knee and is best evaluated by using conventional radiography. Blount disease is a progressive pathologic genu varum centered at the tibia; the three subtypes are infantile, juvenile, and adolescent. In- and out-toeing disorders are caused by abnormal tibial and femoral torsion that usually self-corrects during lower limb growth. The ability to recognize these conditions is essential for differentiating those that will resolve spontaneously versus those that will require treatment. The imaging features of congenital and developmental hip and lower extremity disorders are reviewed, with emphasis on diagnosis, radiologic assessment, associated findings, and classification. © RSNA, 2019.

Purpose To determine whether altered sodium (Na(+)) and chloride (Cl(-)) homeostasis can be visualized in periodic paralyses by using 7-T sodium 23 ((23)Na) and chlorine 35 ((35)Cl) magnetic resonance (MR) imaging. Materials and Methods Institutional review board approval and informed consent of all participants were obtained. (23)Na (repetition time msec/echo time msec, 160/0.35) and (35)Cl (40/0.6) MR imaging of both lower legs was performed with a 7-T whole-body system in patients with genetically confirmed hypokalemic periodic paralysis (Cav1.1-R1239H mutation, n = 5; Cav1.1-R528H mutation, n = 8) and Andersen-Tawil syndrome (n = 3) and in 16 healthy volunteers. Additionally, each participant underwent 3-T proton MR imaging on the same day by using T1-weighted, short-tau inversion-recovery, and Dixon-type sequences. Muscle edema was assessed on short-tau inversion-recovery images, fatty degeneration was assessed on T1-weighted images, and muscular fat fraction was quantified with Dixon-type imaging. Na(+) and Cl(-) were quantified in the soleus muscle by using three phantoms that contained 10-, 20-, and 30-mmol/L NaCl solution and 5% agarose gel as a reference. Parametric data for all subpopulations were tested by using one-way analysis of variance with the Dunnett test, and correlations were assessed with the Spearman rank correlation coefficient. Results Median muscular (23)Na concentration was higher in patients with Cav1.1-R1239H (34.7 mmol/L, P < .001), Cav1.1-R528H (32.0 mmol/L, P < .001), and Kir2.1 (24.3 mmol/L, P = .035) mutations than in healthy volunteers (19.9 mmol/L). Median muscular normalized (35)Cl signal intensity was higher in patients with Cav1.1-R1239H (27.6, P < .001) and Cav1.1-R528H (23.6, P < .001) than in healthy volunteers (12.6), but not in patients with the Kir2.1 mutation (14.3, P = .517). When compared with volunteers, patients with Cav1.1-R1239H and Cav1.1-R528H showed increased muscular edema (P < .001 and P = .003, respectively) and muscle fat fraction (P < .001 and P = .017, respectively). Conclusion With 7-T MR imaging, changes of Na(+) and Cl(-) homeostasis can be visualized in periodic paralyses and are most pronounced in the severe phenotype Cav1.1-R1239H, with up to daily paralytic episodes. (©) RSNA, 2016 An earlier incorrect version of this article appeared online. This article was corrected on April 18, 2016.

Ultrasonography (US) is commonly used to assess the peripheral nerves of the lower extremity because of its many advantages over magnetic resonance (MR) imaging. The most obvious advantages over MR imaging are superior soft-tissue resolution, low cost, portability, lack of magnetic susceptibility artifact, and the ability to image patients who cannot undergo MR imaging. US has been shown to have equal specificity and greater sensitivity than MR imaging in the evaluation of peripheral nerves. Additional benefits are the capability of real-time and dynamic imaging, and the ability to scan an entire extremity quickly without the need for a patient to lie motionless for long periods of time, as with MR imaging. Any abnormal findings can be easily compared against the contralateral side. Published literature has shown that US has clinical utility in patients suspected of having peripheral nerve disease: US can be used to guide diagnostic and therapeutic decisions, as well as help confirm electrodiagnostic findings. Common indications for lower extremity peripheral nerve US are the evaluation for injury due to penetrating trauma, entrapment by scar tissue, or tumor. To confidently perform US of the peripheral nerves of the lower extremity, it is important to gain a thorough knowledge of anatomic landmarks and the course of each nerve. Readers who may not be familiar with US will be introduced to the basics of scanning the peripheral nerves of the lower extremity. Important anatomic landmarks and common sites of injury and entrapment will be reviewed., ((©)RSNA, 2016.)

