Radiography after orthognathic surgery. Part II. Surgical complications

In a retrospective review of the radiographs from 100 patients who had undergone orthognathic surgery, the authors found that 10% of radiographs had evidence of surgical complications. These complications were fractures, temporomandibular joint dislocations, transected tooth roots, retained surgical devices, avascular necrosis, malunion or nonunion of osteotomy fragments, and osteomyelitis. Some of these complications are of little significance, while others require immediate intervention. Opacified maxillary sinuses and lucencies around tooth roots are frequent findings that may be confused with abnormalities; however, they represent postoperative blood in the sinuses and resorption of bone due to stress from orthodontic appliances, respectively.     

CT of the esophagus: I. Normal appearance.

The thoracic esophagus is easily demonstrable throughout its entire length on thoracic computed tomography (CT). The soft tissue planes separating the esophagus from its adjacent mediastinal structures are normally distinct. Blurring or distortion of these tissue interfaces is a reliable indicator of disease. The normal CT anatomy of the esophagus and mediastinal relationships are described. Air in the esophagus is considered a normal finding.     

Transrectal US in evaluation of patients after radical prostatectomy. Part I. Normal postoperative anatomy.

The appearance of the prostatic fossa on transrectal ultrasound (TRUS) scans obtained after radical retropubic prostatectomy (RRP) was studied in 25 patients believed to have no tumor on the basis of their level of serum prostate-specific antigen (PSA) (< or = 0.4 ng/mL). The profile of the vesicourethral anastomosis (VUA) in the midsagittal plane was tapered in 13 patients (52%) and nontapered in 12 patients (48%). The nontapered profile was associated with incontinence in nine of 11 patients (82%) followed up for less than 12 months but in only four of 14 patients (28%) followed up beyond 1 year. In 20 patients (80%), a hypoechoic soft-tissue lesion (average volume, 1.7 cm3) was seen anterior to the VUA and indented the anterior bladder wall. The length of the urethral high-pressure zone increased with muscular contraction of the pelvic floor. Knowledge of the baseline anatomic structures depicted on TRUS scans obtained after RRP may be useful in selection of tissue for TRUS-guided needle biopsy in patients with elevated levels of PSA. The many post-surgical changes reduced the specificity of the TRUS findings.     

Carpal tunnel: MR imaging. Part I. Normal anatomy

To correlate the important structures of the carpal tunnel demonstrated on magnetic resonance (MR) images with gross anatomy, the authors imaged the wrists of 20 normal volunteers and nine cadavers. The cadaver specimens were sectioned in the same planes in which they were imaged, and three other specimens were dissected. The anatomy was directly correlated with the imaged morphology. Axial images delineated well the bone and ligament walls of the carpal tunnel. The median nerve was well delimited and of moderate signal intensity. It was surrounded in some cases by fat but was consistently bound by specific tendons. The ulnar nerve and artery were visualized as they traversed the Guyon canal to their division into superficial and deep branches. Coronal images permitted optimal visualization of the triangular fibrocartilage and the radial and ulnar collateral ligaments. Quantitative studies indicated that the normal median nerve does not significantly increase in size within the carpal tunnel but does become more flattened at the level of the pisiform bone. The normal flexor retinaculum may have a slight palmar bowing.     

Imaging of the aging brain. Part I. Normal findings

A thorough knowledge of the normal changes that occur in the brain with age is critical before abnormal findings are analyzed. Magnetic resonance (MR) imaging improves the ability to distinguish normal and abnormal findings in the brain. The major changes that may occur in elderly individuals without neurologic deficits include enlargement of the ventricles, cortical sulci, and vermian subarachnoid spaces; multifocal areas of hyperintensity in the white matter and basal ganglia; a progressive prominence of hypointensity on T2-weighted images of the putamen, almost equal to that of the globus pallidus; an increase in the oxygen extraction ratio with normal or mildly decreased neuron metabolism; arteriosclerosis in large and small arteries and amyloid angiopathy in leptomeningeal cortical vessels; and decreased dopamine receptor binding in the corpus striatum. Since approximately half of the elderly population exhibits only negligible brain alterations, MR imaging may facilitate the distinction between usual (no neurologic dysfunction) and successful (no brain or vascular changes) aging.     

