Ali Shirkhoda

Peroneal nerve dysfunction as a complication of lateral meniscus repair: A case report and anatomic dissection

A case report is presented in which a complete peroneal nerve palsy complicated lateral meniscus repair. The meniscal repair was performed using the combined method of arthroscopically placed inside-out needles and a posterior incision to view their exit. A cadaver limb was then used to examine the anatomy of lateral meniscus repair. Needles used for meniscus repair were passed into the posterior horn of the lateral meniscus using the inside-out and the outside-in methods. Computerized axial tomography (CAT) was then used to establish the proximity of the needles to the peroneal nerve in the posterolateral corner. The inside-out needles were dangerously close to the peroneal nerve. The outside-in needles had a larger margin of safety. The posterolateral corner was then dissected to verify and photograph these relationships.

CT features of renal infarction

PURPOSEnTo demonstrate the different patterns of renal infarction to avoid pitfalls. To present flip-flop enhancement pattern in renal infarction.nnnMATERIALS AND METHODSnRetrospective review of a total of 41 renal infarction in 37 patients were done. These patients underwent initial CT and the diagnosis of renal infarction was confirmed with either follow up CT or at surgery.nnnRESULTSnTwenty-three patients had wedge-shaped focal infarcts, nine patients had global and five patients had multifocal infarcts of the kidneys. Cortical rim sign was seen predominantly with global infarcts. In five patients, a flip-flop enhancement pattern was observed. In two patients, planned renal biopsies due to tumefactive renal lesions were cancelled because of flip-flop enhancement pattern on follow up CTs.nnnCONCLUSIONnAlthough most of our cases were straightforward for the diagnosis of renal infarction, cases with tumefactive lesions and global infarctions without the well-known cortical rim sign were particularly challenging. We describe a new sign, flip-flop enhancement pattern, which we believe solidified the diagnosis of renal infarction in five of our cases. The authors recommend further investigations for association of flip-flop enhancement and renal infarction.

Hepatic focal nodular hyperplasia: CT and sonographic spectrum

Fifteen patients with pathologically proven focal nodular hyperplasia (FNH) of the liver had abdominal computed tomography (CT) (15) and ultrasound (11). In seven patients, the lesions were incidentally found during gallbladder or renal examination, whereas the other eight had a primary neoplasm and the liver was studied for possible metastasis. In 11 unenhanced CT scans, the ratio of isodense to hypodense lesions was 8 to 3. In 15 contrasten-hanced CT scans, seven were isodense, six were hypodense, and in two, the lesion enhanced (hyperdense). In seven patients a hypodense lesion on unenhanced CT became isodense with contrast injection. Delayed images in three showed the lesions appearing as hypodense in two and displaying a rim of enhancement in one. In one case, unenhanced CT was normal and only enhanced CT showed an area of homogeneous increased density. Ultrasound was done in 11 patients, the lesion was hypoechoic to the liver in five, echogenic in four, and isoechoic in two. Findings of central scar were seen on CT and ultrasound in three cases. Pathologic diagnosis was available in all cases, seven by needle aspiration and eight by surgical resection. In our experience, FNH has many CT and sonographic features that can mimic hemangioma or metastasis. While the presence of a central scar increases the specificity, in a cancer patient, the findings should be interpreted with caution and needle aspiration should be obtained.

Angiofibroma : an outcome review of conventional surgical approaches

Juvenile nasopharyngeal angiofibroma (JNA) is a benign tumor of the nasopharynx, and for its treatment, many surgical approaches have been recommended. However, selecting the appropriate one for the tumor in an advanced stage is still controversial. In this study, we evaluate the rate of recurrence of JNA and its relationship to the preoperative stage as well as various surgical approaches. Thirty-seven patients with pathologically proven JNA were retrospectively analyzed. For each patient, data were obtained regarding the primary extension, various surgical approaches and rate of recurrence. Seven patients were in stage III with intracranial extensions. Two of these patients had symptomatic recurrence that needed surgery. Three of them were disease free, and in two cases residues were demonstrated that were asymptomatic and were chosen only to be observed. Among different surgical approaches used, the transpalatal resulted in 1 recurrence out of 14 patients treated with this approach when the lesion was limited to the nasal cavity, nasopharynx and paranasal sinuses (stage I). No recurrence was observed with the use of this approach with lesions with minimal extension to the pterygopalatine fossa (stage IIA). But among three patients with intracranial extension who were treated with this approach, two resulted in symptomatic recurrence; however, using the Lefort I surgical technique, no evidence of recurrence was observed in the two patients in stage III who were treated with this approach. Involvement of the orbit, middle cranial fossa and base of the pterygoid by the primary JNA results in a higher incident of recurrent tumor. Among different surgical techniques, the lowest recurrence rate is seen either in the transpalatal approach when the tumor is limited to the nasopharynx with extension to the nasal cavity or paranasal sinuses or with the Lefort I approach when skull base invasion is present.

Imaging features of splenic epidermoid cyst with pathologic correlation

The spleen can be involved in a variety of cystic lesions ranging from cystic neoplasms and parasitic cysts to “true” and “false” cysts. Epidermoid splenic cyst is a rare true cyst that is developmental in origin. We present two young patients with such a cyst and illustrate their features on ultrasound, CT, and MRI with pathologic correlation.

LEIOMYOSARCOMA OF THE RENAL VEIN: RADIOLOGIC PATHOLOGIC CORRELATION

Leiomyosarcoma of the renal vein is a rare neoplasm occurring more commonly in women. On sectional imaging it is difficult to differentiate from other primary retroperitoneal tumors. Here is a case report of a right renal vein leiomyosarcoma in a 40-year-old man. The ultrasound findings are described and the magnetic resonance imaging, computed tomography, and angiographic findings are illustrated and correlated with the pathologic findings.

Normal variants and pitfalls in CT of the gastrointestinal and genitourinary tracts.

Computed tomography (CT) and ultrasound are the primary imaging modalities for evaluating the abdomen. Normal variants are often encountered and their recognition is essential. Factors that might lead to misdiagnosis and consequent errors in management include incomplete or inadequate technique, misinterpretation of normal anatomic structures or variations, and postoperative changes and artifacts. This review article addresses recommendations on how to recognize normal variations and avoid diagnostic pitfalls in CT of the abdomen. The gastrointestinal tract, gallbladder, kidneys, urinary bladder, prostate, and testes are specifically addressed.

Pancreatic carcinoma masquerading as renal cell carcinoma

Three cases of pancreatic carcinoma that arose in the tail and extended into the adjacent left kidney are presented. Because of misleading symptoms and radiographic features, the tumors were misdiagnosed as primary renal tumor. In most cases, computed tomography (CT) provides the correct diagnosis and prevents unnecessary surgery.

Spread of Metastatic Disease in the Abdomen and Pelvis

Basic knowledge of the normal intra-abdominal anatomy and of the anatomical variants is essential to understanding the spread of pathology within the peritoneum. Of special importance are constant landmarks, i.e., the anatomical relationships maintained and bounded by peritoneal and fascial attachments as well as by the abdominal adipose tissue. The peritoneal and extraperitoneal spaces and their fascial planes create complex three-dimensional structures with unique radiological characteristics. Intraperitoneal and extraperitoneal adipose tissue provides contrast interfaces between the organs and visceral structures. The intra-abdominal adipose also yields clues as to the spread and localization of many pathological conditions.