Purpose: To study the elastic properties of the medial gastrocnemius (GCM) in children with spastic cerebral palsy., Materials and Methods: The study protocol was approved by the Research Ethics Committee of the hospital, and informed consent was obtained from each child's parent. Fifteen children with spastic cerebral palsy (group 1) and 13 children without neurologic and musculoskeletal disabilities (group 2) were included. Because group 1 included three children with hemiplegia, the total number of legs examined was 27. Children in group 2 had both legs examined, for a total of 26 legs studied. The modified Ashworth scale score of the ankle in group 1 was assessed by a physical therapist. A physiatrist performed ultrasonography and dynamic sonoelastography (DS) together, measured the thickness of the GCM, and calculated the GCM ratio in both groups. On color-scaled DS images, the DS score of the GCM was graded from DS 1 (purple to green: soft) to DS 4 (red: stiff), and the color histogram of the GCM was subsequently analyzed. Strain ratio and local shear wave velocity were calculated in the GCM and the soleus muscle by using acoustic radiation force impulse imaging., Results: The GCM ratio in group 1 was significantly smaller than that in group 2. The DS score of GCM in group 1 was significantly higher than that in group 2. The median red pixel values were significantly higher, and the blue pixel values were significantly lower on color histogram in group 1 than those in group 2. The strain ratio in group 1 was significantly lower than that in group 2, and the local shear wave velocity of GCM in group 1 was higher than that in group 2. There were significant correlations between the modified Ashworth scale scores and DS parameters., Conclusion: DS demonstrated a difference in muscle stiffness in the GCM between children with spastic cerebral palsy and those without neurologic and musculoskeletal disabilities.

Purpose: To retrospectively evaluate multi-detector row computed tomographic (CT) angiography in determining donor- and recipient-site arterial suitability for successful vascularized free-flap transplantation., Materials and Methods: The institutional review board granted approval; informed consent was waived, and the study was HIPAA compliant. Lower extremities of 20 (12 male, eight female; mean age, 51 years; range, 10-84 years) patients undergoing vascularized free-flap procedures were examined at multi-detector row CT angiography. In five patients, legs were assessed as potential fibular free-flap donors for mandibular, maxillary, or radial reconstruction. In 15 patients, legs were assessed as recipient sites for free flaps. Vascular maps obtained with volume rendering, maximum intensity projections, and curved planar reformations were generated, and assessment was made in the depiction of calf vessels and presence of stenosis, occlusion, and anatomic anomaly. Findings of CT angiography, physical examination, and surgery were compared, where applicable, and successful CT-based prediction of the surgical intervention was assessed. Immediate and long-term (>70 days) viability of the graft was assessed in all patients., Results: CT angiography depicted the entirety of all four major calf arteries in 29 of 32 legs scanned. In three legs, external-fixation hardware obscured some segments. There were no discrepancies between CT findings and those identified at the time of surgery. Arterial abnormalities, including stenosis, occlusion, and variant anatomy, were seen in 12 lower extremities in 10 patients. Only two were suspected on the basis of physical examination findings. In five of 20 patients, CT findings resulted in changes to the surgical plan. There was a 100% immediate viability of all grafts, which remained well vascularized between 70 days and 37 months after the procedure., Conclusion: Multi-detector row CT angiography provides a noninvasive means of preoperatively assessing lower extremity arteries for abnormalities, which could jeopardize graft viability or pedal arterial supply after free-flap procedures., (RSNA, 2005)