Urinary bladder MR imaging. Part I. Normal and benign conditions

The normal urinary bladder and several benign entities of the bladder were examined in 50 patients by magnetic resonance (MR) imaging. Specific features assessed included appearance of the bladder wall, optimal repetition (TR) and echo delay (TE) parameters for bladder-wall demonstration, and differentiation among various benign abnormalities, including bladder-wall hypertrophy, inflammation, and mucosal congestion, on MR images. The bladder wall in the 30 healthy subjects was best displayed using a TR = 2 sec, TE = 56 msec image, which gave 60% contrast between the bladder wall and urine and 48% contrast between the bladder wall and fat. Demonstration of bladder-wall hypertrophy required similar imaging; bladder distention was necessary to demonstrate the thickness of the bladder wall. Congestion and inflammation were best demonstrated on TR = 2 sec, TE = 56 msec images, which gave 45% contrast. Normal and/or hypertrophic bladder wall were distinguished from inflammation and congestion on the basis of signal intensity variations and/or T1 and T2 relaxation parameters.     

Non-contrast MR imaging of the glenohumeral joint. Part I. Normal anatomy

MR imaging of the shoulder without contrast is frequently used for evaluation of glenohumeral instability in spite of the popularity of MR arthrography. With proper imaging technique, familiarity with normal anatomy and variants as well as knowledge of the expected pathologic findings high diagnostic accuracy may be achieved.     

Radiography in the United States Army during World War II: Part I

This is the first of two articles highlighting Army radiography through World War II. Topics concentrate on a few important military and civilian events between wars (1918-1941), such as the Army's contributions in (classifying) radiographic knowledge and escalating x-ray commercialization. Peacetime objectives, the mobilization effort, personnel and training, and how WACs and civilians contributed are discussed also.     

Radiology of the ambient cistern Part I: Normal

Summary The angiographic and high-resolution, thin-section CT appearance of the normal ambient cistern is correlated with anatomic dissections and sections of normal, formalin-fixed cadaver brains. Each of three separate anatomic segments of the ambient cistern — the supratentorial segment, the tentorial edge and the subtentorial segment — has a characteristic CT appearance that can be correlated with specific vascular structures on routine angiography.     

Vagina: evaluation with MR imaging. Part I. Normal anatomy and congenital anomalies

The appearance of the vagina was evaluated on magnetic resonance (MR) images of 65 subjects who were healthy or had disease unrelated to the vagina and 24 patients with suspected congenital anomalies of the vagina. MR imaging accurately demonstrated the presence of (n = 78) or complete (n = 7) or partial (n = 4) absence of the vagina in each case. Partial (n = 2) or complete (n = 2) duplication of the vagina was also correctly diagnosed. Regardless of field strength, T2-predominant images were essential for evaluation. The transverse plane was optimal, and a 5-mm section thickness was preferable. Estrogen stimulation affected the appearance of the vagina: The contrast between the vaginal wall and the central mucus-containing area was greatest during the early proliferative and late secretory phases. MR imaging offers unique depiction of congenital anomalies and should be used when results of physical examination or other radiologic studies, such as ultrasound, are inconclusive.     

High-field MR surface-coil imaging of the hand and wrist. Part I. Normal anatomy

High-resolution magnetic resonance (MR) images of the hands and wrists of six healthy volunteers were obtained at 1.5 T with a surface coil. Additionally, the hands and wrists of two fresh cadavers were imaged and were subsequently sectioned for anatomic correlation. High contrast when depicting soft-tissue, coupled with impressive spatial resolution and multiplanar capabilities, enabled delineation of fine structures including nerves, tendons, and blood vessels. Osseous and cartilaginous structures were also well depicted. MR imaging gives anatomic definition of the hand and wrist unmatched by other diagnostic imaging methods.     

MR imaging of the most commonly injured ankle ligaments. Part I. Normal anatomy.

To determine the optimum foot position and imaging plane at magnetic resonance (MR) imaging of each ankle ligament, 10 cadaver ankles were dissected to visualize the orientation, precise attachment sites, and relationships of each ligament. Then eight cadaver ankles were studied with MR imaging and were cryosectioned in the optimum imaging planes. The ankles of 12 healthy volunteers were imaged to ensure consistency in identifying the normal ligaments. With the foot taped into full dorsiflexion of 10 degrees-20 degrees, axial imaging provided optimum views of the anterior, posterior, and inferior tibiofibular ligaments and of the anterior and posterior fibulotalar ligaments and provided an overview of the deltoid ligament. Coronal images provided full-length views of the tibiospring, tibiocalcaneal, and posterior tibiotalar parts of the deltoid ligament. With the foot taped into full plantar flexion of 40 degrees-50 degrees, axial imaging optimized visualization of the fibulocalcaneal ligament and of the tibionavicular and anterior tibiotalar parts of the deltoid ligament. Sagittal images provided the best full-length views of the spring ligament.