Purpose: To establish the safety of withholding anticoagulation therapy after negative findings at a complete lower limb ultrasonographic (US) examination of the symptomatic leg for suspected deep venous thrombosis (DVT)., Materials and Methods: Regional ethics committee approval and patient consent were obtained. A total of 542 consecutive ambulatory patients presented to the emergency department and were prospectively recruited from April 2001 to May 2003. Of these patients, 16 were excluded, and radiology residents and sonographers performed a complete lower limb US examination by means of compression and Doppler US in 526 patients. Patients with negative US findings received no anticoagulation therapy, and they were observed for occurrence of any thromboembolic event for 3 months. Patients with progressive or new symptoms that were indicative of thromboembolism within the follow-up period underwent objective testing with US, computed tomographic (CT) pulmonary angiography, or both., Results: There were 413 patients (78.5%) with US findings that were negative for DVT and 113 patients (21.5%) with findings that were positive. There were 64 patients (56.6%) with DVT isolated to the calf and 49 (43.4%) with proximal DVT. Of the 413 patients with negative initial US findings, 16 (3.9%) underwent a second US examination for new or progressive symptoms of DVT, one patient (0.25%) underwent CT pulmonary angiography for suspected pulmonary embolism, and one patient (0.25%) underwent both US and CT pulmonary angiography during the 3-month follow-up period. One of these patients (0.24%; 95% confidence interval: 0.01%, 1.3%) developed pulmonary embolism, which was diagnosed with CT pulmonary angiography. DVT was not diagnosed in any patient, and no patient died during follow-up. The negative predictive value of a complete single lower limb US examination to exclude clinically important DVT is 99.6% (95% confidence interval: 98.4%, 99.9%)., Conclusion: A single negative complete lower limb US examination is sufficient to exclude clinically important DVT, and it is safe to withhold anticoagulation therapy after negative complete lower limb US findings were obtained in patients suspected of having symptomatic lower limb DVT. New or progressive symptoms require further objective imaging., (RSNA, 2005)

Computed tomographic (CT) angiography is a reliable and convenient imaging modality for diagnosing arterial injuries after blunt and penetrating trauma to the extremities. It is a noninvasive modality that could replace conventional arteriography as the initial diagnostic study for arterial injuries after trauma to the extremities. The technique requires scanning with multidetector helical CT after rapid intravenous injection of iodinated contrast material. The CT angiographic signs of arterial injuries in the extremities are active extravasation of contrast material, pseudoaneurysm formation, abrupt narrowing of an artery, loss of opacification of a segment of artery, and arteriovenous fistula formation. Metallic streak artifact, motion artifact, and inadequate arterial opacification may render a CT angiogram nondiagnostic. Studies have shown the sensitivity of CT angiography to be 90%-95.1% and its specificity 98.7%-100% for detecting arterial injury to the extremities after trauma., (Copyright RSNA, 2005.)

Purpose: To compare the relative use of bilateral versus unilateral extremity radiographic examinations when patients are referred to radiologists for imaging (radiologist referred) versus when studies are performed in the referring physician's office (self-referred)., Materials and Methods: We reviewed 1 year of claims data for extremity radiographic examinations performed by a referring physician or referred to a radiology facility and claims data for related patient office visits. Data were analyzed for orthopedics, podiatry, and rheumatology, and data were divided by the practice pattern of the referring physician into pure self-referring, pure radiologist-referring, and mixed-referring categories. We compared the percentage of unilateral and bilateral studies and the number of unilateral and bilateral studies per 100 office visits in each setting. Statistical analysis of each comparison was performed with a one-tailed Z test., Results: A total of 13 094 (14%) self-referred studies were bilateral, while 778 (10%) radiologist-referred studies were bilateral (P < .001). The rate of self-referred bilateral examinations was 2.21 times higher per 100 office visits than the rate of radiologist-referred bilateral examinations. Combined bilateral and unilateral use by self-referrers was only 1.86 times higher than use by radiologist-referrers. Orthopedists had no clinically meaningful difference in the percentage of self-referred and radiologist-referred bilateral studies, but they ordered 1.98 times as many studies per 100 visits when they self-referred studies. Self-referring podiatrists and rheumatologists ordered bilateral studies up to 3.25 times more frequently than did their radiologist-referring colleagues. Mixed-referring podiatrists had 2.70-times increased use of bilateral examinations when performing imaging in their offices, whereas mixed-referring rheumatologists had 6.40-times increase in that setting., Conclusion: Orthopedists, podiatrists, and rheumatologists use extremity radiography at a higher rate when they self-refer. Moreover, self-referring podiatrists and rheumatologists order radiographic examinations of increased intensity compared with radiologist-referring physicians., ((c) RSNA, 2005.)

Purpose: To compare multi-detector row spiral computed tomographic (CT) angiography with digital subtraction angiography (DSA) in evaluation of the infrarenal aorta and lower-extremity arterial system., Materials and Methods: Fifty patients with peripheral arterial occlusive disease were evaluated with multi-detector row CT angiography and DSA. Arteries depicted at CT angiography and DSA were graded separately for degree of stenosis as 23 anatomic segments (infrarenal aorta, right and left common iliac artery, internal iliac artery, external iliac artery, common femoral artery, superficial femoral artery, deep femoral artery, popliteal artery, anterior tibial artery, tibioperoneal trunk, posterior tibial artery, and peroneal artery). Grades included the following: 1, normal patency; 2, moderate (< or =50%) stenosis; 3, focal severe (>50%) stenosis; 4, multiple severe stenoses; and 5, occlusion. Three readers independently interpreted the images, and statistical analysis was performed. The results of image interpretation were evaluated for strength of agreement by using Cohen kappa statistics. On the basis of consensus readings, sensitivity, specificity, and accuracy for detection of stenotic lesions were calculated, with findings at DSA used as the reference standard., Results: Substantial to almost perfect interobserver agreement was achieved in all cases. At DSA, 349 diseased segments were found among the 1,137 segments evaluated. Sensitivity, specificity, and accuracy, based on a consensus reading of multi-detector row CT angiograms, were 96%, 93%, and 94%, respectively. A statistically significant difference (P <.05) between DSA and multi-detector row CT angiography was present only in arteries graded 1 or 2. Interobserver agreement was almost perfect among the three readers for treatment recommendations based on findings at CT angiography and DSA., Conclusion: Multi-detector row CT angiography appears consistent and accurate in the assessment of patients with peripheral arterial occlusive disease.

A sensitivity-encoded magnetic resonance (MR) angiography protocol was developed in which imaging times in the pelvic and upper-leg positions were reduced and isotropic submillimeter voxel volumes were acquired in the lower-leg position. To achieve this, sensitivity encoding and random central-k-space segmentation in a centric filling order were applied. Results with this technique were compared with those with midstream aortic digital subtraction angiography (DSA) (as the reference standard) and conventional MR angiography in 15 patients with peripheral vascular disease. The results show that sensitivity-encoded MR angiography demonstrates increased diagnostic accuracy in comparison to that with conventional MR angiography and depicts more open infragenual arterial segments compared with both midstream aortic DSA and conventional MR angiography., (Copyright RSNA, 2004)

Purpose: To assess the patterns of lower extremity arterial inflow and runoff opacification with four-channel multi-detector row computed tomographic (CT) angiography in a cohort of patients with disease warranting imaging of the lower extremity arterial system., Materials and Methods: Twenty-four patients with symptomatic lower extremity arterial occlusive or aneurysmal disease underwent imaging with four-channel multi-detector row CT from the supraceliac abdominal aorta through the feet. Transverse sections were acquired with a 2.5-mm nominal detector width and pitch of 6.0 (3.2-mm effective section thickness) following intravenous injection of 174-185 mL of iodinated contrast medium (300 mg iodine per milliliter). In each patient, attenuation measurements were recorded in 16 arterial and 16 venous locations. In 18 patients, two radiologists assessed the detectability and stenosis degree of 21 arterial segments per patient relative to these features at conventional angiography., Results: A mean scanning time of 66 seconds was required to cover a mean of 1,233 mm, resulting in a mean of 908 transverse reconstructions. All 504 arterial segments were depicted and analyzable. Mean arterial attenuation ranged from 253 HU in the midabdominal aorta to 357 HU in the popliteal artery and 253 HU in the dorsalis pedis or posterior tibial artery measured inferior to the tibiotalar joint. Maximum mean venous enhancement (99 HU) was observed in the saphenous vein at the ankle, with all other venous stations measuring less than 74 HU., Conclusion: The arteries of lower extremity inflow and runoff can be reliably depicted with minimal venous enhancement by using multi-detector row CT.

Several postoperative complications associated with pain may develop in the stump of an amputated lower limb. Clinical findings are often nonspecific; however, radiologic evaluation, especially with magnetic resonance (MR) imaging, is useful in the early diagnosis of these complications, thereby helping minimize physical disability with its psychologic and socioeconomic implications. Conventional radiography can demonstrate evidence of osseous origins of pain (eg, aggressive bone edge, heterotopic ossification, osteomyelitis) and should be the first imaging study performed after clinical examination. Videofluoroscopy can help evaluate improper prosthetic fit by demonstrating abnormal residual limb motion, piston action, rolling of soft tissues, and abnormal angle between the limb axis and the prosthesis during gait. Ultrasonography can demonstrate inflammatory changes in the stump as well as soft-tissue fluid collections. However, MR imaging is the modality of choice when clinical and other imaging findings are indeterminate. Because of its high spatial and contrast resolution, MR imaging can demonstrate subtle inflammatory changes, fluid collections, cancers, neuromas, and subtle traumatic bone lesions. Knowledge of various surgical and rehabilitation techniques is required for accurate diagnosis of complications associated with stump pain. Correct diagnosis allows choice of the most appropriate therapy, which may involve treating the stump, remodeling the prosthesis, or both.

Purpose: To compare nonstepping digital subtraction angiography (DSA) (ie, storage phosphor radiography adapted to a stationary imaging plate changer) with conventional screen-film angiography in the evaluation of the lower extremities., Materials and Methods: Fifty-one patients with peripheral vascular disease underwent both nonstepping DSA and screen-film angiography. The angiographic and radiologic techniques of both systems were kept identical for each patient. Three radiologists independently rated the overall quality of each angiogram. In their evaluations for each of 12 arterial segments on all 102 angiograms, they also rated the degree of opacification, the diameter reduction of the most severe stenosis, and their level of confidence., Results: Mean overall quality scores and levels of confidence were better for nonstepping DSA than for screen-film angiography (P < .001). Full opacification was reported in 95.6% and 89.2% of all 1,836 segments with nonstepping DSA and screen-film angiography, respectively (P < .0001). The difference between the mean stenosis grades obtained with screen-film angiography and nonstepping DSA was not statistically significant. Intertechnique agreements were good (kappa = 0.77, 0.81, and 0.81), whereas interobserver agreements were influenced by the observer's experience with the imaging techniques., Conclusion: Nonstepping DSA images of the lower extremity were of better diagnostic quality than were screen-film angiograms. The development of dedicated nonstepping DSA equipment is warranted.

Purpose: To evaluate the appearance of the sciatic nerve after leg amputation., Materials and Methods: Magnetic resonance (MR) images were obtained in seven patients (age at amputation, 11-19 years) who underwent above-knee amputation to treat osteogenic sarcoma. Images were evaluated for sciatic nerve enlargement. Findings were correlated with the time after amputation., Results: All seven patients were found to have a markedly enlarged sciatic nerve in the stump of the amputated leg. The enlargement extended proximally from the point of nerve transection to a level posterior to the femoral neck (8-27 cm) depending on the length of the stump. No evidence of sciatic nerve enlargement was found in the opposite leg or on preoperative MR images that were available in three of the patients. Moreover, in one patient with a sarcoma who underwent a leg-sparing procedure, no sciatic nerve enlargement was seen postoperatively. The thickness of the distal sciatic nerve was related to the time after amputation., Conclusion: Hypertrophy of the sciatic nerve occurred after above-knee amputation in young patients. This finding differed from atrophy of the nerve that has been reported previously in older patients.

Purpose: To establish computed tomographic (CT) criteria for the diagnosis of necrotizing fasciitis., Materials and Methods: Twenty CT scans in 20 patients with pathologically proved necrotizing fasciitis were reviewed retrospectively for fascial thickening, fat infiltration, focal fluid collection, soft-tissue gas, muscle involvement, and intra-abdominal extension; the findings were correlated with clinical factors, including associated illnesses, disease site, treatment, and outcome., Results: Average patient age was 57.8 years; there were 13 men and seven women. Four patients (20%) died. Asymmetric fascial thickening and fat stranding were seen in 16 patients (80%). Gas tracking along fascial planes was present in 11 patients (55%), and abscesses were found in seven patients (35%). Infection sites were scrotum (n = 6), a lower extremity (n = 4), perineum (n = 4), neck (n = 2), back (n = 2), arm (n = 1), and abdomen (n = 1). Underlying illness (n = 17) was diabetes in 10 patients (50%), alcoholism in three (15%), chronic renal failure in two (10%), and drug abuse in two (10%)., Conclusion: CT criteria of asymmetric fascial thickening and gas are valuable in assessing suspected necrotizing fasciitis. CT also can provide information on coexistent deep collections.

Purpose: To review experience with the imaging features of hamstring injuries., Materials and Methods: Imaging findings in 18 male and four female patients with clinically proved hamstring injuries were reviewed. The patients' ages ranged from 13 to 61 years (mean, 26 years). Radiography, conventional tomography, computed tomography (CT), and magnetic resonance (MR) imaging were performed., Results: Plain radiographs obtained less than 1 week after injury were normal or showed avulsion of an ischial apophysis. Plain radiographs and conventional tomograms obtained more than 1 week but less than 3 months after injury were confusing, because callus and osteolysis were present. CT helped identify a healing avulsion of an ischial apophysis. MR imaging was helpful no matter how long after the injury it was performed. It provided a means to evaluate muscle, tendon, and bone., Conclusion: Familiarity with the variable appearance of hamstring injuries over time and with different modalities facilitates accurate characterization.

To the author's knowledge, occurrence of pulmonary embolism during performance of compression ultrasound (US) of the lower extremity has not previously been reported in the radiology literature. The author describes a case in which pulmonary embolism was witnessed during compression US of venous thrombosis in a superficial femoral vein of a 64-year-old man. The embolism was documented with perfusion lung scanning.

Percutaneous aspiration embolectomy (PAE) was performed on acute embolic occlusions of infrainguinal arteries unrelated to percutaneous transluminal angioplasty or chronic atherosclerotic arterial occlusive disease. Of 102 patients, most (62.7% [n = 64]) had limb-threatening ischemia (stages III and IV according to the Fontaine classification); 86.3% (n = 88) had cardiac disease that caused the embolic occlusion. The clinical success rate was 87.3% (n = 89). Major complications occurred in 8.8% (n = 9) of the cases. The 30-day mortality was 3.9% (n = 4). In comparison with Fogarty-catheter embolectomy, PAE has a higher success rate and a lower mortality. PAE has several advantages: It is a simple technique with reduced invasiveness, combines a diagnostic and a therapeutic procedure, enables treatment of tibial and pedal vessels, and can be combined with all other angioplastic methods.

Color flow sonography permits noninvasive examination of the deep venous system in the lower extremity. In many patients, the modality is sufficiently accurate to serve as the sole diagnostic procedure for suspected deep venous thrombosis. Over 1,500 color flow sonographic examinations of the lower extremity have been performed at our institutions with various scanning techniques. For the inexperienced sonographer, we describe our current technique, which is easy, quick, accurate, and well tolerated by patients.

Diastrophic dysplasia is a distinct autosomal recessive disorder originally described in 1960. Since that time, a number of patients with similar but less severe involvement have been diagnosed as having a "diastrophic variant" disorder. This study reviews the radiological features of classic diastrophic dysplasia and compares them with the radiological findings in 26 patients with the diastrophic variant disorder. It is concluded that there is a wide variability in the phenotypic expression of diastrophic dysplasia even within sibships, and that cases of diastrophic variant disorder are actually mild forms of diastrophic dysplasia.

A prospective, three-center study of two contrast agents for leg venography was performed to evaluate both the relative frequency of adverse effects and whether low-osmolality agents provided significant advantages for this procedure. Fifty-four patients were studied with the standard preparation (iothalamate meglumine) and 57 with a nonionic agent (iopamidol). Both were used at an iodine concentration of 200 mg/mL, and there were no differences in volume of contrast material, duration of infusion, percentage of positive studies, or overall diagnostic adequacy. Patient discomfort was less with iopamidol than with iothalamate (18% vs. 44%), although discomfort was generally mild in both groups. By objective follow-up studies, the frequency of postvenographic thrombosis was not significantly different in the two groups (8% vs. 9%). Contrast venography, then, had a low frequency of complications when either a dilute conventional or a low-osmolality agent was employed. Although the frequency of postvenographic thrombosis was low with both agents, patient discomfort was less with the low-osmolality formulation.

Scintigrams of the leg were obtained following antecubital venous injection of 99mTc-sulfur colloid (SC) in 25 patients with suspected deep venous thrombosis. Contrast venograms were taken following the scan in all cases. Of 14 patients with confirmed deep venous thrombosis, 11 had positive scans. Of 11 patients with normal venograms, 10 had negative scintigrams. The simplicity of 99mTc-SC venography and its high rate of accuracy (84% in this series) suggest that it may be useful as a relatively noninvasive means of identifying deep venous thrombosis of the leg.

A double-blind study was performed using the Bettmann-Paulin technique to test the hypothesis that small quantities of Xylocaine mixed with diluted contrast medium would reduce leg cramps in patients during venography. Under random selection, one group of patients received 10 mg/50 ml of Xylocaine per diluted contrast medium; a second group, 20 mg/50 ml; and a third group, plain contrast medium. The findings support the hypothesis, with drug hypersensitivity the only contraindication.

A comparison was made of the incidence of venous thrombophlebitis resulting from the use of a high-osmolality contrast medium (Conray 60%, meglumine ioxaglate) and a low-osmolality contrast medium (Hexabrix 59%, meglumine iothalamate). In 30 patients with varicose veins, Conray was injected into one leg and Hexabrix into the other. The incidence of thrombophlebitis was then determined using the iodine-125 fibrinogen uptake test in a prospective, randomized, double-blind study. There was significantly less thrombophlebitis with Hexabrix than with Conray and the authors conclude that Hexabrix is safer for phlebography. Hexabrix is also stable in solution, only slightly more expensive than Conray, and one fifth the cost of metrizamide.

Fifteen CT scans of 13 patients who had aggressive fibromatosis were generally accurate in showing the extent of disease, although the CT definition of half or more of the margins of nine lesions was poor. Fibromatosis tumors were typically isodense or slightly hypodense with muscle when no contrast medium was used, and they enhanced to hyperdense with better delineation during infusion of contrast medium. Obliterated intermuscular planes did not always signify disease extension; the relationship to bone was often obscured by beam-hardening artifact; and small blood vessels were often invisible. Arteriograms of seven of eight patients showed some hypervascularity and helped to delineate lesions and vessels that were poorly seen on CT scans. In four instances CT findings were clearer, in two instances arteriographic findings were clearer, and twice the findings were equally clear. Three of six bone scintigrams added accurate information about involvement of adjacent bones. Since fibromatosis can microscopically infiltrate beyond the margins indicated by radiographic studies and even by direct palpation at operation, the surgeon should obtain a wide margin beyond the defined tumor limits.

Injection of water-soluble contrast medium into a foot vein in a 5-month-old infant was complicated by intense edema and vesicle formation above the site of injection. This was due to local toxic effect of contrast medium entering the lymphatic system with backflow into the skin. The method by which the contrast medium entered the lymphatics could not be determined.

Xeroradiography proved extremely helpful in (a) evaluation of soft-tissue masses of both the axial and appendicular skeleton; (b) quantifying soft-tissue changes in advanced rheumatoid arthritis; (c) evaluation of bony involvement by an adjacent soft-tissue tumor or infection; (d) evaluation of rib lesions or rib integrity; and (e) assessment of bones in casted extremities. The technique was not helpful in the following conditions: early soft-tissue changes of rheumatoid arthritis; detection of minimal skeletal trauma; arthrography of the knee; evaluation of any portion of the vertebral column; evaluation of submandibular neck masses; or assessment of abdominal films for visceral structures.

Direct cannulation of the deep venous system of the leg was performed in 74 children (79 legs). Both abnormal anatomy and the functional status of the deep venous system were studied. Fifteen legs were normal and 64 exhibited disease of the communicating veins; 33 of the latter patients also had deep venous disease. The communicating veins were described as typical or atypical; a classification comprising two typical and three atypical types is suggested. Four types of deep venous disease were found: (1) aplasia, (b) ectasia, (c) absence of valves, and (d) post-thrombophlebitic obstruction. Normal and abnormal patterns of function are described, and the importance of these findings in treatment and prognosis is discussed.

An alternate technique of performing lower extremity venography is described for use in patients in whom injection into a superficial vein of the foot is not possible.

Accessory muscles covering the posterior tibial neurovascular bundle may be seen in the pre-Achilles fat pad. Two cases are reported.

Nine diabetic and 7 nondiabetic (post-trauma) patients 24 to 63 years of age (mean, 49) were scanned following amputation below the knee, which was bilateral in 4. A three-phase scanning technique (flow, blood pool, and delayed equilibrium images) was employed, using Tc-99m-etidronate. Duration of the arterial and capillary phases was estimated during flow. Activity at the tip of the stump was plotted as a function of (a) time since amputation and (b) flow measurements. Activity was found to diminish over a period of nearly 50 months, usually becoming minimal or undetectable after 18 months. The stump demonstrated relative stasis compared to the intact limb, particularly in diabetics and patients with long-standing amputation.

The extraspinal manifestations of Forestier's disease are described in 21 consecutive cases; diffuse idiopathic skeletal hyperostosis (DISH) is suggested as a more appropriate description of this ossifying diathesis. Characteristic roentgen abnormalities of the spine were present in all individuals and associated with significant axial clinical complaints. In extraspinal locations, hyperostosis at ligament attachments usually occurs in the pelvis, calcaneus, tarsal bones, ulnar olecranon and patella, and is occasionally associated with clinical signs and symptoms requiring surgery. The radiographic appearance in the peripheral skeleton is frequently distinctive and allows the radiologist to suggest the correct diagnosis, even in the absence of axial radiographs.

Xeroradiography is an excellent technique in evaluating the fit of extremity prostheses. Because of its inherent characteristics, xeroradiography can clearly demonstrate the stump-socket relationship. Consequently, the degree of contact achieved and attendant pressure problems, if any, can be precisely determined.

Bilateral lower limb angiography was performed on 58 patients with leprosy and compared with bilateral lower limb angiography performed on 63 non-leprosy patients. The vessels in leprosy were narrow and constricted. Decreased blood flow through arteries in the distal third of the lower limb was present. Abnormal AV fistula formation in the thigh and calf muscles and in trophic ulcers of the feet was also seen. Deep inflammatory granulomatous reaction surrounding the arteries as a result of leprosy is a possible explanation for these angiographic findings and is felt to be related to trophic ulceration. These findings were specific for leprosy, precede clinical manifestations, and are helpful in management.

Interstitial lymphangiography performed with intradermal injection of a new nonionic dimeric contrast agent was used to examine 34 normal lower extremities and 35 lower extremities with proved lymphedema. An infusion pump was used to inject 2 mL of the contrast agent into the intradermal interdigital space at a rate of 0.1 mL/min. In all normal extremities, the injection deposit appeared homogeneous, and one to five lymph vessels could be identified. Diffusion of contrast agent into perilymphatic tissue occurred 30-40 cm proximal to the injection site; inguinal lymph nodes were, therefore, not routinely visualized. The findings at interstitial lymphangiography were abnormal in all extremities with advanced lymphedema. The results indicate that interstitial lymphangiography with the use of a nonionic dimeric contrast agent allows morphologic assessment of lymphatic vessels and facilitates the diagnosis of lymphatic obstructive disease.

Nuclear venograms were supplemented by contrast venograms with use of a 105mm spot film camera under direct visualization. This technique is a simple effective way of resolving questionable areas observed on nuclear venograms.

Lidocaine (60 mg/100 ml) was added to contrast medium (120 ml of Conray-60) in an attempt to decrease pain associated with leg venography in 100 patients. No side effects were seen, and there was a marked reduction in pain as reported by four different examiners in two separate hospital populations.